Guest blog: Emergency surgery in patients with COVID-19

Emergency surgeons may find ourselves attending patients who are potential candidates for emergency surgery and have a COVID-19 infection, with or without evident symptoms. What should we do with these patients? 

The purely descriptive studies published to date show that these patients have a much higher than usual postoperative mortality. Considering these results, avoidance or postponement of surgery has been advised in COVID-positive patients.

However, postponing an emergency surgery may also have its risks. In each individual case, the risk of operating must be weighed against the risk of a non-surgical treatment. Therefore, it is very important to fully understand how and to what extent COVID-19 infection increases postoperative mortality.

Or in other words, is the high mortality observed in COVID-positive patients undergoing surgery entirely due to COVID-19 infection?

If we look closely at these descriptive non comparative studies, most of the COVID-positive patients were older than usual, with many underlying pathologies, and in poor general condition at the time of surgery. Could these factors, rather than the COVID-19 infection itself, explain their bad postoperative outcomes?

Additionally: During the lockdown, patients might have had fear or difficulty of going to the hospital and might therefore be diagnosed in a more advanced stage of their surgical pathologies. Moreover, the collapse of the pandemic could also cause hospitals to have difficulties in rescuing patients with postoperative complications.

If we can measure the true impact of these 3 factors involved (the patient’s context, the lockdown effect and the effect of hospital collapse) we will be able to assess how COVID-19 infection increases the mortality of patients undergoing emergency surgery. And that will allow us to make decisions based on evidence about whether, in each specific case, it is more reasonable to operate or to try not to do so.

The COVIDCIR project was born with the objective of answering that question. From the Bellvitge University Hospital, in Barcelona, we led a registry with 25 participating Spanish hospitals including all emergency general and gastrointestinal surgeries performed during the first wave of the pandemic (from March to June 2020) and during the same period of 2019 . More than 5,000 patients were included.

To assess the impact of COVID infection, we compared COVID-positive patients with COVID-negative patients operated on during the pandemic. This comparison was made using a statistical method called propensity-score matching, which consists of matching COVID-positive patients with COVID-negative controls of similar age, underlying pathologies and general condition at the time of surgery, thus achieving two comparable groups.

We observed that the mortality of these two matched comparable groups was not statistically different. Or, put another way, that the high mortality observed in COVID-infected patients undergoing surgery is more due to their age, underlying pathology and preoperative condition than to a hypothetical COVID risk-multiplier effect.

Thus, the fact that a patient is COVID-positive should not be seen as an absolute impediment to perform an emergency surgery. In each individual patient, the assessment of the risk of performing or postponing surgery should be based, as has always been done, on her or his individual anesthetic risk and its state at the time of diagnosis.

Second, to understand the effect of lockdown, to see if patients were diagnosed too late due to fear or difficulty in accessing, we compared surgical pathologies of COVID-negative patients operated on during the pandemic with those operated during the previous year. We saw that in the pandemic, patients did not present with more advanced peritonitis and that the inflammatory parameters of their laboratory tests were not higher. Thus, the increased mortality observed during the pandemic cannot be attributed to the effect of lockdown.

And finally, to understand the consequences of hospital collapse, we assessed what is called Failure to Rescue of patients: that is, what percentage of patients who present postoperative complications could not be rescued and died as a consequence of the complication. We compared Failure-to-Rescue of COVID-negative patients operated during the pandemic with those operated before the pandemic. Also on this occasion we carried out the propensity-score matching comparison, matching patients from both groups from the same hospital and of similar age, underlying pathologies and severity of surgical pathology.

We found that COVID-negative patients operated on during the COVID-19-pandemic had the same risk of postoperative complications, but a greater Failure-to-Rescue than before. This fact was evident in the 25 participating hospitals and is probably explained by the hospital collapse in the pandemic context.