Background: Pneumonia is the leading cause of mortality in children. Gentamicin is recommended empirically to treat all severe pneumonia, often combined with penicillin. Despite the effectiveness of therapy, the prolongation of length of stay (LOS) in the hospital becomes a burden for the healthcare system.

Purpose: To determine the LOS and predict the factors associated with LOS in pediatric pneumonia with narrow therapeutic index antibiotic therapy.

Methods: We performed a retrospective study in pediatrics with pneumonia (ICD-10 J.18.0, J.18.9, J.15.0, and P.23) who had used gentamicin when admitted to the hospitals during January-December 2020. The data were collected from the patients’ medical records in two hospitals in Banyumas Regency. We used Mann-Whitney U Test and Spearman Correlation to analyze factors associated with LOS patients.

Results: a total of 66 patients met the inclusion criteria and were included in this study. The mean LOS was 6.21±3.64 days. Switching of combination antibiotics was significantly associated with LOS (p-0.015). The prolongation of LOS was correlated with age (p=<0.001, coef.corr -0.516) and duration of gentamicin therapy (p=0.001, coef.corr: 0.825).

Conclusion: Associated factors correlated with LOS are switching of combination antibiotic, age, and duration of gentamicin therapy. The younger the age of patients and longer duration of gentamicin therapy prolonged LOS with moderate and strong corellation respectively.

Keywords: Length of stay, pediatric pneumonia, gentamicin