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Background: High-flow nasal oxygenation is reported to prolong duration of apnea while maintaining adequate oxygen saturation with the mouth closed. Also, buccal oxygenation is known to have similar effects in obese adults. We compared the effect of these two methods on prolongation of acceptable apnea time in pediatric patients with their mouth open., Methods: Thirty-eight patients, aged 0-10 years were randomly allocated to either the high-flow nasal oxygenation group (n = 17) or the buccal oxygenation group (n = 21). After induction of anesthesia including neuromuscular blockade, manual ventilation was initiated until the expiratory oxygen concentration reached 90%. Subsequently, ventilation was paused, and the patient's head was extended, and mouth was opened. The HFNO group received 2 L·min -1 ·kg -1 of oxygen, and the BO group received 0.5 L·min -1 ·kg -1 of oxygen. We set a target apnea time according to previous literature. When the apnea time reached the target, we defined the case as "success" in prolongation of safe apnea time and resumed ventilation. When the pulse oximetry decreased to 92% before the target apnea time, it was recorded as "failure" and rescue ventilation was given., Results: The success rate of safe apnea prolongation was 100% in the high-flow nasal oxygenation group compared to 76% in the buccal oxygenation group (p = .04). Oxygen reserve index, end-tidal or transcutaneous carbon dioxide partial pressure, and pulse oximetry did not differ between groups., Conclusion: High-flow nasal oxygenation is effective in maintaining appropriate arterial oxygen saturation during apnea even in children with their mouth open and is superior to buccal oxygenation. Buccal oxygenation may be a good alternative when high-flow nasal oxygenation is not available., (© 2024 John Wiley & Sons Ltd.)

Introduction: The use of continuous positive airway pressure has been shown to improve the tolerance of the apnea test, a critical component of brain death evaluation. The ability to deactivate the apnea backup setting has made apnea testing possible using several conventional mechanical ventilators. Our goal was to evaluate the safety and efficacy of apnea testing performed on mechanical ventilation, compared with the oxygen insufflation technique, for the determination of brain death., Methods: This was a retrospective study. In 2016, our institution approved a change in policy to permit apnea testing on conventional mechanical ventilation. We examined the records of consecutive adults who underwent apnea testing as part of the brain death evaluation process between 2016 and 2022. Using an apnea test technique was decided at the discretion of the attending physician. Outcomes were successful apnea test and the occurrence of patient instability during the test. This included oxygen desaturation (SpO2) < 90%, hypotension (mean arterial pressure < 65 mm Hg despite titration of vasopressor), cardiac arrhythmia, pneumothorax, and cardiac arrest., Results: Ninety-two adult patients underwent apnea testing during the study period: 58 (63%) with mechanical ventilation, 32 (35%) with oxygen insufflation, and 2 (2%) lacked documentation of technique. Apnea tests could not be completed successfully in 3 of 92 (3%) patients-two patients undergoing the oxygen insufflation technique (one patient with hypoxemia and one patient with hypotension) and one patient on mechanical ventilation (aborted for hemodynamic instability). Hypoxemia occurred in 4 of 32 (12.5%) patients with oxygen insufflation and in zero patients on mechanical ventilation (p = 0.01). Hypotension occurred during 3 of 58 (5%) tests with mechanical ventilation and 4 of 32 (12.5%) tests with oxygen insufflation (p = 0.24). In multivariate analysis, the use of oxygen insufflation was an independent predictor of patient instability during the apnea test (odds ratio 37.74, 95% confidence interval 2.74-520.14)., Conclusions: Apnea testing on conventional mechanical ventilation is feasible and offers several potential advantages over other techniques., (© 2024. The Author(s).)

Background: Preterm infants often require non-invasive breathing support while their lungs and control of respiration are still developing. Non-invasive neurally adjusted ventilatory assist (NIV-NAVA) is an emerging technology that allows infants to breathe spontaneously while receiving support breaths proportional to their effort. This study describes the first Australian Neonatal Intensive Care Unit (NICU) experience of NIV-NAVA., Methods: Retrospective cohort study of infants admitted to a major tertiary NICU between October 2017 and April 2021 supported with NIV-NAVA. Infants were divided into three groups based on the indication to initiate NIV-NAVA (post-extubation; apnoea; escalation). Successful application of NIV-NAVA was based on the need for re-intubation within 48 h of application., Results: There were 169 NIV-NAVA episodes in 122 infants (82 post-extubation; 21 apnoea; 66 escalation). The median (range) gestational age at birth was 25 + 5 weeks (23 + 1 to 43 + 3 weeks) and median (range) birthweight was 963 g (365-4320 g). At NIV-NAVA application, mean (SD) age was 17 days (18.2), and median (range) weight was 850 g (501-4310 g). Infants did not require intubation within 48 h in 145/169 (85.2%) episodes [72/82 (87.8%) extubation; 21/21 (100%) apnoea; 52/66 (78.8%) escalation)., Conclusion: NIV-NAVA was successfully integrated for the three main indications (escalation; post-extubation; apnoea). Prospective clinical trials are still required to establish its effectiveness versus other modes of non-invasive support., (© 2024. The Author(s).)

Aim: Apnoea of prematurity requires prompt intervention to prevent long-term adverse outcomes, but specific recommendations about the stimulation approach are lacking. Our study investigated the modalities of tactile stimulation for apnoea of prematurity in different settings., Methods: In this multi-country observational prospective study, nurses and physicians of the neonatal intensive care units were asked to perform a tactile stimulation on a preterm neonatal manikin simulating an apnoea. Features of the stimulation (body location and hand movements) and source of learning (training course or clinical practice) were collected., Results: Overall, 112 healthcare providers from five hospitals participated in the study. During the stimulation, the most frequent location were feet (72%) and back (61%), while the most frequent techniques were rubbing (64%) and massaging (43%). Stimulation modalities different among participants according to their hospitals and their source of learning of the stimulation procedures., Conclusion: There was a large heterogeneity in stimulation approaches adopted by healthcare providers to counteract apnoea in a simulated preterm infant. This finding may be partially explained by the lack of specific guidelines and was influenced by the source of learning for tactile stimulation., (© 2024 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.)

Competing Interests: Les auteurs déclarent n'avoir aucun lien d'intérêts.

High-flow nasal oxygen can be administered at induction of anaesthesia for the purposes of pre-oxygenation and apnoeic oxygenation. This intervention is claimed to enhance carbon dioxide elimination during apnoea, but the extent to which this occurs remains poorly quantified. The optimal nasal oxygen flow rate for gas exchange is also unknown. In this study, 114 patients received pre-oxygenation with high-flow nasal oxygen at 50 l.min -1 . At the onset of apnoea, patients were allocated randomly to receive one of three nasal oxygen flow rates: 0 l.min -1 ; 70 l.min -1 ; or 120 l.min -1 . After 4 minutes of apnoea, all oxygen delivery was ceased, tracheal intubation was performed, and oxygen delivery was recommenced when SpO 2 was 92%. Mean (SD) PaCO 2 rise during the first minute of apnoea was 1.39 (0.39) kPa, 1.41 (0.29) kPa, and 1.26 (0.38) kPa in the 0 l.min -1 , 70 l.min -1 and 120 l.min -1 groups, respectively; p = 0.16. During the second, third and fourth minutes of apnoea, mean (SD) rates of rise in PaCO 2 were 0.34 (0.08) kPa.min -1 , 0.36 (0.06) kPa.min -1 and 0.37 (0.07) kPa.min -1 in the 0 l.min -1 , 70 l.min -1 and 120 l.min -1 groups, respectively; p = 0.17. After 4 minutes of apnoea, median (IQR [range]) arterial oxygen partial pressures in the 0 l.min -1 , 70 l.min -1 and 120 l.min -1 groups were 24.5 (18.6-31.4 [12.3-48.3]) kPa; 36.6 (28.1-43.8 [9.8-56.9]) kPa; and 37.6 (26.5-45.4 [11.0-56.6]) kPa, respectively; p < 0.001. Median (IQR [range]) times to desaturate to 92% after the onset of apnoea in the 0 l.min -1 , 70 l.min -1 and 120 l.min -1 groups, were 412 (347-509 [190-796]) s; 533 (467-641 [192-958]) s; and 531 (462-681 [326-1007]) s, respectively; p < 0.001. In conclusion, the rate of carbon dioxide accumulation in arterial blood did not differ significantly between apnoeic patients who received high-flow nasal oxygen and those who did not., (© 2023 Association of Anaesthetists.)

