Search

Background: Large variations in respiratory system compliance and resistance may cause the accuracy of tidal volume (VT) delivery beyond the declared range. This study aimed at evaluating the accuracy of VT delivery using a test lung model to simulate pulmonary mechanics under normal or disease conditions., Methods: In vitro assessment of the VT delivery accuracy was carried out on two commercial ventilators. Measurements of the inspired and expired VT from the ventilator and FlowAnalyser were compared to evaluate the separated and combined influences of compliance and resistance on the delivered VT accuracy. To do this, the errors of five delivered volumes (30 ml, 50 ml, 100 ml, 300 ml, and 500 ml) were checked under 29 test conditions involving a total of 27 combinations of resistance and compliance., Results: For the tested ventilator S1 with a flow sensor near the expiratory valve, the average of expired VT errors (ΔVTexp) in three measurements (4 test conditions for each measurement) correlated to test lung compliance (r=-0.96, p = 0.044), and the average of inspired VT errors (ΔVTins) correlated to compliance (r = 0.89, p = 0.106); for the tested ventilator S2 with a flow sensor located at the Y piece, no clear relationship between compliance and ΔVTexp or ΔVTins was found. Furthermore, on two ventilators tested, the current measurements revealed a poor correlation between test lung resistance and ΔVTins or ΔVTexp, and the maximum values of ΔVTexp and ΔVTins correspond to the maximum resistance of 200 cmH 2 O/(L/s), at which the phenomenon of the flap fluttering in the variable orifice flow senor was observed, and the recorded peak inspiratory pressure (Ppeak) was much higher than the Ppeak estimated by the classical equation of motion. In contrast, at the lower resistance values of 5, 20, 50 and 100 cmH 2 O/(L/s), the recorded Ppeak was very close to the estimated Ppeak. Overall, the delivered VT errors were in the range of ± 14% on two ventilators studied., Conclusions: Depending on the placement site of the flow sensor in the ventilator circuit, the compliance and resistance of the test lung have different influences on the accuracy of VT delivery, which is further attributed to different fluid dynamics effects of the compliance and resistance. The main influence of compliance is to raise the peak inspiratory pressure Ppeak, thereby increasing the compression volume within the ventilator circuit; whereas a high resistance not only contributes to elevating Ppeak, but more importantly, it governs the gas flow conditions. Ppeak is a critical predictive indicator for the accuracy of the VT delivered by a ventilator., (© 2024. The Author(s).)

Background: In emergency casualty and evacuation situations, manual ventilation using self-inflating bags remains a critical skill; however, significant challenges exist in ensuring safety and effectiveness, since inaccurate manual ventilation is associated with life-threatening risks (e.g., gastric insufflation with aspiration, barotrauma, and reduced venous return)., Methods: This study assessed the impact of audiovisual feedback from the bag-valve-mask (BVM) emergency narration guided instrument (BENGI), a handheld manual ventilation guidance device, on improving performance and safety, immediately and 2 weeks after, with no additional manual ventilation training. In a crossover manikin simulation study with 20 participants, BENGI immediately and significantly improved tidal volume and respiratory rate accuracy., Results: Intraand inter-participant variations were lower with BENGI, with Poincaré plot analysis showing improved performance that remained for at least 2 weeks following BENGI training., Conclusion: BENGI's audiovisual feedback improves manual immediately and persistently, making it invaluable for training and clinical use in diverse scenarios, from battlespace to civilian emergencies., Competing Interests: The authors have submitted a United States patent application for the BENGI technology presented in this manuscript., (2024.)

Competing Interests: Financial/Nonfinancial Disclosures None declared

Background: Endotracheal tube (ETT) occlusion is reported at a higher frequency among coronavirus disease-2019 (COVID-19) patients. Prior to the COVID-19 pandemic, literature examining patient and ventilator characteristics, including humidification, as etiologies of ETT occlusion yielded mixed results. Our study examines the relationship of humidification modality with ETT occlusion in COVID-19 patients undergoing invasive mechanical ventilation (IMV). Methods: We conducted a retrospective chart review of COVID-19 patients requiring IMV at a tertiary care center in New York from April 2020 to April 2021. Teleflex Neptune heated wire heated humidification (HH) and hygroscopic Intersurgical FiltaTherm and Sunmed Ballard 1500 heat and moisture exchangers (HME) were used. Episodes of ETT occlusion were recorded. Univariate and multivariable logistic regression models were used to investigate the relationship between humidification modality and the occurrence of ETT occlusion. Findings: A total of 201 eligible patients were identified. Teleflex HH was utilized in 50.2% of the population and the others Intersurgical and Sunmed HME devices. Median age was 62 years and 78.6% of patients had at least one medical comorbidity. Precisely, 24% of patients experienced an ETT occlusion after a median of 12 days. The HME group was younger (58.5 vs 64 years), predominantly male (75% vs 59.4%), and experienced more total ventilator days than the HH group (24 vs 12). Those using the studied HME devices had significantly higher odds of ETT occlusion (OR 4.4, 95% CI 1.8-10.6, P  = .0011). Three patients (6.1%) experienced cardiac arrest as a consequence of their occlusion. There were no deaths directly attributed to ETT occlusion. Conclusions: The studied HME devices were significantly associated with higher odds of ETT occlusion in COVID-19 patients requiring invasive mechanical ventilation. These events are not without significant clinical consequences. Prolonged use of under-performing HME devices remains suspect in the occurrence of ETT occlusions., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Tracheostomized patients undergoing liberation from mechanical ventilation (MV) are exposed to the ambient environment through humidified air, potentially heightening aerosol particle dispersion. This study was designed to evaluate the patterns of aerosol dispersion during spontaneous breathing trials in such patients weaning from prolonged MV., Methods: Particle Number Concentrations (PNC) at varying distances from tracheostomized patients in a specialized weaning unit were quantified using low-cost particle sensors, calibrated against a Condensation Particle Counter. Different oxygen delivery methods, including T-piece and collar mask both with the humidifier or with a small volume nebulizer (SVN), and simple collar mask, were employed. The PNC at various distances and across different oxygen devices were compared using the Kruskal-Wallis test., Results: Of nine patients receiving prolonged MV, five underwent major surgery, and eight were successfully weaned from ventilation. PNCs at distances ranging from 30 cm to 300 cm showed no significant disparity (H(4) = 8.993, p = 0.061). However, significant differences in PNC were noted among oxygen delivery methods, with Bonferroni-adjusted pairwise comparisons highlighting differences between T-piece or collar mask with SVN and other devices., Conclusion: Aerosol dispersion within 300 cm of the patient was not significantly different, while the nebulization significantly enhances ambient aerosol dispersion in tracheostomized patients on prolonged MV., Competing Interests: Declaration of competing interest None, (Copyright © 2024 Formosan Medical Association. Published by Elsevier B.V. All rights reserved.)

Nitric oxide (NO), a selective pulmonary vasodilator, can be delivered via conventional ICU and anesthesia machine ventilators. Anesthesia machines are designed for rebreathing of circulating gases, reducing volatile anesthetic agent quantity used. Current cylinder- and ionizing-based NO delivery technologies use breathing circuit flow to determine NO delivery and do not account for recirculated gases; therefore, they cannot accurately dose NO at FGF below patient minute ventilation (MV). A novel, cassette-based NO delivery system (GENOSYL ® DS, Vero Biotech Inc.) uses measured NO concentration in the breathing circuit as an input to an advanced feedback control algorithm, providing accurate NO delivery regardless of FGF and recirculation of gases. This study evaluated GENOSYL ® DS accuracy with different anesthesia machines, ventilation parameters, FGFs, and volatile anesthetics. GENOSYL ® DS was tested with GE Aisys and Dräger Fabius anesthesia machines to determine NO dose accuracy with FGF < patient MV, and with a Getinge Flow-i anesthesia machine to determine NO dose accuracy when delivering various volatile anesthetic agents. Neonatal and adult mechanical ventilation parameters and circuits were used. GENOSYL® DS maintained accurate NO delivery with all three anesthesia machines, at low FGF with recirculation of gases, and with all volatile anesthetic agents at different concentrations. Measured NO 2 levels remained acceptable at ≤ 1 ppm with set NO dose ≤ 40 ppm. GENOSYL ® DS, with its advanced feedback control algorithm, is the only NO delivery system capable of accurately dosing NO with anesthesia machines with rebreathing ventilation parameters (FGF < MV) regardless of anesthetic agent., (© 2024. The Author(s).)

