Rationale
Pneumonia remains the most common major infection after cardiac surgery despite numerous preventive measures.
Objectives
To prospectively examine the timing, pathogens, and risk factors, including modifiable management practices, for post-operative pneumonia and estimate its impact on clinical outcomes.
Methods
5,158 adult cardiac surgery patients were prospectively enrolled in a cohort study across 10 centers. All infections were adjudicated by an independent committee. Competing risk models were used to assess the association of patient characteristics and management practices with pneumonia within 65 days of surgery. Mortality was assessed by Cox proportional hazards model, and length of stay using a multi-state model.
Measurements and Main Results
The cumulative incidence of p neumonia was 2.4% ,33% of which occurred after discharge. Older age, lower hemoglobin level, chronic obstructive pulmonary disease, steroid use, operative time and left ventricular assist device/heart transplant were risk factors. Ventilation time (24–48 vs ≤24 hours;HR,2·83; 95% CI,1·72–4·66; >48 hours HR,4·67; 95% CI,2·70–8·08), nasogastric tubes (HR,1·80; 95% CI,1·10–2·94), and each unit of blood cells transfused (HR,1·16; 95% CI,1·08–1·26) increased pneumonia risk. Prophylactic use of second-generation cephalosporins (HR,0·66; 95% CI, 0·45–0·97) and platelet transfusions (HR, 0·49, 95% CI, 0·30–0·79) were protective. Pneumonia was associated with a marked increase in mortality (HR,8·89; 95% CI,5·02–15·75), and longer LOS of 13·55 ± 1·95 days (bootstrap 95% CI,10·31–16·58).
Conclusions
Pneumonia continues to impose a major impact on the health of patients after cardiac surgery. Adjusting for baseline risk, several specific management practices were associated with pneumonia, which offer targets for quality improvement and further research.
