Practice patterns for antibiotic de-escalation in culture-negative healthcare-associated pneumonia

Published guidelines for the treatment of healthcare-associated pneumonia (HCAP) recommend initial broad-spectrum antibiotics with appropriate de-escalation based on culture results. Guideline recommendations are based on data from intubated patients, in whom cultures are easily obtained. The approach to antibiotic de-escalation for culture-negative patients has not been addressed. Consequently, there are no published reports that describe the current standard of practice.

All patients admitted to a university hospital with a diagnosis of HCAP, as defined by use of a pneumonia orderset, were identified retrospectively over a 2-year period. Antibiotics prescribed on admission, during hospital stay, and on discharge were recorded. De-escalation was defined as a change in the initial antibiotic therapy from broad- to narrow-spectrum coverage within 14 days of the initial prescription. The Pneumonia Severity Index was used for risk-adjustment.

A total of 102 patients were included in the analysis; of these, 72% (n = 73) were culture-negative. There were more males in the culture-negative than culture-positive group; otherwise, baseline characteristics were similar. Antibiotic therapy was de-escalated in 75% of the culture-negative group and 77% of the culture-positive group (p = 1.00). Culture-negative patients were de-escalated approximately 1 day earlier than culture-positive patients (3.93 vs. 5.04 days, p = 0.03). Culture-negative patients who were de-escalated had a shorter length of hospitalization, lower hospital costs, and lower mortality rates. In 70% of the culture-negative patients, a respiratory fluoroquinolone was chosen for de-escalation.

In this single-center study, most of the patients with culture-negative HCAP were safely de-escalated to a respiratory fluoroquinolone.