Purpose: To further identify the effectiveness of trans-nasal humidified rapid insufflation ventilatory exchange (THRIVE) for pre- and apneic oxygenation during the anesthesia induction by comparison to facemask ventilation (FMV) based on current available evidence., Methods: Medline, EMBASE, Web of Science, Cochrane Library and CNKI databases were searched from inception to December 22, 2023 for available randomized controlled trials (RCTs). Primary outcomes were PaO2 and PaCO2 after intubation and safe apnoea time. Secondary outcomes included the O2 desaturation, end expiratory carbon dioxide (EtCO2) and complications. The effect measures for continuous and categorical outcomes were separately the mean difference (MD) and relative risk (RR) with 95% confidence interval., Results: Twelve RCTs with 403 patients in the THRIVE group and 401 patients in th FMV group were included. Pooled results demonstrated that the PaO2 after intubation was significantly higher (MD = 82.90mmHg, 95% CI: 12.25~153.54mmHg, P = 0.02) and safe apnoea time (MD = 103.81s, 95% CI: 42.07~165.56s, P = 0.001) was longer in the THRIVE group. Besides, the incidence rate of O2 desaturation (RR = 0.28, 95% CI: 0.12-0.66, P = 0.004) and gastric insufflation (RR = 0.26, 95% CI: 0.13-0.49, P<0.001) was significantly lower in the THRIVE group., Conclusion: Based on current evidence, THRIVE manifested better effectiveness representing as improved oxygenation, prolonged safe apnoea time and decreased risk of complications compared to standard FMV in surgical patients. Therefore, THRIVE could be served as a novel and valuable oxygenation technology for patients during anesthesia induction., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Zheng et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Objectives: To investigate the impact of a pre-emptive apnoea triggered oxygen response on oxygen saturation (SpO 2 ) targeting following central apnoea in preterm infants., Design: Interventional crossover study of a 12-hour period of automated oxygen control with an apnoea response (AR) module, nested within a crossover study of a 24-hour period of automated oxygen control compared with aggregated data from two flanking 12-hour periods of manual control., Setting: Neonatal intensive care unit PATIENTS: Preterm infants receiving non-invasive respiratory support and supplemental oxygen; median (IQR) birth gestation 27 (26-28) weeks, postnatal age 17 (12-23) days., Intervention: Automated oxygen titration with an automated control algorithm modified to include an AR module. Alterations to inspired oxygen concentration (FiO 2 ) were actuated by a motorised blender. Desired SpO 2 range was 90-94%. Apnoea detection was by capsule pneumography., Main Outcome Measures: Duration, magnitude and area under the curve (AUC) of SpO 2 deviations following apnoea; frequency and duration of apnoeic events. Comparisons between periods of manual, automated and automated control with AR module., Results: In 60 studies in 35 infants, inclusion of the AR module significantly reduced AUC for SpO 2 deviations below baseline compared with both automated and manual control (manual: 87.1%±107.6% s, automated: 84.6%±102.8% s, AR module: 79.4%±102.7% s). However, there was a coincident increase in SpO 2 overshoot (AUC (SpO 2 >SpO 2(onset) ); manual: 44.3±99.9% s, automated: 54.7%±103.4% s, AR module: 65.7%±126.2% s)., Conclusion: Automated control with a pre-emptive apnoea-triggered FiO 2 boost resulted in a modest reduction in post-apnoea hypoxaemia, but was followed by a greater SpO 2 overshoot., Trial Registration Number: ACTRN12616000300471., Competing Interests: Competing interests: The University of Tasmania and Royal Hobart Hospital have jointly lodged a patent application concerning automated control of inspired oxygen concentration in the newborn infant. TJG and PAD are named inventors. The authors have no other conflicts of interest relevant to this article to disclose., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

A primary concern for anesthesiologists is the maintenance of oxygenation during general anesthesia. Extending the safe apnea time, which is the time from the onset of apnea until the oxygen saturation concentration reaches 90% or less, increases the margin of safety with tracheal intubation. Preoxygenation before anesthetic induction has been a widely accepted manoeuver to increase oxygen reserves and hence delay the onset of arterial desaturation during apnea. This study aimed to evaluate the efficacy of pressure support ventilation with/without positive end-expiratory pressure (PEEP) for preoxygenation in adult patients. A total of 132 patients, aged 20 to 50 years, scheduled for elective surgery under general anesthesia, requiring endotracheal intubation, were included and randomly divided into three groups (n = 44 per group): spontaneous ventilation (SV), pressure support ventilation without PEEP (PS), and pressure support ventilation with PEEP (PEEP) groups. In the SV group, the patients breathed spontaneously without any support using a face mask; in the PS group, the patients breathed spontaneously with the inspiratory pressure support of 12 cm H 2 O without PEEP; and in the PEEP group, the patients were subjected to preoxygenation (similar to the PS group) with PEEP at 6 cm H 2 O. Preoxygenation was terminated when the fraction of expired oxygen reached 90% and the duration was recorded. Time from 90 seconds after administration of rocuronium bromide until oxygen saturation fell to 93% was recorded and taken as safe apnea time. The time taken for preoxygenation (the expired oxygen fraction reaches 90) was significantly shorter in patients of PEEP and PS groups when compared to the SV group. The safe apnea time was significantly longer in patients of PEEP and PS groups compared with the SV group. Application of inspiratory pressure support of 12 cm H 2 O and PEEP of 6 cm H 2 O during preoxygenation significantly reduces the preoxygenation time and prolongs the safe apnea time compared with conventional preoxygenation., Competing Interests: None

Background: Evidence is lacking regarding the efficacy of transnasal humidified rapid insufflation ventilatory exchange (THRIVE) in tubeless anesthesia, especially in pediatric patients. This study aimed to evaluate the use of THRIVE for juvenile onset recurrent respiratory papillomatosis (JORRP) patients., Methods: Twenty-eight children aged 2 to 12 years with JORRP, abnormal airways, and ASA physical status II-III that presented for surgical treatment under general anesthesia were included in this study. Each patient received 2 interventions in random order, with a 5-minute washout period between treatments: apnea without oxygen supplementation and apnea with THRIVE intervention. The primary outcome apnea time was defined as the duration from withdrawal of intubation to reintubation and resumption of controlled ventilation. The secondary outcomes were the mean transcutaneous carbon dioxide (tc co2 ) increase rate, the minimum pulse oxygen saturation (Sp o2 ) during apnea, and the occurrence of unexpected adverse effects., Results: The median apnea time in the THRIVE period was significantly longer than that in the control period (8.9 [8.6-9.4] vs 3.8 [3.4-4.3] minutes; mean difference [95% confidence interval (CI)], 5.0 [4.4-5.6]; P < .001) for all patients. The rate of CO 2 change in the control period was higher than that in the THRIVE period both for patients aged 2 to 5 years old (6.29 [5.19-7.4] vs 3.22 [2.92-3.76] mm Hg min -1 ; mean difference [95% CI], 3.09 [2.27-3.67]; P < .001) and for patients aged 6 to 12 years old (4.76 [3.7-6.2] vs 3.38 [2.64-4.0] mm Hg min -1 ; mean difference [95% CI], 1.63 [0.75-2.56]; P < .001). The minimum Sp o2 was significantly higher in the THRIVE period than in the control period (mean difference [95% CI], 19.7 [14.8-22.6]; P < .001)., Conclusions: Our findings demonstrate that THRIVE safely increased the apnea time among children with JORRP undergoing surgery and decreased the rate of carbon dioxide increase. THRIVE is clinically recommended as an airway management technique for tubeless anesthesia in apneic children., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2023 International Anesthesia Research Society.)

