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Aim: In a single-center, double-blind, randomized controlled trial, we evaluated whether pupillometry-controlled use of sufentanil is better than free-choice administration of sufentanil by anesthesiologists. Patients & methods: 61 patients undergoing daycare gynecological or abdominal surgery were enrolled. A pupillometry pain index score chart was introduced for administration guidance of sufentanil. Results: The first objective, patient well-being, did not show a significant difference with painkiller usage and health state index at day 1 postoperatively. Secondly, we experienced difficulty in interpretation of the pupillometry score. Thirdly, opioid usage was higher in the intervention group (20.1 vs 14.8 mcg; p = 0.017). Conclusion: The use of pupillometry and pain index chart for bolus sufentanil with our protocol showed an unwanted higher sufentanil usage without a significant difference in patient wellbeing. Plain language summary: Communication with patients under general anesthesia is impossible. A potential solution is to measure pain. One of seven commercially available options is to use a pupillometer. Automated painful stimuli are given and the dilation of the pupil is measured. We hoped to use this method to better control the dose of the opioid sufentanil. During daycare gynecological and abdominal procedures, we had a 25% higher sufentanil usage in the intervention group. We experienced difficulties in reaching the right pain score in both groups. The well-being of the patients, namely pain and painkiller usage at day 1 after surgery, did not show any significant difference. With our protocol, there is no benefit to controlling the dose of sufentanil by pupillometer measurement.

INTRODUCTION: Current guidelines from the American Society of Anesthesiologists recommend postponing elective surgery on COVID-19-positive patients for a minimum of four to twelve weeks. However, literature focusing on the outcomes of COVID-19-positive patients undergoing surgery is scarce. In this case series, the outcome of asymptomatic COVID-19 patients undergoing acute or semi-urgent surgery was evaluated. CASE PRESENTATION: A case series of four patients between 32 and 82 years old with a confirmed SARS-CoV-2 infection undergoing acute or semi-urgent surgery was presented here. All four patients were asymptomatic for COVID-19, developing severe respiratory failure following endo CABG, caesarian section, a thyroidectomy, or abdominal surgery. ICU admission, together with invasive ventilation, was necessary for all patients. Two patients required venovenous extracorporeal membrane oxygenation treatment. A mortality of 50% was observed. CONCLUSIONS: In conclusion, the present case series suggests that elective surgery in asymptomatic SARS-CoV-2 infected patients might elicit an exacerbated COVID-19 disease course. This study endorses the current international guidelines recommending postponing elective surgery for SARS-CoV-2-positive patients for seven weeks, depending on the severity of the surgery and perioperative morbidities, to minimize postoperative mortality. ispartof: Anesth Pain Med vol:12 issue:5 pages:e127356- ispartof: location:Netherlands status: Published online

Objective/background: Surgical interventions for obstructive sleep apnea (OSA) are less effective in obese than in normal-weight children. However, the mechanisms that underpin this relationship are not fully understood. Therefore, this study aimed to explore how body weight influences upper airway collapse and treatment outcome in children with OSA. Methods: We conducted a retrospective analysis of prospectively collected data on polysomnography, drug-induced sleep endoscopy (DISE), and treatment outcome in otherwise healthy children with OSA. Associations between body mass index (BMI) z-score and upper airway collapse during DISE were assessed using logistic regression modelling. Treatment success was defined as obstructive apnea-hypopnea index (oAHI) < 5 events/hour and cure as oAHI < 2 events/hour with obstructive apnea index < 1 event/hour. Results: A total of 139 children were included [median (Q1-Q3); age 4.5 (3.1-8.4) years; BMI z-score 0.3 (-0.8 to 1.4); oAHI 10.8 (6.8-18.0) events/hour]. Twenty-five of them were overweight and 21 were obese. After adjusting for age and history of upper airway surgery, BMI z-score was significantly correlated with circumferential upper airway collapse during DISE (odds ratio 1.67; 95% confidence interval 1.12-2.65; P = 0.011). Outcome of DISE-directed treatment was similar in normal-weight (success: 91.4%; cure: 78.5%), overweight (success: 88.0%; cure: 80.0%), and obese (success: 90.5%; cure: 76.5%) children. Children with circumferential collapse responded better to continuous positive airway pressure than to (adeno)tonsillectomy. Conclusion: Increasing body weight is associated with circumferential upper airway collapse during DISE and, accordingly, may require treatment strategies other than (adeno)tonsillectomy. (C) 2021 Elsevier B.V. All rights reserved.

Background Few randomized studies have assessed recovery from rocuronium- or vecuronium-induced moderate or deep neuromuscular blockade with sugammadex in pediatric participants. Aim To assess sugammadex for reversal of neuromuscular blockade in pediatric participants. Methods This was a randomized, phase IV, active comparator-controlled, double-blind study. Participants aged 2 to = 0.9 in participants receiving sugammadex 2 mg/kg versus neostigmine for reversal of moderate neuromuscular blockade, analyzed by analysis of variance adjusted for neuromuscular blocking agent and age. Results Of 288 randomized participants, 272 completed the study and 276 were included in the analyses. Clinically relevant bradycardia was experienced by 2.0%, 1.6%, and 5.9% of participants in the sugammadex 2 mg/kg, sugammadex 4 mg/kg, and neostigmine groups, respectively. No hypersensitivity or anaphylaxis events were observed. Recovery to a train-of-four ratio of >= 0.9 with sugammadex 2 mg/kg was faster than neostigmine (1.6 min, 95% CI 1.3 to 2.0 vs. 7.5 min, 95% CI 5.6 to 10.0; p < .0001) and was comparable to sugammadex 4 mg/kg (2.0 min, 95% CI 1.8 to 2.3). Conclusions Pediatric participants recovered from rocuronium- or vecuronium-induced moderate neuromuscular blockade significantly faster with sugammadex 2 mg/kg than with neostigmine. Time to reversal of deep neuromuscular blockade with sugammadex 4 mg/kg was consistent with that of moderate neuromuscular blockade reversal. No meaningful differences in clinically relevant bradycardia, hypersensitivity, or anaphylaxis were seen with sugammadex vs neostigmine. These results support the use of sugammadex for reversal of moderate and deep rocuronium- and vecuronium-induced neuromuscular blockade in patients aged 2 to

