Simplified Parsonnet risk scale identifies limits to early patient discharge

Background. Fast-track recovery after coronary artery bypass surgery has in fluenced patient care positively. Predicting patients who fall off track an d require prolonged (greater than or equal to7 days) hospitalization remain s uncertain. The Parsonnet risk assessment score is effective in predicting length of stay, but is limited by inaccurate subdivision of risk categorie s. We simplified the Parsonnet risk scale to better identify patients eligi ble for fast-track recovery. Method: The cases of 604 consecutive patients who underwent isolated coronary artery bypass grafting (CABG) using cardiop ulmonary bypass (CPB) were reviewed retrospectively. A rapid recovery proto col emphasizing reduced CPB time, preoperative intra-aortic balloon pump (I ABP) criteria, and atrial fibrillation prophylaxis was applied to all patie nts. The five original divisions of the Parsonnet risk scale were reduced t o three risk categories: Low (0-10; Group A), Intermediate (11-20; Group B) , High (>20; Group C). Comparisons of progressive risk categories were anal yzed to identify predictive factors associated with fast-track outcomes. Re sults: The thirty-day operative mortality for the entire group was 3.6%. Th ree clinical features were identified that distinguished risk progression-f emale gender, reoperative CABG, and increased age. Additionally, the presen ce of diabetes (p<0.05), congestive heart failure (p<0.01), and peripheral vascular disease (p<0.001) distinguished Groups A and B, while acute myocar dial infarction (p<0.05) influenced outcomes in Group C. Group A (48%) mean risk score 5.9 +/-3.2 was compared to Group B (34%) 14.8 +/-2.6, which was further compared to Group C (18%) 26.4 +/-2.8. The mean length of stay for Group A (5.3 +/-4.1 days) was notably less than Group B (6.1 +/-4.7 days; p<0.05); however, both groups responded favorably to fast-track techniques. Group C did not respond comparably (9.2<plus/minus>9.2 vs 6.1 +/-4.7 days; p<0.001) and experienced prolonged recovery. The simplified Parsonnet risk scale did not identify differences in operative mortality and revealed onl y pneumonia (p<0.05) and atrial fibrillation (p<0.01) to be greater in Grou p C. As risk increased, significantly less revascularization was performed (Group A 3.6<plus/minus>1.2 grafts/patient vs Group B 3.3 +/-1.2 [p<0.01]; Group B 3.3<plus/minus>1.2 vs Group C 2.5 +/-1.0 [p<0.001]). Conclusion: A simplified Parsonnet risk scale (three categories) is an effective tool in identifying factors limiting fast-track recovery. Low- and intermediate-ris k patients represent the majority (82%) and respond well to fast-track meth ods. High-risk patients (18%) are limited by a greater percentage of female patients, reoperative CABG, and the very elderly, resulting in fast-track failure. Strategies to improve recovery in high-risk patients may include e volving off-pump techniques.