A recent study by researchers at Stanford University reported that the composition of anesthesia care teams is not linked to differences in patient mortality, hospital length of stay or inpatient care costs.

The researchers, led by Eric C. Sun, MD, PhD, an assistant professor of anesthesiology, perioperative and pain medicine at Stanford University in California, compared care teams including either nurse anesthetists or anesthesiologist assistants under the supervision of a physician anesthesiologist, to detect any differences in postsurgical outcomes.

Dr. Sun and his team compared 421,230 surgical cases that included a nurse anesthetist and 21,868 cases with an anesthesiologist assistant between Jan. 1, 2004 and Dec. 31, 2011. All cases involved a geriatric patient between the ages of 65 and 89 years, and a physician anesthesiologist functioned as the supervisor in all cases.

The investigators found that the mortality rate was 1.6% when the care team included anesthesiologist assistants versus 1.7% for care teams that included nurse anesthetists. Hospital length of stay was shorter and medical spending was slightly less for care teams that involved anesthesiologist assistants, with decreases in length of stay of 0.009 days and a reduction in spending of $56. These differences were not statistically significant.

Currently, anesthesiologist assistants are certified to practice in only 16 states and are required to work directly under a physician anesthesiologist. Nurse anesthetists are certified throughout the United States and function as team members alongside physicians or in a nurses-only model.

Because of the lack of differences found in mortality, length of stay and medical spending, the researchers concluded that the surgical care provided by an anesthesiologist assistant or nurse anesthetist is equivalent when each is supervised by a physician anesthesiologist.

—Deanna DePeau