Predicting Length of Intensive Care Unit Stay in Coronary Artery Bypass Patients

Monday, 13 July 2009: 3:05 PM

Vivian Nowazek, PhD, MSN, RN-BC, CNS-CC, CCRN
School of Nursing, The University of Houston Victoria, Sugar Land, TX

Learning Objective 1: state predictors of length of stay in coronary artery bypass surgery patients recovering in the CVICU.

Learning Objective 2: predict length of stay greater than 2 days in coronary artery bypass surgery patients recovering in the CVICU.

Purpose: Coronary artery bypass graft (CABG) surgery is among the most common operations performed in the United States and accounts for more resources expended in cardiovascular medicine than any other single procedure. The post-procedure cardiovascular intensive care unit (CVICU) length of stay (LOS) goal is two days or less. A longer CVICU LOS is associated with a prolonged hospital LOS, poor health outcomes, greater use of limited resources, and increased medical costs. Research has shown that experienced clinicians can predict length of stay no better than chance. The primary aim of this study was to identify modifiable pre-and intra-operative predictors of CVICU LOS greater than two days for CABG surgery patients with cardiopulmonary bypass (CPB). 


Data were extracted from 416 medical records of CABG surgery patients with CPB, 50 to 80 years of age, recovered in the CVICU of a large teaching, referral hospital in southeastern Texas, during the calendar year 2004 and the first quarter of 2005.  Exclusion criteria included Diagnosis Related Group (DRG) 106, CABG surgery without CPB, CABG surgery with other procedures, and operative deaths.  The data were analyzed using multivariate logistic regression for an alpha=0.05, power=0.80, and correlation=0.26. 


This study found age, history of peripheral arterial disease (PAD), and total operative time equal to and greater than four hours to be predictors of CVICU LOS greater than two days.  The equation for the estimated logit is: -2.872941 + .0323081 (age in years) + .8177223 (history of peripheral arterial disease) + .70379 (operative time) and the estimated logistic probability is e estimated logit/1+e estimated logit.

Conclusion: This study identified one potentially modifiable (total operative time) and two non-modifiable (age and history of peripheral arterial disease) factors predictive of CIVU LOS greater than two days.