Estimation of Physiologic Ability and Surgical Stress (E-PASS) as a new prediction scoring system for postoperative morbidity and mortality followingelective gastrointestinal surgery

Overwhelming surgical stress exceeding a patient's reserve capacity causes a disruption of homeostasis, leading to various postoperative complications . This study was undertaken to develop a new storing system, "E-PASS", stan ding for the Estimation of Physiologic Ability and Surgical Stress, that pr edicts the postsurgical risk by quantification of the patient's reserve and surgical stress. E-PASS comprises the preoperative risk score (PRS), the s urgical stress score (SSS), and the comprehensive risk score (CRS) that is determined by both scores. These scores were computed by a multiple regress ion analysis conducted on 292 consecutive patients who underwent elective c ommon gastrointestinal operations at one hospital between 1992 and 1995 (in ternal group). The usefulness of the scores was evaluated in 989 consecutiv e patients who underwent the same surgical procedures during the same perio d at another hospital (external group). The morbidity and mortality rates i ncreased similarly in both groups as the CRS increased. A marked step-up of both rates was observed at a CRS > 1.0, reaching mortality rates of 20% in the internal subjects and 28.5% in the external subjects. These results su ggest that the E-PASS scoring system is reproducible, and that it mag be us eful for surgical decision making. This system requires no special examinat ions and can be used in every hospital.