The number of comorbidities as an important cofactor to ASA class in predicting postoperative outcome: An international multicentre cohort study.

BACKGROUND: Multimorbidity is a growing burden in our ageing society and is associated with perioperative morbidity and mortality. Despite several modifications to the ASA physical status classification, multimorbidity as such is still not considered. Thus, the aim of this study was to quantify the burden of comorbidities in perioperative patients and to assess, independent of ASA class, its potential influence on perioperative outcome. METHODS: In a subpopulation of the prospective ClassIntra® validation study from eight international centres, type and severity of anaesthesia-relevant comorbidities were additionally extracted from electronic medical records for the current study. Patients from the validation study were of all ages, undergoing any type of in-hospital surgery and were followed up until 30 days postoperatively to assess perioperative outcomes. Primary endpoint was the number of comorbidities across ASA classes. The associated postoperative length of hospital stay (pLOS) and Comprehensive Complication Index (CCI®) were secondary endpoints. On a scale from 0 (no complication) to 100 (death) the CCI® measures the severity of postoperative morbidity as a weighted sum of all postoperative complications. RESULTS: Of 1421 enrolled patients, the mean number of comorbidities significantly increased from 1.5 in ASA I (95% CI, 1.1-1.9) to 10.5 in ASA IV (95% CI, 8.3-12.7) patients. Furthermore, independent of ASA class, postoperative complications measured by the CCI® increased per each comorbidity by 0.81 (95% CI, 0.40-1.23) and so did pLOS (geometric mean ratio, 1.03; 95% CI, 1.01-1.06). CONCLUSIONS: These data quantify the high prevalence of multimorbidity in the surgical population and show that the number of comorbidities is predictive of negative postoperative outcomes, independent of ASA class.

Oropharyngeal leak pressure of the LMA Protector™ vs the LMA Supreme™; a prospective, randomized, controlled clinical trial.

BACKGROUND: Clinical characteristics such as oropharyngeal leak pressure (OLP) and ventilation peak pressure are important factors for successful use of supraglottic airway devices in general anaesthesia. We hypothesized that the LMA Protector™ compared to the LMA Supreme™ may develop a higher OLP, which could be of clinical significance. METHODS: Ninety-six patients were randomized to the LMA Protector™ or LMA Supreme™ groups. We measured oropharyngeal leak pressure within 5 minutes after insertion of the supraglottic airway device with a standardized cuff pressure at 60 cm H2 O. Secondary parameters, such as insertion time of the supraglottic airway device, the number of attempts inserting the supraglottic airway device and the gastric tube, volume of gastric contents, and maximum airway pressure, as well as pulse oximetry throughout the operation were measured. Further, blood staining after removal of the supraglottic airway device and postoperative airway morbidity 3 hours after surgery were determined. RESULTS: The mean difference of oropharyngeal leak pressure was 5.2 (95% CI 2.8-7.6), ie, 30.9 (7.4) cmH2 O for the LMA Protector™ vs 25.6 (4.4) cmH2 O for the LMA Supreme™ (P < 0.001; mean(SD)). Similarly, there was a mean difference between OLP and maximal ventilation peak pressure 5.6 (95% CI 3.1-8.2) ie 19.6 (7.7) cmH2 O for the LMA Protector™ vs 14.0 (4.4) cmH2 O for the LMA Supreme™ (P < 0.001). No difference was found between the groups for other secondary parameters, as well as postoperative airway morbidity. CONCLUSION: The LMA Protector™ enabled a higher OLP compared to the LMA Supreme™. This finding may be important for patients requiring a higher peak pressure for sufficient supraglottic airway device ventilation.

Fiberoptic intubation of severely obese patients through supraglottic airway: A prospective, randomized trial of the Ambu® AuraGain™ laryngeal mask vs the i-gel™ airway.