Hyperthermia, the procedure of raising the temperature of a part of the entire body above normal for a defined period of time, is applied alone or as an adjunctive treatment to various established cancer treatment modalities such as radiotherapy and chemotherapy. Whole-Body Hyperthermia (WBHT), in contrast to local or regional hyperthermia, represents the only hyperthermia modality available for patients with disseminated malignancies. The biological rationale for the treatment of malignant disease by heat is driven by a number of reasons; a) the survival of cells depends on the temperature and duration of heating in a predictable and repeatable way; b) the tumor cell environment (such as hypoxia, poor nutrition, and low pH) that negatively influences the tumor cell killing by ionizing radiation and some chemotherapy regimens, is beneficially influenced by heat therapy; c) the differential sensitivity of normal and tumor cells to heat is dependent on cell type and environmental conditions; d) heat treatment enhances the biological effect of both radiation and chemotherapy agents. The biological rationale is based on a direct cell-killing effect at temperatures in the range of 41– 42°C. A systematic review of van der Horst et al, 2018, addressed clinical trials that used local or whole-body hyperthermia treatment (at variable temperatures) in pancreatic cancer patients. In those described trials, the weighted estimate of the treated population median overall survival was 11.7 compared to 5.6 for the control cohorts. In addition, locoregional hyperthermia (42-44°C) clinical trials showed that the weighted estimate median overall survival of the treated population was 15 months compared to 9 months in control cohorts. The MATTERS trial is a first in-human clinical investigation in advanced solid cancer patients or pancreatic adenocarcinoma patients (TxNxM1). The justification of the design is based on evaluation of pre-clinical data and clinical evaluation of clinical data, safety and/or performance of similar devices/therapies. The study is a mono-centric, non-randomized trial in which the safety and preliminary efficacy of whole-body hyperthermia will be evidenced. Well designed and performed early-stage correlative studies have the potential to strongly influence further clinical development of oncology clinical trials, and correlative data obtained from early stage trials has the potential to provide important guidance on the design and ultimate success of later stage trials. Blood samples will be collected for analysis of immunological panels (e.g. cytokines, chemokines), exosome research, RNA expression profiles. Urine will be collected for analysis of exosome research. The samples will be collected during different timepoints (before, during and after treatment). Citation Format: Ivana Gorbaslieva, Dana Mustafa, Robin Colenbier, Marc Peeters, Dirk Ysebaert, Vera Saldien, Luigi Brancato, Oleg Rudenko, Johan Van den Bossche, John Paul Bogers. First in-human, safety and preliminary efficacy study of (neo)adjuvant, model-based, whole-body hyperthermia treatment in advanced solid cancer patients or stage IV (TxNxM1) metastatic pancreatic adenocarcinoma patients: Liquid biopsies [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr A023.

Background: Allylnitrile is a compound found in cruciferous vegetables and has the same lethality and toxic effects as the other nitriles. In 2013, a viable allylnitrile ototoxicity mouse model was established. The toxicity of allylnitrile was limited through inhibition of CYP2E1 with trans-1,2-dichloroethylene (TDCE). The allylnitrile intoxication model has been extensively tested in the 129S1 mouse strain for vestibular function, which showed significant HC loss in the vestibular organ accompanied by severe behavioral abnormalities. However, the effect of allylnitrile on auditory function remains to be evaluated. Commonly used anesthetics to conduct hearing measurements are isoflurane and ketamine/xylazine anesthesia but the effect of these anesthetics on hearing assessment is still unknown. In this study we will evaluate the otovestibular effects of oral allylnitrile administration in mice. In addition, we will compare the influence of isoflurane and ketamine/xylazine anesthesia on hearing thresholds.Methods and Materials: Fourteen Coch+/– CBACa mice were randomly allocated into an allylnitrile (n = 8) and a control group (n = 6). Baseline measurements were done with isoflurane and 1 week later under ketamine/xylazine anesthesia. After baseline audiovestibular measurements, mice were co-administered with a single dose of allylnitrile and, to reduce systemic toxicity, three intraperitoneal injections of TDCE were given. Hearing loss was evaluated by recordings of auditory brainstem responses (ABR) and distortion product otoacoustic emissions (DPOAE). Specific behavioral test batteries for vestibular function were used to assess alterations in vestibular function.Results: Hearing thresholds were significantly elevated when using isoflurane anesthesia compared to ketamine/xylazine anesthesia for all frequencies of the ABR and the mid-to-high frequencies in DPOAE. Allylnitrile-treated mice lacked detectable ABR thresholds at each frequency tested, while DPOAE thresholds were significantly elevated in the low-frequency region of the cochlea and completely lacking in the mid-to high frequency region. Vestibular function was not affected by allylnitrile administration.Conclusion: Isoflurane anesthesia has a negative confounding effect on the measurement of hearing thresholds in mice. A single oral dose of allylnitrile induced hearing loss but did not significantly alter vestibular function in mice. This is the first study to show that administration of allylnitrile can cause a complete loss of hearing function in mice.

TPS625 Background: Whole-Body Hyperthermia (WBHT) represents the only hyperthermia modality available for patients with disseminated malignancies. The rationale for the treatment of malignant disease by heat is based on a direct cell-killing effect at temperatures in the range of 41– 42°C and driven by a number of reasons. Phase-I mining and phase-I veterinary (dog) clinical study proved the safety of WBHT treatment alone and in combination with standard of care therapy in dogs with cancer. A systematic review addressed clinical trials that used WBHT in pancreatic cancer patients. In these trials, the weighted estimate of the treated population median overall survival was 11.7 compared to 5.6 for the control cohorts. Methods: The is a first in-human, mono-centric, non-randomized trial to establish the safety and preliminary efficacy of WBHT treatment with the TempoCure (medical device) alone in patients with advanced solid cancer (cohort A) or in combination to SOC chemotherapy treatment in patients with stage IV metastatic pancreatic adenocarcinoma (cohort B). The study of 12 to 20 patients is not powered for any statistical analysis. The analysis will be limited to descriptive statistics, considered the doses provided and the extra blood sampling taken at different time points. The treatment is applied under deep anaesthesia in a unit connected to the operating room at the hospital. Cohort A1. Three patients with advanced solid cancer will be subjected to repetitive WBHT starting with 2 hours (day 1), 4 hours (day 8) and 6 hours (day 15) using the TempoCure to keep the patient at a temperature of 41.5°C. The patient’s body temperature will be monitored by specific sensors (liver, oesophageal, rectal and cutaneous). Cohort A2. The highest WBHT duration with acceptable side effects from cohort A1 will be applied to three additional patients with advanced solid cancer, once a week and for 15 days in total. Cohort B1. Three pancreatic cancer patients will be subjected to repetitive WBHT starting with 2 hours (day 1), 4 hours (day 8) and 6 hours (day 15) using the TempoCure to keep the patient at a temperature of 41.5°C and in combination with the standard of care chemotherapy. Cohort B2. The highest WBHT duration with acceptable side effects from cohort B1 will be applied in combination with chemotherapy to three pancreatic cancer patients, once a week and for 15 days in total. Major inclusion criteria are: Adequate liver structure (confirmed by CT scan) allowing the placement of the liver sensor; Adequate coagulation defined as; PT (%) ≥ 70%; aPTT ≤ ULN; Von Willebrand Factor Antigen ≥ LLN; Von Willebrand Factor Activity ≥ LLN; PFA COL/EPI CT ≤ 1.15 ULN; PFA COL/ADP CT ≤ 1.15 ULN. Enrollment to Cohort A1 began in July 2021. Clinical trial information: NCT04467593.

