March 11, 2021 -- Seven weeks appears to be the ideal amount of time to delay surgery, when possible, after someone tests positive for COVID-19, researchers in the United Kingdom report.
Risk fof death was about 3.5 to 4 times higher in the first 6 weeks after surgery among more than 3000 people with a COVID-19 diagnosis compared with patients without COVID-19. After 7 weeks, the 30-day mortality rate dropped to normal levels.
The study was published online March 9, in Anaesthesia.
Surgery should be further delayed for people who remain symptomatic 7 weeks after diagnosis, lead author Dmitri Nepogodiev, told Medscape.
The study did not look at best options for long-haul COVID-19 patients, said Nepogodiev, research fellow at the NIHR Global Health Research Unit on Global Surgery at the University of Birmingham in the United Kingdom. He suggests that be the focus of another study.
The international, multicenter, study is notable for its sheer size — more than 15,000 investigators reported outcomes for 140,231 surgical patients from 1,674 hospitals across 116 countries. In all, 2.2% of these patients tested positive for coronavirus prior to surgery.
Surgery of any type performed in October 2020 was assessed. A greater proportion of patients with a preoperative COVID-19 diagnosis had emergency surgery, 44%, compared with 30% of people who never had a COVID-19 diagnosis.
Most patients were asymptomatic at the time of surgery, either because they never experienced COVID-19 symptoms or their symptoms resolved
The ‘Why’ Remains Unknown
The reasons for the association between a COVID-19 diagnosis and higher postoperative death rates remain unknown. However, Nepogodiev said that it could be related to "some degree of lung injury, even if patients are initially asymptomatic."
Intubation and mechanical ventilation during surgery could exacerbate the existing lung injury, he said, thereby leading to more severe COVID-19.
In fact, Nepogodiev and colleagues found that lung complications after surgery followed a pattern similar to the findings on death. They reported higher rates of pneumonia, acute respiratory distress syndrome, and unexpected breathing problems in the first 6 weeks following a COVID-19 diagnosis. Again, at 7 weeks and beyond, the rates returned to be relatively the same as those for people who never had COVID-19.
"Waiting for 7 or more weeks may allow time for the initial COVID-19 injury to resolve," Nepogodiev said.
'An Important Study'
Adrian Diaz, MD, MPH, told Medscape that Nepogodiev’s study was “important.”.
Diaz, from the University of Michigan Institute for Healthcare Policy and Innovation in Ann Arbor,. was lead author of a June 2020 review article on elective surgery in the time of COVID-19, published in TheAmerican Journal of Surgery.
"As with nearly all studies of this nature, results must be interpreted on a case-by-case basis for individual patients. However, this study does add important information for patients and providers in helping them have an informed discussion on the timing of surgery," said Diaz, who is also a fellow in the Center for Healthcare Outcomes and Policy and a resident in general surgery at Ohio State University.
Nepogodiev and colleagues included both urgent and elective surgeries in the study. Diaz said this was a potential limitation because emergency operations "should never be delayed, by definition." In addition, there is a lack of details on the types of surgeries and information on cause of death in the study.