Antibiotic stewardship and microbiological aspects of ventilator-associated pneumonia in patients undergoing cardiac surgery

Abstract

Purpose: Infections are a serious threat in the postoperative period in cardiac surgical patients. Ventilator-associated pneumonia (VAP) is caused by multidrug-resistant organisms resulting in high mortality. Our aim is to study the prevalence of VAP, the organism associated with it and the appropriate management. Materials and Methods: Three thousand consecutive patients who underwent cardiac surgery were included and followed from admission till discharge. All baseline characteristics and intra- and postoperative details were collected. Data on microbiological sampling were noted. The duration of ventilation and time point at which samples were sent, microbiological growth, its sensitivity, and antibiotics used were analyzed. The reassessment of the need for antibiotics at the end of 48 h of sending culture and switching based on the sensitivity (antibiotic time-out) was also captured. Results: Forty-eight patients had VAP (12.78 per 1000 ventilator days); 38 patients had culture-proven growth. The most common organism in our setting was Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa. The resistance to β-lactams, cephalosporins, and carbapenems was high. Dual and triple antibiotic therapies were noted in 64% of patients. Failure to adhere to antibiotic time-out was associated with mortality in patients when it was adhered and not adhered (27% vs. 74%, respectively) (<0.015). Conclusions: The incidence of VAP in our setting is very low. However, VAP remains a serious threat and carries a high mortality. A high degree of suspicion, timely diagnosis, usage of appropriate antibiotics based on local antibiogram, and following antibiotic time-out will help to reduce the intensive care stay and mortality.