Testing Procalcitonin Levels to Guide Antimicrobial Stewardship

Could the fight against bacterial antimicrobial resistance begin with children? A new study, presented at the 51st Critical Care Congress, noted that up to 80% of pediatric intensive care unit (PICU) patients receive antibiotics.

When pathogens are exposed to excess antibiotics, they can mutate to develop resistance. Procalcitonin (PCT) is elevated in bacterial infections, and more specific than C-reactive protein or white blood cell count. The study sought to bolster antimicrobial stewardship efforts where they were most needed, in PICU, using PCT to guide protocol.

The investigators performed a quality improvement project by utilizing a retrospective cohort chart review. Next, they conducted a prospective cohort study of antibiotics use in a tertiary care children’s hospital PICU and intermediate care unit. The study included pediatric patients with suspected bacterial respiratory infections, such as uncomplicated/complicated pneumonia (PNA), tracheitis, and ventilator-associated pneumonia (VAP). All patients received antibiotics for their suspected respiratory infections.

The study protocol was informed by preexisting adult and pediatric literature. Investigators measured PCT levels on day 0 and day 1, before obtaining levels every other day. If PCT was less than 0.25ng/ml, stopping antibiotics was strongly encouraged. If PCT decreased by more than 80% of peak levels or was 0.25-0.5ng/ml, patients were encouraged to stop antibiotics. If PCT decreased by more than 80% of peak and PCT remained above 0.5ng/ml, continuing antibiotics was encouraged. Finally, if PCT increased above peak and PCT was above 0.5ng/ml, changing antibiotics was recommended.

A total of 53 pediatric patients met the inclusion criteria. The cohort was divided into 34 pre-protocol patients and 19 post-protocol; the latter group received PCT-guided antibiotic stewardship recommendations. The pre-protocol group was 58% male and the average age was 11.5 years, and the post-protocol group was 76% male and averaged 4.1 years of age. In the pre-protocol group, 12% of patients had pneumonia and 88% had tracheitis. In the post-protocol group, 68% of patients had pneumonia, 26% had tracheitis, and 5% had ventilator-associated pneumonia.

The primary outcome of the study was total number of days on antibiotics. The pre-protocol group averaged 9.2 days on antibiotics, while the post-group received antibiotics for an average of 5.3 days. The investigators noted that the PCT-guided antibiotic stewardship decreased the number of antibiotic days in the post-protocol group, despite this cohort having a greater proportion of pneumonia patients.

The study authors concluded that PCT-guided stewardship decreased total antibiotic days without leading to therapy failure. Their findings suggest that using procalcitonin levels to dictate antibiotics usage is a promising way to curb antimicrobial resistance.

The study, “Procalcitonin-Guided Antibiotic Stewardship Decreases Antibiotics for Respiratory Infections in PICU,” was presented virtually on April 18 during the 51st Critical Care Congress.