Determinants of prolonged intensive care unit stay after cardiac surgery in the elderly

Objectives: In the last decade, there has been a rapid increase in the number of elderly patients referred for cardiac surgery. Recent studies have identified risk factors for prolonged intensive care unit (ICU) stay in cardiac surgery patients. The aims of this study was to evaluate pre-operative risk factors for ICU stay longer than 3 days in a cardiac surgery elderly population, and whether prolonged ICU stay may influence disability, functional recovery and length of rehabilitation. Methods: Two hundred and fifty elderly (≧65 years) cardiac surgery patients were consecutively evaluated at enter in cardiac rehabilitation after ICU dismissal from January 2008 to July 2009. Univariate and multivariate analyses for risk factors were performed for ICU stay longer than 3 days. Thereafter, 6-minute walking test (6MWT), Barthel Index (BI), BI percent recovery and length of stay (LOS) in rehabilitation were evaluated. Results: Mean age was 72.9±4.8 yrs, 170 (68%) patients underwent cardiac surgery for coronary artery by-pass grafting (CABG), 56 (22.4%) for valve replacement and 24 (9.6%) for both CABG and valve replacement. Mean ICU stay was 1.9±1.5 days and 72 patients (28.8%) spent more than 3 days in ICU. Age, New York Heart Association class ≧3, Cumulative Illness Rating Scale (CIRS) score, prevalence of stroke and renal failure were significantly higher in patients with than in those without ICU stay ≧3 days. Off-pump CABG, Physical Activity Scale for the Elderly (PASE), BI and 6MWT were significantly lower in patients with than in those without ICU stay ≧3 days. Multivariate analysis shows that female sex, a NYHA class ≧3, CIRS and PASE score are predictors of ICU stay ≧3 days independently of age, off-pump CABG, stroke and renal failure. Multiple linear regression shows that ICU stay ≧3 days is negatively associated with 6MWT, BI at entry and BI percent recovery, whereas it is positively associated with a longer rehabilitation LOS. Conclusions: Pre-operative comprehensive assessment in the elderly could help to identify predictors of long ICU stay after cardiac surgery. This approach could help to better define the elderly cardiac surgery patients and their needs throughout the cardiac rehabilitation program in order to maximize functional capacity recovery, reducing disability and rehabilitation LOS.