Respiratory multiplex PCR and procalcitonin to reduce antibiotic exposure in severe SARS-CoV-2 pneumonia: a multicentre randomized controlled trial.

Objectives: We aimed at assessing the efficacy and safety on antibiotic exposure of a strategy combining a respiratory multiplex PCR (mPCR) with enlarged panel and daily procalcitonin (PCT) measurements, as compared with a conventional strategy, in adult patients who were critically ill with laboratory-confirmed SARS-CoV-2 pneumonia.

Methods: This multicentre, parallel-group, open-label, randomized controlled trial enrolled patients admitted to 13 intensive care units (ICUs) in France. Patients were assigned (1:1) to the control strategy, in which antibiotic streamlining remained at the discretion of the physicians, or interventional strategy, consisting of using mPCR and daily PCT measurements within the first 7 days of randomization to streamline initial antibiotic therapy, with antibiotic continuation encouraged when PCT was >1 ng/mL and discouraged if < 1 ng/mL or decreased by 80% from baseline. All patients underwent conventional microbiological tests and cultures. The primary end point was antibiotic-free days at day 28.

Results: Between April 20th and November 23rd 2020, 194 patients were randomized, of whom 191 were retained in the intention-to-treat analysis. Respiratory bacterial co-infection was detected in 48.4% (45/93) and 21.4% (21/98) in the interventional and control group, respectively. The number of antibiotic-free days was 12.0 (0.0; 25.0) and 14.0 (0.0; 24.0) days, respectively (difference, -2.0, (95% CI, -10.6 to 6.6), p=0.89). Superinfection rates were high (51.6% and 48.5%, respectively). Mortality rates and ICU lengths of stay did not differ between groups.

Discussion: In severe SARS-CoV-2 pneumonia, the mPCR/PCT algorithm strategy did not affect 28-day antibiotics exposure nor the major clinical outcomes, as compared with routine practice.