Study Objective: Investigate a low-cost, nasopharyngeal apnoeic oxygenation technique, establish its efficacy, and compare it to preoxygenation only in an obese population. The study's hypothesis was that nasopharyngeal apnoeic oxygenation at 18 l.min -1 would significantly prolong safe apnoea time compared to preoxygenation alone., Design: Randomised controlled study., Setting: Theatre complex of a resource constrained hospital., Patients: 30 adult, obese (BMI ≥ 35 kg.m -2 ) patients presenting for elective surgery. Patients with limiting cardio-respiratory disease, suspected difficult airway, risk of aspiration, and that were pregnant, were excluded. Patients were allocated by block randomisation in a 1:2 ratio to a preoxygenation-only (No-AO) and an intervention group (NPA-O 2 )., Interventions: All patients were preoxygenated to an Et-O2 > 80%, followed by a standardised induction. The intervention group received oxygen at 18 l.min -1 via the nasopharyngeal catheter intervention. The desaturation process was documented until an SpO 2 of 92% or 600 s was reached., Measurements: Baseline demographic and clinical characteristics were collected. The primary outcome was safe apnoea time, defined as the time taken to desaturate to an SpO 2 of 92%. Secondary outcomes were rate of carbon dioxide accumulation and factors affecting the risk of desaturation., Main Results: The study was conducted in a morbidly obese population (NoAO = 41,1 kg.m -2 ; NPA-O 2  = 42,5 kg.m -2 ). The risk of desaturation was signifantly lower in the intervention group (Hazzard Ratio = 0,072, 95% CI[0,019-0,283]) (Log-Rank test, p < 0.001). The median safe apnoea time was significantly longer in the intervention group (NoAO = 262 s [IQR 190-316]; NPA-O 2  = 600 s [IQR 600-600]) (Mann-Whitney-U test, p < 0.001). The mean rate of CO 2 accumalation was significantly slower in the intervention group (NoAO = 0,47 ± 0,14 kPa.min -1 ; NPA-O 2  = 0,3 ± 0,09 kPa.min -1 ) (t-test, p = 0.003). There were no statistically significant risk factors associated with an increased risk of desaturation found., Conclusions: Nasopharyngeal apnoeic oxygenation at 18 l/min prolongs safe apnoea time, compared to preoxygenation alone, and reduces the risk of desaturation in morbidly obese patients., Clinical Trial Registration: PACTR202202665252087; WC/202004/007., Competing Interests: Declaration of Competing Interest There were no conflict of interest of either authors in the production of this wok. The research was conducted for completion of Degree purposes. There was no funding, grants, stock ownership or patent applications made. There are no academic disclosures to mention., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Recently, a non-commercial oxygenation laryngoscope was able to maintain apneic oxygenation during simulated intubation efforts. Since that prototype was 3 mm wider than a standard Macintosh laryngoscope blade, the intubation performance of this device may differ from standard blades. A new prototype of an oxygenation laryngoscope was developed, consisting of a standard-size Macintosh blade and a fixed oxygen supply line to the side. Actually, it is unclear at which point of this blade the oxygen supply line should end to facilitate the best possible oxygen supply for apneic oxygenation., Methods: In this simulation study using a standardized human airway manikin, the efficacy of apneic oxygenation by oxygen insufflation using standard and modified Macintosh blades was compared: a standard Macintosh blade without oxygen supply line as control, one with an additional oxygen supply line ending proximal near the handle, one with the line ending at the middle of the blade, and one with the line ending near the tip. A preoxygenated test lung was connected to an oximeter with a flow rate of 200ml/min, simulating oxygen consumption of a male adult, and to the trachea of an anatomically correctly shaped airway manikin. Apneic oxygenation was performed and oxygen content was measured over a 20-minutes observation period. Experiments were repeated five times for each laryngoscope blade., Results: Oxygen percentage in the test lung dropped from 100 ± 0% at the start of the experiment to 53 ± 1.5% in the room air control group (p < 0.001 compared to all other groups), and to 74 ± 2.5% in the proximal oxygen line group, whereas oxygen percentage remained at 100% in both the medium and distal oxygen line groups (p = 1 between these groups; p < 0.001 between all other groups)., Conclusions: In this simulation study with a preoxygenated airway manikin, the use of a modified Macintosh laryngoscope blade with oxygen line attached at the tip or at the middle were able to maintain apneic oxygenation without measurable drop of oxygen content over 20 min. Proximal placement of the oxygen supply line still showed an advantage against room air, however it did not completely prevent room air from entering the airway., Trial Registration: Not applicable., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Rationale: Transnasal humidified rapid-insufflation ventilatory exchange (THRIVE) is used in tracheostomy but not in cases of airway obstruction. This case report explores the use of THRIVE for managing airway obstruction during tracheostomy in patients with subglottic and tracheal stenosis, thereby addressing the current knowledge gap and exploring its potential for airway management., Patient Concerns: A 63-year-old female with subglottic and tracheal stenoses underwent tracheostomy. Multiple attempts to establish a patent airway were unsuccessful, and oxygen saturation dropped to 56%., Diagnosis: Endotracheal tube was directed toward the tracheal wall, causing airway obstruction., Interventions: THRIVE was administered to the patient. Subsequently, the tube position was adjusted to enhance ventilation., Outcomes: The patient's oxygen saturation increased to 99%. The postoperative complications, including subcutaneous emphysema, pneumothorax, pneumomediastinum and pneumopericardium, resolved. The patient was discharged on postoperative day 9., Lessons: THRIVE could be considered a temporary measure to enhance oxygenation before initiating a definitive treatment strategy., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2023 the Author(s). Published by Wolters Kluwer Health, Inc.)

Background: Apnoeic oxygenation with high-flow nasal oxygen prolongs the safe apnoeic period during induction of general anaesthesia. However, central haemodynamic effects and the characteristics of central gaseous exchange remain unexplored., Objective: To describe mean pulmonary arterial pressure along with arterial and mixed venous blood gases and central haemodynamic parameters during apnoeic oxygenation with low-flow and high-flow nasal oxygen in pigs., Design: Experimental crossover study., Setting: Animal study of 10 healthy Swedish landrace pigs at Karolinska Institutet, Sweden, April-May 2021., Intervention: The pigs were anaesthetised, their tracheas intubated and their pulmonary arteries catheterised. The animals were preoxygenated and paralysed before apnoea. Apnoeic periods between 45 and 60 min were implemented with either 70 or 10 l min -1 100% O 2 delivered via nasal catheters. In addition, seven animals underwent an apnoea without fresh gas flow. Cardiopulmonary parameters and blood gases were measured repeatedly., Main Outcome Measures: Mean pulmonary arterial pressure during apnoeic oxygenation with high-flow and low-flow oxygen., Results: Nine pigs completed two apnoeic periods of at least 45 min with a Pa O 2 not lower than 13 kPa. The mean pulmonary arterial pressure increased during 45 min of apnoea, from 18 ± 1 to 33 ± 2 mmHg and 18 ± 1 to 35 ± 2 mmHg, at 70 and 10 l min -1 O 2 , respectively ( P  < 0.001); there was no difference between the groups ( P  = 0.87). The Pa CO 2 increased by 0.48 ± 0.07 and 0.52 ± 0.04 kPa min -1 , at 70 and 10 l min -1 O 2 , respectively; there was no difference between the groups ( P  = 0.22). During apnoea without fresh gas flow, the SpO 2 declined to less than 85% after 155 ± 11 s., Conclusion: During apnoeic oxygenation in pigs, the mean pulmonary arterial pressure increased two-fold and Pa CO 2 five-fold after 45 min, while the arterial oxygen levels were maintained over 13 kPa, irrespective of high-flow or low-flow oxygen., (Copyright © 2023 European Society of Anaesthesiology and Intensive Care. Unauthorized reproduction of this article is prohibited.)

Background: Nasal continuous positive airway pressure (NCPAP) is a useful method for providing respiratory support after extubation. Nasal intermittent positive pressure ventilation (NIPPV) can augment NCPAP by delivering ventilator breaths via nasal prongs., Objectives: Primary objective To determine the effects of management with NIPPV versus NCPAP on the need for additional ventilatory support in preterm infants whose endotracheal tube was removed after a period of intermittent positive pressure ventilation. Secondary objectives To compare rates of abdominal distension, gastrointestinal perforation, necrotising enterocolitis, chronic lung disease, pulmonary air leak, mortality, duration of hospitalisation, rates of apnoea and neurodevelopmental status at 18 to 24 months for NIPPV and NCPAP. To compare the effect of NIPPV versus NCPAP delivered via ventilators versus bilevel devices, and assess the effects of the synchronisation of ventilation, and the strength of interventions in different economic settings., Search Methods: We used standard, extensive Cochrane search methods. The latest search date was January 2023., Selection Criteria: We included randomised and quasi-randomised trials of ventilated preterm infants (less than 37 weeks' gestational age (GA)) ready for extubation to non-invasive respiratory support. Interventions were NIPPV and NCPAP., Data Collection and Analysis: We used standard Cochrane methods. Our primary outcome was 1. respiratory failure. Our secondary outcomes were 2. endotracheal reintubation, 3. abdominal distension, 4. gastrointestinal perforation, 5. necrotising enterocolitis (NEC), 6. chronic lung disease, 7. pulmonary air leak, 8. mortality, 9. hospitalisation, 10. apnoea and bradycardia, and 11. neurodevelopmental status. We used GRADE to assess the certainty of evidence., Main Results: We included 19 trials (2738 infants). Compared to NCPAP, NIPPV likely reduces the risk of respiratory failure postextubation (risk ratio (RR) 0.75, 95% confidence interval (CI) 0.67 to 0.84; number needed to treat for an additional beneficial outcome (NNTB) 11, 95% CI 8 to 17; 19 trials, 2738 infants; moderate-certainty evidence) and endotracheal reintubation (RR 0.78, 95% CI 0.70 to 0.87; NNTB 12, 95% CI 9 to 25; 17 trials, 2608 infants, moderate-certainty evidence), and may reduce pulmonary air leaks (RR 0.57, 95% CI 0.37 to 0.87; NNTB 50, 95% CI 33 to infinite; 13 trials, 2404 infants; low-certainty evidence). NIPPV likely results in little to no difference in gastrointestinal perforation (RR 0.89, 95% CI 0.58 to 1.38; 8 trials, 1478 infants, low-certainty evidence), NEC (RR 0.86, 95% CI 0.65 to 1.15; 10 trials, 2069 infants; moderate-certainty evidence), chronic lung disease defined as oxygen requirement at 36 weeks (RR 0.93, 95% CI 0.84 to 1.05; 9 trials, 2001 infants; moderate-certainty evidence) and mortality prior to discharge (RR 0.81, 95% CI 0.61 to 1.07; 11 trials, 2258 infants; low-certainty evidence). When considering subgroup analysis, ventilator-generated NIPPV likely reduces respiratory failure postextubation (RR 0.49, 95% CI 0.40 to 0.62; 1057 infants; I 2 = 47%; moderate-certainty evidence), while bilevel devices (RR 0.95, 95% CI 0.77 to 1.17; 716 infants) or a mix of both ventilator-generated and bilevel devices likely results in little to no difference (RR 0.87, 95% CI 0.73 to 1.02; 965 infants)., Authors' Conclusions: NIPPV likely reduces the incidence of extubation failure and the need for reintubation within 48 hours to one-week postextubation more effectively than NCPAP in very preterm infants (GA 28 weeks and above). There is a paucity of data for infants less than 28 weeks' gestation. Pulmonary air leaks were also potentially reduced in the NIPPV group. However, it has no effect on other clinically relevant outcomes such as gastrointestinal perforation, NEC, chronic lung disease or mortality. Ventilator-generated NIPPV appears superior to bilevel devices in reducing the incidence of respiratory failure postextubation failure and need for reintubation. Synchronisation used to deliver NIPPV may be important; however, data are insufficient to support strong conclusions. Future trials should enrol a sufficient number of infants, particularly those less than 28 weeks' GA, to detect differences in death or chronic lung disease and should compare different categories of devices, establish the impact of synchronisation of NIPPV on safety and efficacy of the technique as well as the best combination of settings for NIPPV (rate, peak pressure and positive end-expiratory). Trials should strive to match the mean airway pressure between the intervention groups to allow a better comparison. Neurally adjusted ventilatory assist needs further assessment with properly powered randomised trials., (Copyright © 2023 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.)

