June 1, 2020

Postoperative pulmonary complications, mortality "disproportionately high" in SARS-CoV-2-infected patients

According to a study published in The Lancet looking at the impact of coronavirus disease 2019 (COVID-19) on patients undergoing surgery, just over half of patients with perioperative severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection went on to develop at least one pulmonary complication within 30 days of their procedure. In addition, pulmonary complications were experienced by over 80% of patients who died in the study.

"These pulmonary complication and mortality rates are greater than those reported for even the highest-risk patients before the pandemic," Dmitri Nepogodiev, University of Birmingham, UK, and colleagues wrote. "Even considering differences in the case-mix, the incidence of, and mortality associated with, pulmonary complications in SARS-CoV-2-infected patients is disproportionately high."

The study was conducted at 235 hospitals in 24 countries, predominantly in Europe, and included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality, while the main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome (ARDS) or unexpected postoperative ventilation.

The study included 1128 patients who had surgery between January 1 and March 31, 2020, of whom 835 (74.0%) had emergency surgery and 280 (24.8%) had elective surgery, while urgency information was missing for 13 patients. SARS-CoV-2 infection was diagnosed preoperatively in 294 (26.1%) patients and postoperatively in 806 (71.5%), with timing of diagnosis missing for 28 patients. 

Overall, the 30-day mortality rate in the study was 23.8% (268/1128). The authors noted that mortality was disproportionately high across all subgroups, including a rate of 18.9% among those who underwent elective surgery (53/280) and 25.6% among those who had emergency surgery (214/835). For patients undergoing minor surgery such as appendicectomy or hernia repair, the postoperative 30-day mortality rate was 16.3% (41/251), while the rate for those who underwent major procedures, such as hip surgery or colon cancer surgery, was 26.9% (226/841).

The study also found that 51.2% (577/1128) of patients had at least one pulmonary complication, with the authors pointing out that this rate is "far higher than the pre-pandemic baseline." They cited findings from the POPULAR multicentre, prospective, observational study of 211 hospitals from 28 European countries in 2014–15, showing that the pulmonary complication rate was 8%. 

Meanwhile, in the current study, patients who developed pulmonary complications had a higher 30-day mortality rate than those who did not (38.0% versus 8.7%, p<0.0001). Pulmonary complications also occurred in 81.7% (219/268) of the patients who died, and among those who had such complications, the 30-day death rate was highest in those who developed ARDS (63.0%).

The authors reported that SARS-CoV-2-infected patients had greater mortality than even the highest-risk subgroups of the UK's National Emergency Laparotomy Audit (NELA). "The 2019 NELA report presented 30-day mortality rates of 16.9% in patients with a high preoperative risk of death, 16.8% in patients with an unexpected critical care admission, and 23.4% in frail patients older than 70 years," the authors noted. 

Further, they said mortality rates identified in the current study were also higher than those previously reported across international settings, including one study involving 58 countries that reported a 30-day mortality of 14.9% in the high-risk subgroup who had emergency midline laparotomy. "Postoperative mortality rates in SARS-CoV-2-infected patients with postoperative pulmonary complications approach those of the sickest patients with community-acquired COVID-19 who are admitted to intensive care," the authors added. 

The study also identified that 30-day mortality rates were higher:

  • in men versus women (28.4% [172/605] vs 18.2% [94/517], p<0·0001)
  • in patients aged 70 years or older versus those younger than 70 years (33.7% [188/558] vs 13.9% [79/567], p<0·0001).
  • after emergency surgery (25.6% [214/835]) versus elective surgery (18.9% [53/280]; p=0·023)

In adjusted analyses, predictors of 30-day mortality were:

  • male sex (OR 1.75 [95% CI 1.28–2.40], p<0·0001)
  • being 70 years or older versus younger than 70 years (2.30 [1.65–3.22], p<0·0001)
  • American Society of Anesthesiologists (ASA) grades 3–5 versus grades 1–2 (2.35 [1.57–3.53], p<0·0001)
  • malignant versus benign or obstetric diagnosis (1.55 [1.01–2.39], p=0.046)
  • emergency versus elective surgery (1.67 [1.06–2.63], p=0.026)
  • major versus minor surgery (1.52 [1.01–2.31], p=0.047).

"Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older," the authors wrote. They also recommended that consideration should be given for postponing non-critical procedures and promoting non-operative treatment to delay or avoid the need for surgery during SARS-CoV-2 outbreaks.

SOURCE: The Lancet