BACKGROUND AND OBJECTIVE: Intraoperative rupture of a cerebral aneurysm during neurosurgery can be a devastating event that increases perioperative morbidity and mortality. Rapid ventricular pacing (RVP) is a technique to obtain flow arrest for short periods of time during dissection or rupture of the aneurysm. The objective of this study was to evaluate the neurological and cardiac effects of repetitive periods of RVP during cerebrovascular surgery. METHODS: Data from patients who underwent repetitive RVP during craniotomy for cerebrovascular disorders were retrospectively analyzed from a single-center medical records database (Cegeka Medical Health Care Systems). We compared preoperative and postoperative troponin levels (cTnl) to assess cardiac ischemia. Preoperative and postoperative magnetic resonance imaging (MRI) results were screened for RVP-induced infarcts by evaluating diffusion restriction in the hemisphere contralateral to the operated side and the fossa posterior. RESULTS: A total of 37 patients were analyzed. An immediate decrease of systolic arterial blood pressure (

Background In response to noxious stimulation, pupillary dilation reflex (PDR) occurs even in anaesthetized patients. The aim of the study was to evaluate the ability of pupillometry with an automated increasing stimulus intensity to monitor intraoperative opioid administration. Methods Thirty‐four patients undergoing elective surgery were enrolled. Induction by propofol anaesthesia was increased progressively until the sedation depth criteria (SeD) were attained. Subsequently, a first dynamic pupil measurement was performed by applying standardized nociceptive stimulation (SNS). A second PDR evaluation was performed when remifentanil reached a target effect‐site concentration. Automated infrared pupillometry was used to determine PDR during nociceptive stimulations generating a unique pupillary pain index (PPI). Vital signs were measured. Results After opioid administration, anaesthetized patients required a higher stimulation intensity (57.43 mA vs 32.29 mA, P

Purpose Adenotonsillectomy (AT) is the first-line treatment for obstructive sleep apnea (OSA) in children irrespective of clinical upper airway (UA) findings. We aimed to investigate whether drug-induced sedation endoscopy (DISE) changes treatment decision and outcome in otherwise healthy children and infants with OSA. Methods Retrospective analysis of prospectively collected data on polysomnography, DISE, and treatment in surgically naive, otherwise healthy infants (n = 34) and children (n = 75) with OSA. Treatment success is defined as post-treatment obstructive apnea/hypopnea index (oAHI) < 5 h-5(-)1, and cure is defined as oAHI < 2 h(-1). Results Based upon UA findings during DISE, AT was performed in 22 infants and 57 children. oAHI improved from 16.5 h(-1) (8.1-28.3) to 0.8 h(-1) (0.3-4.2) (p = 0.01) in infants and from 28.6 h(-1) (23.4-34.9) to 0.7 h(-1) (0.4-1.8) (p < 0.001) in children. AT was successful in 84.2% of infants and 91.4% of children. A cure was obtained in 68.4% of infants and 78.7% of children. DISE changed the treatment decision in 1/3rd of infants and 1/4th of children, and they did not undergo AT. In the non-AT group, isolated adenoidectomy/tonsillectomy or non-surgical treatment was successful in 86.6% of children and in 100% of infants. Cure was achieved in 66.6% of children and 75% of infants. Conclusions DISE performed in otherwise healthy and surgically na < ve infants and children with OSA altered the therapeutic decision making in up to 1/3rd to 1/4th of the cases and resulted in comparable treatment outcomes as standard treatment by AT. The present data suggest that DISE may provide individually tailored treatment of OSA in otherwise healthy infants and children.

Item does not contain fulltext BACKGROUND: The benefit of using neuromuscular-blocking agents to facilitate tracheal intubation in pediatric patients remains unclear due to variations in design, treatments, and results among trials. By combining the available evidence, we aimed to establish whether scientific findings are consistent and can be generalized across various populations, settings, and treatments. METHODS: A systematic search for randomized controlled trials, related to the use of neuromuscular-blocking agents for tracheal intubation in American Society of Anesthesiologists class I-II participants (0-12 years), was performed. We considered all randomized controlled trials that studied whether intubation conditions and hemodynamics obtained by using neuromuscular-blocking agents were equivalent to those that were achieved without neuromuscular-blocking agents. We combined the outcomes in Review Manager 5.3 (RevMan, The Cochrane Collaboration) by pairwise random-effects meta-analysis using a risk ratio (RR) for intubation conditions and mean difference for hemodynamic values (mean [95% Confidence Intervals]). Heterogeneity among trials was explored using sensitivity analyses. RESULTS: We identified 22 eligible randomized controlled trials with 1651 participants. Overall, the use of a neuromuscular-blocking agent was associated with a clinically important increase in the likelihood of both excellent (RR = 1.41 [1.19-1.68], I(2) = 76%) and acceptable (RR = 1.13 [1.07-1.19], I(2) = 68%) intubating conditions. There is strong evidence that both unacceptable intubation conditions (RR = 0.35 [0.22-0.46], I(2) = 23%) and failed first intubation attempts (RR = 0.25 [0.14-0.42], I(2) = 0%) were less likely to occur when a neuromuscular-blocking agent was used compared with when it was not. Higher systolic or mean arterial pressures (mean difference = 13.3 [9.1-17.5] mm Hg, I(2) = 69%) and heart rates (mean difference = 15.9 [11.0-20.8] beats/min, I(2) = 75%) as well as a lower incidence of arrhythmias were observed when tracheal intubation was facilitated by neuromuscular-blocking agents. CONCLUSION: The use of a neuromuscular-blocking agent during light-to-moderate depth of anesthesia can improve the quality as well as the success rate of tracheal intubation and is associated with better hemodynamic stability during induction of anesthesia.

Objectives Children with laryngomalacia may present with obstructive sleep apnea (OSA). The role of polysomnography (PSG) in treatment decision making for laryngomalacia is not well defined. We aimed to investigate the prevalence of OSA in children with laryngomalacia and the role of PSG in treatment decision. Methods Retrospective medical record review of children with laryngomalacia, confirmed by direct laryngoscopy, during a period of 3 years. Demographic data, presenting symptoms, severity classification, comorbidities and pre- and postoperative PSG data were retrieved and analyzed. Data are expressed as a median (25th – 75th percentile). Results Forty-six patients were with diagnosed laryngomalacia between March 2016 and April 2019. A complete data set was available for 44 patients, 24 males and 20 females. The median age at the time of PSG was 12 weeks (6.3–29.8). Thirty-four children (77.4%) were diagnosed with concomitant OSA. A diagnosis of OSA changed the severity classification and treatment decision in 24 cases (54.5%). Twenty-three patients underwent supraglottoplasty, five patients were treated with continuous positive airway pressure (CPAP) and nine patients had both treatments. Seven patients received conservative treatment. The obstructive apnea/hypopnea index decreased from 8.9 events/hour (4.4–12.1) to 2.4 events/hour (1.5–4.4) after supraglottoplasty (p = 0.009). Conclusions A diagnosis of OSA was established in 77.4% of patients with larygomalacia The presence of OSA may increase the severity of symptoms in laryngomalacia, leading to a transition from watchful-waiting to active intervention with CPAP therapy or supraglottoplasty. Supraglottoplasty is a safe and effective surgical procedure for laryngomalacia. When performed in the setting of laryngomalacia with concomitant OSA, it also significantly improves OSA symptomatology.

