Critical airway-related incidents and near misses in anaesthesia: a qualitative study of a critical incident reporting system.

BACKGROUND: Many serious adverse events in anaesthesia are retrospectively rated as preventable. Anonymous reporting of near misses to a critical incident reporting system (CIRS) can identify structural weaknesses and improve quality, but incidents are often underreported. METHODS: This prospective qualitative study aimed to identify conceptions of a CIRS and reasons for underreporting at a single Swiss centre. Anaesthesia cases were screened to identify critical airway-related incidents that qualified to be reported to the CIRS. Anaesthesia providers involved in these incidents were individually interviewed. Factors that prevented or encouraged reporting of critical incidents to the CIRS were evaluated. Interview data were analysed using the Framework method. RESULTS: Of 3668 screened airway management procedures, 101 cases (2.8%) involved a critical incident. Saturation was reached after interviewing 21 anaesthesia providers, who had been involved in 42/101 critical incidents (41.6%). Only one incident (1.0%) had been reported to the CIRS, demonstrating significant underreporting. Interviews revealed highly variable views on the aims of the CIRS with an overall high threshold for reporting a critical incident. Factors hindering reporting of cases included concerns regarding identifiability of the reported incident and involved healthcare providers. CONCLUSIONS: Methods to foster anonymity of reporting, such as by national rather than departmental critical incident reporting system databases, and a change in culture is required to enhance reporting of critical incidents. Institutions managing a critical incident reporting system need to ensure timely feedback to the team regarding lessons learned, consequences, and changes to standards of care owing to reported critical incidents. Consistent reporting and assessment of critical incidents is required to allow the full potential of a critical incident reporting system.

Risk patterns of consecutive adverse events in airway management: a Bayesian network analysis.

BACKGROUND: Minor adverse airway events play a pivotal role in the safety of airway management. Changes in airway management strategies can reduce such events, but the broader impact on airway management remains unclear. METHODS: Minor, frequently occurring adverse airway events were audited before and after implementation of changes to airway management strategies. We used two Bayesian networks to examine conditional probabilities of subsequent airway events and to compute the likelihood of certain events given that certain previous events occurred. RESULTS: Independent of sex, age, and American Society of Anesthesiologists physical status, targeted changes to airway management strategies reduced the risk of a first event. Obese patients were an exception, in whom no risk reduction was achieved. Frequently occurring event sequences were identified, for example the most likely event to follow difficult bag-mask ventilation was a Cormack-Lehane grade ≥3, with a risk of 14.3% (95% credible interval [CI], 11.4-17.2%). An impact of the targeted changes was detected on the likelihood of some event sequences, for example the likelihood of no consecutive event after a tracheal tube-related event increased from 43.3% (95% CI, 39.4-47.6%) to 56.4% (95% CI, 52.0-60.5%). CONCLUSIONS: Identification of risk patterns and typical structures of event sequences provides a clinically relevant perspective on airway incidents. It further provides a means to quantify the impact of targeted airway management changes. These targeted changes can influence some event sequences, but overall, the benefit results from the cumulative effect of improvements in multiple events. Targeted airway management changes with knowledge of risk patterns and event sequences can potentially further improve patient safety in airway management. CLINICAL TRIAL REGISTRATION: NCT02743767.

Stress of emergency physicians during helicopter operations: impact of patients' diagnoses, severity of diagnoses, and physicians' work experience.

PURPOSE: Emergency physicians are in danger of developing illnesses due to stress in their demanding work environment. Until today, scholars have not identified stressors or resilience factors that qualify to promote the preservation of emergency physicians' well-being. Therefore, potential influencing variables such as patients' diagnoses, the severity of diagnoses, as well as physicians' work experience have to be considered. The present study aims at investigating emergency physicians in the Helicopter Emergency Medical Service (HEMS)' autonomic nervous system activity during emergency operations in one shift with respect to patients' diagnoses, severity of diagnoses, and physicians' work experience. METHODS: Measurement of HRV (employing the parameters RMSSD and LF/HF) for 59 EPs (age: M = 39.69, SD = 6.19) was performed during two complete air-rescue-days, the alarm and landing phase being investigated in particular. Besides patients' diagnoses, the National Advisory Committee for Aeronautics Score (NACA) was included as an indicator for severity. Diagnoses' and NACA's effect on HRV were examined using a linear mixed model. RESULTS: Both HRV parameters indicate a significant decrease of the parasympathetic nervous system as a function of the diagnoses. Furthermore, high NACA scores (≥ V) predicted a significantly lower HRV. In addition, a lower HRV/RMSSD with increasing work experience was observed as well as a positive association between physicians' work experience and sympathetic activation (LF/HF). CONCLUSION: The present study showed that pediatric diagnoses as well as time-critical diagnoses are most stressful and have the highest impact on the physicians' ANS. This knowledge allows the development of specific training to reduce stress.