Purpose: There is an elevated incidence of hypoxemia during the airway management of the morbidly obese. We aimed to assess whether optimizing body position and ventilation during pre-oxygenation allow a longer safe non-hypoxic apnea period (SNHAP)., Methods: Fifty morbidly obese patients were recruited and randomized for this study. Patients were positioned and preoxygenated for three minutes in the ramp position associated with spontaneous breathing without additional CPAP or PEEP (RP/ZEEP group) or in the reverse Trendelenburg position associated with pressure support ventilation mode with pressure support of 8 cmH 2 O and an additional 10 cmH 2 O of PEEP while breathing spontaneously (RT/PPV group) according to randomization., Results: The SNHAP was significantly longer in the RT/PPV group (258.2 (55.1) vs. 216.7 (42.3) seconds, p = 0.005). The RT/PPV group was also associated to a shorter time to obtain a fractional end-tidal oxygen concentration (FEtO 2 ) of 0.90 (85.1(47.8) vs 145.3(40.8) seconds, p < 0.0001), a higher proportion of patients that reached the satisfactory FEtO 2 of 0.90 (21/24, 88% vs. 13/24, 54%, p = 0.024), a higher FEtO 2 during preoxygenation (0.91(0.05) vs. 0.89(0.01), p = 0.003) and a faster return to 97% oxygen saturation after ventilation resumption (69.8 (24.2) vs. 91.4 (39.2) seconds, p = 0.038)., Conclusion: In the morbidly obese population, RT/PPV, compared to RP/ZEEP, lengthens the SNHAP, decreases the time to obtain optimal preoxygenation conditions, and allows a faster resuming of secure oxygen saturation. The former combination allows a more significant margin of time for endotracheal intubation and minimizes the risk of hypoxemia in this highly vulnerable population., Trial Registration: NCT02590406, 29/10/2015., (© 2023. The Author(s).)

The placement of an endotracheal tube for children with acute or critical illness is a low-frequency and high-risk procedure, associated with high rates of first-attempt failure and adverse events, including hypoxaemia. To reduce the frequency of these adverse events, the provision of oxygen to the patient during the apnoeic phase of intubation has been proposed as a method to prolong the time available for the operator to insert the endotracheal tube, prior to the onset of hypoxaemia. However, there are limited data from randomised controlled trials to validate the efficacy of this technique in children. The technique known as transnasal humidified rapid insufflation ventilatory exchange (THRIVE) uses high oxygen flow rates (approximately 2 L/kg/min) delivered through nasal cannulae during apnoea. It has been shown to at least double the amount of time available for safe intubation in healthy children undergoing elective surgery. The technique and its application in real time have not previously been studied in acutely ill or injured children presenting to the emergency department or admitted to an intensive care unit. The Kids THRIVE trial is a multicentre, international, randomised controlled trial (RCT) in children less than 16 years old undergoing emergent intubation in either the intensive care unit or emergency department of participating hospitals. Participants will be randomised to receive either the THRIVE intervention or standard care (no apnoeic oxygenation) during their intubation. The primary objective of the trial is to determine if the use of THRIVE reduces the frequency of oxygen desaturation and increases the frequency of first-attempt success without hypoxaemia in emergent intubation of children compared with standard practice. The secondary objectives of the study are to assess the impact of the use of THRIVE on the rate of adverse events, length of mechanical ventilation and length of stay in intensive care. In this paper, we describe the detailed statistical analysis plan as an update of the previously published protocol., (© 2023. Crown.)

The objective of this study is to describe the clinical features of young infants with apneas as a clinical sign of COVID-19. We reported the cases of 4 infants who needed respiratory support in our PICU for a severe course of COVID-19 complicated with recurrent apneas. Moreover, we conducted a review of the literature about COVID-19 and apneas in infants ≤ 2 months of corrected age. A total of 17 young infants were included. Overall, in most of the cases (88%), apnea was an initial symptom of COVID-19, and in two cases, it recurred after 3-4 weeks. Regarding neurological workup, most children underwent a cranial ultrasound, while a minority underwent electroencephalography registration, neuroimaging, and lumbar punctures. One child showed signs of encephalopathy on electroencephalogram, with further neurological workup resulting normal. SARS-CoV-2 was never found in the cerebrospinal fluid. Ten children required intensive care unit admission, with five of them needing intubation and three non-invasive ventilation. A less invasive respiratory support was sufficient for the remaining children. Eight children were treated with caffeine. All patients had a complete recovery.  Conclusion: Young infants with recurrent apneas during COVID-19 usually need respiratory support and undergo a wide clinical work-up. They usually show complete recovery even when admitted to the intensive care unit. Further studies are needed to better define diagnostic and therapeutic strategies for these patients. What is Known: • Although the course of COVID-19 in infants is usually mild, some of them may develop a more severe disease needing intensive care support. Apneas may be a clinical sign in COVID-19. What is New: • Infants with apneas during COVID-19 may require intensive care support, but they usually show a benign course of the disease and full recovery., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Obese patients desaturate rapidly during the apneic period after induction of anesthesia for elective surgery. Administration of oxygen using high-flow nasal cannulae (HFNCs) may prevent desaturation in nonobese patients compared to facemask (FM) preoxygenation. The aim of this meta-analysis was to compare the effectiveness of HFNC to FM preoxygenation techniques in reducing preintubation desaturation in obese patients undergoing elective surgery., Methods: This study protocol was registered on PROSPERO (CRD42022309391). Adult studies that compared HFNC and FM preoxygenation in obese patients requiring general anesthesia for elective surgery were included. The primary outcome was desaturation resulting in oxygen saturation of <92% from induction of anesthesia until intubation. Secondary outcomes included the lowest arterial oxygen content before intubation expressed in mm Hg, safe apnea time expressed in seconds, the lowest oxygen saturation before intubation expressed as a percentage, patient-reported discomfort, the need for rescue ventilation, and the incidence of aspiration of gastric contents during intubation. Risk of bias was assessed using the Cochrane Collaboration tool. Certainty was assessed following the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach., Results: Six studies including 351 participants were eligible for analysis. There was no difference in odds of oxygen desaturation <92% between HFNC and FM (odds ratio [OR], 0.49; 95% confidence interval [CI], 0.15-1.63; P = .24). The HFNC group had a significantly longer safe apnea time (mean difference [MD], -124.20 with 95% CI, -200.47 to -47.93; P = .001). There was no difference between HFNC and FM in the lowest arterial oxygen content (MD, -23.90; 95% CI, -88.64 to 40.85; P = .47) and the lowest peripheral oxygenation saturation (MD, -0.47 with 95% CI, -5.07 to 4.12; P = .84). HFNC had a lower odd of discomfort than FM (OR, 0.13; 95% CI, 0.03-0.52; P = .004). There was no difference in the odds of aspiration of gastric contents between HFNC and FM (OR, 0.33; 95% CI, 0.01-8.21; P = .50). The risk of bias for our primary and secondary outcomes was low. The GRADE assessment for our primary outcome indicated a low level of certainty. For secondary outcomes, the GRADE assessment indicated a very low certainty for all outcomes except for patient discomfort, which was indicated as a moderate level of certainty., Conclusions: There may be no difference between HFNC and FM preoxygenation in preventing oxygen desaturation <92% or the lowest oxygen saturation before intubation. Preparation remains important to prevent and manage desaturation during induction of obese patients., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2022 International Anesthesia Research Society.)

Introduction: Currently, there is an increase in people practicing freediving (FD) both in competition and leisure. As a sports practice, its modalities are grouped into static, dynamic, and constant weight apnea. The aim of this systematic review and meta-analysis (PROSPERO-CRD42021230322) was to identify the training methods used to improve the static apnea time (AT) performance., Evidence Acquisition: Ten training protocols were analyzed from eight studies published until March 09, 2022. The effect size (Hedge's g) and its confidence interval (CI95%) were calculated from the AT measured pre- and post-training., Evidence Synthesis: Three different apnea training methods were verified, the breath-hold (BH) that uses BH exercises, physical training with strength and cardiorespiratory exercises, and cross training that combines BH exercises with physical training. These training methods were applied to 138 participants of both sexes with or without experience in apnea episode or diving practice. In general, the AT improvement showed a large effect after the interventions (g=1.30, CI95%=0.85-1.76, P<0.01)., Conclusions: All three methods were effective in improving static AT, however from the existing protocols is not possible to recommend an ideal to improve AT and therefore FD performance.

