Inattentional blindness in anesthesiology: A simulation study.

STUDY OBJECTIVES: Inattentional blindness is the psychological phenomenon of inability to see the unexpected even if it is in plain view. We hypothesized that anesthesiologists may overlook unexpected intraoperative events whereas medical students, lacking in intraoperative monitoring experience and knowledge, may be more likely to notice such events. DESIGN: A simulation study using a video of a simulated septic patient undergoing abdominal surgery. SETTING: A large academic center. PARTICIPANTS: 31 certified anesthesiologists and 46 upper-year medical students. INTERVENTIONS: None. Participants watched a video of a simulated surgery and scored the abnormalities they saw. MEASUREMENTS: These abnormalities included abnormal physiologic parameters consistent with the condition of the simulated septic patient, and two unexpected but plausible events: head movement and a leaky central line catheter. MAIN RESULTS: Students were significantly more likely than anesthesiologists to notice head movement (p<0.001).

Heliox vs air-oxygen mixtures for the treatment of patients with acute asthma: a systematic overview.

OBJECTIVE: To evaluate, by systematic review, the efficacy of heliox on respiratory mechanics and outcomes in patients with acute asthma. METHODS: The search strategy included searching electronic databases (MEDLINE, EMBASE, and The Cochrane Library) and the references of relevant articles. Study quality was assessed based on allocation concealment. Randomized controlled trials (RCTs) comparing heliox to an air-oxygen mixture (airO(2)) as an adjunct treatment in patients with acute asthmatic attacks were analyzed. For the qualitative portion of the analysis, all reports of the use of heliox in patients with acute asthma were included. RESULTS: Four RCTs (n = 278) were found to have a common respiratory parameter (peak expiratory flow rate as a percentage of predicted) suitable for meta-analysis. Within the 92% confidence interval (CI), there was a small benefit with the use of heliox compared to airO(2) (weighted mean difference, + 3%; 95% CI, - 2 to + 8%). There was also a slight improvement in the dyspnea index (weighted mean difference, 0.60; 95% CI, 0.04 to 1.16) with the use of heliox over airO(2). Overall, five RCTs, one nonrandomized unblinded parallel trial, one retrospective case-matched control trial, three case series, and one case report had results in favor of heliox; one RCT and one case series showed no improvement with heliox; one RCT showed a possible detrimental effect with heliox; and 1 small RCT was inconclusive. Most investigators did not prevent entrainment of room air during heliox use or compensate for the lower nebulizing efficiency of heliox. CONCLUSION: Based on surrogate markers, heliox may offer mild-to-moderate benefits in patients with acute asthma within the first hour of use, but its advantages become less apparent beyond 1 h, as most conventionally treated patients improve to similar levels, with or without it. The effect of heliox may be more pronounced in more severe cases. There are insufficient data on whether heliox can avert tracheal intubation, or change intensive care and hospital admission rates and duration, or mortality.