Intraoperative blood product resuscitation and mortality in ruptured abdominal aortic aneurysm

Abstract

The resuscitation of patients with ruptured abdominal aortic aneurysms (RAAAs) has not been well studied, and the potential benefit of autotransfusion (AT) is unknown. The increased use of fresh-frozen plasma (FFP) has been associated with decreased mortality rates in trauma patients and may also improve RAAA survival. We explored the influence of intraoperative AT and FFP resuscitation on mortality rates in massively transfused RAAA patients. A single-center review of RAAA patient records from April 1989 to October 2009 was undertaken. Clinical data and outcomes were studied. Operative and anesthesia records were queried for intraoperative transfusion totals. Massive transfusion was defined as ≥10 units of red blood cells (RBCs) inclusive of AT units. We identified 151 RAAA patients, of which 89 (60%) received a massive transfusion and comprised the study population. These 89 patients had an in-hospital mortality rate of 44%. Univariate predictors of mortality included increased age, preoperative hypotension, operative blood loss, and crystalloid, RBCs, and FFP volume. AT was used in 85 patients, with an increased ratio of AT:RBC units associated with survival. Mortality was 34% with AT:packed RBCs (PRBC) ≥1 (high AT) and 55% with AT:PRBC of <1 (low AT; P = .04). On multivariate analysis, age > 74 years (P = .03), lowest preoperative systolic blood pressure (SBP) <90 mm Hg (P = .06), blood loss >6 liters (P = .06), and low AT (P = .02) independently predicted mortality. The mean RBC:FFP ratio was similar in those that died (2.7) and in those that lived (2.9; P = .66). RBC:FFP ≤2 (high FFP) was present in 38 (43%) patients, with mortality of 49%. RBC:FFP >2 (low FFP) had 40% mortality (P = .39). RBC:FFP ratios decreased over time from 3.6 (years 1989 to 1999) to 2.2 (years 2000 to 2009; P < .001), but more liberal use of FFP was not associated with decreased mortality (47% vs 41%; P = .56). AT:PRBC ratios were stable over time (range, 1.4-1.2; P = .18). Greater use of AT but not of FFP was associated with survival in massively transfused RAAA patients. No mortality benefit was seen with increased FFP, but few patients had high FFP transfusion ratios. Further study to identify RAAA patients at risk for massive transfusion should be undertaken and a potentially greater role for AT in RAAA resuscitation investigated.