Background: Obesity is a risk factor for airway-related incidents during anaesthesia. High-flow nasal oxygen has been advocated to improve safety in high-risk groups, but its effectiveness in the obese population is uncertain. This study compared the effect of high-flow nasal oxygen and low-flow facemask oxygen delivery on duration of apnoea in morbidly obese patients., Methods: Morbidly obese patients undergoing bariatric surgery were randomly allocated to receive either high-flow nasal (70 L min -1 ) or facemask (15 L min -1 ) oxygen. After induction of anaesthesia, the patients were apnoeic for 18 min or until peripheral oxygen saturation decreased to 92%., Results: Eighty patients were studied (41 High-Flow Nasal Oxygen, 39 Facemask). The median apnoea time was 18 min in both the High-Flow Nasal Oxygen (IQR 18-18 min) and the Facemask (inter-quartile range [IQR], 4.1-18 min) groups. Five patients in the High-Flow Nasal Oxygen group and 14 patients in the Facemask group desaturated to 92% within 18 min. The risk of desaturation was significantly lower in the High-Flow Nasal Oxygen group (hazard ratio=0.27; 95% confidence interval [CI], 0.11-0.65; P=0.007)., Conclusions: In experienced hands, apnoeic oxygenation is possible in morbidly obese patients, and oxygen desaturation did not occur for 18 min in the majority of patients, whether oxygen delivery was high-flow nasal or low-flow facemask. High-flow nasal oxygen may reduce desaturation risk compared with facemask oxygen. Desaturation risk is a more clinically relevant outcome than duration of apnoea. Individual physiological factors are likely to be the primary determinant of risk rather than method of oxygen delivery., Clinical Trial Registration: NCT03428256., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Aim: We compared effects of infant positioning and feed-rate interventions on respiratory events and oximetry parameters in spontaneously breathing preterm infants born <32 weeks gestation managed in a neonatal unit., Methods: A randomised triple crossover design was employed. n = 68 infants underwent three test conditions A: control (supine/flat, gravity bolus feeds), B: position intervention (propped/prone) and C: feed-rate intervention (continuous pump feeds) in randomised sequence over three consecutive days. Primary outcomes were number of events (apnoea, bradycardia and desaturation) and percentage time SpO 2  < 80% over 24 h. The secondary outcome was percentage time SpO 2  ≥ 88%. Treatment effects were estimated using linear mixed-effects models., Results: Propped/prone positioning significantly reduced events and improved percentage time SpO 2  < 80% and ≥88% compared to both other conditions (all P < 0.001). Outcomes for the feed-rate intervention were not significantly different to control., Conclusions: Alternative infant positioning should be considered in preterm infants managed in the neonatal unit., (© 2022 The Authors. Journal of Paediatrics and Child Health published by John Wiley & Sons Australia, Ltd on behalf of Paediatrics and Child Health Division (The Royal Australasian College of Physicians).)

Background: Among autonomic seizures apnea still represent a challenge for physicians, and it might constitute the only isolated sign of neurological disorder. The aim of this review is to describe ictal apnea (IA) and its treatment options., Methods: MeSH and keywords were combined: "neonatal seizures", "ictal neonatal apnea", "apneic seizures". All identified papers were screened for neonatal seizures titles and abstracts; case reports describing patients with IA as an isolated manifestation of neonatal seizures were included., Results: Eight studies including a total of 13 patients were identified. Among 13 patients, 9 were full-term and 4 were preterm neonates. All patients developed IA within twenty-one days from birth. Etiologies of seizures included: temporal lobe hemorrhage (3 pt), occipital stroke (1 pt), hypoxic-ischemic encephalopathy (HIE) (1 pt), parasagittal injury (1 pt), 18 trisomy (2 pt). Five patients showed no structural CNS alterations. Ten patients had the ictal focus localized in the temporal lobe; the occipital lobe was the second most involved site. Phenobarbital was administered in 76 % of cases with IA (10 pt), and showed efficacy in 74 % of them; 2 required a second anti-epileptic drug (AED) to reach seizure control. Levetiracetam was given to 11 % (2 pt) successfully. Only one was treated with midazolam and one did not require any anticonvulsant., Conclusions: Not homogeneous data and paucity of isolated IA currently reported in literature limits agreement about definition, management and treatment of entity, however an ever-growing attention is needed, and EEG/aEEG, despite their possible controversies in the diagnosis, should be performed to investigate unexplained forms of apnea., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Background: Hypoxaemia during general anaesthesia can cause harm. Apnoeic oxygenation extends safe apnoea time, reducing risk during airway management. We hypothesised that low-flow nasal oxygenation (LFNO) would extend safe apnoea time similarly to high-flow nasal oxygenation (HFNO), whilst allowing face-mask preoxygenation and rescue., Methods: A high-fidelity, computational, physiological model was used to examine the progression of hypoxaemia during apnoea in virtual models of pregnant women in and out of labour, with BMI of 24-50 kg m -2 . Subjects were preoxygenated with oxygen 100% to reach end-tidal oxygen fraction (FE'O 2 ) of 60%, 70%, 80%, or 90%. When apnoea started, HFNO or LFNO was commenced. To simulate varying degrees of effectiveness of LFNO, periglottic oxygen fraction (FgO 2 ) of 21%, 60%, or 100% was configured. HFNO provided FgO 2 100% and oscillating positive pharyngeal pressure., Results: Application of LFNO (FgO 2 100%) after optimal preoxygenation (FE'O 2 90%) resulted in similar or longer safe apnoea times than HFNO FE'O 2 80% in all subjects in labour. For BMI of 24, the time to reach SaO 2 90% with LFNO was 25.4 min (FE'O 2 90%/FgO 2 100%) vs 25.4 min with HFNO (FE'O 2 80%). For BMI of 50, the time was 9.9 min with LFNO (FE'O 2 90%/FgO 2 100%) vs 4.3 min with HFNO (FE'O 2 80%). A similar finding was seen in subjects with BMI ≥40 kg m -2 not in labour., Conclusions: There is likely to be clinical benefit to using LFNO, given that LFNO and HFNO extend safe apnoea time similarly, particularly when BMI ≥40 kg m -2 . Additional benefits to LFNO include the facilitation of rescue face-mask ventilation and ability to monitor FE'O 2 during preoxygenation., (Copyright © 2022 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.)

Background: Modern human patient simulators (HPSs) could be used for researching critical scenarios such as apnea oxygenation. We aimed to study the use of a high-fidelity HPS to assess prolonged apnea using various oxygenation strategies with a simple high-flow nasal cannula (15 L/min)., Methods: An experimental simulation study using an HPS (CAE Healthcare™) was conducted after obtaining approval from the Institutional Review Board. The HPS responded according to real-time physiologically modeled responses to external gases, such as oxygen (O2). Apnea experiments were performed with different physiological settings, such as shunt fraction (5%) and O2 consumption (250, 500, and 750 ml/min). The following four apnea experiments were conducted: no oxygenation (NO), apnea oxygenation alone (AO), preoxygenation alone (PO), and para-oxygenation (PAO). The time to 92%, 75%, and 50% saturation was recorded. Alveolar and arterial gas levels were recorded till 50% saturation., Results: At 250 ml/min, PO (1121 s) and PAO (1274.5 s) had a significantly longer time to 50% saturation (400% increase) compared to NO (222.5 s) and AO (239 s). A similar trend was observed for the time to 92% and 75% saturation. At higher O2 consumption rates, a shorter time to desaturation was observed., Conclusions: Apnea trends in the HPS correlated with similar prior human experiments. AO without preoxygenation was found to provide no additional benefit. Preoxygenation with high-flow O2 via nasal cannula prolonged the time to desaturation in the PAO more than PO scenario. Therefore, HPSs can be used in future studies where patient safety is a concern.

