Does individual experience affect performance during cardiopulmonary resuscitation with additional external distractors?

Cardiopulmonary resuscitation is perceived as a stressful task. Additional external distractors, such as noise and bystanders, may interfere with crucial tasks and might adversely influence patient outcome. We investigated the effects of external distractors on resuscitation performance of anaesthesia residents and consultants with different levels of experience. Thirty physicians performed two simulated resuscitation scenarios in random order, one scenario without additional distractors (control) and one scenario with additional distractors (noise, scripted family member). Resuscitation performance was assessed by a score based on European Resuscitation Council guidelines, presented as median (IQR [range]). We found that performance scores were lower under experimental conditions (11.8 (9.0-19.5 [-9.0 to 28.5]) than under control conditions 19.5 (14.0-25.5 [5.0-29.5]), p = 0.0002). No interaction was observed between additional distractors and experience level (p = 0.4480). External distractors markedly reduce the quality of cardiopulmonary resuscitation. This suggests that all team members, including senior healthcare providers, require training to improve performance under stressful conditions.

The effect of audible alarms on anaesthesiologists' response times to adverse events in a simulated anaesthesia environment: a randomised trial.

Alarms are ubiquitous in anaesthetic practice, but their net effect on anaesthesiologists' performance and patient safety is debated. In this study, 27 anaesthesiologists performed two simulation sessions in random order; one session was programmed to include an alarm condition, with a standard, frequent, clearly audible alarm sound. During these sessions, adverse events were simulated and anaesthesiologists' response times to these events were recorded. Perceived workload was assessed with the NASA Task Load Index. Response times to adverse events and perceived workload were similar in both groups. Pooled response times to atrial fibrillation and desaturation were fast, with a median (range [IQR]) of 8 (4-14 [1-41]) s and 9 (6-16 [1-44]) s, respectively. Pooled response times to an ST segment elevation on the ECG and an obstructed intravenous line were significantly slower, with median (IQR[range]) times of 34 (21-76[4-300]) s and 227 (95-399 [2-600]) s, respectively (p < 0.001). This study shows that in a simulated anaesthesia environment, response times to adverse events are similar in the absence or presence of an audible alarm, and that response times to various critical events differ.

Application of current guidelines for chest compression depth on different surfaces and using feedback devices: a randomized cross-over study.

BACKGROUND: Current cardiopulmonary resuscitation (CPR)-guidelines recommend an increased chest compression depth and rate compared to previous guidelines, and the use of automatic feedback devices is encouraged. However, it is unclear whether this compression depth can be maintained at an increased frequency. Moreover, the underlying surface may influence accuracy of feedback devices. We investigated compression depths over time and evaluated the accuracy of a feedback device on different surfaces. METHODS: Twenty-four volunteers performed four two-minute blocks of CPR targeting at current guideline recommendations on different surfaces (floor, mattress, 2 backboards) on a patient simulator. Participants rested for 2 minutes between blocks. Influences of time and different surfaces on chest compression depth (ANOVA, mean [95% CI]) and accuracy of a feedback device to determine compression depth (Bland-Altman) were assessed. RESULTS: Mean compression depth did not reach recommended depth and decreased over time during all blocks (first block: from 42 mm [39-46 mm] to 39 mm [37-42 mm]). A two-minute resting period was insufficient to restore compression depth to baseline. No differences in compression depth were observed on different surfaces. The feedback device slightly underestimated compression depth on the floor (bias -3.9 mm), but markedly overestimated on the mattress (bias +12.6 mm). This overestimation was eliminated after correcting compression depth by a second sensor between manikin and mattress. CONCLUSION: Strategies are needed to improve chest compression depth, and more than two providers should alternate with chest compressions. The underlying surface does not necessarily adversely affect CPR performance but influences accuracy of feedback devices. Accuracy is improved by a second, posterior, sensor.

Tracheal intubation with a camera embedded in the tube tip (Vivasight(™) ).

We studied tracheal intubation in manikins and patients with a camera embedded in the tip of the tracheal tube (Vivasight(™) ). Four people in two teams and two individuals attempted intubation of a manikin through an i-gel(™) 10 times each. The tracheas of 12 patients with a Mallampati grade of 1 were intubated with a Vivasight tracheal tube through a Berman airway, passed over a Frova(™) introducer. All 60 manikin intubations were successful, taking a mean (SD) time of 1.4 (0.5) s. The fastest intubation was performed in 0.5 s. All 12 participants' tracheas were successfully intubated in a median (IQR [range]) time of 90 (70-120 [50-210]) s. Seven participants complained of a sore throat, comparable with earlier findings for standard laryngoscopy and intubation: five mild; one moderate; and one severe. Tracheal intubation with the Vivasight through the i-gel or Berman airway is an alternative to existing techniques, against which it should be compared in randomised controlled trials in human participants. It has potential as a fast airway rescue technique.

Cormack-Lehane classification revisited.

BACKGROUND: The Cormack-Lehane (CL) classification is broadly used to describe laryngeal view during direct laryngoscopy. This classification, however, has been validated by only a few studies reporting inconclusive data concerning its reliability. This discrepancy between widespread use and limited evidence prompted us to investigate the knowledge about the classification among anaesthesiologists and its intra- and inter-observer reliability. METHODS: One hundred and twenty interviews were performed at a major European anaesthesia congress. Participants were interviewed about their general knowledge on grading systems to classify laryngeal view during laryngoscopy and were subsequently asked to define the grades of the CL classification. Inter- and intra-observer reliabilities were tested in 20 anaesthesiologists well familiar with the CL classification, who performed 100 laryngoscopies in a full-scale patient simulator. RESULTS: Although 89% of interviewed subjects claimed to know a classification to describe laryngeal view during laryngoscopy, 53% were able to name a classification. When specifically asked about the CL classification, 74% of the interviewed subjects stated to know this classification, whereas 25% could define all four grades correctly. In the simulator-based part of the study, inter-observer reliability was fair with a kappa coefficient of 0.35 and intra-observer reliability was poor with a kappa of 0.15. CONCLUSIONS: The CL classification is poorly known in detail among anaesthesiologists and reproducibility even in subjects well familiar with this classification is limited.