The Ventrain is a small, manually operated, single-use, inspiratory flow-adjustable ventilation device that generates positive pressure during inspiration and, through a Bernoulli effect within the device, active suction during expiration. It was designed to provide emergency ventilation during airway obstruction via narrow-bore cannulae. The device has been used successfully in elective procedures lasting >1 hour. It remains to be seen if its theoretical advantages in "can't intubate, can't oxygenate" (CICO) scenarios translate to reliable clinical benefit and allow inclusion in future airway algorithms. We advocate for regular simulation training and the detailed reporting of clinical experience with this encouraging new tool.

Background and aims Adolescent idiopathic scoliosis (AIS) is the most common form of scoliosis, mostly affecting children. Although AIS is a benign disorder with no severe long-term consequences, literature suggests that besides pain, self-image is lower among cohorts with untreated AIS. Posterior spinal fusion (PSF) for AIS correction has a challenging pain management and patients are at risk for persistent postoperative pain. The purpose of this study is the implementation of an enhanced recovery pathway (ERP) including all aspects of integrated biopsychosocial care. Methods We developed a stepwise approach that started with the critical appraisal of the current perioperative standardized multimodal analgesic protocol for PSF in AIS at our institution. We reviewed the literature considering all aspects of perioperative patient care and evaluated several scores for their potential to quantify biopsychosocial elements that reflect patient wellbeing. Primary outcome parameter was post-operative pain reduction. Secondary outcomes are opioid-related side-effects and mobilization onset. A novel strategy including preemptive gabapentine, a single intraoperative dose of methadone IV (0.2 mg/kg), NSAID and acetaminophen perioperatively in addition to rescue sublingual buprenorphine, was implemented. Results An ERP was implemented including psychological screening using Web-based questionnaires, early treatment if necessary, extensive patient related outcome measure registration, preemptive multimodal analgesic protocol and long-term follow up using eHealth based telemonitoring devices and online daily questionnaire. Final results are expected 2020. Conclusions ERP could result in reduced pain and opioid-related side-effects, faster mobilization, earlier hospital discharge and may improve patient satisfaction.

Background Spine surgery is associated with considerable postoperative pain and can be challenging to treat. A loco-regional technique suitable for spine surgery should cover the dorsal root of the spinal nerves at the levels where surgery is performed. The erector spinae block is a loco-regional technique with promising results and was recently described at the thoracic level. There are no randomized trials of this technique on a lumbar level. This study tests the hypothesis that the 24-h postoperative morphine consumption is significantly lower in patients undergoing posterior lumbar inter-body fusion surgery with a lumbar erector spinae (LUMBES) block when compared with a sham block. Methods This prospective randomized double-blind multicenter study will randomly allocate 80 adult patients undergoing elective posterior lumbar inter-body fusion surgery during general anesthesia to one of two groups as follows: (1) bilateral erector spinae block (20 mL 0.25% levobupivacaine) or (2) bilateral sham block (20 mL NaCl 0.9%). Our primary endpoint is 24-h postoperative morphine consumption. Secondary endpoints include 72-h morphine consumption, intraoperative sufentanil dosage, postoperative pain scores at regular time intervals both at rest and during movement, time to first postoperative mobilization, and the Quality of Recovery 40 survey score. Discussion The LUMBES trial is a pragmatic clinical study that will provide evidence of whether a bilateral lumbar erector spinae block is effective in reducing 24-h postoperative morphine consumption in patients undergoing lumbar inter-body fusion surgery. If this hypothesis is confirmed, this finding could contribute to more widespread implementation of this technique. Trial registration Local ethics committee B300201837508, ClinicalTrials.gov identifier: NCT03825198. Registered on 31 Jan 2019. Electronic supplementary material The online version of this article (10.1186/s13063-019-3541-y) contains supplementary material, which is available to authorized users.

Background: Rapid ventricular pacing (RVP) can be used to produce short periods of flow arrest during dissection or rupture of a cerebral aneurysm but carries the risk of inducing cerebral ischemia. This study evaluates the intraoperative effect of RVP on local cerebral blood flow (CBF) and cerebral oxygenation during neurovascular surgery. Materials and Methods: Five patients undergoing elective cerebrovascular surgery were included in a single-center prospective study. RVP was applied in pacing periods of 40 seconds with 30% and 100% FiO2. Regional cerebral oxygenation was monitored using a Foresight near-infrared spectroscopy sensor. A Clark-type electrode and a thermal diffusion microprobe located in the white matter were used to monitor brain tissue pO(2)and CBF, respectively. Results: CBF response to RVP closely followed the blood pressure pattern and resulted in a low-flow state. Unlike CBF, brain tissue pO(2)and regional cerebral oxygenation showed a delayed response to RVP, decreasing beyond the pacing period and slowly recovering after RVP cessation. We found a correlation between brain tissue pO(2)and regional cerebral oxygenation. Increasing the inspired oxygen concentration had a positive impact on absolute regional cerebral oxygenation and brain tissue pO(2)values, but the pattern resulting from applying RVP remained unaltered. Conclusions: RVP reduces CBF and cerebral oxygenation. Brain tissue pO(2)and regional cerebral oxygenation are correlated but unlike CBF respond to RVP in a delayed manner. Further research is required to evaluate the impact of longer RVP bursts on brain oxygenation.

