General anesthesia is not without risks. Which of the following statement(s) is/are true concerning the risk associated with general anesthesia

b. Human error accounts for between 50 and 75% of anesthetic-related deaths

d. The most common problems associated with adverse anesthetic outcomes are related to the airway

Anesthetic agents effectively obtund or completely block nearly all physiologic protective mechanisms, therefore, there is an associated risk even without a surgical procedure. Fortunately, with the advent of newer agents and monitoring techniques, it is estimated the mortality due to anesthesia alone has decreased from approximately 1:10,000 in the 1950s to as low as 1:100,000 or less for healthy patients today. It has been estimated that between 50–75% of anesthetic-related deaths are due to human error and are preventable. The most common problems associated with adverse outcomes are related to the airway: inadequate ventilation, unrecognized esophageal intubation, unrecognized extubation, and unrecognized disconnection from the ventilator.