Carbon Dioxide Changes during High-flow Nasal Oxygenation in Apneic Patients: A Single-center Randomized Controlled Noninferiority Trial.

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

Airway management in a Helicopter Emergency Medical Service (HEMS): a retrospective observational study of 365 out-of-hospital intubations.

BACKGROUND: Airway management is a key skill in any helicopter emergency medical service (HEMS). Intubation is successful less often than in the hospital, and alternative forms of airway management are more often needed. METHODS: Retrospective observational cohort study in an anaesthesiologist-staffed HEMS in Switzerland. Patient charts were analysed for all calls to the scene (n = 9,035) taking place between June 2016 and May 2017 (12 months). The primary outcome parameter was intubation success rate. Secondary parameters included the number of alternative techniques that eventually secured the airway, and comparison of patients with and without difficulties in airway management. RESULTS: A total of 365 patients receiving invasive ventilatory support were identified. Difficulties in airway management occurred in 26 patients (7.1%). Severe traumatic brain injury was the most common indication for out-of-hospital Intubation (n = 130, 36%). Airway management was performed by 129 different Rega physicians and 47 different Rega paramedics. Paramedics were involved in out-of-hospital airway manoeuvres significantly more often than physicians: median 7 (IQR 4 to 9) versus 2 (IQR 1 to 4), p < 0.001. CONCLUSION: Despite high overall success rates for endotracheal intubation in the physician-staffed service, individual physicians get only limited real-life experience with advanced airway management in the field. This highlights the importance of solid basic competence in a discipline such as anaesthesiology.

Optimisation of airway management strategies: a prospective before-and-after study on events related to airway management.

BACKGROUND: Poor medical outcomes often result from series of minor events. The present study assessed events related to airway management to determine whether targeted changes to departmental strategies for airway management can reduce the incidence. METHODS: This prospective before-and-after study was performed with ethics committee approval and written informed consent from patients. Major and minor events related to airway management were prospectively recorded for 9 weeks. After implementation of changes to departmental strategies for airway management, events were again prospectively recorded over 9 weeks. Primary outcome was number of cases with events. Secondary outcomes were various predefined events. RESULTS: At study baseline, 3668 cases and at follow-up 3786 cases were assessed. Cases with events decreased from 566 (15.4%) to 433 (11.4%) (risk ratio [RR]=0.74; 95% confidence interval [CI], 0.66-0.83; P<0.01). As secondary outcomes, the following events decreased: Cormack-Lehane grade 3 or 4 (4.3-2.9%; RR=0.67; 95% CI, 0.52-0.85; P<0.01); difficult bag-mask ventilation (3.8-2.7%; RR=0.69; 95% CI, 0.54-0.89; P<0.01); hypoxaemia (3.8-2.9%; RR=0.75; 95% CI, 0.59-0.96; P=0.03); unplanned use of special equipment (3.2-2.0%; RR=0.62; (95% CI, 0.47-0.83; P<0.01); oesophageal intubation (1.3-0.8%; RR=0.61; 95% CI, 0.39-0.96; P=0.03); bleeding (0.8-0.2%; RR=0.30; 95% CI, 0.14-0.63; P<0.01); insufficient spontaneous breathing (0.3-0.0%; RR=0.09; 95% CI, 0.01-0.68; P<0.01); communication errors (0.1-0.0%; RR=0; 95% CI, 0-NA; P=0.03). CONCLUSIONS: Implementation of changes to departmental strategies for airway management significantly reduced cases with events related to airway management. Analysis of events and implementation of strategies that specifically target identified issues might be key to improving airway management. CLINICAL TRIAL REGISTRATION: NCT02743767.

Cricothyroidotomy competence and injuries using nonmedical equipment: A crossover noninferiority randomised controlled trial in a porcine cadaver model.