Objective: To describe the pattern of upper airway (UA) obstruction in surgically naive children with Down syndrome and obstructive sleep apnea (OSA), and to evaluate the outcome of drug-induced sedation endoscopy (DISE)-directed treatment. Methods: A prospective study of DISE in surgically naive children with Down syndrome and OSA was performed. Treatment was individually tailored based on the DISE findings and was evaluated by control polysomnography (PGS). Results are presented as median (lower-upper quartile) unless otherwise stated. Results: In 41 children, aged 4.2 years (range, 2.8-6.0) with a body mass z score of 1.04 (-0.55 to 1.82) and obstructive apnea-hypopnea index (oAHI) of 10.1/h (range, 6.3-23.0), DISE was performed. Adeno-/tonsillar obstruction was found in 75.6% of the patients, and these patients subsequently underwent UA surgery. Seven patients were non-surgically treated, and three received a combined treatment. A multilevel collapse was present in 85.4%. Tongue base obstruction was present in ten patients (24.4%) and epiglottic collapse in 48.8%. Pre- and postoperative PSG data were available for 25 children (adenotonsillectomy, n = 16; tonsillectomy, n = 7; adenoidectomy, n =2). A significant improvement in oAHI from 11.4/h (range, 7.7-27.0) to 5.5/h (range, 2.1-7.6) was found. Persistent OSA was present in 52% of the children. No significant association between different DISE findings and persistent OSA could be found. Conclusion: Most patients with Down syndrome and OSA present with multilevel collapse on DISE. Adenotonsillectomy results in a significant improvement of the oAHI; however more than half of the patients had persistent OSA, probably due to multilevel collapse. Upper airway evaluation may provide more insights into the pattern of UA obstruction in patients with persistent OSA. (C) 2016 Elsevier B.V. All rights reserved.

Background The use of neostigmine after neuromuscular blockade (NMB) has been associated with postoperative respiratory complications. In previous studies, we found lower diaphragmatic activity after neostigmine reversal of NMB, compared to sugammadex. It is still unclear whether the adequate use of neostigmine guarantees normal respiratory muscle function after NMB. In this study, we wanted to assess the effect of commonly used degrees of NMB and their possible reversal strategies on respiratory muscle activity after the return of normal neuromuscular transmission. Methods This is a randomized, controlled, parallel-group, single-centre, double-blind study in patients scheduled for intracranial surgery at a tertiary academic hospital in Belgium. All participants received target controlled propofol/remifentanil anesthesia and were randomized into one of five groups, receiving either a shallow NMB with no reversal (shallow/saline), a shallow NMB with sugammadex reversal (shallow/sugammadex), a moderate NMB with neostigmine reversal (moderate/neostigmine), a moderate NMB with sugammadex reversal (moderate/sugammadex), or a deep NMB with sugammadex reversal (deep/sugammadex). Primary and secondary outcome parameters were diaphragm and intercostal electromyographic (EMG) activity at the moment of resumed spontaneous breathing activity, defined as a maximal interval of 10 min after the first spontaneous breath. Results For the five groups, a total of 55 patients could be included in the final analysis. Median time of spontaneous breathing analyzed was 5 min (IQR 3–9.5 min). Both the moderate/sugammadex and the moderate/neostigmine groups had lower levels of diaphragm EMG compared to the shallow/sugammadex group. The moderate/neostigmine group had lower levels of intercostal EMG activity compared to the shallow/saline group. Conclusions In this study, the depth of neuromuscular blockade and type of reversal strategy impacts respiratory muscle activity at the moment of resumed spontaneous breathing and recovery of neuromuscular blockade. Both groups that received moderate NMB had lower levels of diaphragm EMG, compared to the shallow NMB group with sugammadex reversal. Compared to the shallow NMB group with no reversal, the moderate NMB with neostigmine reversal group had lower intercostal EMG activity. Trial registration Clinicaltrials.gov NCT01962298 on October 9, 2013 and EudraCT 2013–001926-25 on October 10, 2013.

BACKGROUND Pectus excavatum and pectus carinatum are the most common chest wall deformities. Although minimally invasive correction (MIPC) has become common practice, it remains associated with severe postoperative pain. Preoperative psychosocial factors such as anxiety and low self-esteem can increase postsurgical pain. Early detection of psychological symptoms, effective biopsychosocial perioperative management of patients and prevention of pain chronification using an enhanced recovery pathway (ERP) may improve outcomes. The incidence of the latter is poorly described in adolescents undergoing MIPC. OBJECTIVE To evaluate whether an ERP after surgery facilitated early recovery and to assess persistent postsurgical pain three months after surgery in pediatric patients undergoing MIPC using m-Health technology. METHODS A population-based cohort study was conducted with prospectively collected data from patients undergoing pectus surgery between June 2017 and December 2017. An ERP was initiated preoperatively and included patient education, eHealth-based psychological screening, multimodal preemptive analgesia, nausea prophylaxis as well as early Foley catheter removal and respiratory exercises. After hospital discharge, patients were assessed for up to ten weeks by evaluating pain and underwent rehabilitation using online diary and Bluetooth-connected telemonitoring devices. Retrospectively derived control patients in our hospital who were undergoing the same procedure without an ERP were matched by age (≤ 18 years). RESULTS Twenty-nine adolescents were enrolled using the developed ERP. Preemptive multimodal analgesia pain rating scores were low during hospital admission and were comparable between the groups. Optimal epidural placement occurred in 26 of the 29 participants (90%), hereby no motor block or Horner syndrome occurred. Bladder and epidural catheters were removed after 3.41 ± 1.50 and 5.76 ± 1.02 days, respectively. Low numeric pain rating scores (NRSs) and decreased incidence of nausea contributed to improved early rehabilitation. Telemonitoring at home was feasible in adolescents after hospital discharge despite adherence difficulties. Although pain scores at the final interview were low (0.81 ± 1.33), 9 out of 27 long-term follow up ERP patients (33%) still experienced frequent disturbing thoracic pain requiring analgesic administration, school absenteeism and multiple doctor (re)visits. CONCLUSIONS Allocating patients to the appropriate level of care preoperatively and immediately after surgery may improve long-term outcome variables. Using internet-based technologies and feasible, objective monitoring tools can help clinicians screen surgical patients for risk factors and initiate early treatment if necessary. Future research should focus on improving risk stratification and including a psychological assessment and evaluation of the effect of perioperative care pathways in children undergoing major surgery. CLINICALTRIAL ClinicalTrials.gov, NCT03100669, https://clinicaltrials.gov/ct2/show/NCT03100669

Background Pupillary response by pupillary dilatation reflex (PDR) is a robust reflex, even measurable during general anaesthesia. However, the ability of infrared pupillometry to detect PDR differences obtained by intraoperative opioid administration in anaesthesized patients remains largely unknown. We analyzed the performance of automated infrared pupillometry in detecting differences in pupillary dilatation reflex response by a inbuilt standardized nociceptive stimulation program in patients under general anesthesia with a standardized propofol/fentanyl scheme. Methods In this single center, interventional cohort study 38 patients (24-74 years) were enrolled. Patients were anesthetized with propofol until loss of consciousness. Two dynamic pupil measurements were performed in each patient (before opioid administration and after opioid steady state). Automated infrared pupillometry was used to determine PDR during nociceptive stimulations (10-60 mA) applied by a inbuilt pupillary pain index protocol (PPI) to the skin area innervated by the median nerve. Increasing stimulations by protocol are device specific and automatically performed until pupil dilation of > 13%. Pupil characteristics, blood pressure, heart rate values were collected. Results After opioid administration, patients needed a higher stimulation intensity (45.26 mA vs 30.79 mA, p = 0.00001). PPI score showed a reduction after analgesic treatment (5.21 vs 7.68, p = 0.000001), resulting in a 32.16% score reduction. Conclusions PDR via automated increased tetanic stimulation may reflect opioid effect under general anaesthesia. Further research is required to detect possible confounding factors such as medication interaction and optimization of individualized opioid dosage.