INTRODUCTION: Airway management in severely obese patients remains a challenging issue for anaesthetists and may lead to life-threatening situations. Supraglottic airway devices, such as the i-gel™ or the AuraGain™, were developed, with the possibility to ventilate the patient or use them as a conduit for endotracheal intubation. METHODS: In our randomized prospective trial, we hypothesized a 10 seconds faster fiberoptic trans-device intubation time through the AuraGain™ laryngeal mask compared to the i-gel™ laryngeal mask in severely obese patients. We randomly assigned 44 patients to the AuraGain or i-gel group and measured trans-device intubation time after 5 minutes of successful ventilation through the device. Secondary parameters relating to the trans-device intubation success, oropharyngeal leak pressure, and parameters regarding insertion of the supraglottic airway devices were measured. Postoperative airway morbidity was determined 5 hours after surgery. RESULTS: Mean (SD) intubation time was 55.7 (5.8) seconds for the AuraGain™ vs 54.1 (8.5) for i-gel™ mask (95% CI -2.7 to 5.9; P = 0.474), respectively, on a mean body mass index (BMI) of 39.4 kg/m2 in the AuraGain™ group vs 38.9 kg/m2 in i-gel™ group. No difference could be found in the other studied parameters. CONCLUSIONS: Time for intubation through both supraglottic airway devices was similar. Attributed to fast possibility of securing the airway with both supraglottic airway devices, we believe that both, AuraGain™ and i-gel™, can be a good alternative in the airway management in obese patients.

Flexible bronchoscopic intubation through the AuraGain™ laryngeal mask versus a slit Guedel tube: a non-inferiority randomized-controlled trial.

PURPOSE: AuraGainTM, a novel third-generation laryngeal mask, can facilitate insertion of a gastric tube and provide the potential advantage of intubation. Data are lacking on intubation through the AuraGain laryngeal mask. METHODS: Eighty-eight hip or knee surgery patients were enrolled in this parallel randomized-controlled trial. We hypothesized that intubation time using the AuraGain laryngeal mask would be no longer than that for standard flexible bronchoscopic intubation over a slit Guedel tube, with a non-inferiority margin of five seconds. The following data were recorded during a maximum of three intubation attempts: intubation time, number of intubation attempts, degree of resistance to advance the endotracheal tube, and mask placement (i.e., Brimacombe score). Follow-up outcomes, including neck pain, hoarseness, and dysphagia, were also measured two and 24 hr postoperatively. Patients and outcome assessors remained blinded until the last examination. RESULTS: Mean intubation time was similar between the Guedel tube and AuraGain groups (23.6 sec vs 21.4 sec, respectively). The upper limit of the 95% confidence interval (CI) of the difference in mean intubation time between groups fell below our pre-specified non-inferiority margin; therefore, we found the AuraGain laryngeal mask to be non-inferior to the slit Guedel tube (adjusted group difference, -1.6 sec; 95% CI, -3.7 to 0.5). Successful intubation was achieved in the majority of patients (≥ 95%) in each group on the first attempt. No resistance to insertion of the endotracheal tube was encountered in the majority of patients in each group, and no complications were reported during the 24-hr postoperative period. There was no difference in the Brimacombe score or in the status of postoperative morbidity between the two groups. CONCLUSION: We conclude that flexible bronchoscopic intubation through an AuraGain laryngeal mask can be achieved at least as fast as standard bronchoscopic intubation without contributing to additional patient morbidity or postoperative discomfort. TRIAL REGISTRATION: www.clinicaltrials.gov , NCT 02570269. Registered 23 September 2015.

Transfer of skills and comparison of performance between king vision® video laryngoscope and macintosh blade following an AHA airway management course.

