Figure 24-4 Relationship between adverse events in the American Society of Anesthesiologists (ASA) Closed Claims Study and preventable complications. Preventable events related to respiratory complications were significantly more common than those related to all nonrespiratory complications. Of the respiratory complications, difficult intubation had the least number of preventable complications (P < 0.05 compared with nonrespiratory claims). (From Caplan RA, Posner KL, Ward RJ, Cheney FW: Adverse respiratory events in anesthesia: A closed claims analysis. Anesthesiology 72:828, 1990.)