BACKGROUND: International guidelines recommend cricothyroidotomy as a life-saving procedure for 'cannot intubate, cannot ventilate' situations. Although commercially available sets facilitate surgical cricothyroidotomy, regular training seems to be the key to success. OBJECTIVES: The goal was to investigate if trained anaesthetists are able to transfer their skill in one surgical cricothyroidotomy technique to another. The primary hypothesis postulated that trained anaesthetists could perform an emergency cricothyroidotomy equally fast and successfully with a pocketknife compared with a surgical cricothyroidotomy set. DESIGN: Crossover noninferiority randomised controlled trial. SETTING: After written informed consent and ethics committee approval, this single-centre study was performed at the University Hospital of Bern, Bern, Switzerland. PARTICIPANTS: Altogether, 61 study participants already familiar with surgical cricothyroidotomy were included. INTERVENTION: The use of a commercially available cricothyroidotomy set was compared with a short-bladed pocketknife and ballpoint pen barrel. A pig-larynx cadaver model including trachea, with pig skin overlaid, was used. Participants underwent additional training sessions in both procedures. MAIN OUTCOME MEASURES: The primary outcome was the time necessary to position the tracheal tube or pen barrel in the trachea. Other outcome parameters were success rate, tracheal and laryngeal injuries and preferred device. RESULTS: Cricothyroidotomy with the pocketknife was performed significantly faster and equally successfully as compared with the cricothyroidotomy sets. Tracheal and laryngeal injuries were similar in both groups. Paratracheal or submucosal placement of the pen barrel occurred in 32%, compared with 29% for the tracheal tube. Sixty-six per cent of participants preferred the cricothyroidotomy set. CONCLUSION: Regularly trained anaesthetists are able to accomplish cricothyroidotomy irrespective of the equipment used. A pocketknife with a ballpoint pen barrel was just as effective as a commercially available surgical set.

Hormonal and Subjectively Perceived Stress of the Emergency Physicians of the Airborne Rescue Service.

Due to their work activities, emergency physicians are regularly exposed to exceptional mental and physical situations. In order to prevent stress-related illnesses, the triggers of hormonal and subjectively perceived stress must be understood better. On a sample of emergency physicians from two air rescue services (N = 80), the cortisol awakening response (CAR) was determined on flight rescue days, clinic days, and days off. Pearson correlations showed significant connections between the CAR on flight rescue days and individual scales of the Trier Inventory for Chronic Stress (TICS) and the Perceived Stress Scale (PSS). The results indicate that a lower subjective stress level is associated with higher levels of hormonal stress. Stepwise regression analyses showed a significant influence of the number of professional years, subjectively perceived stress, pressure to succeed, and social isolation. The results suggest that the hormonal stress burden of emergency physicians is in a complex relationship with perceived strain.

Emergency front of neck access in children: a new learning approach in a rabbit model.

BACKGROUND: Cannot intubate-cannot ventilate situations in healthy children are uncommon but are often associated with poor outcome. Several airway management algorithms suggest emergency tracheal access. Little agreement exists on how to perform emergency front of the neck access (eFONA) in children <8 yr. We studied the learning curves of clinicians performing simulated paediatric eFONA. METHODS: After watching an instructional video, 50 physicians, from five medical specialties, performed 10 emergency tracheotomies on rabbit cadavers. We analysed their learning curves relative to performance time and concurring injuries. RESULTS: With an overall success rate of 94%, performance time decreased from 107 s (standard deviation [sd], 45) to 55 s (sd 17) over 10 attempts. The learning curve was steep between the first and the fourth attempts with an 11% decrease in performance time (95% confidence interval [CI], 9-13%; P<0.001) per attempt and then flattened to a 4% (95% CI, 3-5%; P<0.001) decrease per attempt between the fourth and the tenth attempt. Age, years of clinical experience, and sex showed a significant effect on the learning curve, whereas medical specialty and adult eFONA experience did not. The 58% (95% CI, 44-72%) probability for severe injury during the first attempt decreased to 14% (95% CI, 8-20%) at the second attempt. Men were more likely to cause minor injuries than women (P<0.001). CONCLUSIONS: Irrespective of medical specialty, paediatric clinicians acquired the eFONA technique within four attempts and were on average able to establish an airway in <1 min when performing emergency tracheotomy on a paediatric airway simulator. CLINICAL TRIAL REGISTRATION: NCT03576352.