Background: Previous studies concerning humidified, heated high-flow nasal oxygen delivered in spontaneously breathing patients postulated an increase in functional residual capacity as one of its physiological effects. It is unclear wheter this is also true for patients under general anesthesia., Methodology: The sincle-center noninferiority trial was registered at ClinicalTrials.gov (NCT NCT03478774). This secondary outcome analysis shows estimated differences in lung volume changes using electrical impedance tomography between different flow rates of 100% oxygen in apneic, anesthetized and paralyzed adults prior to intubation. One hundred and twenty five patients were randomized to five groups with different flow rates of 100% oxygen: i) minimal-flow: 0.25 l.min-1 via endotracheal tube; ii) low-flow: 2 l.min-1 + continuous jaw thrust; iii) medium-flow: 10 l.min-1 + continuous jaw thrust; iv) high-flow: 70l.min-1 + continuous jaw thrust; and v) control: 70 l.min-1 + continuous video-laryngoscopy. After standardized anesthesia induction with non-depolarizing neuromuscular blockade, the 15-minute apnea period and oxygen delivery was started according to the randomized flow rate. Continuous electrical impedance tomography measurements were performed during the 15-minute apnea period. Total change in lung impedance (an estimate of changes in lung volume) over the 15-minute apnea period and times to 25%, 50% and 75% of total impedance change were calculated., Results: One hundred and twenty five patients completed the original study. Six patients did not complete the 15-minute apnea period. Due to maloperation, malfunction and artefacts additional 54 measurements had to be excluded, resulting in 65 patients included into this secondary outcome analysis. We found no differences between groups with respect to decrease in lung impedance or curve progression over the observation period., Conclusions: Different flow rates of humidified 100% oxygen during apnea result in comparable decreases in lung volumes. The demonstrated increase in functional residual capacity during spontaneous breathing with high-flow nasal oxygenation could not be replicated during apnea under general anesthesia with neuromuscular blockade., Competing Interests: TR does receive consulting fees from Sentec AG, Landquart, Switzerland and reports also that he has received a grant from the Swiss Foundation for Research on Muscle Diseases for a different research project. All other authors declare that they have no competing interests. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Objective: The study aimed to systematically review and analyze the impact of nasal intermittent positive pressure ventilation (NIPPV) versus continuous positive airway pressure (CPAP) on apnea of prematurity (AOP) in preterm neonates., Study Design: In this systematic review and meta-analysis, experimental studies enrolling preterm infants comparing NIPPV (synchronized, nonsynchronized, and bi-level) and CPAP (all types) were searched in multiple databases and screened for the assessment of AOP. Primary outcome was AOP frequency per hour (as defined by authors of included studies)., Results: Out of 4,980 articles identified, 18 studies were included with eight studies contributing to the primary outcome. All studies had a high risk of bias, with significant heterogeneity in definition and measurement of AOP. There was no difference in AOPs per hour between NIPPV versus CPAP (weighted mean difference = -0.19; 95% confidence interval [CI]: -0.76 to 0.37; eight studies, 456 patients). However, in a post hoc analysis evaluating the presence of any AOP (over varying time periods), the pooled odds ratio (OR) was lower with NIPPV (OR: 0.46; 95% CI: 0.32-0.67; 10 studies, 872 patients)., Conclusion: NIPPV was not associated with decrease in AOP frequency, although demonstrated lower odds of developing any AOP. However, definite recommendations cannot be made based on the quality of the published evidence., Key Points: · AOP is a common clinical complication related to preterm birth.. · NIPPV is often used to mitigate AOP and complications.. · Relative impact of NIPPV and CPAP on AOP remains unclear.., Competing Interests: None declared., (Thieme. All rights reserved.)

Apnoea, a pause in respiration, is ubiquitous in preterm infants and are often associated with physiological instability, which may lead to longer-term adverse neurodevelopmental consequences. Despite current therapies aimed at reducing the apnoea burden, preterm infants continue to exhibit apnoeic events throughout their hospital admission. Bedside staff are frequently required to manually intervene with different forms of stimuli, with the aim of re-establishing respiratory cadence and minimizing the physiological impact of each apnoeic event. Such a reactive approach makes apnoea and its associated adverse consequences inevitable and places a heavy reliance on human intervention. Different approaches to improving apnoea management in preterm infants have been investigated, including the use of various sensory stimuli. Despite studies reporting sensory stimuli of various forms to have potential in reducing apnoea frequency, non-invasive intermittent positive pressure ventilation is the only automated stimulus currently used in the clinical setting for infants with persistent apnoeic events. We find that the development of automated closed-looped sensory stimulation systems for apnoea mitigation in preterm infants receiving non-invasive respiratory support is warranted, including the possibility of stimulation being applied preventatively, and in a multi-modal form. IMPACT: This review examines the effects of various forms of sensory stimulation on apnoea mitigation in preterm infants, namely localized tactile, generalized kinesthetic, airway pressure, auditory, and olfactory stimulations. Amongst the 31 studies reviewed, each form of sensory stimulation showed some positive effects, although the findings were not definitive and comparative studies were lacking. We find that the development of automated closed-loop sensory stimulation systems for apnoea mitigation is warranted, including the possibility of stimulation being applied preventatively, and in a multi-modal form., (© 2021. The Author(s), under exclusive licence to the International Pediatric Research Foundation, Inc.)

Background: Cardiopulmonary events (CPE) have a central, obstructive, or mixed etiology. Lack of standardized diagnosis and management of CPE may prolong the length of stay (LOS)., Objective: To increase the accuracy of CPE diagnosis and decrease LOS by 10% for preterm infants over a 12-month period., Methods: Develop an evidence-based algorithm to identify type of CPE, determine management approach, and evaluate cardio-respiratory monitors output. Apply model for improvement and statistical process control charts to determine special cause variation., Results: Identification of central apnea increased from 15 to 39% (p < 0.01). LOS decreased 26% from 52.6 days to 39.2 days, with an estimated cost savings of $13,119 per each of the 225 infants in the initiative., Conclusion: After implementing an evidence-based algorithm for management of neonatal CPE, a significant increase in the accuracy of the diagnosis of central apnea and cost savings associated with a decrease in LOS were observed., (© 2022. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Purpose of Review: Apneic oxygenation is increasingly used in pediatric anesthesia. Its benefit for specific applications depends on the effect of apneic oxygenation on safe apnea time and carbon dioxide (CO2) elimination, on differences between low and high flow oxygen delivery, and on possible adverse effects. The present review summarizes current evidence on these pathophysiological aspects of apneic oxygenation as well as its applications in pediatric anesthesia., Recent Findings: Apneic oxygenation with both low flow and high flow nasal oxygen increases the safe apnea time, but does not lead to increased CO2 elimination. Airway pressures and adverse effects like atelectasis formation, oxidative stress and aerosol generation under apneic oxygenation are not well studied in pediatric anesthesia. Data from adults suggest no important effect on airway pressures when the mouth is open, and no significant formation of atelectasis, oxidative stress or aerosol generation with high flow nasal oxygen., Summary: Apneic oxygenation in pediatric anesthesia is mainly used during standard and difficult airway management. It is sometimes used for airway interventions, but CO2 accumulation remains a major limiting factor in this setting. Reports highlight the use of high flow nasal oxygen in spontaneously breathing rather than in apneic children for airway interventions., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

This meta-analysis aimed at investigating the efficacy of high-flow nasal oxygenation (HFNO) against hypoxemia in patients with obesity compared with conventional oxygenation therapy and non-invasive ventilation. Databases were searched from inception to August 2021. Studies involving peri- or post-procedural use of HFNO were included. The primary outcome was risk of hypoxemia, while the secondary outcomes included status of oxygenation and carbon dioxide elimination. Ten randomized controlled trials (RCTs) were included. We found that HFNO prolonged the safe apnea time at induction compared to control group [mean difference (MD) = 73.88 s, p = 0.0004; 2 RCTs] with no difference in risk of peri-procedural hypoxemia [relative risk (RR) = 0.91, p = 0.64; 4 RCTs], minimum SpO2 (MD = 0.09%, p = 0.95; 4 RCTs), PaO2 (MD = - 8.13 mmHg, p = 0.86; 3 RCTs), PaCO2 (MD = - 6.71%, p = 0.2; 2 RCTs), EtCO2 (MD = - 0.28 mmHg, p = 0.8; 4 RCTs) between the two groups. HFNO also did not improve postprocedural PaO2/FiO2 ratio (MD = 41.76, p = 0.58; 2 RCTs) and PaCO2 (MD = - 2.68 mmHg, p = 0.07; 2 RCTs). This meta-analysis demonstrated that the use of HFNO may be associated with a longer safe apnea time without beneficial impact on the risk of hypoxemia, oxygenation, and CO2 elimination in patients with obesity. The limited number of trials warranted further large-scale studies to support our findings., (© 2022. The Author(s).)

Background: In recent years, high flow nasal oxygen (HFNO) has been widely used in clinic, especially in perioperative period. Many studies have discussed the role of HFNO in pre- and apneic oxygenation, but their results are controversial. Our study aimed to examine the effectiveness of HFNO in pre- and apneic oxygenation by a meta-analysis of RCTs., Methods: EMBASE, PUBMED, and COCHRANE LIBRARY databases were searched from inception to July 2021 for relevant randomized controlled trails (RCTs) on the effectiveness of HFNO versus standard facemask ventilation (FMV) in pre- and apenic oxygenation. Studies involving one of the following six indicators: (1) Arterial oxygen partial pressure (PaO 2 ), (2) End expiratory oxygen concentration (EtO 2 ), (3) Safe apnoea time, (4) Minimum pulse oxygen saturation (SpO 2min ), (5) Oxygenation (O 2 ) desaturation, (6) End expiratory carbon dioxide (EtCO 2 ) or Arterial carbon dioxide partial pressure(PaCO 2 ) were included. Due to the source of clinical heterogeneity in the observed indicators in this study, we adopt random-effects model for analysis, and express it as the mean difference (MD) or risk ratio (RR) with a confidence interval of 95% (95%CI). We conducted a risk assessment of bias for eligible studies and assessed the overall quality of evidence for each outcome., Results: Fourteen RCTs and 1012 participants were finally included. We found the PaO 2 was higher in HFNO group than FMV group with a MD (95% CI) of 57.38 mmHg (25.65 to 89.10; p = 0.0004) after preoxygenation and the safe apnoea time was significantly longer with a MD (95% CI) of 86.93 s (44.35 to 129.51; p < 0.0001) during anesthesia induction. There were no significant statistical difference in the minimum SpO 2 , CO 2 accumulation, EtO 2 and O 2 desaturation rate during anesthesia induction between the two groups., Conclusions: This systematic review and meta-analysis suggests that HFNO should be considered as an oxygenation tool for patients during anesthesia induction. Compared with FMV, continuous use of HFNO during anesthesia induction can significantly improve oxygenation and prolong safe apnoea time in surgical patients., (© 2022. The Author(s).)