BACKGROUND The use of neuromuscular blocking agents has been associated with severe postoperative respiratory morbidity. Complications can be attributed to inadequate reversal, and reversal agents may themselves have adverse effects. OBJECTIVE To compare the electromyographic activity of the diaphragm (EMGdi) during recovery from neuromuscular blockade using neostigmine and sugammadex. The hypothesis was that there would be better neuromuscular coupling of the diaphragm when sugammadex was used. DESIGN A randomised, controlled, parallel-group, single-centre, double-blinded study. SETTING District general hospital in Belgium. PARTICIPANTS Twelve healthy male volunteers. INTERVENTIONS Individuals were anaesthetised with propofol and remifentanil. After rocuronium 0.6 mg kg(-1), a transoesophageal electromyography (EMG) recorder was inserted. For reversal of neuromuscular blockade, volunteers received sugammadex 2 mg kg(-1) (n = 6) or neostigmine 70 mu g kg(-1) (n = 6). MAIN OUTCOME MEASURES EMGdi, airway pressure and flow were continuously measured during weaning from the ventilator until tracheal extubation. Arterial blood gas samples were obtained for PaO2 and PaCO2 analysis at the first spontaneous breathing attempt and after tracheal extubation. RESULTS During weaning, 560 breaths were retained for analysis. The median (95% CI) peak EMGdi was 1.1 (0.9 to 1.5) mu V in the neostigmine group and 1.6 (1.3 to 1.9) mV in the sugammadex group (P < 0.001). Individuals in the neostigmine group had 125 of 228 (55%) breaths with associated EMGdi at least 1 mV vs. 220 of 332 (66%) breaths in the sugammadex group (P = 0.008). The median (95% CI) tidal volume was 287 (256 to 335) ml after neostigmine and 359 (313 to 398) ml after sugammadex (P = 0.013). The median (95% CI) PaO2 immediately after extubation was 30.5 (22.8 to 37.1) kPa after sugammadex vs. 20.7 (12.9 to 27.5) kPa after neostigmine (P = 0.03). CONCLUSION EMGdi, tidal volume and PaO2 following tracheal extubation were increased after sugammadex compared with neostigmine, reflecting diaphragm-driven inspiration after sugammadex administration. Sugammadex may free more diaphragmatic acetylcholine receptors than neostigmine, which has an indirect effect.

BACKGROUND There is some evidence that anaesthetists often perform neuraxial blocks at a higher lumbar interspace than intended. It may be questioned whether parturients are at greater risk for neurological damage when the dura is perforated at a more cephalad interspace than L2-L3. METHODS Thirty-six patients scheduled for elective Caesarean delivery under CSE anaesthesia were selected for study. Using a B-D Durasafe Adjustable needle combination, the skin-to-epidural distance and the width of the epidural space were measured and matched with 36 female patients undergoing the same anaesthetic technique for orthopaedic procedures. RESULTS Pregnant patients had a higher bodyweight (77 vs. 67 kg, p = 0.007) than those scheduled for orthopaedic surgery. The skin-to-epidural distance was similar in both groups (5.3 vs. 5.1 cm, p = 0.3). The width of the epidural space was 1.1 mm larger in parturients (8.2 vs. 7.1 mm, p = 0.04). More patients in this group had tip-to-tip distances exceeding 10 mm (25 vs. 12%). CONCLUSION The greater epidural space or tip-to-tip distance between the epidural and spinal needle points in term parturients results in a lower margin of safety with respect to the distance from the dura to spinal cord or conus medullaris. Puncturing the correct interspace is, therefore, of crucial importance in pregnant patients.

The use of regional anaesthesia techniques for intra-operative anaesthesia and postoperative analgesia remains very controversial for patients scheduled to undergo spinal interventions. Spine surgeries, especially the most extensive types, are mostly performed under general anaesthesia. This has to be explained by the position required during surgery, the preference of the surgeon and/or anaesthesiologist and lack of sufficient literature supporting locoregional anaesthesia. In addition, there is an increasing trend to prefer general anaesthesia for spinal surgery. Nevertheless, with respect to spine surgeries more than 80% of the actual literature on neuraxial blocks is dated less than 12 years. The present overview was focused in the first place on the feasibility of (loco) regional techniques to be used intra-operatively. These techniques are also of interest for postoperative analgesia, either with a single bolus injection of local anaesthetics, opioids and adjuvants, alone or in combination, in continuous or intermittent administration and requiring the presence of foreign material in the neighborhood of the surgical field. As all techniques described offered variable success rates, future research is mandatory to determine their superiority over general intra-operative anaesthesia and conventional pain therapy with paracetamol, NSAIDs, opioids used alone or in combination.Utilizarea tehnicilor de anestezie regională în vederea obţinerii anesteziei chirurgicale sau a analgeziei postoperatorii, în cazul pacienţilor supuşi intervenţiilor la nivelul coloanei vertebrale, rămâne şi în prezent un subiect extrem de controversat. Chirurgia coloanei se desfăşoară în continuare, mai ales în cazul intervenţiilor majore, sub anestezie generală. Acest fapt este explicat prin poziţionarea specială a pacientului, preferinţa chirurgului şi anestezistului, şi de lipsa literaturii care să susţină suficient tehnicile locoregionale. În plus, există o tendinţă actuală de a prefera anestezia generală în chirurgia vertebro-medulară. În ceea ce priveşte chirurgia coloanei, peste 80% din informaţiile din literatură referitoare la blocurile neuraxiale datează de peste 12 ani. Această actualizare s-a concentrat în primul rând asupra aplicabilităţii tehnicilor loco-regionale în perioada intraoperatorie. Aceste tehnici sunt însă de interes şi pentru analgezia postoperatorie fie sub forma lor simplă de bolus cu anestezic local, opioid sau adjuvant, fie în administrare continuă sau intermitentă, necesitând în acest caz prezenţa unui material străin în proximitatea câmpului operator. Ca toate tehnicile descrise, acestea oferă rate de succes variabile, iar cercetări viitoare sunt necesare pentru a demonstra superioritatea tehnicilor regionale în raport cu anestezia generală sau cu terapia analgezică postoperatorie convenţională cu paracetamol, antiinflamatoare nesteroidiene, opioide utilizate izolat sau în asociere.