Objective: Respiratory regulation is critical for patients with respiratory dysfunction. Clinically used ventilators can lead to long-term dependence and injury. Extracorporeal assistance approaches such as iron-lung devices provide a noninvasive alternative, however, artificial actuator counterparts have not achieved marvelous biomimetic ventilation as human respiratory muscles. Here, we propose a bionic soft exoskeleton robot that can achieve extracorporeal closed-loop respiratory regulation by emulating natural human breath., Methods: For inspiration, a soft vacuum chamber is actuated to produce negative thoracic pressure and thus expand lung volume by pulling the rib cage up and outward through use of external negative pressure. For expiration, a soft origami array under positive pressure pushes the abdominal muscles inward and the diaphragm upward. To achieve in vitro measurement of respiratory profile, we describe a wireless respiratory monitoring device to measure respiratory profiles with high accuracy, validated by quantitative comparisons with spirometer as gold-standard reference. By constructing a human-robot coupled respiratory mechanical model, a model-based proportional controller is designed for continuous tracking of the target respiratory profile., Results: In experiments with ten healthy participants and ten patients with respiratory difficulty, the robot can adjust its assistive forces in real time and drive human-robot coupling respiratory system to track the target profile., Conclusion: The biomimetic robot can achieve extracorporeal closed-loop respiratory regulation for a diverse population., Significance: The soft robot has important potential to assist respiration for people with respiratory difficulty, whether in a hospital or a home setting.

Objectives: To determine efficacy of non-invasive positive pressure face mask ventilation using a ventilator device (NIPPmV) for achieving early effective ventilation compared to that by self-inflating bag (SIB) or T- piece resuscitator (TPR)., Methods: The authors video recorded 33 trained resuscitators using NIPPmV (provided using ventilator device), SIB [a 500 ml silicone SIB without a positive end expiratory pressure (PEEP) valve] and a TPR. Using a continuous pressure recording system and a neonatal manikin, the authors evaluated the efficacy of the ventilation to achieve early effective ventilation during 30 s of ventilation. The primary outcome was time to achieve effective chest rise. Secondary outcomes were peak inspiratory pressure (PIP), ventilation rate and the need to perform ventilation corrective steps during positive pressure ventilation (PPV) among the devices., Results: Total 99 videos were recorded. The time(s) taken to achieve the first chest rise was significantly lesser in NIPPmV group compared to SIB and TPR (3.0 ± 1.7 vs. 3.7 ± 1.9 vs. 7.5 ± 5.4, respectively, p <0.001). The mean PIP delivered by NIPPmV compared to SIB & TPR (19.8 ± 1.6 vs. 35.6 ± 7.4 vs. 17.8 ± 2.0 cm H 2 0 respectively; p <0.001) was more accurate with preset PIP. Ventilation, in terms of breath rate, was observed to be controlled more accurately with NIPPmV compared to SIB & TPR (50 vs. 42 vs. 33 per min respectively; p <0.001)., Conclusions: The non-invasive positive pressure face mask ventilation using a ventilator (NIPPmV) resulted in achieving early, effective and consistent ventilation., (© 2023. The Author(s), under exclusive licence to Dr. K C Chaudhuri Foundation.)

Introduction: The stability of a new hyperbaric ventilator (Shangrila590, Beijing Aeonmed Company, Beijing, China) at different clinically relevant pressures in a hyperbaric chamber during pressure-controlled ventilation (PCV) was investigated., Methods: The ventilator was connected to a test lung in the multiplace hyperbaric chamber. The inspiratory pressure (PI) of the ventilator was set to 1.0, 1.5, 2.0, 2.5 and 3.0 kPa (approximately 10, 15, 20, 25 and 30 cmH₂O). The compliance and resistance of the test lung were set to 200 mL·kPa⁻¹ and 2 kPa·L⁻¹·s⁻¹, respectively. Experiments were conducted at 101, 203 and 284 kPa ambient pressure (1.0, 2.0 and 2.8 atmospheres absolute respectively). At each of the 5 PI values, the tidal volume (VT), peak inspiratory pressure (Ppeak) and peak inspiratory flow (Fpeak) displayed by the ventilator and the test lung were recorded for 20 cycles. Test lung data were considered the actual ventilation values. The ventilation data were compared among the three groups to evaluate the stability of the ventilator., Results: At every PI, the Ppeak detected by the ventilator decreased slightly with increasing ambient pressure. The Fpeak values measured by the test lung decreased substantially as the ambient pressure increased. Nevertheless, the reduction in VT at 284 kPa and PI 30 cmH₂O (compared to performance at 101 kPa) was comparatively small (approximately 60 ml)., Conclusions: In PCV mode this ventilator provided relatively stable VT across clinically relevant PI values to ambient pressures as high as 284 kPa. However, because Fpeak decreases at higher ambient pressure, some user adjustment might be necessary for precise VT maintenance during clinical use at higher PIs and ambient pressures., Competing Interests: The authors report no conflicts of interest in this work., (Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.)

Although there has been an increase in bench test evaluation of mechanical ventilators in recent years, a publication gap remains in assessing Pressure Control Continuous Mandatory Ventilation Modes with a set point targeting scheme PC-CMVs. This study evaluates the operational variability in PC-CMVs of eleven transport and emergency ventilators used in ICU units in Brazil during the COVID-19 pandemic. The assessment involved a comprehensive set of test scenarios derived from existing literature and the NBR ISO 80601-2-12:2014 standard. Nine parameters were computed for five consecutive breaths, offering a comprehensive characterization of pressure and flow waveforms. Most ventilators had Inspiratory pressure and PEEP values that fell outside of the tolerance ranges. Notably, three mechanical ventilators failed to reach the target pressures within the specified inspiratory times during test scenarios with a higher time constant (τ). We observed significant differences among emergency and transport ventilators in all assessed parameters, indicating a performance difference in PC-CMVs modes. The current results might help clinicians determine which ventilator models are suitable for specific clinical situations, particularly when unfavorable circumstances compel doctors to use ventilators that may not provide adequate support for patients in intensive care units., (© 2024. The Author(s).)

Background: During invasive mechanical ventilation, where medical gases are very dry and the upper airway is bypassed, appropriate gas conditioning and humidification are mandatory at all times. Results of in vitro studies suggest that dry gases may improve lung deposition during nebulization, but this has not been confirmed through in vivo studies. The objective of this study was to measure gas humidity under multiple conditions to better describe gas hygrometry when heated humidifiers are turned off., Methods: We measured, on a bench, the hygrometry of different gases at steady state: medical gases, at the Y-piece without humidifier, with the humidifier switched off, and with humidifier switched on. We measured gas humidity every 10-60 s during dynamic conditions after switching off the heated humidifier and after switching on the heated humidifier. Hygrometry was measured by using the psychrometric method with at least 3 measurements for each tested condition., Results: We performed 287 psychrometric measurements in different situations. The mean ± SD gas absolute humidity at steady state during different conditions were the following: 1.6 ± 0.2 mg H 2 O/L for the medical gases, 4.5 ± 0.9 mg H 2 O/L at the Y-piece without humidifier, 9.1 ± 0.3 mg H 2 O/L at the Y-piece with heated humidifier turned off, and 34.2 ± 2.2 mg H 2 O/L at the Y-piece with the heated humidifier turned on. During the dynamic evaluation, after turning off the humidifier, humidity was < 30 mg H 2 O/L after a few minutes, attained 15 mg H 2 O/L after 15 min, and was below 10 mg H 2 O/L after 1 h but never reached the level of dry medical gases. After turning on the heated humidifier, the gas hygrometry reached 30 mg H 2 O/L after 5 min., Conclusions: When heated humidifiers are turned off, gas humidity levels are very low but not as low as medical gases. The clinical impact of repeated shutdowns is unknown. As recommended, heated humidifiers should never be turned off during nebulization., Competing Interests: Dr Lellouche’s laboratory has received funding from Fisher & Paykel to develop an educational application (VentilO) and funded several projects of research. Mr Bouchard has disclosed no conflicts of interest., (Copyright © 2024 by Daedalus Enterprises.)