BACKGROUND: To potentially optimize intubation skill teaching in an American Heart Association® Airway Management Course® for novices, we investigated the transfer of skills from video laryngoscopy to direct laryngoscopy and vice versa using King Vision® and Macintosh blade laryngoscopes respectively. METHODS: Ninety volunteers (medical students, residents and staff physicians) without prior intubation experience were randomized into three groups to receive intubation training with either King Vision® or Macintosh blade or both. Afterwards they attempted intubation on two human cadavers with both tools. The primary outcome was skill transfer from video laryngoscopy to direct laryngoscopy assessed by first attempt success rates within 60 s. Secondary outcomes were skill transfer in the opposite direction, the efficacy of teaching both tools, and the success rates and esophageal intubation rates of Macintosh blade versus King Vision®. RESULTS: Performance with the Macintosh blade was identical following training with either Macintosh blade or King Vision® (unadjusted odds ratio [OR] 1.09, 95% confidence interval [95% CI] 0.5-2.6). Performance with the King Vision® was significantly better in the group that was trained on it (OR 2.7, 95% CI 1.2-5.9). Success rate within 60 s with Macintosh blade was 48% compared to 52% with King Vision® (OR 0.85, 95% CI 0.4-2.0). Rate of esophageal intubations with Macintosh blade was significantly higher (17% versus 4%, OR 5.0, 95% CI 1.1-23). CONCLUSIONS: We found better skill transfer from King Vision® to Macintosh blade than vice versa and fewer esophageal intubations with video laryngoscopy. For global skill improvement in an airway management course for novices, teaching only video laryngoscopy may be sufficient. However, success rates were low for both devices.

Looking in the mirror: self-debriefing versus instructor debriefing for simulated crises.

OBJECTIVE: To examine the effectiveness of self-debriefing as compared to instructor debriefing in the change of nontechnical skills performance of anesthesiology residents. DESIGN: Prospective, randomized, controlled study. SETTING: A university hospital simulation center. SUBJECTS: : Fifty anesthesiology residents. INTERVENTIONS: Subjects were instructed in the principles of nontechnical skills for crisis management. Subsequently, each resident participated in a high-fidelity simulated anesthesia crisis scenario (pretest). Participants were randomized to either a video-assisted self-debriefing or instructor debriefing. In the self-debriefing group, subjects reviewed their pretest scenario by themselves, guided by the Anesthetists' Non-Technical Skills scale. The instructor debriefing group reviewed their pretest scenario guided by an expert instructor also using the Anesthetists' Non-Technical Skills scale as a framework. Immediately following their respective debriefings, subjects managed a second simulated crisis (post-test). MEASUREMENTS AND MAIN RESULTS: After all data were collected, two blinded experts independently rated videos of all performances in a random order using the Anesthetists' Non-Technical Skills scale. Performance significantly improved from pretest to post-test (p < .01) regardless of the type of debriefing received. There was no significant difference in the degree of improvement between self-debriefing and instructor debriefing (p = .58). CONCLUSIONS: Nontechnical skills for crisis resource management improved with training, as measured by the Anesthetists' Non-Technical Skills scale. Crisis resource management can be taught, with measurable improvements. Effective teaching of nontechnical skills can be achieved through formative self-assessment even when instructors are not available.

Simulation-based training improves physicians' performance in patient care in high-stakes clinical setting of cardiac surgery.

BACKGROUND: Simulation-based training is useful in improving physicians' skills. However, no randomized controlled trials have been able to demonstrate the effects of simulation teaching in real-life patient care. This study aimed to determine whether simulation-based training or an interactive seminar resulted in better patient care during weaning from cardiopulmonary bypass (CPB)-a high stakes clinical setting. METHODS: This study was conducted as a prospective, single-blinded, randomized controlled trial. After institutional research board approval, 20 anesthesiology trainees, postgraduate year 4 or higher, inexperienced in CPB weaning, and 60 patients scheduled for elective coronary artery bypass grafting were recruited. Each trainee received a teaching syllabus for CPB weaning 1 week before attempting to wean a patient from CPB (pretest). One week later, each trainee received a 2-h training session with either high-fidelity simulation-based training or a 2-h interactive seminar. Each trainee then weaned patients from CPB within 2 weeks (posttest) and 5 weeks (retention test) from the intervention. Clinical performance was measured using the validated Anesthesiologists' Nontechnical Skills Global Rating Scale and a checklist of expected clinical actions. RESULTS: Pretest Global Rating Scale and checklist performances were similar. The simulation group scored significantly higher than the seminar group at both posttest (Global Rating Scale [mean +/- standard error]: 14.3 +/- 0.41 vs. 11.8 +/- 0.41, P < 0.001; checklist: 89.9 +/- 3.0% vs. 75.4 +/- 3.0%, P = 0.003) and retention test (Global Rating Scale: 14.1 +/- 0.41 vs. 11.7 +/- 0.41, P < 0.001; checklist: 93.2 +/- 2.4% vs. 77.0 +/- 2.4%, P < 0.001). CONCLUSION: Skills required to wean a patient from CPB can be acquired through simulation-based training. Compared with traditional interactive seminars, simulation-based training leads to improved performance in patient care by senior trainees in anesthesiology.