The skill of tracheal intubation with rigid scopes - a randomised controlled trial comparing learning curves in 740 intubations.

BACKGROUND: Rigid scopes are successfully used for management of difficult airways, but learning curves have not been established. METHODS: This randomised controlled trial was performed at the University Hospital Bern in Switzerland to establish learning curves for the rigid scopes Bonfils and SensaScope and to assess their performance. Fifteen consultant anaesthetists and 15 anaesthesia registrars performed a total of 740 intubations (10 to 20 intubations with each device per physician) in adult patients without predictors of a difficult airway under general anaesthesia. According to randomisation, physicians intubated the patient's trachea with either the Bonfils or the SensaScope. A maximum of three intubation attempts was allowed. Primary outcome was overall time to successful intubation. Secondary outcome parameters included first attempt success, first attempt success within 60 s, failures and adverse events. RESULTS: A clear learning effect was demonstrated: Over 20 trials, intubations became 2.5-times quicker and first attempt intubation success probability increased by 21-28 percentage points. Fourteen and 20 trials were needed with the Bonfils and the SensaScope, respectively, to reach a 90% first attempt success probability. Intubation times were 23% longer (geometric mean ratio 1.23, 95% confidence interval 1.12-1.36, p < 0.001) and first attempt success was less likely (odds ratio 0.64, 95% confidence interval 0.45-0.92, p = 0.016) with the SensaScope. Consultants showed a tendency for a better first attempt success compared to registrars. Overall, 23 intubations (10 Bonfils, 13 SensaScope) failed. Adverse events were rare and did not differ between devices. CONCLUSIONS: A clear learning effect was demonstrated for both rigid scopes. Fourteen intubations with the Bonfils and 20 intubations with the SensaScope were required to reach a 90% first attempt success probability. Learning of the technique seemed more complex with the SensaScope compared to the Bonfils. TRIAL REGISTRATION: Current Controlled Trials, ISRCTN14429285 . Registered 28 September 2011, retrospectively registered.

Pre-induction checklists and discomfort in patients. An observational study.

BACKGROUND: Since the WHO release of the Safe Surgery Saves Lives Program in 2008, peri-operative checklists minimise errors and improve patient safety worldwide. Anaesthesia professionals are often reluctant to use these checklists in front of patients because they fear causing patients' discomfort before anaesthesia and surgery. OBJECTIVE: To assess and compare the subjective level of patient discomfort caused by the use of pre-induction checklists with the patient discomfort estimated by anaesthesia providers. DESIGN: Prospective observational study. SETTING: The current single-centre trial included 110 anaesthesia providers and 125 nonpremedicated ear, nose and throat or maxillofacial surgery patients in Switzerland from June to August 2016. Inclusion criterion: signed general research consent. EXCLUSION CRITERIA: received premedication, less than 18 years old, day-care patients, dementia or other mental illnesses. INTERVENTIONS: Anaesthesia healthcare providers and patients before surgery and on the first postoperative day were asked to rate three statements: MAIN OUTCOME MEASURES: All statements were rated on a 100-mm visual analogue scale, where 0 meant no agreement and 100 meant total agreement. RESULTS: Patients overwhelmingly agreed that anaesthesia providers should use checklists in front of them. Anaesthesia providers rated the patient discomfort much higher than actually perceived by patients. Both, patients and anaesthesia providers rated the possibility of reducing the risk of errors high. CONCLUSION: Patients experience far less discomfort observing the use of pre-induction checklists than anaesthesia providers expect. Patients value the potential safety benefit significantly higher than anaesthesia providers. These results further support the implementation of peri-operative checklists in the operating room environment. TRIAL REGISTRATION: The current observational study had no intervention, therefore, was not registered.

Dislocation rates of postoperative airway exchange catheters - a prospective case series of 200 patients.