Background: A model system described in International Organization for Standardization 9360 is the standard method for estimating the humidifying performance of heat and moisture exchangers (HMEs). However, there are no reliable bedside methods for evaluating the ongoing humidification performance of HMEs. Therefore, this study aimed to develop 2 clinically applicable methods for estimating the ongoing humidifying performance of HMEs and to evaluate their reliability in a model system., Methods: Physiologically expired gas was simulated using a heated humidifier, and ventilation was delivered using a ventilator with constant flow through 3 different types of HMEs. Relative humidity (RH) was measured using a capacitive-type moisture sensor. Water content lost during expiration was calculated by integrating absolute humidity (AH), instantaneous gas flow measured at the expiratory outlet of the ventilator, and time. We also calculated the water content released and captured by the HMEs during tidal ventilation by integrating the difference in AH across the HMEs, instantaneous gas flow, and time., Results: We found that the RH, temperature, and AH were almost constant on the expiratory outlet of the ventilator but rapidly varied near the HMEs. The water content lost by the 3 HMEs was associated with the manufacturer-reported values and inversely correlated with the calculated values of the water content exchanged by the HMEs. The water content released and captured by HMEs was closely correlated with the difference in HME weight measured at the end of inspiration and expiration; however, the water content captured by HMEs seemed to be overestimated., Conclusions: Our results demonstrated that our system was able to detect the differences in the performance of 3 models of HMEs and suggest that our method for calculating water loss is reliable for estimating the water retention performance of HMEs during mechanical ventilation, even in the presence of a constant flow., Competing Interests: The authors have disclosed no conflicts of interest., (Copyright © 2024 by Daedalus Enterprises.)

Background: Ventilator-associated pneumonia (VAP) is the second most prevalent nosocomial infection in emergency care settings. An emerging strategy to reduce this risk involves coating endotracheal tubes (ETTs) with noble elements, leveraging the antimicrobial properties of elements such as silver, gold, and palladium. This systematic review and meta-analysis aimed to evaluate the effectiveness of noble element coatings on ETTs in reducing VAP incidence rates, mortality, duration of mechanical ventilation, and length of stay in the intensive care unit (ICU)., Methods: Adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a comprehensive search was conducted across 5 databases up to 2024. The quality of the randomized controlled trials was assessed using the updated Cochrane Risk of Bias (RoB) 2 tool. A random-effects meta-analysis was performed using RevMan 5.4 Comprehensive Meta-Analysis software. Statistical heterogeneity among the studies was evaluated using the Higgins I2 value, with P < .05 indicating statistical significance., Results: Seven randomized controlled trials from 5 countries were identified. Four studies had some concerns regarding bias, 2 had a high RoB, and 1 had a low RoB. Noble metal-coated ETTs resulted in a lower incidence of VAP compared to noncoated ETTs (relative risk, 0.76 [95% confidence interval [CI], 0.60-0.96]). However, there was no significant difference in mortality rates (relative risk, 1.06 [95% CI, 0.93-1.20]), duration of mechanical ventilation (mean difference, -0.10 [95% CI, -1.62 to 1.41]), and ICU stay (mean difference, 0.07 [95% CI, -1.98 to 2.12])., Conclusion: Noble metal-coated ETTs effectively reduce the incidence of VAP but do not significantly impact mortality rates, the duration of mechanical ventilation, or ICU stay. Therefore, these coated ETTs should be integrated into a holistic care plan addressing all aspects of patient management in emergency care settings., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Patients with compromised respiratory function frequently require mechanical ventilation to survive. Unfortunately, non-uniform ventilation of injured lungs generates complex mechanical forces that lead to ventilator induced lung injury (VILI). Although investigators have developed lung-on-a-chip systems to simulate normal respiration, modeling the complex mechanics of VILI as well as the subsequent recovery phase is a challenge. Here we present a novel humanized in vitro ventilator-on-a-chip (VOC) model of the lung microenvironment that simulates the different types of injurious forces generated in the lung during mechanical ventilation. We used transepithelial/endothelial electrical impedance measurements to investigate how individual and simultaneous application of mechanical forces alters real-time changes in barrier integrity during and after injury. We find that compressive stress ( i.e. barotrauma) does not significantly alter barrier integrity while over-distention (20% cyclic radial strain, volutrauma) results in decreased barrier integrity that quickly recovers upon removal of mechanical stress. Conversely, surface tension forces generated during airway reopening (atelectrauma), result in a rapid loss of barrier integrity with a delayed recovery relative to volutrauma. Simultaneous application of cyclic stretching (volutrauma) and airway reopening (atelectrauma), indicates that the surface tension forces associated with reopening fluid-occluded lung regions are the primary driver of barrier disruption. Thus, our novel VOC system can monitor the effects of different types of injurious forces on barrier disruption and recovery in real-time and can be used to interogate the biomechanical mechanisms of VILI.

Objectives: The aims of the study was to assess the placement of the V-gel Advanced (V-gel-A) and to evaluate tracheal selectivity during controlled mechanical ventilation, using CT., Methods: In this prospective clinical study, 20 healthy cats undergoing general anaesthesia for an elective procedure underwent four successive CT scans from the nose to the mid-abdomen: at baseline (no device); after the placement of the V-gel-A, after a controlled mechanical ventilation (CMV) period of 5 mins; and after the placement of an endotracheal tube (ETT). Using both a purpose designed position score and a gas score estimating the quantity of gas in different digestive regions, the position of the V-gel-A and presence of gas in the digestive tract at each step were evaluated. Number of attempts and times required to place the V-gel-A and ETT were recorded and compared., Results: The V-gel-A was found to be correctly placed, with position scores of 3/5 in six cats, 4/5 in 13 cats and 5/5 in one cat. Imperfect positioning was due to minor axial rotation or incomplete occlusion of the oesophagus by the tip of the device. The gas scores significantly increased after placement of the V-gel-A compared with baseline and after CMV was initiated. Correct positioning of the device was mostly achieved at the first attempt; no significant difference was found in the time required to place V-gel-A vs ETT, nor in the number of attempts ( P >0.05)., Conclusions and Relevance: The V-gel-A was clinically easy to place and use in both spontaneous and controlled ventilation. The device properly fitted the larynx and was never observed to occlude the airway. However, incomplete occlusion of the oesophagus was frequently observed and may lead to a lack of complete tracheal selectivity., Competing Interests: Conflict of interestThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Objective: This study aimed to evaluate the effect of continuous control cuff pressure (CCCP) versus intermittent control cuff pressure (ICCP) for the prevention of ventilator-associated pneumonia (VAP) in critically ill patients., Methods: Relevant literature was searched in several databases, including PubMed, Embase, Web of Science, ProQuest, the Cochrane Library, Wanfang Database and China National Knowledge Infrastructure between inception and September 2022. Randomized controlled trials were considered eligible if they compared CCCP with ICCP for the prevention of VAP in critically ill patients. This meta-analysis was performed using the RevMan 5.3 and Trial Sequential Analysis 0.9 software packages. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework was used to assess the level of evidence., Results: We identified 14 randomized control trials with a total of 2080 patients. Meta-analysis revealed that CCCP was associated with a significantly lower incidence of VAP compared with ICCP (relative risk [RR] = 0.52; 95% confidence interval [CI]: 0.37-0.74; P  < 0.001), although considerable heterogeneity was observed ( I 2  = 71%). Conducting trial sequential analysis confirmed the finding, and the GRADE level was moderate. Subgroup analysis demonstrated that CCCP combined with subglottic secretion drainage (SSD) had a more significant effect on reducing VAP (RR = 0.39; 95% CI = 0.29-0.52; P  < 0.001). The effect of CCCP on ventilator-associated respiratory infection (VARI) incidence was uncertain (RR = 0.81; 95% CI = 0.53-1.24; P  = 0.34; I 2  = 61%). Additionally, CCCP significantly reduced the duration of mechanical ventilation (MV) (mean difference [MD] = -2.42 days; 95% CI = -4.71-0.12; P  = 0.04; I 2  = 87%). Descriptive analysis showed that CCCP improved the qualified rate of cuff pressure. However, no significant differences were found in the length of intensive care unit (ICU) stay (MD = 2.42 days; 95% CI = -1.84-6.68; P  = 0.27) and ICU mortality (RR = 0.86; 95% CI = 0.74-1.00; P  = 0.05)., Conclusion: Our findings suggest that the combination of CCCP and SSD can reduce the incidence of VAP and the duration of MV and maintain the stability of cuff pressure. A combination of CCCP and SSD applications is suggested for preventing VAP., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

