Combined use of respiratory multiplex PCR and procalcitonin to reduce antibiotic exposure in acute chest syndrome

Acute chest syndrome (ACS) is a severe complication of sickle cell anemia. Although an associated lower respiratory infection accounts for around 30%, antibiotherapy is recommended and its de-escalation is challenging. Procalcitonin (PCT) in ACS can shorten antibiotic treatment. Also, multiplex Polymerase Chain Reaction (mPCR) with a bacterial panel may improve antibiotic stewardship by detecting bacteria more effectively. We hypothesized that a strategy combining the use of mPCR with repeated dosing of PCT can reduce antibiotic exposure during ACS in adult. We conducted a randomized, controlled, parallel group, open-label multicenter study in two French hospitals. Consecutive ACS were randomly assigned to conventional or intervention strategy where antibiotherapy was targeted on mPCR results from admission respiratory sample and antibiotic discontinuation based on PCT values and kinetics. Primary outcome was the number of days of antibiotic exposure at D28 following ACS diagnosis. From June 2020 to September 2022, 72 patients with an ACS diagnosis were included: 37 in the interventional strategy, 35 in the conventional strategy. Microbiological documentation of ACS was significantly higher in the interventional strategy versus conventional strategy, respectively 25 (67.6%) and 13 (37.1%) (difference: 30.4%; IC95%: 6.7% to 51.5%). Number of days of antibiotic exposure at D28 was similar: 6 days (difference = 0.0 day; CI95%: -2.1 to 2.1; p=0.22). No difference was found regarding time to clinical stability, superinfection, or length of stay. Using a broad panel mPCR on respiratory samples with a PCT-based algorithm during ACS in hospitalized adults did not reduce antibiotic use at Day 28.