COVID-19 infection in the 60 days prior to surgery was not associated with risk of adverse postoperative outcomes, a cohort study among veterans showed.
Of more than 29,000 veterans who underwent surgery, adverse postoperative outcomes occurred among 4.7% of those in the group without a recent COVID infection, 7.6% of those with a recent infection (1 to 30 day prior), and 3.2% of those with a slightly less recent infection (31 to 60 days prior), reported William J. O'Brien, MS, of Veterans Affairs Boston, and colleagues.
The odds ratios for postoperative outcomes were 1.40 (95% CI 0.77-2.35) among those with infection in preoperative days 1 to 30 and 0.68 (95% CI 0.26-1.42) among those with infection in preoperative days 31 to 60, they noted in a research letter published in .
"The message here for surgeons is, if you think your patient who had COVID-19 is otherwise a good candidate for surgery, and you decide to proceed with surgery, on average, they are at no higher risk of [adverse] outcomes compared to a patient who did not have recent COVID-19," O'Brien told 鶹ý.
Importantly, the study was limited to patients already selected for surgery. "We don't have information about patients who the surgeons decided were too frail, or were not fit for surgery for some other reason," O'Brien added. "Our study addresses one consideration among many; postoperative outcomes are not the only consideration."
In , the American Society of Anesthesiologists and the Anesthesia Patient Safety Foundation recommended delaying elective surgeries for 7 weeks following COVID infection when a patient is unvaccinated. They also recommended that surgeons consider the severity of the initial COVID infection, the potential risk of ongoing symptoms, comorbidities and frailty status, and the complexity of the surgery.
"These guidelines are very cautious. Our study findings suggest there should not be a fixed timeline," O'Brien noted. "The surgical team should take everything into account, and should look at all observational studies, including ours."
In their discussion, the researchers pointed out that one detected higher mortality at 90 days among patients undergoing surgery within 8 weeks of a positive COVID test compared with matched controls and "found lower perioperative risk for vaccinated patients and for unvaccinated patients not given general anesthesia."
"These studies may shift the timing of surgery relative to recent infection," wrote O'Brien and co-authors. "Our study further rebalances the scale in favor of performing surgery in recently recovered patients."
The study was conducted during a period when vaccines had become widely available (Jan. 1 to Sept. 30, 2021). Although more people were vaccinated by the end of the study, O'Brien said, more than half of the entire cohort (54%) had not been vaccinated, 7.9% had been partially vaccinated, and 38.1% were fully vaccinated.
For this target trial emulation with pseudorandomization, the researchers included 29,093 patients who underwent surgery across 123 hospitals. Mean age was 66.1, 90% were men, and 67.5% were white.
Among the 15,553 surgical procedures performed for inpatients, the mean length of stay was 5 days. The median time between infection and surgery was 30 days (interquartile range 13-44 days).
All participants were encouraged to receive vaccination, and no oral outpatient therapies were in use.
Endpoints included death, cardiac events, central nervous system outcomes, respiratory outcomes, surgical infection, or thromboembolic events within 30 days after surgery.
O'Brien and team noted that though they chose to conduct a target trial emulation to reduce certain biases, "some bias will remain due to unmeasured covariates and a selection bias related to patients who did not undergo surgery due to clinical status."
Disclosures
O'Brien reported no conflicts of interest. A co-author reported holding equity in Pfizer, Moderna, and Abbott.
Primary Source
JAMA Network Open
O'Brien WJ, et al "Estimated risk of adverse surgical outcomes among patients with recent COVID-19 infection using target trial emulation methods" JAMA Netw Open 2023; DOI: 10.1001/jamanetworkopen.2023.4876.