The association of Robin sequence (RS) with temporomandibular joint (TMJ) ankylosis is not a common occurrence. Due to restricted mouth opening, difficult bag valve mask ventilation and difficult intubation, such cases are always challenging for anaesthesiologists.A male patient in early childhood with RS and bilateral TMJ ankylosis was scheduled for bilateral gap arthroplasty. Airway management was planned with fibreoptic intubation under sedation to preserve spontaneous ventilation. After sedating the patient, a nasopharyngeal airway modified by using an endotracheal tube connector was inserted in the left nostril and connected to the ventilator circuit with a 15 mm universal connector. Pressure support ventilation was given with continuous end-tidal CO 2 monitoring. Fibreoptic intubation was done through the right nostril with maintenance of spontaneous ventilation.Nasal pressure support ventilation assembly can be made with available equipment in the operation theatre. It can be a substitute for a high-flow nasal cannula in particular cases., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: Our study objective was to evaluate changes in ETT tube depth throughout the initial intubation course in very and extremely preterm infants in order to evaluate the risk of outgrowing an endotracheal tube (ETT)., Methods: This was a retrospective cohort study of preterm infants born at <32 weeks of gestation who were admitted to the NICU between 2012 and 2021 and required intubation for mechanical ventilation. Infants who were intubated only for surfactant administration and those with airway malformations were excluded. Descriptive statistics were used to define the range of ETT depths at the time of extubation, stratified by gestational age (<28 weeks vs 28-32 weeks of gestation). Relative ETT depth was defined as the final depth minus the initial depth., Results: Out of 496 infants, 140 patients met all criteria for inclusion. Descriptive analysis of extubation depths across the populations demonstrated median relative ETT depth of 0 cm for the 28-32-week gestational age group, and -0.25 cm for the <28-week gestational age group. The 95th percentile for both gestational age groups was a relative depth of 0.5 cm and the 99th percentile was 1.0-1.5 cm., Conclusion: The results of our study suggest that the vast majority of patients in the NICU are unlikely to "outgrow" ETT tube length which should be taken into account when deciding where to trim the ETT in order to minimize airway resistance.

Introduction: Despite the significant need for mechanical ventilation in- and out-of-hospital, mechanical ventilators remain inaccessible in many instances because of cost or size constraints. Mechanical ventilation is especially critical in trauma scenarios, but the impractical size and weight of standard mechanical ventilators restrict first responders from carrying them in medical aid bags, leading to reliance on imprecise manual bag-mask ventilation. This is particularly important in combat-related injury, where airway compromise and respiratory failure are leading causes of preventable death, but medics are left without necessary mechanical ventilation. To address the serious gaps in mechanical ventilation accessibility, we are developing an Autonomous, Modular, and Portable Ventilation platform (AMP-Vent) suitable for austere environments, prolonged critical care, surgical applications, mass casualty incidents, and stockpiling. The core system is remarkably compact, weighing <2.3 kg, and can fit inside a shoebox (23.4 cm × 17.8 cm × 10.7 cm). Notably, this device is 65% lighter than standard transport ventilators and astoundingly 96% lighter than typical intensive care unit ventilators. Beyond its exceptional portability, AMP-Vent can be manufactured at less than one-tenth the cost of conventional ventilators. Despite its reduced size and cost, the system's functionality is uncompromised. The core system is equipped with closed-loop sensors and advanced modes of ventilation (pressure-control, volume-control, and synchronized intermittent mandatory ventilation), enabling quality care in a portable form factor. The current prototype has undergone preliminary preclinical testing and optimization through trials using a breathing simulator (ASL 5000) and in a large animal model (swine). This report aims to introduce a novel ventilation system and substantiate its promising performance through evidence gathered from preclinical studies., Materials and Methods: Lung simulator testing was performed using the ASL 5000, in accordance with table 201.105 "pressure-control inflation-type testing" from ISO 80601-2-12:2020. Following simulations, AMP-Vent was tested in healthy 10-kg female domestic piglets. The Children's Hospital of Philadelphia Institutional Animal Care and Use Committee approved all animal procedures. Swine received 4-min blocks of alternating ventilation, where AMP-Vent and a conventional anesthesia ventilator (GE AISYS CS2) were used to titrate to varied end-tidal carbon dioxide (EtCO2) goals with the initial ventilator switching for each ascending target (35, 40, 45, 50, 55 mmHg)., Results: During ASL 5000 simulations, AMP-Vent exhibited consistent performance under varied conditions, maintaining a coefficient of variation of 2% or less within each test. In a large animal study, AMP-Vent maintained EtCO2 and SpO2 targets with comparable performance to a conventional anesthesia ventilator (GE AISYS CS2). Furthermore, the comparison of minute ventilation (Ve) distributions between the conventional anesthesia ventilator and AMP-Vent at several EtCO2 goals (35, 40, 45, 50, and 55 mmHg) revealed no statistically significant differences (p = 0.46 using the Kruskal-Wallis rank sum test)., Conclusions: Preclinical results from this study highlight AMP-Vent's core functionality and consistent performance across varied scenarios. AMP-Vent sets a benchmark for portability with its remarkably compact design, positioning it to revolutionize trauma care in previously inaccessible medical scenarios., (© The Association of Military Surgeons of the United States 2024. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site–for further information please contact journals.permissions@oup.com.)

Objective: This study aims to evaluate a novel prone position ventilation device designed to enhance patient safety, improve comfort, and reduce adverse events, facilitating prolonged tolerance in critically ill patients., Methods: A randomized controlled trial was conducted on 60 critically ill patients from January 2020 to June 2023. Of which, one self-discharged during treatment and another was terminated due to decreased oxygenation, leaving an effective sample of 58 patients. Patients were allocated to either a control group receiving traditional prone positioning aids (ordinary sponge pads and pillows) or an intervention group using a newly developed adjustable prone positioning device. A subset of patients in each group also received life support technologies such as extracorporeal membrane oxygenation (ECMO) and continuous renal replacement therapy (CRRT). We assessed prone position ventilation tolerance, oxygen saturation increments postintervention, duration of prone positioning, CRRT filter lifespan, and the incidence of adverse events., Results: The intervention group exhibited significantly longer average tolerance to prone positioning (16.6 hours vs. 8.3 hours, P < 0.001 with a difference of 8.3 (4.4, 12.2) hours), higher increases in oxygen saturation postventilation (9% vs. 6%, P < 0.001 with a difference of 3.0 (1.5, 4.5)), and reduced time required for medical staff to position patients (11.7 min vs. 21.8 min, P < 0.001 with a difference of -10.1 (-11.9, -8.3)). Adverse events, including catheter displacement or blockage, facial edema, pressure injuries, and vomiting or aspiration, were markedly lower in the intervention group, with statistical significance ( P < 0.05). In patients receiving combined life support, the intervention group demonstrated improved catheter blood drainage and extended CRRT filter longevity., Conclusion: The newly developed adjustable prone ventilation device significantly improves tolerance to prone positioning, enhances oxygenation, and minimizes adverse events in critically ill patients, thereby also facilitating the effective application of life support technologies., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2024 Yufeng Li et al.)

