Figure 27-18 Relationship of postoperative myocardial ischemia (black bars) and morbid cardiac events (red bars) to hematocrit for 27 high-risk patients undergoing infrainguinal arterial bypass. (Data from Nelson AH, Fleisher LA, Rosenbaum SH: The relationship between postoperative anemia and cardiac morbidity in high risk vascular patients in the ICU. Crit Care Med 21:860, 1993.)