['The interplay between baseline physiology, operative performance, and postoperative recovery is poorly defined. We describe the beneficial effect of a successful operation on outcomes across the full spectrum of physiologic risk for an elective high-acuity procedure.', 'Four hundred twelve consecutive pancreatic resections, performed between 2001 and 2008, were analyzed according to the Physiologic and Operative Severity Score for the Enumeration of Mortality and Morbidity. Baseline physiology was classified according to the Physiologic Severity Score: minor (< or = 16); intermediate (17 to 23); vulnerable (> or = 24). Surgical performance was assigned by the Operative Severity Score: class I (< or = 14); class II (15 to 17); class III (> or = 18). Physiologic and operative predictions were independently correlated with actual clinical and economic outcomes and then merged to measure the influence of surgical performance beyond baseline physiology.', 'As baseline physiology declines, patients suffer more complications and require more therapeutic and invasive interventions. Within each physiologic risk grade, class I operations (optimal surgical performances) were associated with lower rates of morbidity, shorter hospital stays, and improved cost efficiency. Deeper analysis reveals that intraoperative blood loss is the most variable and influential factor affecting physiologic risk. Each additional unit (375 mL) of blood loss increases the odds of morbidity by 45%, prolongs hospital stay by 1 day, and costs an additional $4,000 per patient.'] Does optimal surgical performance attenuate physiologic risk in high-acuity operations?