This month’s Paper of the Month comes from the COVIDSurg and GlobalSurg collaboratives.

Timing of surgery following SARS-CoV-2 infection: an international prospective cohort study. COVIDSurg Collaborative and GlobalSurg Collaborative. Published: Anaesthesia 09 March 2020:

What is known about this subject?

The postoperative mortality and pulmonary complications are higher in patients with SARS-COV-2 infection and elective surgery should be delayed in this group of patients to reduce this risk. However, There has been no agreement on the time this group of patients should wait for before being offered elective surgery and whether this interval should be different according to the severity and duration of SARS-CoV-2 symptoms.

Method and outcomes


International, multicentre, prospective cohort study.


  • Patients undergoing any type of surgery (elective or emergency) for any indication in October 2020.
  • Patients with a history of preoperative SARS-CoV-2 were classified into three groups: asymptomatic; symptomatic but symptoms now resolved; or symptomatic with ongoing symptoms.
  • Time from the diagnosis of SARS-CoV-2 infection to the day of surgery was collected as a categorical factor and pre-determined to be analysed in the following categories: 0–2 weeks; 3–4 weeks; 5–6 weeks; and ≥ 7 weeks.

Primary outcome

30-day postoperative mortality.

Secondary outcomes

The incidence of 30-day postoperative pulmonary complications.


  • 140,231 patients across 1674 hospitals in 116 countries were included.
  • 3127 (2.2%) patients had a pre-operative SARS-CoV-2 diagnosis.
  • The overall 30-day postoperative mortality rate was 1.5%
  • The time from SARS-CoV-2 diagnosis to surgery and associated mortality:
    • 0-2 weeks in 1138 patients (36.4%) → 30-day mortality 9.1%
    • 3-4 weeks in 461 patients (14.7%) → 30-day mortality 6.9%
    • 5-6 weeks in 326 patients (10.4%) → 30-day mortality 5.5%
    • >7 weeks in 1202 patients (38.4%) → 30-day mortality 2.0%
  • The 30-day mortality rate in patients who did not have a pre-operative SARS-CoV-2 infection was 1.4%
  • These findings were also consistent across subgroups stratified by age, ASA physical status, and the grade and urgency of surgery.
  • Patients with persistent symptoms at surgery had higher 30-day mortality compared with patients whose symptoms have resolved or were asymptomatic. This also includes patients who had surgery >7 weeks after infection.
  • Similar results were reported for postoperative pulmonary complications in relation to the duration between SARS-CoV-2 infection and surgery

Implications for colorectal practice?

This study provides important data on the impact of the interval between SARS-CoV-2 infection and surgery on postoperative mortality and pulmonary complication. It provides important guidance for recovery planning and restarting elective surgery. In patients with SARS-CoV-2 infection, postoperative mortality risk is high if they undergo any surgery at the first 6 weeks from the onset of SARS-CoV-2 infection and if they have persistent symptoms. These patients should wait for at least 7 weeks before being offered elective surgery. The study findings should inform shared decision-making and help the benefit versus risk discussion between anaesthetists, surgeons and patients when more urgent surgery might be indicated such as patients with advanced cancers.