Invasive devices are routinely used in the care of critically ill patients. Although they are often essential components of patient care, devices such as intravascular catheters, endotracheal tubes, and ventilators are a common source of complications in the intensive care unit. Critical care practitioners who use these devices need to use strategies for risk reduction and understand approaches to management when adverse events occur. This review discusses the identification, prevention, and management of complications of vascular, airway, and mechanical support devices commonly used in the intensive care unit., Competing Interests: Competing interests: We have read and understood the BMJ policy on declaration of interests and declare the following interests: none., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Background: Developments and technological advances in neonatal and pediatric intensive care units have led to a prolonged life expectancy of pediatric patients with chronic respiratory failure. Therefore, the number of hemodynamically stable pediatric patients with chronic respiratory failure who need mechanical ventilator assistance throughout the day has significantly increased., Aims: Numerous conditions, including parenchymal lung diseases, airway disorders, neuromotor disorders, or respiratory defects, can lead to chronic respiratory failure. For individuals who cannot tolerate non-invasive mechanical ventilation (NIMV), invasive mechanical ventilation (IMV) is the only suitable choice. Due to increasing need, mechanical ventilator technology is continuously evolving., Results: As a result of this process, home-type mechanical ventilators have been produced for patients requiring long-term IMV. Patients with chronic respiratory failure can be safely monitored at home with these ventilators., Discussion: Home follow-up of these patients has many benefits such as an increase in general quality of life and a positive contribution to their emotional and cognitive development., Conclusion: In this compilation, indications for home-based IMV, features of home invasive mechanical ventilators (HMVs), patient monitoring, and the detailed advantages of using IMV at home will be elucidated., (© 2024 Wiley Periodicals LLC.)

Background: There is insufficient evidence supporting the theory that mechanical ventilation can replace the manual ventilation method during CPR., Research Question: Is using automatic mechanical ventilation (MV) feasible and comparable to the manual ventilation method during CPR?, Study Design and Methods: This pilot randomized controlled trial compared MV and manual bag ventilation (BV) during CPR after out-of-hospital cardiac arrest (OHCA). Patients with medical OHCA arriving at the ED were randomly assigned to two groups: an MV group using a mechanical ventilator and a BV group using a bag valve mask. Primary outcome was any return of spontaneous circulation (ROSC). Secondary outcomes were changes of arterial blood gas analysis results during CPR. Tidal volume, minute volume, and peak airway pressure were also analyzed., Results: A total of 60 patients were enrolled, and 30 patients were randomly assigned to each group. There were no statistically significant differences in basic characteristics of OHCA patients between the two groups. The rate of any return of spontaneous circulation was 56.7% in the MV group and 43.3% in the BV group, indicating no significant (P = .439) difference between the two groups. There were also no statistically significant differences in changes of PH, Pco 2 , Po 2 , bicarbonate, or lactate levels during CPR between the two groups (P values = .798, 0.249, .515, .876, and .878, respectively). Significantly lower tidal volume (P < .001) and minute volume (P = .009) were observed in the MV group., Interpretation: In this pilot trial, the use of MV instead of BV during CPR was feasible and could serve as a viable alternative. A multicenter randomized controlled trial is needed to create sufficient evidence for ventilation guidelines during CPR., Clinical Trial Registration: ClinicalTrials.gov; No.: NCT05550454; URL: www., Clinicaltrials: gov., Competing Interests: Financial/Nonfinancial Disclosures None declared., (Copyright © 2024 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Children on long-term home mechanical ventilation are a growing population due to clinical and technological advances and the benefit for the child's quality of life. Invasive home ventilation is one of the most complex therapies offered in the home setting, requiring adequate home environment and appropriate equipment and supplies before discharge. The transition from hospital to home represents a vulnerable period that can be facilitated with an established transition plan with multidisciplinary team involvement. Readiness for home care is achieved when the patient is stable and has been transitioned from a critical care ventilator to a home mechanical ventilator. In parallel, comprehensive competency-based training regarding the knowledge and skills needed to help families use the equipment confidently and safely. Before discharge, families should be counseled on an adequate home environment to ensure a safe transition. The residence arrangement may include physical space modifications, verifying electrical installation, or moving to another home. Durable medical equipment and supplies must be ordered, and community healthcare support arranged. Parents should receive practical advice on setting up the equipment at home and on preventive measures to minimize complications related to tracheostomy and ventilator dependence, including regular maintenance and replacement of necessary equipment. Given the overall impact of invasive ventilation on home life, a structured home care action package is essential to alleviate the burdens involved., (© 2023 Wiley Periodicals LLC.)

Background: The bag-valve-mask (BVM) or manual resuscitator bag is used as a first-line technique to ventilate patients with respiratory failure. Volume-restricted manual resuscitator bags (eg, pediatric bags) have been suggested to minimize overventilation and associated complications. There are studies that both support and caution against the use of a pediatric resuscitator bag to ventilate an adult patient. In this study, we evaluated the ability of pre-hospital clinicians to adequately ventilate an adult manikin with both an adult- and pediatric-size manual resuscitator bag without the assistance of an advanced airway or airway adjunct device., Methods: This study was conducted at an international conference in 2022. Conference attendees with pre-hospital health care experience were recruited to ventilate an adult manikin using a BVM for 1 min with both an adult and pediatric resuscitator bag, without the use of adjunct airway devices, while 6 ventilatory variables were collected or calculated: tidal volume (V T ), breathing frequency, adequate breaths (V T > 150 mL), proportion of adequate breaths, peak inspiratory pressure (PIP), and estimated alveolar ventilation (EAV)., Results: A total of 208 participants completed the study. Ventilation with the adult-sized BVM delivered an average V T of 290.4 mL compared to 197.1 mL ( P < .001) when using the pediatric BVM. PIP with the adult BVM was higher than with the pediatric BVM (10.6 cm H 2 O vs 8.6 cm H 2 O, P < .001). The median EAV with the adult bag (1,138.1 [interquartile range [IQR] 194.0-2,869.9] mL/min) was markedly greater than with the pediatric BVM (67.7 [IQR 0-467.3] mL/min, P < .001)., Conclusions: Both pediatric- and adult-sized BVM provided lower ventilation volumes than those recommended by professional guidelines for an adult. Ventilation with the pediatric BVM was significantly worse than with the adult bag when ventilating a simulated adult subject., Competing Interests: Dr Slutsky discloses a relationship with SafeBVM Corporation. The remaining authors have disclosed no conflicts of interest., (Copyright © 2024 by Daedalus Enterprises.)

