Predictors and outcomes of extended intensive care unit length of stay in patients undergoing coronary artery bypass graft surgery.

OBJECTIVE

To assess risk predictors of increased intensive care unit (ICU) length of stay in patients undergoing isolated coronary artery bypass surgery (CABG) and assess outcomes associated with increased ICU length of stay.

METHODS

We conducted a nested case-control study from a 9-year hospitalization cohort with prospective data collection (N = 9869). Cases were CABG patients with ICU greater than or equal to 168 hours (N = 236) and controls were CABG patients with an ICU stay of less than 168 hours (N = 708). We examined 15 risk factors and 11 outcomes.

RESULTS

Nine risk factors proved significant in predicting an increased ICU length of stay. Cases were more likely to be older, with an increased pump time, and a lower body surface area. Cases tended to be female, with COPD, hypertension, and undergoing an urgent surgical procedure. Controls tended to have hypercholesterolemia and abnormal left ventricular hypertrophy. There was no significant difference between the cases and controls for the remaining six risk factors. Five of the nine significant predictors correlated with four predictors: age, urgent surgical procedure, pump time, and chronic obstructive pulmonary disorder (COPD). Using logistic regression analysis, we found that patients undergoing CABG had an increased ICU length of stay if they were older than 70 years (OR 2.59, 95% CI 1.86 to 3.62), with longer pump time (OR 2.45, 95% CI 1.75 to 3.44), had COPD (OR 2.04, 95% CI 1.36 to 3.05), and had an urgent surgical procedure (OR 1.59, 95% CI 1.12 to 2.26). Patients with an extended ICU length of stay were also found to experience 11 additional negative outcomes.

CONCLUSION

In patients undergoing CABG surgery an increased age, increased pump time, COPD, and urgent surgical procedure significantly increased the risk of an increased ICU length of stay. Patients with an increased ICU length of stay also experienced more negative outcomes.