All surgical procedures have potential complications that can increase the risks of a negative outcome, whether specific to the procedure or after surgery has been completed, but the operating room is the highest risk area for serious complications.

One survey of 7,900 surgeons found those who had made a serious surgical error in the previous three months were more likely to have a lower quality of life and increased probability of symptoms of burnout and depression.

Emotional reactions range from loss of confidence to anger and worries about their careers. Many reported that they receive inadequate support from their institutions for dealing with such incidents.

An earlier report suggested that 98,000 patients die each year in the U.S. as a result of medical error. In fact, complications are common in surgical patients and are usually contributed to provider error. Time of surgery seems to play a part.

Surgeries performed at night lead to worse outcomes, especially for patients undergoing coronary angioplasty, orthopedic surgery, transplant surgery, colorectal surgery and cardiac arrest. Almost any work done at night has a higher risk of complications.

In a recent study, researchers evaluated all patients undergoing neurological surgery between 2007 and 2014 in the University of Michigan Health System. This study included 15,807 patients; 785 complications were identified through the self-reported morbidity and mortality reports created by faculty and resident neurosurgeons.

The study showed that the odds of a complication were increased by more than 50 percent for procedures with start times between 9 p.m. and 7 a.m. The odds of a complication were even greater for later time periods.

The only statistically significant factor that predicted severity of the complication was if the operation was an emergency compared to an elective surgery. Patient demographics across start time groups indicated that the average age of patients varied across the surgical day with higher ages earlier in the day, and lower ages later in the day. While other patient factors varied over the course of the day, no variations were considered significant.

Other possible explanations for surgical complications may be that medical practitioners are fatigued later in the day, putting them at greater risk of errors or that night shift staff tend to be less experienced and thus more prone to errors. Also, as it gets later in the day, the percentage of elective cases decreases while emergency cases predominate.

The researchers acknowledge that there could be other explanations. For example, it could be that patients treated after normal business hours are inherently sicker than patients treated during normal business hours in ways that the researchers were unable to measure, leading to increased complications rates.

Considering all the possible explanations, it seems clear that the various relationships need to be studied further to minimize surgery-related complications. One such approach may be increasing the number of surgical teams and operating rooms to allow for a greater number of daytime surgeries, thereby leaving later surgeries for emergency procedure. In the meantime, it might be best to be the first surgery of the day.