High-fidelity simulation demonstrates the influence of anesthesiologists' age and years from residency on emergency cricothyroidotomy skills.

BACKGROUND: Age-related deterioration in both cognitive function and the capacity to control fine motor movements has been demonstrated in numerous studies. However, this decline has not been described with respect to complex clinical anesthesia skills. Cricothyroidotomy is an example of a complex, lifesaving procedure that requires competency in the domains of both cognitive processing and fine motor control. Proficiency in this skill is vital to minimize time to reestablish oxygenation during a "cannot intubate, cannot ventilate" scenario. In this prospective, controlled, single-blinded study, we tested the hypothesis that age affects the learning and performance of emergency percutaneous cricothyroidotomy in a high-fidelity simulated cannot intubate/cannot ventilate scenario. METHODS: Thirty-six staff anesthesiologists (19 aged younger than 45 years and 17 older than 45 years) managed a high-fidelity cannot intubate/cannot ventilate scenario in a high-fidelity simulator before and after a 1-hour standardized training session. The group division cutoff age of 45 years was based on the median age of our sample subject population before enrollment. The scenarios required the insertion of an emergency percutaneous cricothyroidotomy. We compared cricothyroidotomy skills in the older group with those in the younger group using procedural time, 5-point task-specific checklist score, and global rating scale score. Correlation based on age, years from residency, weekly clinical hours worked, previous continuing medical education in airway management, and previous simulation experience was also performed. RESULTS: In both prestandardization and poststandardization, age and years from residency correlated with procedural time, checklist scores, and global rating scores. Baseline, prestandardization variables were all better for the younger group, with a mean age of 37 years, compared with the older group, with a mean age of 58 years. Procedural time was 100 (72-128) seconds versus 152 (120-261) seconds. Checklist scores were 7.0 (6.1-8.0) versus 6.0 (4.8-8.0). Global rating scale scores were 22.0 (17.8-29.8) versus 17.5 (10.4-20.6). After the 1-hour standardized training session, the younger group continued to perform better than the older group with procedural time of 75 (66-91) seconds versus 87 (78-123) seconds, checklist scores of 10.0 (9.1-10.0) versus 9.0 (8.0-10.0), and global rating scale scores of 35.0 (32.1-35.0) versus 32.0 (29.0-33.8). Regression analysis was performed on the poststandardization data. Both age and years from residency independently affected procedural time, checklist scores, and global rating scale scores (all P < 0.05). CONCLUSIONS: Baseline proficiency with simulated emergency cricothyroidotomy is associated with age and years from residency. Despite standardized training, operator age and years from residency were associated with decreased proficiency. Further research should explore the potential of using age and years from residency as factors for implementing periodic continuing medical education.

Incomplete adherence to the ASA difficult airway algorithm is unchanged after a high-fidelity simulation session.