Background: Anesthesia studies using high-flow, humidified, heated oxygen delivered via nasal cannulas at flow rates of more than 50 l · min-1 postulated a ventilatory effect because carbon dioxide increased at lower levels as reported earlier. This study investigated the increase of arterial partial pressure of carbon dioxide between different flow rates of 100% oxygen in elective anesthetized and paralyzed surgical adults before intubation., Methods: After preoxygenation and standardized anesthesia induction with nondepolarizing neuromuscular blockade, all patients received 100% oxygen (via high-flow nasal oxygenation system or circuit of the anesthesia machine), and continuous jaw thrust/laryngoscopy was applied throughout the 15-min period. In this single-center noninferiority trial, 25 patients each, were randomized to five groups: (1) minimal flow: 0.25 l · min-1, endotracheal tube; (2) low flow: 2 l · min-1, continuous jaw thrust; (3) medium flow: 10 l · min-1, continuous jaw thrust; (4) high flow: 70 l · min-1, continuous jaw thrust; and (5) control: 70 l · min-1, continuous laryngoscopy. Immediately after anesthesia induction, the 15-min apnea period started with oxygen delivered according to the randomized flow rate. Serial arterial blood gas analyses were drawn every 2 min. The study was terminated if either oxygen saturation measured by pulse oximetry was less than 92%, transcutaneous carbon dioxide was greater than 100 mmHg, pH was less than 7.1, potassium level was greater than 6 mmol · l-1, or apnea time was 15 min. The primary outcome was the linear rate of mean increase of arterial carbon dioxide during the 15-min apnea period computed from linear regressions., Results: In total, 125 patients completed the study. Noninferiority with a predefined noninferiority margin of 0.3 mmHg · min-1 could be declared for all treatments with the following mean and 95% CI for the mean differences in the linear rate of arterial partial pressure of carbon dioxide with associated P values regarding noninferiority: high flow versus control, -0.0 mmHg · min-1 (-0.3, 0.3 mmHg · min-1, P = 0.030); medium flow versus control, -0.1 mmHg · min-1 (-0.4, 0.2 mmHg · min-1, P = 0.002); low flow versus control, -0.1 mmHg · min-1 (-0.4, 0.2 mmHg · min-1, P = 0.003); and minimal flow versus control, -0.1 mmHg · min-1 (-0.4, 0.2 mmHg · min-1, P = 0.004)., Conclusions: Widely differing flow rates of humidified 100% oxygen during apnea resulted in comparable increases of arterial partial pressure of carbon dioxide, which does not support an additional ventilatory effect of high-flow nasal oxygenation., (Copyright © 2021, the American Society of Anesthesiologists. All Rights Reserved.)

Oxygen application and apneic oxygenation may reduce the risk of hypoxemia due to apnea during awake fiberoptic intubation or failed endotracheal intubation. High flow devices are recommended, but their effect compared to moderate deep oropharyngeal oxygen application is unknown. Designed as an experimental manikin trial, we made a comparison between oxygen application via nasal prongs at 10 L/min (control group), applying oxygen via oropharyngeal oxygenation device (at 10 L/min), oxygen application via high flow nasal oxygen with 20 L/min and 90% oxygen (20 L/90% group), oxygen application via high flow nasal oxygen with 60 L/min and 45% oxygen (60 L/45% group), and oxygen application via sealed face mask with a special adapter to allow for fiberoptic entering of the airway. We preoxygenated the lung of a manikin and measured the decrease in oxygen level during the following 20 minutes for each way of oxygen application. Oxygen levels fell from 97 ± 1% at baseline to 75 ± 1% in control group, and to 86 ± 1% in oropharyngeal oxygenation device group. In the high flow nasal oxygen group, oxygen level dropped to 72 ± 1% in the 20 L/90% group and to 44 ± 1% in the 60 L/45% group. Oxygen level remained at 98 ± 0% in the face mask group. In conclusion, in this manikin simulation study of apneic oxygenation, oxygen insufflation using a sealed face mask kept oxygen levels in the test lung at 98% over 20 minutes, oral oxygenation device led to oxygen levels at 86%, whereas all other methods resulted in the decrease of oxygen levels below 75%., Competing Interests: None

High-flow nasal oxygen used before and during apnoea prolongs time to desaturation at induction of anaesthesia. It is unclear how much oxygenation before apnoea prolongs this time. We randomly allocated 84 participants to 3 minutes of pre-oxygenation by one of three methods: 15 l.min -1 by facemask; 50 l.min -1 by high-flow nasal cannulae only; or 50 l.min -1 by high-flow nasal cannulae plus 15 l.min -1 by mouthpiece. We then anaesthetised and intubated the trachea of 79 participants and waited for oxygen saturation to fall to 92%. Median (IQR [range]) times to desaturate to 92% after pre-oxygenation with facemask oxygen, high-flow nasal oxygen only and high-flow nasal oxygen with mouthpiece, were: 309 (208-417 [107-544]) s; 344 (250-393 [194-585]) s; and 386 (328-498 [182-852]) s, respectively, p = 0.014. Time to desaturation after facemask pre-oxygenation was shorter than after combined nasal and mouthpiece pre-oxygenation, p = 0.006. We could not statistically distinguish high-flow nasal oxygen without mouthpiece from the other two groups for this outcome. Median (IQR [range]) arterial oxygen partial pressure after 3 minutes of pre-oxygenation by facemask, nasal cannulae and nasal cannulae plus mouthpiece, was: 49 (36-61 [24-66]) kPa; 57 (48-62 [30-69]) kPa; and 61 (55-64 [36-72]) kPa, respectively, p = 0.003. Oxygen partial pressure after 3 minutes of pre-oxygenation with nasal and mouthpiece combination was greater than after facemask pre-oxygenation, p = 0.002, and after high-flow nasal oxygen alone, p = 0.016. We did not reject the null hypothesis for the pairwise comparison of facemask pre-oxygenation and high-flow nasal pre-oxygenation, p = 0.14., (© 2021 Association of Anaesthetists.)

Preoxygenation during endotracheal intubation is important to ensure the safety of the procedure. This systematic review and meta-analysis aimed to evaluate the efficacy of preoxygenation in the head-elevated position as compared to the supine position. The Medline, PubMed, Scopus, Embase, and CENTRAL databases were searched systematically from inception of the study until 29 June 2021. Only randomized controlled trials (RCTs) were included. The Cochrane Risk of Bias Assessment Tool and GRADE assessment of certainty of evidence were used. Seven RCTs (n = 508) were analysed, of which 6 were included in the meta-analysis (n = 227). Six studies were carried out in the operating theatre (OT), while one was performed in the critical care (ICU) setting. Compared to the supine position, the head-elevated position significantly increased the duration of the safe apnoea period (mean difference 61.99 s; 95% confidence interval 42.93-81.05 s; P < 0.00001; I2 = 30%; certainty of evidence = high). This improvement was seen in both the obese and non-obese population (I2 = 0%). No differences were seen between both groups with regard to recovery time after apnoea, arterial oxygen tension after preoxygenation, and the incidence of adverse events. In the ICU setting, no difference was found between groups for the incidence of hypoxaemia and the lowest oxygen saturation between induction and after intubation. This meta-analysis demonstrated that the head-elevated position significantly improved the efficacy of preoxygenation during elective intubation in the OT. Clinicians should consider the head-elevated position as a starting intubating position for all patients undergoing anaesthesia in view of its many benefits and the lack of proven adverse consequences. Protocol Registration: This systematic review was registered prospectively in PROSPERO (CRD42019128962).

