The effect of perioperative blood transfusion thresholds on patient outcomes in orthopaedic surgery: a literature review.

Abstract

Blood transfusions are one of the most common interventions required perioperatively in orthopaedic patients. There exist two main schools of thought in relation to perioperative blood transfusion - transfusing at a haemoglobin level of 70 g/L or below (termed 'restrictive protocol' in the literature), versus transfusing at a haemoglobin threshold of 100 g/L (which the literature terms 'liberal'). Few reviews of the literature exist comparing the impact of different transfusion strategies on the postoperative outcomes of these orthopaedic patients. This review analyses the 11 currently available studies on transfusion protocols in orthopaedics and associated findings related to patient outcomes. The literature showed no clear consensus on whether one transfusion protocol is superior in the orthopaedic patient. There was strong evidence for reduced transfusion rates among groups receiving transfusion at <70 g/L, and hence a reduction in complication directly related to transfusions. Despite this, other measured patient outcomes, including length of stay, postoperative complication rate, and mortality rate, were unchanged between the groups. Some evidence exists that a Hb threshold of 100 g/L results in earlier postoperative ambulation in hip surgery patients. One study suggests using preoperative haemoglobin as a preoperative risk factor to aid in determining whether patients are more suited to one approach over the other. Further high-quality clinical trials in orthopaedic cohorts must become available to determine whether a haemoglobin threshold of 70 g/L can safely be adopted to reduce transfusion rates without adversely impacting patient outcomes.