PURPOSE: Although guidelines for difficult airway management have been published, the extent to which consultant anesthesiologists follow these guidelines has not been determined. The purpose of this study is to observe how consultant anesthesiologists manage a "cannot intubate, cannot ventilate" (CICV) scenario in a high-fidelity simulator and to evaluate whether a simulation teaching session improves their adherence to the American Society of Anesthesiologists (ASA) difficult airway algorithm. METHODS: With Ethics Board approval and informed consent, all staff anesthesiologists in a single tertiary care institution were invited to enrol in this study where they managed a simulated unanticipated CICV scenario in a high-fidelity simulator. The scenario involved a patient with a difficult airway whose trachea could not be intubated and where it was impossible to ventilate the patient's lungs. Airway management options, including laryngeal mask airway, a fibreoptic bronchoscope, and a Glidescope were available for use but scripted to fail. A percutaneous cricothyroidotomy was required to re-establish adequate ventilation. Following the scenario, there was a personalized one-hour video-assisted expert debriefing focusing on the ASA difficult airway guidelines and "hands-on" cricothyroidotomy teaching. The second scenario followed immediately with an identical CICV scenario. The content to either scenario was not revealed beforehand. Outcome measures included: 1) major deviations from the ASA difficult airway guidelines; 2) time to start cricothyroidotomy; and 3) time to achieve ventilation. RESULTS: Thirty-eight anesthesiologists agreed to participate. The number of major deviations from the ASA algorithm was similar in the first and second sessions. These deviations included: multiple laryngoscopies (0 vs 2 pre-post; P = 0.49), use of fibreoptic bronchoscope (8 vs 7 pre-post; P = 1.0), bypass of laryngeal mask airway attempt (7 vs 13 pre-post; P = 0.19), and failure to call for anesthetic help (12 vs 8 pre-post; P = 0.43). However, more participants failed to call for surgical help in the second session (7 vs 16; P = 0.04). The times to start cricothyroidotomy and the times to achieve ventilation were significantly shorter in the second session (205.5 +/- 61.3 sec vs 179.7 +/- 65.1 sec; P = 0.01 and 356.9 +/- 117.2 sec vs 269.4 +/- 77.43 sec; P = 0.0002, respectively). CONCLUSION: No substantial changes in airway management in a CICV scenario were observed after an intense one-hour personalized video-assisted airway-focused simulation debriefing session with an expert. It appears that multiple factors other than airway algorithms come into play in emergency airway decision-making processes, including one's personal clinical experience with the many available airway devices.

Prospective validation of classification of intraoperative adverse events (ClassIntra): international, multicentre cohort study.

OBJECTIVE: To prospectively assess the construct and criterion validity of ClassIntra version 1.0, a newly developed classification for assessing intraoperative adverse events. DESIGN: International, multicentre cohort study. SETTING: 18 secondary and tertiary centres from 12 countries in Europe, Oceania, and North America. PARTICIPANTS: The cohort study included a representative sample of 2520 patients in hospital having any type of surgery, followed up until discharge. A follow-up to assess mortality at 30 days was performed in 2372 patients (94%). A survey was sent to a representative sample of 163 surgeons and anaesthetists from participating centres. MAIN OUTCOME MEASURES: Intraoperative complications were assessed according to ClassIntra. Postoperative complications were assessed daily until discharge from hospital with the Clavien-Dindo classification. The primary endpoint was construct validity by investigating the risk adjusted association between the most severe intraoperative and postoperative complications, measured in a multivariable hierarchical proportional odds model. For criterion validity, inter-rater reliability was evaluated in a survey of 10 fictitious case scenarios describing intraoperative complications. RESULTS: Of 2520 patients enrolled, 610 (24%) experienced at least one intraoperative adverse event and 838 (33%) at least one postoperative complication. Multivariable analysis showed a gradual increase in risk for a more severe postoperative complication with increasing grade of ClassIntra: ClassIntra grade I versus grade 0, odds ratio 0.99 (95% confidence interval 0.69 to 1.42); grade II versus grade 0, 1.39 (0.97 to 2.00); grade III versus grade 0, 2.62 (1.31 to 5.26); and grade IV versus grade 0, 3.81 (1.19 to 12.2). ClassIntra showed high criterion validity with an intraclass correlation coefficient of 0.76 (95% confidence interval 0.59 to 0.91) in the survey (response rate 83%). CONCLUSIONS: ClassIntra is the first prospectively validated classification for assessing intraoperative adverse events in a standardised way, linking them to postoperative complications with the well established Clavien-Dindo classification. ClassIntra can be incorporated into routine practice in perioperative surgical safety checklists, or used as a monitoring and outcome reporting tool for different surgical disciplines. Future studies should investigate whether the tool is useful to stratify patients to the appropriate postoperative care, to enhance the quality of surgical interventions, and to improve long term outcomes of surgical patients. TRIAL REGISTRATION: ClinicalTrials.gov NCT03009929.

