There continues to be great debate about the role of transfusions in patients undergoing surgical procedures. In our March 2011 What’s New in the Patient Safety World column “Downside of Transfusions in Surgery” we discussed the mounting evidence that transfusions during surgery are associated with increased morbidity and mortality. We also noted that some performance improvement programs were successful in reducing the frequency of transfusions and resulted in considerable cost savings.
But a recent study (Musallam 2011) using the American College of Surgeons’ NSQIP database showed that preoperative anemia, even when mild, was independently associated with increased risk of 30-day morbidity and mortality in patients undergoing major non-cardiac surgery.
No one disputes the findings of the Musallam study. But it does not specifically answer the question: “Does correction of anemia by transfusion improve morbidity and mortality in surgical patients?”. Newly published results of the FOCUS study (Carson 2011) do address this question. This study looked at over 2000 patients, aged 50 or older and having risk factors for cardiovascular disease, who were undergoing surgery for hip fracture. All patients had hemoglobin levels below 10 gm per deciliter. They randomized the patients to a “liberal” transfusion strategy or a “restrictive” strategy. The liberal strategy allowed transfusion at a hemoglobin threshold of 10 gm or below. The restrictive strategy used a hemoglobin threshold below 8 gm. Transfusions could be given for symptomatic anemia in either strategy. They found no statistically significant difference between the 2 strategies for the primary outcome of death or inability to walk across a room without human assistance at 60 days. There was also no statistically significant difference between the 2 strategies for in-hospital acute coronary syndrome or death or 60-day mortality. Rates of other complications were also similar, though the study was not powered to fully assess all the latter.
The FOCUS study and the accompanying editorial (Barr 2011) recommend that the decision to transfuse should be based upon a combination of signs, symptoms and laboratory values and not just based upon a single hemoglobin level but that more restrictive transfusion policies may be safe and likely to be cost-effective.
Changing practice, though, is likely to be more difficult. In our August 2011 What’s New in the Patient Safety World column “CPOE Alerts Reduce Blood Transfusions in Children” we cited a study in children (Adams 2011) which demonstrated that evidence-based rules to alert physicians if parameters were outside those recommended for transfusion successfully reduced RBC transfusions. But not all attempts to use clinical decision supports within CPOE have been successful in reducing unnecessary transfusions. At Brigham and Women’s Hospital (Scheurer 2010) studied appropriateness of transfusions 2 years after transfusion guidelines were instituted and clinical decision support tools implemented within CPOE. Over half the transfusions ordered were still considered inappropriate 2 years after implementation. It was found that decision support was bypassed altogether in two-thirds of transfusion orders (by indicating “active bleeding” even though chart review failed to substantiate that in almost half the cases) and that over two-thirds of the overrides indicated a superior had instructed the transfusion. The authors conclude that clinical decision support, by itself, is not likely to eliminate inappropriate transfusions and that other front-end interventions aimed at the decision maker are likely needed. The authors felt that this study showed that the decision to transfuse had “already been made” prior to the CPOE so that, in effect, the clinical decision support was rendered too late. In addition, they felt that CPOE targeted the intern or more junior resident in most cases and might be better directed toward the more senior clinicians making the decision to transfuse.
So, while best practices may be developing to be more conservative regarding transfusions, best practices for implementing such practices are lagging behind. Audit and constructive feedback may prove more fruitful than CPOE reminders.
Musallam KM, Tamim HM, Richards T, et al. Preoperative anaemia and postoperative outcomes in non-cardiac surgery: a retrospective cohort study
The Lancet 2011; 378(9800): 1396 - 1407, 15 October 2011
Carson JL, Terrin ML, Noveck H, et al. Liberal or Restrictive Transfusion in High-Risk Patients after Hip Surgery. NEJM 2011; published online first December 14, 2011
Barr PJ, Bailie KEM. Transfusion Thresholds in FOCUS (editorial). NEJM 2011; published online first December 14, 2011
Adams ES, Longhurst CA, Pageler N. Computerized Physician Order Entry With Decision Support Decreases Blood Transfusions in Children. Pediatrics 2011; 127(5): e1112 -e1119 (doi: 10.1542/peds.2010-3252)
Scheurer DB, Roy CL, McGurk S, Kachalia A. Effectiveness of Computerized Physician Order Entry with Decision Support to Reduce Inappropriate Blood Transfusions. JCOM 2010; 17(1): 17-26