Objectives/Hypothesis To describe upper airway (UA) collapse patterns during drug-induced sleep endoscopy (DISE) in a large cohort of patients with sleep-disordered breathing (SDB) and to assess associations with anthropometric and polysomnographic parameters. Study Design Observational study. Methods A total of 1,249 patients [age 47 ± 10 y; apnea–hypopnea index (AHI) 18.9 ± 15.3/h; body mass index (BMI) 27.2 ± 3.7 kg/m2] underwent polysomnography and DISE. DISE findings were categorized to the following UA levels: palate, oropharynx, tongue base, and hypopharynx. The degree of collapse was reported as complete, partial, or none. The pattern of the obstruction was described as anteroposterior, lateral, or concentric. Associations between DISE findings and anthropometric and polysomnographic parameters were analyzed. Results Palatal collapse was seen most frequently (81%). Multilevel collapse was noted in 68.2% of all patients. The most frequently observed multilevel collapse pattern was a combination of palatal and tongue base collapse (25.5%). Palatal collapse was seen most frequently (81%). The prevalence of complete collapse, multilevel collapse, and hypopharyngeal collapse increased with increasing severity of obstructive sleep apnea (OSA). Multilevel and complete collapse were more prevalent in obese patients and in those with more severe OSA. Both higher BMI and AHI values were associated with a higher probability of complete concentric palatal collapse. Conclusion The current study provides an overview of UA collapse patterns in a large cohort of SDB patients who underwent DISE. The associations found in this study may indicate that UA collapse patterns observed during DISE cannot be fully explained by selected baseline polysomnographic and anthropometric characteristics. Level of Evidence 4. Laryngoscope, 124:797–802, 2014

The aim of this study was to assess the value of drug-induced sleep endoscopy (DISE) using a custom-made simulation bite in maximal comfortable protrusion (MCP) of the mandible, in the prediction of treatment outcome for obstructive sleep apnoea (OSA) with a mandibular advancement device (MAD). Two hundred patients (74% male; age 46 ± 9 years; apnoeahypopnoea index [AHI] 19 ± 13 h−1 sleep; body mass index [BMI] 27 ± 4 kg m−2) with sleep-disordered breathing underwent DISE with a simulation bite in MCP. One hundred and thirty-five patients with an established diagnosis of OSA commenced MAD treatment. The associations between the findings during DISE with simulation bite and treatment outcome were evaluated. Treatment response was defined as a reduction in AHI following MAD treatment of ≥ 50% compared to baseline. Overall MAD treatment response in the studied population was 69%. The results of this study demonstrated a statistically significant association between a positive effect of the simulation bite on the upper airway patency during DISE and treatment response with MAD (P < 0.01). The results of this study suggest that the use of a simulation bite in maximal comfortable protrusion (MCP) of the mandible, as used during DISE in patients with OSA, tends to be effective in predicting treatment response of MAD treatment.

We report a case of acute respiratory distress after upper airway obstruction following routine palatoplasty in an otherwise healthy 6-year-old boy. We believe that extreme variation of intrathoracal pressure was the basis of the development of the acute respiratory distress. We recommend after palatoplasty a more than careful postoperative clinical observation to detect and treat postoperative obstruction and hypoxemia.

Aim: To describe the pattern of upper airway (UA) obstruction during drug-induced sedation endoscopy (DISE) and to evaluate the outcome of DISE-directed treatment. Methods: Prospective study of DISE in surgically naive obstructive sleep apnea syndrome (OSAS) children without syndromic comorbidity or craniofacial abnormalities. Treatment was individually tailored according to UA findings during DISE and polysomnographic data. Reported values are median (lower-upper quartile). Results: Thirty-seven children aged 4.1 years (2.1-6.0), with body mass index z-score 0.3 (-0.9 to 0.9), and obstructive apnea-hypopnea index (oAHI) 9.0/h (6.1-19.3) were included. Adenotonsillar obstruction was found in 33 cases (89%) as an isolated entity or as part of a multi-level obstruction. These children were treated with adenotonsillectomy (n = 28), adenoidectomy (n = 3), or tonsillectomy (n = 2). The remaining four patients received non-surgical treatment. Pre-postoperative polysomnographic data in 22 patients showed a significant improvement in oAHI from 8.6/h (6.7-20.7) to 1.0/h (0.6-2.0) (P = 0.001). Only two of these 22 children had residual OSAS (oAHI >= 5/h), indicating a success rate of 91%. Conclusions: Based on UA findings during DISE, a non-surgical treatment was proposed for 11% of children. A 91% success rate was obtained in those treated with (adeno) tonsillectomy. These data suggest that DISE may be helpful to identify patients most likely to benefit from UA surgery. (C) 2014 Elsevier B.V. All rights reserved.

BACKGROUND Intraoperative rupture of a cerebral aneurysm can be a devastating event that increases operative morbidity and mortality. Rapid ventricular pacing (RVP) is a technique used in interventional cardiology to obtain flow arrest for short periods of time. OBJECTIVE To present our experience using RVP for flow arrest during cerebrovascular surgery. METHODS We used RVP to produce flow arrest for periods of 40 seconds in 12 patients who underwent craniotomy for a cerebrovascular disorder (11 aneurysms and 1 arteriovenous malformation). RESULTS During RVP, there was an immediate and significant reduction of blood pressure in each patient. The maximum degree of hypotension was obtained 3.2 ± 0.7 seconds (mean ± SD) after the start of RVP. When RVP was terminated, normal sinus rhythm returned instantaneously, along with recovery of indexes of hemodynamic function. Subjectively, the decrease in blood pressures facilitated dissection, and during clipping, the aneurysm sac felt softer and was easier to manipulate. No complications related to RVP occurred. CONCLUSION Rapid ventricular pacing during cerebrovascular surgery is an effective method for lowering the arterial blood pressure in a controlled and directly reversible manner. Advances in cardiology now make RVP a promising and safe technique that can facilitate complex cerebrovascular surgery.

BACKGROUND: Sugammadex is the first of a new class of selective muscle relaxant binding drugs developed for the rapid and complete reversal of neuromuscular blockade induced by rocuronium and vecuronium. Many studies have demonstrated a dose-response relationship with sugammadex for reversal of neuromuscular blockade in patients induced and maintained under propofol anesthesia. However, sevoflurane anesthesia, unlike propofol, can prolong the effect of neuromuscular blocking drugs (NMBDs) such as rocuronium and vecuronium. METHODS: We designed this randomized, open-label, dose-response trial to explore the dose-response relationship of sugammadex for the reversal of deep neuromuscular blockade induced by rocuronium or vecuronium under propofol-induced and sevoflurane-maintained anesthesia. As a secondary objective, the safety variables of sugammadex were evaluated. After anesthesia induction with propofol, 102 patients aged >=20 and =4 mg/kg provides rapid reversal of deep rocuronium- and vecuronium-induced neuromuscular blockade under sevoflurane maintenance anesthesia.