BACKGROUND: The dislocation rate of oral versus nasal airway exchange catheters (AEC) in the postoperative care unit (PACU) are unknown. Our aim was to establish dislocation rates and to assess the usefulness of waveform capnography to detect dislocation. METHODS: In this non-randomized, prospective observational trial at the University Hospital Bern, Switzerland, we included 200 patients admitted to PACU after extubation via AEC, having provided written informed consent. The study was approved by the local ethical committee. AEC position was assessed by nasal fiberoptic endoscopy at beginning of PACU stay and before removal of the AEC. Capnography was continuously recorded via the AEC. Additional measurements included retching and coughing of the patient, and re-intubation, if necessary. RESULTS: Data from 182 patients could be evaluated regarding dislocation. Overall dislocation rate was not different between oral and nasal catheters (7.2% vs. 2.7%, p = 0.16). Retching was more often noted in oral catheters (26% vs. 8%, p < 0.01). Waveform capnography was unreliable in predicting dislocation (negative predictive value 17%). Re-intubation was successful in all five of the nine re-intubations where an AEC was still in situ. In four patients, the AEC was already removed when re-intubation became necessary, and re-intubation failed once, with a front of neck access as a rescue maneuver. CONCLUSIONS: We found no difference in dislocation rate between nasal and oral position of an airway exchange catheter. However, nasal catheters seemed to be tolerated better. In the future, catheters like the staged extubation catheter may further increase tolerance. TRIAL REGISTRATION: The study was registered in a clinical study registry ( ISRCTN 96726807 ) on 10/06/2010.

Limitations of pediatric supraglottic airway devices as conduits for intubation - an in vitro study.

PURPOSE: Supraglottic airway devices (SGAs) can be used as conduits for intubation, but data and manufacturers' recommendations for pediatric SGA are incomplete and sometimes misleading. This situation can result in the use of incompatible combinations of SGAs and endotracheal tubes (ETTs). To address this mismatch possibility, we performed an in vitro study to establish an overview of possible combinations of SGAs and ETTs. METHODS: We tested the passage of ETTs through SGAs in vitro and subsequent SGA removal with eight pediatric SGAs and six ETTs of different sizes in vitro. Results were compared with manufacturers' recommendations. Outcome parameters were the feasibility of passing the ETT through the SGA and then removing the SGA over the ETT. RESULTS: The Air-Q® and the Air-Q®sp™ SGAs showed the best compatibility with ETTs across all sizes. Whenever intubation was possible, removal was possible for all SGAs with uncuffed ETTs. With many cuffed ETTs, however, SGA removal was impossible because the ETT cuff's pilot balloon was larger than the inner diameter of the SGA. Thus, although intubation was possible, removal of the SGA was not. The manufacturers' booklets do not warn of this limitation. CONCLUSIONS: The use of combinations of SGA and ETTs with a size mismatch can lead to airway complications during intubation or to accidental extubation and tearing of the cuff pilot balloon line when removing the SGA. To avoid these problems, we devised a table that simplifies the choice of an appropriate SGA and ETT combination.

Pediatric supraglottic airway devices in clinical practice: A prospective observational study.

BACKGROUND: Supraglottic airway devices (SGA) are commonly used in pediatric anesthesia and serve as primary or back-up devices for difficult airway management. Most SGA are marketed without proper clinical evaluation. The purpose of this study was to evaluate the performance of the pediatric LMA Supreme™, Air-Q® and Ambu® Aura-i™. METHODS: This prospective observational study was performed at Bern University Hospital, Switzerland. With ethics committee approval and a waiver for written informed consent 240 children undergoing elective surgery with an ASA class I-III and a weight of 5-30 kg were included. Three different pediatric supraglottic airway devices were assessed: The LMA Supreme™, Air-Q® and Ambu® Aura-i™. Primary outcome parameter was airway leak pressure. Secondary outcome parameters included first attempt and overall success rate, insertion time, fiberoptic view through the SGA, and adverse events. The primary hypothesis was that the mean airway leak pressure of each tested SGA was 20 cmH2O ± 10%. RESULTS: None of the SGA showed a mean airway leak pressure of 20 cmH2O ± 10%, but mean airway leak pressures differed significantly between devices [LMA Supreme™ 18.0 (3.4) cmH2O, Air-Q® 15.9 (3.2) cmH2O, Ambu® Aura-i™ 17.3 (3.7) cmH2O, p < 0.001]. First attempt success rates (LMA Supreme™ 100%, Air-Q® 90%, Ambu® Aura-i™ 91%, p = 0.02) and overall success rates (LMA Supreme™ 100%, Air-Q® 91%, Ambu® Aura-i™ 95%, p = 0.02) also differed significantly. Insertion times ranged from 20 (7) seconds (Air-Q®) to 24 (6) seconds (LMA Supreme™,

Loss of resistance: A randomised controlled trial assessing four low-fidelity epidural puncture simulators.

