Aerosolized or powdered forms of polymyxin have been used as prophylaxis for ventilator associated infections in adults. In 2015, Children’s National Medical Center neonatal intensive care unit (NICU) protocol recommended that neonates <1000 grams receive polymyxin endotracheal tube suction catheter flushes with the goal to reduce acquired respiratory infection. The objective of this study is to describe the clinical characteristics and outcomes of patients who received polymyxin endotracheal tube flushes compared with those who received saline.
A retrospective cohort study of infants weighing <1000 grams ventilated for >48 hours in the NICU, 1/1/2015-06/30/2016 was performed. Data were collected from an internal NICU database, medication billing data, and through chart review of the electronic health record. Demographics, antibiotic treatment days, ventilator days, length of stay, mortality, and microbiologic culture data were compared between patients receiving polymyxin and saline using chi squared for binary and t-test for continuous variables.
Results: Of the 71 patients included, 38 received polymyxin and 33 received saline. Mean gestational age at birth was 24.1 weeks (23.9 polymyxin vs. 24.2 saline, p= 0.06); median age on admission 4 days (3 vs 12, p-= 0.019); median admission weight 700 g (640 vs 800, p= 0.002); 52% were male (58% vs 45% group). Median antibiotic days was 52 (77 vs 41, p= 0.056), median ventilator days 39 (43.5 vs 33, p= 0.06). Pathogenic bacteria was cultured in 38% of patients in whom at least one lower respiratory tract (LRT) culture was obtained (62.5% vs 38.1% p= 0.24). Pathogenic bacteria resistant to at least one antibiotic class to which is normally susceptible was found in 10% (13% vs 6%, p= 0.32). No differences were seen in mortality (16% vs 15%, p= 0.94) or median length of stay (101 vs 92, p= 0.41).
Conclusion: A NICU protocol recommending prophylactic polymyxin use for ELBW infants was implemented more frequently in younger and more premature neonates. Mortality and length of stay did not differ among babies who received polymyxin. Patients who received polymyxin did not grow a statistically significant higher proportion of pathogenic or resistant bacteria from LRT cultures compared with those receiving saline .
M. Jacobs, None
R. Hamdy, None