Introduction: Traumatic brain injury (TBI) is the leading cause of combat casualties in modern war with an estimated 20% of casualties experiencing head injury. Since the release of the Brain Trauma Foundation's Guidelines for the Management of Severe Traumatic Brain Injury in 1995, recommendations for management of TBI have included the avoidance of routine hyperventilation. However, both published and anecdotal data suggest that many patients with TBI are inappropriately ventilated during transport, thereby increasing the risk of morbidity and mortality from secondary brain injury., Materials and Methods: Enlisted Air Force personnel with prior emergency medical technician training completing a 3-week trauma course were evaluated on their ability to provide manual ventilation. Participants provided manual ventilation using either an in-situ endotracheal tube (ETT) or standard face mask on a standardized simulated patient manikin with TBI on the first and last days of the course. Manual ventilation was provided via a standard manual ventilator and a novel manual ventilator designed to limit tidal volume (VT) and respiratory rate (RR). Participants were given didactic and hands-on training on the third day of the course. Half of the participants were given simulator feedback during the hands-on training. All students provided 2 minutes of manual ventilation with each respirator. Data were collected on the breath-to-breath RR, VT, and peak airway pressures generated by the participant for each trial and were averaged for each trial. A minute ventilation (MV) was then derived from the calculated RR and VT., Results: One hundred fifty-six personnel in the trauma course were evaluated in this study. Significant differences were found in the participant's performance with manual ventilation with the novel compared to the traditional ventilator. Before training, MV with the novel ventilator was less than with the traditional ventilator by 2.1 ± 0.4 L/min (P = .0003) and 1.6 ± 0.5 L/min (P = .0489) via ETT and face mask, respectively. This effect persisted after training with a difference between the devices of 1.8 ± 0.4 L/min (P = .0069) via ETT. Both traditional education interventions (didactics with hands-on training) and simulator-based feedback did not make a significant difference in participant's performance in delivering MV., Conclusions: The use of a novel ventilator that limits RR and VT may be useful in preventing hyperventilation in TBI patients. Didactic education and simulator-based feedback training may not have significant impact on improving ventilation practices in prehospital providers., (© The Association of Military Surgeons of the United States 2024. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Atelectasis has been reported in 68 to 100% of children undergoing general anaesthesia, a phenomenon that persists into the recovery period. Children receiving recruitment manoeuvres have less atelectasis and fewer episodes of oxygen desaturation during emergence. The optimal type of recruitment manoeuvre is unclear and may be influenced by the airway device chosen., Objective: We aimed to investigate the different effects on lung mechanics as assessed by the forced oscillation technique (FOT) utilising different recruitment strategies: repeated inflations vs. one sustained inflation and different airway devices, a supraglottic airway device vs. a cuffed tracheal tube., Design: Pragmatic enrolment with randomisation to the recruitment strategy., Setting: We conducted this single-centre trial between February 2020 and March 2022., Participants: Seventy healthy patients (53 boys) aged between 2 and 16 years undergoing general anaesthesia were included., Interventions: Forced oscillations (5 Hz) were superimposed on the ventilator waveform using a customised system connected to the anaesthesia machine. Pressure and flow were measured at the inlet of the airway device and used to compute respiratory system resistance and reactance. Measurements were taken before and after recruitment, and again at the end of surgery., Main Outcome Measures: The primary endpoint measured is the change in respiratory reactance., Results: Statistical analysis (linear model with recruitment strategy and airway device as factors) did not show any significant difference in resistance and reactance between before and after recruitment. Baseline reactance was the strongest predictor for a change in reactance after recruitment: prerecruitment Xrs decreased by mean (standard error) of 0.25 (0.068) cmH 2 O s l -1 per  1 cmH 2 O -1  s l -1 increase in baseline Xrs ( P  < 0.001). After correcting for baseline reactance, the change in reactance after recruitment was significantly lower for sustained inflation compared with repeated inflation by mean (standard error) 0.25 (0.101) cmH 2 O ( P  = 0.0166)., Conclusion: Although there was no significant difference between airway devices, this study demonstrated more effective recruitment via repeated inflations than sustained inflation in anaesthetised children., Trial Registration: Australian New Zealand Clinical Trials Registry: ACTRN12619001434189., (Copyright © 2024 European Society of Anaesthesiology and Intensive Care. Unauthorized reproduction of this article is prohibited.)

Background: Tracheostomies provide many advantages for the care of patients who are critically ill but may also result in complications, including tracheostomy-related pressure injuries. Research efforts into the prevention of these pressure injuries has resulted in specialized clinical care teams and pathways. These solutions are expensive and labor intensive, and fail to target the root cause of these injuries; namely, pressure at the device-skin interface. Here we measure that pressure directly and introduce a medical device, the tracheostomy support system, to reduce it., Methods: This was a cross-sectional study of 21 subjects in the ICU, each with a tracheostomy tube connected to a ventilator. A force-sensing resistor was used to measure baseline pressures at the device-skin interface along the inferior flange. This pressure was then measured again with the use of the tracheostomy support system in the inactive and active states. Resultant pressures and demographics were compared., Results: Fifteen male and 6 female subjects, with an average age of 47 ± 14 (mean ± SD) years, were included in this study. Average pressures at the tracheostomy-skin interface at baseline in these 21 ICU subjects were 273 ± 115 (mean ± SD) mm Hg. Average pressures were reduced by 59% (median 62%, maximum 98%) with the active tracheostomy support system to 115 ± 83 mm Hg ( P < .001). All the subjects tolerated the tracheostomy support system without issue., Conclusions: Despite best clinical practice, pressure at the tracheostomy-skin interface can remain quite high. Here we provide measures of this pressure directly and show that a tracheostomy support system can be effective at minimizing that pressure., Competing Interests: Dr Vahabzadeh-Hagh is the inventor of the tracheostomy support system, the device used in this study, which is investigational and not commercially available. This technology is licensed to Larynnovation, which Dr Vahabzadeh-Hagh founded. Larynnovation was not part of the institutional review board study, did not have access to the results, nor did it provide any funding for this non-funded human study. The terms of this arrangement have been reviewed and approved by the University of California, San Diego, in accordance with its conflicts of interest policies. The other authors have disclosed no conflicts of interest., (Copyright © 2024 by Daedalus Enterprises.)

Context: Amid the COVID-19 pandemic, this study delves into ventilator shortages, exploring simple split ventilation (SSV), simple differential ventilation (SDV), and differential multiventilation (DMV). The knowledge gap centers on understanding their performance and safety implications., Hypothesis: Our hypothesis posits that SSV, SDV, and DMV offer solutions to the ventilator crisis. Rigorous testing was anticipated to unveil advantages and limitations, aiding the development of effective ventilation approaches., Methods and Models: Using a specialized test bed, SSV, SDV, and DMV were compared. Simulated lungs in a controlled setting facilitated measurements with sensors. Statistical analysis honed in on parameters like peak inspiratory pressure (PIP) and positive end-expiratory pressure., Results: Setting target PIP at 15 cm H2O for lung 1 and 12.5 cm H2O for lung 2, SSV revealed a PIP of 15.67 ± 0.2 cm H2O for both lungs, with tidal volume (Vt) at 152.9 ± 9 mL. In SDV, lung 1 had a PIP of 25.69 ± 0.2 cm H2O, lung 2 at 24.73 ± 0.2 cm H2O, and Vts of 464.3 ± 0.9 mL and 453.1 ± 10 mL, respectively. DMV trials showed lung 1's PIP at 13.97 ± 0.06 cm H2O, lung 2 at 12.30 ± 0.04 cm H2O, with Vts of 125.8 ± 0.004 mL and 104.4 ± 0.003 mL, respectively., Interpretation and Conclusions: This study enriches understanding of ventilator sharing strategy, emphasizing the need for careful selection. DMV, offering individualization while maintaining circuit continuity, stands out. Findings lay the foundation for robust multiplexing strategies, enhancing ventilator management in crises., Competing Interests: Dr. Roy is partial owner of a company that manufactures a ventilator multiplexor. The remaining authors have disclosed that they do not have any potential conflicts of interest., (Copyright © 2024 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of the Society of Critical Care Medicine.)

