Panos Kougias1, Sonia Orcutt2, Peter H. Lin2, George Pisimisis1, Neal R. Barshes1, Carlos F. Bechara1
1Michael E. DeBakey VAMC, Houston, TX; 2Baylor College of Medicine, Houston, TX.
OBJECTIVES: Controversy surrounds the topic of transfusion policy after non-cardiac operations. This study assessed the combined impact of postoperative nadir hemoglobin (nHb) levels and blood transfusion on adverse events after open surgical intervention in patients with PAD.
METHODS: Consecutive patients (n=1,182) who underwent PAD-related operations were matched on propensity scores calculated as their probability to have nHb more or less than 10gm/dl on the basis of operation type, demographics and comorbidities, including the revised cardiac risk index. Logistic and Cox proportional hazards regressions were used to assess the impact of nHb and number of transfused units on 1) a composite endpoint (CE) of death, myocardial infarction and stroke; 2) respiratory and wound complications.
RESULTS: After adjusting for nHb level, the number of units transfused was a strong predictor for the perioperative occurrence of the CE (OR:1.12, p=0.02) and respiratory complications (OR: 1.27, p=0.004). Adjusted for the number of units transfused, nHb had no impact on the perioperative CE (OR: 0.6, p=0.3) or respiratory events(OR: 0.40, p=0.17). An interaction term between transfusion and nHb level remain non-significant (p=0.543), indicating that the impact of blood transfusion was the same regardless of nHb level. Perioperative wound infections were less common in patients with nHb > 10gm/dl (OR: 0.59, p=0.04), whereas transfusion had no impact on wound infection rates (OR: 0.98, p=0.84). During an average follow up of 24 months transfused patients were more likely to develop the CE (HR: 1.13, p=0.02), whereas nHb level did not impact the long term adverse event rate (HR: 0.7, p=0.26).
CONCLUSIONS: Blood transfusion increases the incidence of perioperative and long-term mortality and cardiovascular adverse events regardless of the associated nHb. It also increases the risk of perioperative respiratory complications. A restrictive transfusion strategy is justified in patients with PAD.
AUTHOR DISCLOSURES: N. R. Barshes, Nothing to disclose; C. F. Bechara, Nothing to disclose; P. Kougias, Nothing to disclose; P. H. Lin, Nothing to disclose; S. Orcutt, Nothing to disclose; G. Pisimisis, Nothing to disclose.
Posted April 2012