Background Sugammadex reverses the neuromuscular blocking effects of rocuronium by chemical encapsulation. The efficacy, safety, and pharmacokinetics of sugammadex for reversal of profound rocuronium-induced neuromuscular blockade were evaluated. Methods Ninety-eight male adult patients were randomly assigned to receive sugammadex (1, 2, 4, 6, or 8 mg/kg) or placebo at 3, 5, or 15 min after 0.6 mg/kg rocuronium. Patients were anesthetized with propofol and fentanyl. The primary endpoint of the study was the time to achieve a recovery of train-of-four ratio to 0.9. Neuromuscular blockade was measured using acceleromyography. Concentrations of rocuronium and sugammadex were determined in venous blood and urine samples. A population pharmacokinetic model using NONMEM (GloboMax LLC, Hanover, MD) was applied. Results The mean time to recovery of the train-of-four ratio to 0.9 after dosing at 3, 5, and 15 min decreased from 52.1, 51.7, and 35.6 min, respectively, after administration of placebo to 1.8, 1.5, and 1.4 min, respectively, after 8 mg/kg sugammadex. Sugammadex was safe and well tolerated. However, 20.4% of patients showed signs of inadequate anesthesia after its administration. The median cumulative excretion of rocuronium in the urine over 24 h was 26% in the placebo group and increased to 58-74% after 4-8 mg/kg sugammadex. The mean plasma clearances of sugammadex and rocuronium were 0.084 and 0.26 l/min, respectively. Conclusions In male subjects, sugammadex safely reversed profound neuromuscular blockade induced by 0.6 mg/kg rocuronium in a dose-dependent manner. Sugammadex enhanced the renal excretion of rocuronium, and its clearance is approximately one third that of rocuronium.

In this study we investigated whether the novel reversal drug, sugammadex, is equally effective at reversing rocuronium-induced neuromuscular block (NMB) in patients under propofol or sevoflurane maintenance anesthesia. After receiving propofol for induction, patients were randomized to propofol (n = 21) or sevoflurane (n = 21). Rocuronium 0.6 mg/kg was administered for tracheal intubation. NMB was monitored using acceleromyography. At reappearance of the second twitch of the train-of-four ratio, sugammadex 2.0 mg/kg was administered by IV bolus. The primary end-point was time from start of sugammadex administration to recovery of train-of-four ratio to 0.9. Mean recovery time was 1.8 min after both propofol and sevoflurane anesthesia. The 95% confidence interval for the difference in recovery time between the 2 groups (-0.5 to +0.4 min) was well within the predefined equivalence interval (-1 to +1 min), indicating that recovery from NMB was unaffected by maintenance anesthesia. Thirteen patients (propofol n = 4; sevoflurane n = 9) experienced adverse events; these were treatment-related in 4 patients (propofol n = 3; sevoflurane n = 1). There were no treatment-related serious adverse events and no discontinuations or deaths. No residual paralysis occurred. The safety profile of sugammadex was somewhat more favorable under propofol than under sevoflurane anesthesia.

Background. We aimed to evaluate whether area under the curve (AUC) analysis of pharmacodynamic data can be used to compare pharmacokinetic models taken from the literature, during a target controlled infusion (TCI) of rocuronium. Methods. Seventy-two patients scheduled for orthopaedic surgery received a TCI of rocuronium (Stanpump) based on one of four pharmacokinetic models: those described by Szenohradszky, Alvarez-Gomez, Wierda, and Cooper. The resulting theoretical plasma concentration versus time curve was calculated for all patients based on all four pharmacokinetic models. Predicted effect versus time curves were calculated following the pharmacokinetic‐pharmacodynamic link model (Sheiner and colleagues). Neuromuscular block was evaluated acceleromyographically. The difference between the area under the observed effect (AUCOE) and predicted effect (AUCPE) versus time curves was used for comparison. Results. AUCPE differed significantly from AUCOE in the Szenohradszky and Alvarez-Gomez models, both with the reference link-pharmacodynamic data and with altered link-pharmacodynamic variables. AUCPE and AUCOE were comparable for the Wierda and Cooper models. The mean AUCOE was 25.1 (SD 11.9)% block3h. AUCPE‐AUCOE was significantly larger in the Szenohradszky model when compared with all other pharmacokinetic models. This difference remained when link or pharmacodynamic variables were modified. The smallest AUCPE‐AUCOE difference was found with the Wierda model. Conclusion. It was possible to use AUC analysis for identification of the pharmacokinetic model that best predicted the pharmacodynamic characteristics of our patients. Br J Anaesth 2003; 90: 183‐8

In a double-blind, randomized trial, 98 parturients undergoing cesarean section received either hyperbaric or plain bupivacaine 6.6 mg combined with sufentanil 3.3 pg as part of a combined spinal-epidural procedure. To prevent hypotension, 1000 mL of lactated Ringer’s solution, 500 mL of hydroxyethyl starch 6%, and ephedrine 5 mg were administered IV. The height of the block was equal in both groups, but more patients in the plain group had blocks that were either too high or too low (P < 0.01). The number of patients requiring epidural supplementation was equal in both groups. Strict criteria were used to treat hypotension. The overall incidence of systolic blood pressure (

Sufentanil or a sufentanil-clonidine combination was evaluated to determine whether the basal rate in patient-controlled epidural analgesia (PCEA) might affect the daily consumption, quality of analgesia or incidence of side effects. Following Caesarean section delivery, 60 patients were randomly assigned to receive one of the four following PCA regimens (15 patients per group) for the relief of post-operative pain by the epidural route: sufentanil 2 micrograms mL-1 in 0.9% NaCl, demand dose 5 micrograms i.e. 2.5 mL, (group S+ with, group S without an infusion at 2.5 mL hr-1) or sufentanil 2 micrograms mL-1 + clonidine 3 micrograms mL-1, demand dose 5 micrograms sufentanil + 7.5 micrograms clonidine i.e. 2.5 mL (group SC+ with and SC without an infusion of 2.5 ml hr-1). The other PCA settings (Bard I PCA pump) were a lock out of interval of 10 min and a 1 h limit of 20 micrograms sufentanil and 30 micrograms clonidine i.e. 10 mL. The parameters measured were the analgesic drug consumption and number of dose demands during the first 24 h, pain scores at 6 h intervals, side effects and quality of sleep. The concurrent infusion increased the dose requirements regardless of the content of the syringe. Consumption of sufentanil was the highest in those patients receiving the plain solution with a basal infusion. Clonidine addition reduced the dose requirements but only significantly in those receiving the background infusion. Patients treated with the mixture tended to reach lower pain scores than those receiving sufentanil only without basal rate. Patients receiving the mixture with basal rate requested significantly fewer additional demands compared with the three other groups, but this did not influence the quality of sleep. Since side effects were more frequently registered in the patients in this group, it was concluded that the optimum regimen was the sufentanil-clonidine combination but with deletion of the basal rate.