Introduction: Maximizing the capabilities of available lowflow oxygen is key to providing adequate oxygen to prevent/treat hypoxemia and conserve oxygen. We designed a closed-circuit system that allows rebreathing of gases while scrubbing carbon dioxide (CO2) in conjunction with portable mechanical ventilators in a bench model., Methods: We evaluated the system using two portable mechanical ventilators currently deployed by the Department of Defense-Zoll 731 and AutoMedx SAVe II-over a range of ventilator settings and lung models, using 1 and 3L/min low-flow oxygen into a reservoir bag. We measured peak inspired oxygen concentration (FiO2), CO2-absorbent life, gas temperature and humidity, and the effect of airway suctioning and ventilator disconnection on FiO2 on ground and at altitude., Results: FiO2 was =0.9 across all ventilator settings and altitudes using both oxygen flows. CO2-absorbent life was >7 hours. Airway humidity range was 87%-97%. Mean airway temperature was 25.4°C (SD 0.5°C). Ten-second suctioning reduced FiO2 22%-48%. Thirtysecond ventilator disconnect reduced FiO2 29%-63% depending on oxygen flow used., Conclusion: Use of a rebreathing system with mechanical ventilation has the potential for oxygen conservation but requires diligent monitoring of inspired FiO2 and CO2 to avoid negative consequences., (2024.)

Objective: To investigate the effects of FLow-controlled EXpiration (FLEX) ventilation expiration time and speed on respiratory and pulmonary mechanics in anesthetized horses in dorsal recumbency., Animals: 6 healthy adult research horses., Methods: In this randomized crossover experimental study, horses were anesthetized 3 times and were ventilated each time for 60 minutes using conventional volume-controlled ventilation (VCV), linear emptying of the lung over 50% of the expiratory time (FLEX50), or linear emptying of the lung over 100% of the expiratory time (FLEX100) in a randomized order. The primary outcome variables were dynamic compliance (Cdyn), hysteresis, and alveolar dead space. The data was analyzed using two-factor ANOVA. Significance was set to P < .05., Results: Horses ventilated using FLEX50 and FLEX100 showed significantly higher Cdyn and significantly lower hysteresis values compared to horses ventilated using VCV. Horses ventilated using FLEX50 had significantly lower alveolar dead space compared to horses ventilated using FLEX100 or VCV. Horses ventilated using FLEX100 had significantly lower alveolar dead space compared to VCV horses., Clinical Relevance: Our results demonstrate improved Cdyn, hysteresis, and alveolar dead space in horses ventilated with either FLEX50 or FLEX100 relative to traditional VCV. The use of FLEX with a faster exhalation speed (FLEX50) offers additional respiratory advantages.

This study aims to resolve the unmet need for ventilator surge capacity by developing a prototype device that can alter patient-specific flow in a shared ventilator setup. The device is designed to deliver a predictable tidal volume (VT), requiring minimal additional monitoring and workload. The prototyped device was tested in an in vitro bench setup for its performance against the intended use and design criteria. The ventilation parameters: VT and airway pressures, and ventilation profiles: pressure, flow and volume were measured for different ventilator and device settings for a healthy and ARDS simulated lung pathology. We obtained VTs with a linear correlation with valve openings from 10 to 100% across set inspiratory pressures (IPs) of 20 to 30 cmH 2 O. Airway pressure varied with valve opening and lung elastance but did not exceed set IPs. Performance was consistent in both healthy and ARDS-simulated lung conditions. The ventilation profile diverged from traditional pressure-controlled profiles. We present the design a flow modulator to titrate VTs in a shared ventilator setup. Application of the flow modulator resulted in a characteristic flow profile that differs from pressure- or volume controlled ventilation. The development of the flow modulator enables further validation of the Individualized Shared Ventilation (ISV) technology with individualization of delivered VTs and the development of a clinical protocol facilitating its clinical use during a ventilator surge capacity problem., (© 2024. The Author(s).)

Background: Some experts recommend specific ventilator settings during nebulization for mechanically ventilated patients, such as inspiratory pause, high inspiratory to expiratory ratio, and so on. However, it is unclear whether those settings improve aerosol delivery. Thus, we aimed to evaluate the impact of ventilator settings on aerosol delivery during mechanical ventilation (MV). Methods: Salbutamol (5.0 mg/2.5 mL) was nebulized by a vibrating mesh nebulizer (VMN) in an adult MV model. VMN was placed at the inlet of humidifier and 15 cm away from the Y-piece of the inspiratory limb. Eight scenarios with different ventilator settings were compared with endotracheal tube (ETT) connecting 15 cm from the Y-piece, including tidal volumes of 6-8 mL/kg, respiratory rates of 12-20 breaths/min, inspiratory time of 1.0-2.5 seconds, inspiratory pause of 0-0.3 seconds, and bias flow of 3.5 L/min. In-line suction catheter was utilized in two scenarios. Delivered drug distal to the ETT was collected by a filter, and drug was assayed by an ultraviolet spectrophotometry (276 nm). Results: Compared to the use of inspiratory pause, the inhaled dose without inspiratory pause was either higher or similar across all ventilation settings. Inhaled dose was negatively correlated with inspiratory flow with VMN placed at 15 cm away from the Y-piece ( r s  = -0.68, p  < 0.001) and at the inlet of humidifier ( r s  = -0.83, p  < 0.001). The utilization of in-line suction catheter reduced inhaled dose, regardless of the ventilator settings and nebulizer placements. Conclusions: When VMN was placed at the inlet of humidifier, directly connecting the Y-piece to ETT without a suction catheter improved aerosol delivery. In this configuration, the inhaled dose increased as the inspiratory flow decreased, inspiratory pause had either no or a negative impact on aerosol delivery. The inhaled dose was greater with VMN placed at the inlet of humidifier than 15 cm away the Y-piece.

Background: Reconnection to the ventilator for 1 h following a successful spontaneous breathing trial (SBT) may reduce reintubation rates compared with direct extubation. However, the physiologic mechanisms leading to this effect are unclear., Research Question: Does reconnection to the ventilator for 1 h reverse alveolar derecruitment induced by SBT, and is alveolar derecruitment more pronounced with a T-piece than with pressure-support ventilation (PSV)?, Study Design and Methods: This is an ancillary study of a randomized clinical trial comparing SBT performed with a T-piece or with PSV. Alveolar recruitment was assessed by using measurement of end-expiratory lung volume (EELV)., Results: Of the 25 patients analyzed following successful SBT, 11 underwent SBT with a T-piece and 14 with PSV. At the end of the SBT, EELV decreased by -30% (95% CI, -37 to -23) compared with baseline prior to the SBT. This reduction was greater with a T-piece than with PSV: -43% (95% CI, -51 to -35) vs -20% (95% CI, -26 to -13); P < .001. Following reconnection to the ventilator for 1 h, EELV accounted for 96% (95% CI, 92 to 101) of baseline EELV and did not significantly differ from prior to the SBT (P = .104). Following 10 min of reconnection to the ventilator, EELV wasted at the end of the SBT was completely recovered using PSV (P = .574), whereas it remained lower than prior to the SBT using a T-piece (P = .010)., Interpretation: Significant alveolar derecruitment was observed at the end of an SBT and was markedly more pronounced with a T-piece than with PSV. Reconnection to the ventilator for 1 h allowed complete recovery of alveolar derecruitment., Clinical Trial Registration: ClinicalTrials.gov; No.: NCT04227639; URL: www., Clinicaltrials: gov., Competing Interests: Financial/Nonfinancial Disclosures The authors have reported to CHEST the following: R. C. reports fees and nonfinancial support from Fisher and Paykel Healthcare, outside the submitted work. J.-P. F. reports grants from the French Ministry of Health, fees from SOS oxygène and Fisher and Paykel Healthcare, and nonfinancial support from SOS oxygène and Fisher and Paykel Healthcare, outside the submitted work. A. W. T. reports grant from the French Ministry of Health for the seminal study, and fees and nonfinancial support from Fisher and Paykel Healthcare, outside the submitted work. None declared (A. L., M. R., C. R., F. A., S. L. P.)., (Copyright © 2024 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Aim: The commonly recommended endotracheal tube cuff pressure is 20-30 cmH 2 O. However, some patients require a cuff pressure of >30 cmH 2 O to prevent air leakage. The study aims to determine the risk factors that contribute to the endotracheal tube cuff pressure of >30 cmH 2 O to prevent air leakage., Design: A multi-centre prospective observational study., Methods: Eligible patients undergoing mechanical ventilation in the intensive care unit of three hospitals between March 2020 and July 2022 were included. The endotracheal tube cuff pressure to prevent air leakage was determined using the minimal occlusive volume technique. The patient demographics and clinical information were collected., Results: A total of 284 patients were included. Among these patients, 55 (19.37%) patients required a cuff pressure of >30 cmH 2 O to prevent air leakage. The multivariate logistic regression results revealed that the surgical operation (odds ratio [OR]: 8.485, 95% confidence interval [CI]: 1.066-67.525, p = 0.043) was inversely associated with the endotracheal tube cuff pressure of >30 cmH 2 O, while the oral intubation route (OR: 0.127, 95% CI: 0.022-0.750, p = 0.023) and cuff inner diameter minus tracheal area (OR: 0.949, 95% CI: 0.933-0.966, p < 0.001) were negatively associated with the endotracheal tube cuff pressure of >30 cmH 2 O. Therefore, a significant number of patients require an endotracheal tube cuff pressure of ＞30 cmH 2 O to prevent air leakage. Several factors, including the surgical operation, intubation route, and difference between the cuff inner diameter and tracheal area at the T3 vertebra, should be considered when determining the appropriate cuff pressure during mechanical ventilation., (© 2024 The Author(s). Nursing Open published by John Wiley & Sons Ltd.)