BACKGROUND: Detecting loss of resistance (LOR) can either be taught with dedicated simulators, with a cost ranging from &OV0556;1500 to 3000, or with the 'Greengrocer's Model', requiring simply a banana. OBJECTIVES: The purpose of this study was to compare three dedicated epidural puncture training simulators and a banana in their ability to simulate LOR. Our hypothesis was that there was a difference between the four simulators when comparing the detection of LOR. DESIGN: Single-blinded, randomised, controlled study. SETTING: Department of Anaesthesiology and Pain Therapy, Bern University Hospital, Switzerland. PARTICIPANTS: Fifty-five consultant anaesthesiologists. INTERVENTIONS: The participants were asked to insert an epidural catheter in four different epidural puncture training simulators: Lumbar Puncture Simulator II (Kyoto Kagaku, Kyoto, Japan), Lumbar Epidural Injection Trainer (Erler-Zimmer, Lauf, Germany), Normal Adult Lumbar Puncture/Epidural Tissue (Simulab Corp., Seattle, Washington, USA) and a banana. The simulators were placed in identical boxes to blind the participants. MAIN OUTCOME MEASURES: The primary outcome was the detection of LOR rated on a 100-mm visual analogue scale, in which 0 mm represented 'completely unrealistic' and 100 mm represented 'indistinguishable from a real patient'. RESULTS: The mean visual analogue scale scores for LOR in the four simulators were significantly different: 60 ±â€Š25 mm [95% confidence interval (CI), 55 to 65 mm], 50 ±â€Š29 mm (95% CI, 44 to 55 mm), 64 ±â€Š24 mm (95% CI, 58 to 69 mm) and 49 ±â€Š32 mm (95% CI, 44 to 54 mm); P less than 0.001, Friedman test. CONCLUSION: Two of the three dedicated epidural simulators were rated more realistic in detecting LOR than the banana, but some participants preferred the banana to the other three simulators. Given the relative cost of a banana compared with a dedicated simulator, we suggest that a banana be used to teach the technique of LOR for epidural puncture. TRIAL REGISTRATION: KEK Nr: Req-2015-z087.

High-flow nasal cannula therapy and apnea time in laryngeal surgery.

In small children, high-flow nasal cannula therapy may prolong apnea time even when an inspiratory oxygen fraction below 100% is used. This will be beneficial in prolonged intubation attempts, but especially during procedures requiring prolonged apnea time, leading to fewer airway manipulations and markedly enhanced surgical conditions.

Intravenous Delta-9-Tetrahydrocannabinol to Prevent Postoperative Nausea and Vomiting: A Randomized Controlled Trial.

BACKGROUND: Evidence suggests that cannabinoids can prevent chemotherapy-induced nausea and vomiting. The use of tetrahydrocannabinol (THC) has also been suggested for the prevention of postoperative nausea and vomiting (PONV), but evidence is very limited and inconclusive. To evaluate the effectiveness of IV THC in the prevention of PONV, we performed this double-blind, randomized, placebo-controlled trial with patient stratification according to the risk of PONV. Our hypothesis was that THC would reduce the relative risk of PONV by 25% compared with placebo. METHODS: With IRB approval and written informed consent, 40 patients at high risk for PONV received either 0.125 mg/kg IV THC or placebo at the end of surgery before emergence from anesthesia. The primary outcome parameter was PONV during the first 24 hours after emergence. Secondary outcome parameters included early and late nausea, emetic episodes and PONV, and side effects such as sedation or psychotropic alterations. RESULTS: The relative risk reduction of overall PONV in the THC group was 12% (95% confidence interval, -37% to 43%), potentially less than the clinically significant 25% relative risk reduction demonstrated by other drugs used for PONV prophylaxis. Calculation of the effect of treatment group on overall PONV by logistic regression adjusted for anesthesia time gave an odds ratio of 0.97 (95% confidence interval, 0.21 to 4.43, P = 0.97). Psychotropic THC side effects were clinically relevant and mainly consisted of sedation and confusion that were not tampered by the effects of anesthesia. The study was discontinued after 40 patients because of the inefficacy of THC against PONV and the finding of clinically unacceptable side effects that would impede the use of THC in the studied setting. CONCLUSIONS: Because of an unacceptable side effect profile and uncertain antiemetic effects, IV THC administered at the end of surgery before emergence from anesthesia cannot be recommended for the prevention of PONV in high-risk patients.

