General Anaesthesia - Perioperative Mortality

Perioperative Mortality

Most perioperative mortality is attributable to complications from the operation (such as haemorrhage, sepsis, and failure of vital organs. This also may include memory loss or slowing down of the thought processes) or pre-existing medical conditions. Most current estimates of perioperative mortality range from 1 death in 53 anaesthetics to 1 in 5,417 anaesthetics. However, a 1997 Canadian retrospective review of 2,830,000 oral surgical procedures in Ontario between 1973–1995 reported only four deaths in cases in which either an oral and maxillofacial surgeon or a dentist with specialized training in anaesthesia administered the general anaesthetic or deep sedation. The authors calculated an overall mortality rate of 1.4 per 1,000,000. The largest and most recent study of postoperative mortality was published in 2010. In this review of 3.7 million elective open surgical procedures performed on inpatients at 102 hospitals in the Netherlands during 1991–2005, postoperative mortality from all causes was observed in 67,879 patients, for an overall rate of 1.85%. The wide disparity between the results of these studies may be the result of differences in operational definitions and reporting sources.

Mortality directly related to anaesthetic management is significantly less common, and may include such causes as pulmonary aspiration of gastric contents, asphyxiation and anaphylaxis. These in turn may result from malfunction of anaesthesia-related equipment or more commonly, human error. A 1978 study found that 82% of preventable anaesthesia mishaps were the result of human error. In a 1954 review of 599,548 surgical procedures at 10 hospitals in the United States between 1948–1952, 384 deaths were attributed to anaesthesia, for an overall mortality rate of 0.064%. In 1984, after a television programme highlighting anaesthesia mishaps aired in the United States, American anaesthesiologist Ellison C. Pierce appointed a committee called the Anesthesia Patient Safety and Risk Management Committee of the American Society of Anesthesiologists. This committee was tasked with determining and reducing the causes of peri-anaesthetic morbidity and mortality. An outgrowth of this committee, the Anesthesia Patient Safety Foundation was created in 1985 as an independent, nonprofit corporation with the vision that "that no patient shall be harmed by anesthesia". As with perioperative mortality rates in general, the current mortality attributable to the management of general anaesthesia is controversial. The incidence of perioperative mortality that is directly attributable to anaesthesia ranges from 1 in 6,795 to 1 in 200,200 anaesthetics.