Use of procalcitonin and C-reactive protein in the diagnosis of bacterial infection in infants with severe bronchiolitis.

The objective was to evaluate the use of procalcitonin (PCT) and C-reactive protein (CRP) for the diagnosis of bacterial infection in bronchiolitis patients. A prospective, single-centre, descriptive, and comparative observational study was carried out on patients with severe bronchiolitis admitted to the paediatric intensive care unit (PICU), from January 2011 to July 2017. Two cohorts were compared: patients with invasive bacterial infection (IBI) and patients with no bacterial infection (NBI). We included 675 patients, 399 of whom were males (59.1%), with median age of 47 days (IQR 25-100.3). Of them, 181 patients were diagnosed with IBI (26.8%). Seventy-two had sepsis (10.7%), 106 had pneumonia (15.7%), and 41 had a urinary tract infection (6.1%). PCT and CRP values were significantly higher in patients with IBI. ROC curves compared the ability of PCT and CRP to diagnose IBI at admission, 24 h, and 48 h. PCT showed a better AUC for diagnosing IBI, with statistically significant differences at all time points (p < 0.001). The best PCT cut-off for IBI diagnosis at admission was 1.4 ng/mL, with a sensitivity of 69% (95% CI 58.4-74.9) and a specificity of 91% (95% CI 88.1-92.5). Procalcitonin showed a better AUC for diagnosing both sepsis and pneumonia, which makes it an excellent predictor.Conclusion: We present PCT as a novel test in comparison with the traditional CRP screening test to discern which bronchiolitis patients have IBI. We highlight the importance of PCT for the diagnosis of pneumonia and sepsis, as it proved to be more sensitive and specific than CRP, with statistically significant differences. What is Known: • Bronchiolitis should be treated with antibiotics only when a bacterial infection is present. • The rate of antibiotic prescription in severe bronchiolitis is extremely high, so diagnostic tools are needed. What is New: • PCT is a good biomarker to discern which bronchiolitis patients have IBI, specially for pneumonia and sepsis diagnoses. It is more sensitive and specific than CRP, with statistically significant differences. • Implementation of PCT cut-off values may prevent unnecessary antibiotic use.

Procalcitonin-guided protocol decreased the antibiotic use in paediatric patients with severe bronchiolitis.

AIM: Our aim was to determine the effectiveness and safety of a procalcitonin-guided protocol to decrease antibiotic use in infants with severe bronchiolitis. METHODS: This prospective, observational study was conducted at the Hospital Sant Joan de Déu from 2010 to 2017. Patients under the age of one were included if they were diagnosed with bronchiolitis, had a suspected bacterial infection and were admitted to the paediatric intensive care unit. A procalcitonin-guided protocol was established in 2014, and two cohorts were compared before and after implementation: 340 in 2010-2014 and 366 in 2015-2017. RESULTS: We recruited 706 patients (58.6% male) with a median age of 47 days and an interquartile range of 25.0-100.2. The rate for antibiotic use was 79.9%, and this differed before and after implementation (88.2% vs 72.1%, P = .003). Antibiotic stewardship and withdrawal decisions were higher after implementation (22.3% vs 36.4%, P = .005). The length of antibiotic treatment was also different between the two periods (8.65 ± 4.8 days vs 5.05 ± 3.18 days, P = .023). No adverse outcomes were observed due to the implementation of the protocol. CONCLUSION: The implementation of a procalcitonin-guided protocol seems to lead to a safe and general decrease in antibiotic use in paediatric patients with severe bronchiolitis.