Prognostic factors associated with mortality in patients undergoing emergency surgery for abdominal aortic aneurysms

Abstract

Surgical mortality rates following emergency surgery for ruptured abdominal aortic aneurysms (AAAs) remain high. This study investigated the mortality rate and identified prognostic factors affecting mortality in patients undergoing emergency repair of AAAs in our hospital. Between January 2005 and June 2010, a total of 42 patients underwent emergency surgery for AAAs and were included in this retrospective study. The following variables concerning each patient were collected by chart review and compared between survivors and nonsurvivors: age; gender; preoperative levels of hemoglobin (Hb), hematocrit (Ht), platelets (Plts), base excess (BE), and serum glucose and lactate; presence of preoperative shock defined as hypotension (systolic blood pressure of less than 80mmHg); incidence of blood transfusion, whether AAA was ruptured or impending; interval from admission to the hospital or arrival in the operating room until aortic cross-clamping; surgical duration; and volume of intraoperative blood loss and transfusion, total fluid infusion, and urine output. Nine patients died within 30days postoperatively, a 30-day mortality rate of 21.4%. Among these nine nonsurvivors, eight had shown persistent preoperative shock (P=0.0004 vs. survivors). Compared with the survivors, nonsurvivors were significantly older (P=0.0052) and had lower preoperative levels of Hb/Ht (P<0.0001), Plts (P=0.0003), and BE (P<0.0001), an elevated lactate level (P=0.0048), shorter interval from admission (P=0.0459) or arrival in the operating room (P=0.0288) until aortic clamping, and intraoperatively more hemorrhage (P=0.0038) associated with larger amounts of blood transfusion (P=0.0083) and less urine output (P=0.0004). The authors clarified that certain features such as age, persistent preoperative shock, and greater amounts of transfusion associated with greater blood loss and anemia were factors affecting the mortality in patients undergoing emergency surgery for AAAs. It might be of great importance to correct preoperative shock and anemia caused by massive bleeding before the onset of hemodynamic deterioration.