Blind intubation of anaesthetised children with supraglottic airway devices AmbuAura-i and Air-Q cannot be recommended: A randomised controlled trial.

BACKGROUND: Paediatric supraglottic airway devices AmbuAura-i and Air-Q were designed as conduits for tracheal intubation. Although fibreoptic-guided intubation has proved successful, blind intubation as a rescue technique has never been evaluated. OBJECTIVE: Evaluation of blind intubation through AmbuAura-i and Air-Q. On the basis of fibreoptic view data, we hypothesised that the success rate with the AmbuAura-i would be higher than with the Air-Q. DESIGN: A randomised controlled trial. SETTING: University Childrens' Hospital; September 2012 to July 2014. PATIENTS: Eighty children, American Society of Anesthesiologists (ASA) class I to III, weight 5 to 50 kg. INTERVENTIONS: Tracheal intubation was performed through the randomised device with the tip of a fibrescope placed inside and proximal to the tip of the tracheal tube. This permitted sight of tube advancement, but without fibreoptic guidance (visualised blind intubation). MAIN OUTCOME MEASURES: Primary outcome was successfully visualised blind intubation; secondary outcomes included supraglottic airway device success, insertion times, airway leak pressure, fibreoptic view and adverse events. RESULTS: Personal data did not differ between groups. In contrast to our hypothesis, blind intubation was possible in 15% with the Air-Q and in 3% with the AmbuAura-i [95% confidence interval (95% CI) 6 to 31 vs. 0 to 13%; P = 0.057]. First attempt supraglottic airway device insertion success rates were 95% (Air-Q) and 100% (AmbuAura-i; 95% CI 83 to 99 vs. 91 to 100; P = 0.49). Median leak pressures were 18 cmH2O (Air-Q) and 17 cmH2O [AmbuAura-i; interquartile range (IQR) 14 to 18 vs. 14 to 19 cmH2O; P = 0.66]. Air-Q insertion was slower (27 vs. 19 s, P < 0.001). There was no difference in fibreoptic view, or adverse events (P > 0.05). In one child (Air-Q size 1.5, tube size 3.5), the tube dislocated during device removal. CONCLUSION: Ventilation with both devices is reliable, but success of blind intubation is unacceptably low and cannot be recommended for elective or rescue purposes. If intubation through a paediatric supraglottic airway device is desired, we suggest that fibreoptic guidance is used. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT01692522.

Propofol sedation in routine endoscopy: A case series comparing target controlled infusion vs manually controlled bolus concept.

BACKGROUND: Many studies have addressed safety and effectiveness of non-anaesthesiologist propofol sedation (NAPS) for gastrointestinal (GI) endoscopy Target controlled infusion (TCI) is claimed to provide an optimal sedation regimen by avoiding under- or oversedation. AIM: To assess safety and performance of propofol TCI sedation in comparison with nurse-administered bolus-sedation. METHODS: Fouty-five patients undergoing endoscopy under TCI propofol sedation were prospectively included from November 2016 to May 2017 and compared to 87 patients retrospectively included that underwent endoscopy with NAPS. Patients were matched for age and endoscopic procedure. We recorded time of sedation and endoscopy, dosage of medication and adverse events. RESULTS: There was a significant reduction in dose per time of propofol administered in the TCI group, compared to the NAPS group (8.2 ± 2.7 mg/min vs 9.3 ± 3.4 mg/min; P = 0.046). The time needed to provide adequate sedation levels was slightly but significantly lower in the control group (5.3 ± 2.7 min vs 7.7 ± 3.3 min; P < 0.001), nonetheless the total endoscopy time was similar in both groups. No differences between TCI and bolus-sedation was observed for mean total-dosage of propofol rate as well as adverse events. CONCLUSION: This study indicates that sedation using TCI for GI endoscopy reduces the dose of propofol necessary per minute of endoscopy. This may translate into less adverse events. However, further and randomized trials need to confirm this trend.