HOW SAFE IS ANESTHESIA IN THE 21ST CENTURY?

Richard Novak, MD May 3, 2010 61 Comments

Deep down, every surgical patient has the same worry: How safe is anesthesia and surgery? Methods of evaluating anesthetic mortality are inexact and controversial.

In 1999 the Institute of Medicine published their report entitled To Err is Human: Building a Safer Health Care System. In this report, the Committee on Quality of Health Care in America stated that, “anesthesia is an area in which very impressive improvements in safety have been made.” The Committee cited anesthesia mortality rates that decreased from 1 death per 5,000 anesthetics administered during the 1980s, to 1 death per 200,000-300,000 anesthetics administered in 1999. These statistics reflected the frequency of all patients, healthy or ill, who died in the operating room.

However, this conclusion that anesthesia mortality has plummeted is not universal. When mortality is defined as any patient who dies within 48 hours following surgery, the statistics are much different. In 2002, anesthesiologist Dr. Robert S. Lagasse of the Albert Einstein College of Medicine in New York published a study in Anesthesiology, the specialty’s leading journal, which challenged the Institute of Medicine report.

Lagasse presented data on surgical mortality from two academic New York hospitals between the years 1992 and 1999. When mortality was defined as anydeath occurring within 48 hours following surgery, there were 351 deaths in 184,472 surgeries–an overall surgical mortality rate of 1 death per 532 cases.

Deaths related to anesthesia errors were much less–only 14 deaths out of 184,472 surgeries–a rate of 1 death per 13,176 cases. However, Lagasse’s anesthesia-related mortality rate of 1 per 13,176 surgeries was significantly different that the Institute of Medicine’s rate of 1 death per 200,000-300,000 surgeries. Lagasse wrote, “We must dispel the myth that anesthesia-related mortality has improved by an order of magnitude. Science does not support this claim.”

Lagasse compared anesthesia to the aviation industry: “The safety of airline travel, for example, has increased dramatically in this century, but since the 1960s there has been minimal improvement in fatality rates. This may be due to the effect that improved safety technology has had on air traffic density. Technology has made it possible to meet production pressures of the commercial airline industry by allowing more takeoffs and landings with less separation between aircraft. With this increased aircraft density comes increased danger, thereby offsetting potential improvements in safety. This may be analogous to the practice of anesthesiology in which improvements in medical technology have led to increased anesthetic management of older patients with significantly more concurrent disease.”

Today’s surgery patients are sicker than ever. Five percent of all surgical patients die within one year of surgery. For patients over the age of 65 years, 10% of all surgical patients die within one year of surgery. The authors of this data wrote, “Death during the first year after surgery is primarily associated with the natural history of preexisting conditions. However, cumulative deep hypnotic time and intraoperative hypotension were also significant, independent predictors of increased mortality. These associations suggest that intraoperative anesthetic management may affect outcomes over longer time periods than previously appreciated.”

In a recent update, Dr. Jeana Havidich, an associate professor of anesthesiology at Dartmouth-Hitchcock Medical Center in New Hampshire, presented the following preliminary data at the October 2014 American Society of Anesthesiologist convention:

From more than 3.2 million cases of anesthesia use between 2010 and 2013, the rate of complications decreased from 11.8 percent to 4.8 percent. The most common minor complication was nausea and vomiting (nearly 36 percent) and the most common major complication was medication error (nearly 12 percent).
The death rate remained at three deaths per 10,000 surgeries/procedures involving anesthesia.
Among the other findings: complication rates were not higher among patients who had evening or holiday procedures; patients older than 50 had the highest rates of serious complications; and healthier patients having elective daytime surgery had the highest rates of minor complications.

Data published in 2015, in a study of mortality in surgical cases from 2010 to 2014 (Whitlock EL, Feiner, JR, Chen LI, Perioperative Mortality, 2010 to 2014 A Retrospective Cohort Study Using the National Anesthesia Clinical Outcomes Registry. Anesthesiology, V 123, No 6, Dec 2015, 1312-1321) showed the following:

The authors analyzed 2,866,141 cases and 944 deaths (crude mortality rate, 33 per 100,000)
Independent risk factors for higher mortality were: emergency case status, surgical cases beginning between 4 p.m. and 6:59 a.m., patient age less than one year or greater than or equal to 65 years, and sicker patients with an increased American Society of Anesthesiologists physical status score.

Anesthesia is safer than it has ever been, but risk factors such as emergencies, very young or old patients, or sicker patients, do increase the risk. The new finding in this 2015 publication was that surgeries which began late in the day or night (after 4 p.m. until 6:59 a.m.) had increased mortality.

Anesthesia-related mortality has fallen from 6.4/10,000 in the 1940s to 0.4/100,000 at present, largely because of the introduction of safety standards and improved training.

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