Ventilator-associated pneumonia after cardiac surgery: a meta-analysis and systematic review

Ventilator-associated pneumonia (VAP) is the most common and serious nosocomial infection that threatens patients who have undergone cardiac surgery. This article summarizes its clinical characteristics and provides theoretical evidence for prevention and treatment.

A literature search was conducted using PubMed, Embase, the Cochrane Library, and Web of Knowledge databases and by manual search. Data involving the prevalence, etiology, risk factors, or clinical outcomes were extracted for systematic review and meta-analysis.

Eleven studies on VAP after cardiac surgery were included. When the results were merged the VAP rate was 21.27/1000 ventilator-days. The prevalence reached 6.37% of all patients and 35.2% of patients who were on mechanical ventilation for more than 48 hours. Among the isolated pathogens, Pseudomonas aeruginosa had the highest detection rate, with an average of 23.19%, followed by Staphylococcus aureus (20.15%), Haemophilus influenzae (19.53%), Acinetobacter baumannii (10.68%), Escherichia coli (10.18%), Klebsiella pneumoniae (9.52%), and Candida albicans (7.20%). Risk factors were also analyzed. We found that New York Heart Association cardiac function class IV, pulmonary hypertension, chronic obstructive pulmonary disease, peripheral vascular disease, renal disease, emergency surgery, intra-aortic balloon counterpulsation, cardiopulmonary bypass time, aortic crossclamp time, mechanical ventilation time, reintervention, and reintubation were closely related to the occurrence of VAP; there was no association with gender and diabetes mellitus. Once patients had VAP, mortality and length of stay in the intensive care unit were significantly increased.

VAP in patients after cardiac surgery is common and has a poor prognosis. It is mainly caused by gram-negative bacteria, and could be affected by a series of factors.