Background: Lung protective ventilation is considered standard of care in the intensive care unit. However, modifying the ventilator settings can be challenging and is time consuming. Closed loop modes of ventilation are increasingly attractive for use in critically ill patients. With closed loop ventilation, settings that are typically managed by the ICU professionals are under control of the ventilator's algorithms., Objectives: To describe the effectiveness, safety, efficacy and workload with currently available closed loop ventilation modes., Design: Systematic review of randomised clinical trials., Data Sources: A comprehensive systematic search in PubMed, Embase and the Cochrane Central register of Controlled Trials search was performed in January 2023., Eligibility Criteria: Randomised clinical trials that compared closed loop ventilation with conventional ventilation modes and reported on effectiveness, safety, efficacy or workload., Results: The search identified 51 studies that met the inclusion criteria. Closed loop ventilation, when compared with conventional ventilation, demonstrates enhanced management of crucial ventilator variables and parameters essential for lung protection across diverse patient cohorts. Adverse events were seldom reported. Several studies indicate potential improvements in patient outcomes with closed loop ventilation; however, it is worth noting that these studies might have been underpowered to conclusively demonstrate such benefits. Closed loop ventilation resulted in a reduction of various aspects associated with the workload of ICU professionals but there have been no studies that studied workload in sufficient detail., Conclusions: Closed loop ventilation modes are at least as effective in choosing correct ventilator settings as ventilation performed by ICU professionals and have the potential to reduce the workload related to ventilation. Nevertheless, there is a lack of sufficient research to comprehensively assess the overall impact of these modes on patient outcomes, and on the workload of ICU staff., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the European Society of Anaesthesiology and Intensive Care.)

Introduction: During the COVID-19 pandemic, ventilator shortages necessitated the development of new, low-cost ventilator designs. The fundamental requirements of a ventilator include precise gas delivery, rapid adjustments, durability, and user-friendliness, often achieved through solenoid valves. However, few solenoid-valve assisted low-cost ventilator (LCV) designs have been published, and gas exchange evaluation during LCV testing is lacking. This study describes the development and performance evaluation of a solenoid-valve assisted low-cost ventilator (SV-LCV) in vitro and in vivo, focusing on gas exchange and respiratory mechanics., Methods: The SV-LCV, a fully open ventilator device, was developed with comprehensive hardware and design documentation, utilizing solenoid valves for gas delivery regulation. Lung simulator testing calibrated tidal volumes at specified inspiratory and expiratory times, followed by in vivo testing in a porcine model to compare SV-LCV performance with a conventional ventilator., Results: The SV-LCV closely matched the control ventilator's respiratory profile and gas exchange across all test cycles. Lung simulator testing revealed direct effects of compliance and resistance changes on peak pressures and tidal volumes, with no significant changes in respiratory rate. In vivo testing demonstrated comparable gas exchange parameters between SV-LCV and conventional ventilator across all cycles. Specifically, in cycle 1, the SV-LCV showed arterial blood gas (ABG) results of pH 7.54, PCO2 34.5 mmHg, and PO2 91.7 mmHg, compared to the control ventilator's ABG of pH 7.53, PCO2 37.1 mmHg, and PO2 134 mmHg. Cycle 2 exhibited ABG results of pH 7.53, PCO2 33.6 mmHg, and PO2 84.3 mmHg for SV-LCV, and pH 7.5, PCO2 34.2 mmHg, and PO2 93.5 mmHg for the control ventilator. Similarly, cycle 3 showed ABG results of pH 7.53, PCO2 32.1 mmHg, and PO2 127 mmHg for SV-LCV, and pH 7.5, PCO2 35.5 mmHg, and PO2 91.3 mmHg for the control ventilator., Conclusion: The SV-LCV provides similar gas exchange and respiratory mechanic profiles compared to a conventional ventilator. With a streamlined design and performance akin to commercially available ventilators, the SV-LCV presents a viable, readily available, and reliable short-term solution for overcoming ventilator supply shortages during crises., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Shyu 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.)

The humidification process of medical gases plays a crucial role in both invasive and non-invasive ventilation, aiming to mitigate the complications arising from bronchial dryness. While passive humidification systems (HME) and active humidification systems are prevalent in routine clinical practice, there is a pressing need for further evaluation of their significance. Additionally, there is often an incomplete understanding of the operational mechanisms of these devices. The current review explores the historical evolution of gas conditioning in clinical practice, from early prototypes to contemporary active and passive humidification systems. It also discusses the physiological principles underlying humidity regulation and provides practical guidance for optimizing humidification parameters in both invasive and non-invasive ventilation modalities. The aim of this review is to elucidate the intricate interplay between temperature, humidity, and patient comfort, emphasizing the importance of individualized approaches to gas conditioning.

Background: High-quality chest compressions (CC) are an important factor of neonatal resuscitation. Mechanical CC devices may provide superior CC delivery and improve resuscitation outcomes. We aimed to compare the hemodynamic effects of CC delivered by machine and human using a neonatal piglet model., Methods: Twelve asphyxiated piglets were randomized to receive CC during resuscitation using an automated mechanical CC device ("machine") or the two-thumb encircling technique ("human"). CC was superimposed with sustained inflations., Results: Twelve newborn piglets (age 0-3 days, weight 2.12 ± 0.17 kg) were included in the study. Machine-delivered CC resulted in an increase in stroke volume, and minimum and maximum rate of left ventricle pressure change (dp/dt min and dp/dt max ) compared to human-delivered CC., Conclusions: During machine-delivered CC, stroke volume and left ventricular contractility were significantly improved. Mechanical CC devices may provide improved cardiopulmonary resuscitation outcomes in neonatal cardiac arrest induced by asphyxia., Impact: Machine chest compression leads to changes in hemodynamic parameters during resuscitation of asphyxiated neonatal piglets, namely greater stroke volume and left ventricular contractility, compared with standard two-thumb compression technique. Mechanical chest compression devices may provide improved cardiopulmonary resuscitation outcomes in neonatal and pediatric asphyxia-induced cardiac arrest., (© 2023. The Author(s).)