A prospective, randomized trial of the Ambu AuraGain™ laryngeal mask versus the LMA® protector airway in paralyzed, anesthetized adult men.

BACKGROUND: We hypothesize that oropharyngeal leak pressures differ between the LMA® Protector™ and the AuraGain™, two novel supraglottic airway devices offering the possibility of intubation. METHODS: Ninety-eight male patients ASAI-II were randomly assigned to the AuraGainTM or ProtectorTM group. Oropharyngeal leak pressure was measured by incrementing cuff volume in 10 mL steps from 10 mL to 40 mL. The primary outcome was oropharyngeal leak pressure at 40 mL cuff volume. Secondary parameters such as transdevice intubation success, intubation time, the number of intubation attempts, and resistance during advancement of the endotracheal tube were determined. RESULTS: Mean (SD) oropharyngeal leak pressures at cuff volume of 40 mL was 30.1 (6) cmH2O for the AuraGainTM and 28.2 (7) cmH2O for the LMA ProtectorTM (P=0.142). The mean intracuff pressure for the AuraGainTM was 154 (41) cmH2O and 200 (43) cmH2O for the LMA Protector (P≤0.001). The number of attempts to insert the laryngeal mask was higher for the AuraGainTM group (P=0.002). Intubation time was lower in the AuraGainTM group (15.7 s vs. 18.5 s [ProtectorTM group]; P=0.004), and less resistance in advancing the tracheal tube through the AuraGainTM compared to LMA ProtectorTM device (P<0.001). There were no differences in fiberoptic placement of the endotracheal tube, the number of intubation attempts or postoperative morbidity between the groups. CONCLUSIONS: Because of the higher success rate in first time insertion of the laryngeal mask and the gastric tube, respectively, as well as the lower resistance to insertion of the endotracheal tube we conclude a possible easier handling of the AuraGainTM in anesthetized male patients.

Effect of continuous positive airway pressure on the measurement of thoracoabdominal asynchrony and minute ventilation in children anesthetized with sevoflurane and nitrous oxide.

STUDY OBJECTIVE: s: To quantify thoracoabdominal asynchrony (TAA) in children during anesthesia, and to measure the effect of continuous positive airway pressure (CPAP) on TAA, tidal volume (VT), and minute ventilation (E). DESIGN: Prospective, nonrandomized, controlled study. SETTING: Operating room of a university children's hospital. PARTICIPANTS: Ninety children aged 2 to 9 years scheduled for elective outpatient day surgery who were enrolled prospectively. METHODS: Each subject was anesthetized with sevoflurane 3% in equal parts O2 and N2O while breathing spontaneously through a facemask. Respiratory impedance plethysmography was used to calculate TAA indexes (phase angle [PA], phase relation in inspiration [PhRIB], phase relation in expiration, phase relation in total breath [PhRTB], and ratio of the inspiratory time to the total duration of the respiratory cycle [TI/TTOT]), VT, and E. Tidal gas flows were measured with a dual-hotwire anemometer with the sensor inserted between the facemask and the Y-piece of the anesthetic breathing circuit. This enabled the volume calibration of the respiratory impedance plethysmography equipment. The following conditions were compared: (1) no CPAP, (2) CPAP of 5 cm H2O, and (3) CPAP of 10 cm H2O. RESULTS: Eighty-one children completed the study protocol. All measurements of TAA with an inspiratory component (PA, PhRIB, PhRTB, and TI/TTOT) decreased significantly from baseline with the addition of CPAP to the circuit. Application of CPAP of 10 cm H2O decreased significantly mean VTs and Es compared with CPAP of 5 cm H2O and no CPAP. There were no differences in TAA for all conditions when comparing children scheduled for adenoidectomy with other surgical procedures. CONCLUSIONS: With spontaneously breathing anesthetized children, TAA decreases with the application of CPAP. CPAP of 5 cm H2O was as effective as CPAP of 10 cm H2O in reducing PA, PhRIB, PhRTB, and TI/TTOT. However, CPAP of 10 cm H2O also caused a significant decrease in VT and E.