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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 for death was about 3.5 to 4 times higher in the first 6 weeks after surgery among more than 3000 people with a preoperative COVID-19 diagnosis compared with patients without COVID-19. After 7 weeks, the 30-day mortality rate dropped to a baseline level.
Surgery should be further delayed for people who remain symptomatic at 7 weeks postdiagnosis, lead author Dmitri Nepogodiev, MBChB, told Medscape Medical News.
“In this group we recommend waiting until COVID-19 symptoms resolve, if possible. However, our study did not capture specific data on long COVID…so we are unable to make specific recommendations for this group,” said Nepogodiev, research fellow at the NIHR Global Health Research Unit on Global Surgery at the University of Birmingham in the United Kingdom.
“This should be an area for future research,” he added.
The international, multicenter, prospective cohort study is notable for its sheer size — more than 15,000 investigators reported outcomes for 140,231 surgical patients from 1674 hospitals across 116 countries. In total, 2.2% of these patients tested positive for SARS-CoV-2 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 30-day mortality rate was the primary outcome.
Death Rates Among Surgical Patients With Preoperative COVID-19 Diagnosis
|Time of Surgery Since COVID-19 Diagnosis||30-Day Mortality Rate|
|0 to 2 weeks||9.1%|
|3 to 4 weeks||6.9%|
|5 to 6 weeks||5.5%|
|7 weeks or longer||2.0%|
For comparison, the 30-day mortality rate for surgical patients without a preoperative COVID-19 diagnosis was 1.4%. A COVID-19 diagnosis more than 7 weeks before surgery did not make a significant difference on outcomes.
The “Why” Remains Unknown
The reasons for the association between a COVID-19 diagnosis and higher postoperative death rates remain unknown. However, Nepogodiev speculated 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 postoperative pulmonary complications followed a pattern similar to the findings on death. They reported higher rates of pneumonia, acute respiratory distress syndrome, and unexpected reventilation 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”
“This is an important study of postoperative mortality among patients recovered from COVID-19,” Adrian Diaz, MD, MPH, told Medscape Medical News when asked to comment.
The large cohort and numerous practice settings are among the strengths of the research, said Diaz, from the University of Michigan Institute for Healthcare Policy and Innovation in Ann Arbor. He was lead author of a June 2020 review article on elective surgery in the time of COVID-19, published in The American 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, lack of indications for the surgeries and information on cause of death were additional limitations.
Future research should evaluate any benefit in delaying surgery longer than 7 or more weeks, Diaz added, perhaps looking specifically at 10, 12, or 14 weeks, or considering outcomes as a continuous variable. This would help healthcare providers “garner more insight into risk and benefits of delaying surgery beyond 7 weeks.”
Anaesth. Published online March 9, 2021. Full text
Nepogodiev and Diaz disclosed no relevant financial relationships. The study had multiple funding sources, including the National Institute for Health Research (NIHR) Global Health Research Unit, the Association of Upper Gastrointestinal Surgeons, the British Association of Surgical Oncology, Medtronic, and more.
Damian McNamara is a staff journalist based in Miami. He covers a wide range of medical specialties, including infectious diseases, gastroenterology, and critical care. Follow Damian on Twitter: @MedReporter.