Background: Neonatal endotracheal intubation is often associated with physiological instability. The Neonatal Resuscitation Program recommends a time-based limit (30 s) for intubation attempts in the delivery room, but there are limited physiological data to support recommendations in the neonatal intensive care unit (NICU). We aimed to determine the time to desaturation after ceasing spontaneous or assisted breathing in preterm infants undergoing elective endotracheal intubation in the NICU., Methods: Observational study at The Royal Women's Hospital, Melbourne. A secondary analysis was performed of video recordings of neonates ≤32 weeks' postmenstrual age undergoing elective intubation. Infants received premedication including atropine, a sedative and muscle relaxant. Apnoeic oxygenation time (AOT) was defined as the time from the last positive pressure or spontaneous breath until desaturation (SpO 2 <90%)., Results: Seventy-eight infants were included. The median (IQR) gestational age at birth was 27 (26-29) weeks and birth weight 946 (773-1216) g. All but five neonates desaturated to SpO 2 <90% (73/78, 94%). The median (IQR) AOT was 22 (14-32) s. The median (IQR) time from ceasing positive pressure ventilation to desaturation <80% was 35 (24-44) s and to desaturation <60% was 56 (42-68) s. No episodes of bradycardia were seen., Conclusions: This is the first study to report AOT in preterm infants. During intubation of preterm infants in the NICU, desaturation occurs quickly after cessation of positive pressure ventilation. These data are important for the development of clinical guidelines for neonatal intubation., Trial Registration Number: ACTRN12614000709640., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Preoxygenation and application of apneic oxygenation are standard to prevent patients from desaturation e.g. during emergency intubation. The time before desaturation occurs can be prolonged by applying high flow oxygen into the airway. Aim of this study was to scientifically assess the flow that is necessary to avoid nitrogen entering the airway of a manikin model during application of pure oxygen via high flow nasal oxygen., Methods: We measured oxygen content over a 20-min observation period for each method in a preoxygenated test lung applied to a human manikin, allowing either room air entering the airway in control group, or applying pure oxygen via high flow nasal oxygen at flows of 10, 20, 40, 60 and 80 L/min via nasal cannula in the other groups. Our formal hypothesis was that there would be no difference in oxygen fraction decrease between the groups., Results: Oxygen content in the test lung dropped from 97 ± 1% at baseline in all groups to 43 ± 1% in the control group (p < 0.001 compared to all other groups), to 92 ± 1% in the 10 L/min group, 92 ± 1% in the 20 L/min group, 90 ± 1% in the 40 L/min group, 89 ± 0% in the 60 L/min group and 87 ± 0% in the 80 L/min group. Apart from comparisons 10 l/ min vs. 20 L/min group (p = .715) and 10/L/min vs. 40 L/min group (p = .018), p was < 0.009 for all other comparisons., Conclusions: Simulating apneic oxygenation in a preoxygenated manikin connected to a test lung over 20 min by applying high flow nasal oxygen resulted in the highest oxygen content at a flow of 10 L/min; higher flows resulted in slightly decreased oxygen percentages in the test lung., (© 2021. The Author(s).)

Objective: Because of the abundance of complications associated with peri-intubation hypoxia, maintaining adequate oxygen saturation during endotracheal intubation (ETI) is of great concern. In addition to standard preoxygenation techniques, apneic oxygenation (AO), the continuous flow of passive oxygenation, is a potential tool that can be used to eliminate hypoxia during ETI. Although scarcely studied in the pediatric population, AO has proven effective in reducing the incidence of hypoxia in adult patients with minimal side effects. The objective of this study is to evaluate the use of apneic oxygenation in pediatric patients and to determine its efficacy in preventing or delaying oxygen desaturation during the apneic period of ETI., Methods: This literature review examines 4 studies that evaluate the practice of AO in pediatric patients. A total of 712 patients across 3 randomized control trials and 1 observational study were assigned to either a control group that did not receive any form of AO, a group that did not receive 100% fraction of inspired oxygen (FiO2), or an intervention group where various methods of AO were delivered., Results: Each AO method that provided 100% FiO2 saw a significantly longer time until initial desaturation when compared with those that did not receive any form of AO or those not receiving 100% FiO2., Conclusions: The findings in this study confirm that the practice of AO is not only efficacious in increasing the time until initial desaturation but also reduces the overall incidence of hypoxia during laryngoscopy in children., Competing Interests: Disclosure: The author declares no conflict of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

This narrative review provides a broad perspective on immature control of breathing, which is universal in infants born premature. The degree of immaturity and severity of clinical symptoms are inversely correlated with gestational age. This immaturity presents as prolonged apneas with associated bradycardia or desaturation, or brief respiratory pauses, periodic breathing, and intermittent hypoxia. These manifestations are encompassed within the clinical diagnosis of apnea of prematurity, but there is no consensus on minimum criteria required for diagnosis. Common treatment strategies include caffeine and noninvasive respiratory support, but other therapies have also been advocated with varying effectiveness. There is considerable variability in when and how to initiate and discontinue treatment. There are significant knowledge gaps regarding effective strategies to quantify the severity of clinical manifestations of immature breathing, which prevent us from better understanding the long-term potential adverse outcomes, including neurodevelopment and sudden unexpected infant death., (© 2021. This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply.)

Transnasal humidified rapid insufflation ventilatory exchange prolongs safe apnoeic oxygenation time in children. In adults, transnasal humidified rapid insufflation ventilatory exchange is reported to have a ventilatory effect with PaCO 2 levels increasing less rapidly than without it. This ventilatory effect has yet to be reproduced in children. In this non-inferiority study, we tested the hypothesis that children weighing 10-15 kg exhibit no difference in carbon dioxide clearance when comparing two different high-flow nasal therapy flow rates during a 10-min apnoea period. Following standardised induction of anaesthesia including neuromuscular blockade, patients were randomly allocated to high-flow nasal therapy of 100% oxygen at 2 or 4 l.kg -1 .min -1 . Airway patency was ensured by continuous jaw thrust. The study intervention was terminated for safety reasons when SpO 2 values dropped < 95%, or transcutaneous carbon dioxide levels rose > 9.3 kPa, or near-infrared spectroscopy values dropped > 20% from their baseline values, or after an apnoeic period of 10 min. Fifteen patients were included in each group. In the 2 l.kg -1 .min -1 group, mean (SD) transcutaneous carbon dioxide increase was 0.46 (0.11) kPa.min -1 , while in the 4 l.kg -1 .min -1 group it was 0.46 (0.12) kPa.min -1 . The upper limit of a one-sided 95%CI for the difference between groups was 0.07 kPa.min -1 , lower than the predefined non-inferiority margin of 0.147 kPa.min -1 (p = 0.001). The lower flow rate of 2 l.kg -1 .min -1 was non-inferior to 4 l.kg -1 .min -1 relative to the transcutaneous carbon dioxide increase. In conclusion, an additional ventilatory effect of either 2 or 4 l.kg -1 .min -1 high-flow nasal therapy in apnoeic children weighing 10-15 kg appears to be absent., (© 2020 Association of Anaesthetists.)

High-flow nasal oxygen is increasingly used for oxygenation during apnoea. Extending apnoea duration using this technique has mainly been investigated during minor laryngeal surgery, but it is unclear how long it can be administered for before it should be discontinued due to acidosis. We aimed to describe the dynamics of arterial blood gases during apnoeic oxygenation with high-flow nasal oxygen with jaw thrust only, to explore the limits of this technique. We included adult orthopaedic patients scheduled for general anaesthesia. After pre-oxygenation, anaesthesia with neuromuscular blockade was induced and high-flow nasal oxygen (70 l.min -1 ) was continued with jaw thrust as the only means of airway management, with monitoring of vital signs and arterial blood gas sampling every 5 minutes. Apnoeic oxygenation with high-flow nasal oxygen was discontinued when arterial carbon dioxide tension (PaCO 2 ) exceeded 12 kPa or pH fell to 7.15. This technique was used in 35 patients and median (IQR [range]) apnoea time was 25 (20-30 [20-45]) min and was discontinued in all patients when pH fell to 7.15. The mean (SD) PaCO 2 increase was 0.25 (0.06) kPa.min -1 but it varied substantially (range 0.13-0.35 kPa.min -1 ). Mean (SD) arterial oxygen tension was 48.6 (11.8) kPa when high-flow nasal oxygen was stopped. Patients with apnoea time > 25 minutes were significantly older (p = 0.025). We conclude that apnoeic oxygenation with high-flow nasal oxygen resulted in a significant respiratory acidosis that varies substantially on the individual level, but oxygenation was maintained., (© 2020 Association of Anaesthetists.)

Background: Poisoning and deaths by organo-phosphorous (OP) compounds are one of the major causes of death in developing and poor countries, and a common admission in the emergency ward and the ICU. OP compounds act by irreversibly binding to pseudocholinesterase enzyme and hence prolong the apnea in patients being given suxamethonium. We present a unusual case of OP poisoning (OPP) in which prolonged apnea ensued in a patient of severe depression following MECT (modified electroconvulsive therapy) in which suxamethonium was used as muscle relaxant, in whom we were cautious of the side-effect of prior organophosphorus poisoning. Since the cases of OPP are very high worldwide, a thorough knowledge of the interaction of the action of the drug and the receptors on which it acts takes pride of place. This article highlights the nuances in the field of psychiatry and anaesthesia in diagnosis and management of prolonged apnea after ECT., Case Presentation: A 53/F patient consumed OP 38 days prior to MECT. Since existing literature recommend a delay of 4 weeks and a subminimal dose of suxamethonium to prevent prolonged apnea, both these points were taken into consideration. Despite 38 days post exposure to OP, and a dose of succinylcholine of < 0.3 mg/kg, the patient remained apneic for 3 h. Suxamethionum apnea was managed with elective ventilation. After recovery, patient had no residual effect. Subsequently her pseudocholinesterase levels were done which were found to be very low., Conclusion: This case is being presented to emphasize that behaviour of post synaptic receptors cannot be relied upon after OP poisoning and pseudocholinesterase levels needs to be mandatorily checked, irrespective of duration post-exposure. In strong suspects dibucaine number and fluoride number also needs to be estimated.