Classifying transfusions related to the anemia of critical illness in burn patients.

ABSTRACT

BACKGROUND: Critically ill patients require transfusions because of acute blood loss and the anemia of critical illness. In critically ill burn patients, typically, no distinction is made between transfusions related to acute surgical blood loss and those related to the anemia of critical illness. We sought to identify the percentage of blood transfusions due to the anemia of critical illness and the clinical characteristics associated with these transfusions in severely burned patients. METHODS: Sixty adult patients with ≥20% total body surface area (TBSA) burn who were transfused at least 1 unit of packed red blood cells during their hospitalization were studied. Clinical variables including age, %TBSA burn, Acute Physiology and Chronic Health Evaluation (APACHE) II score, number of ventilator days, inhalation injury, and number of operative events were correlated with the total number of packed red blood cell units and percentage of nonsurgical transfusions in these patients. Nonsurgical transfusions were defined as transfusions occurring after postoperative day 1 for each distinct operative event and were classified as being caused by the anemia of critical illness. RESULTS: Patients were transfused an average of 16.6 units ± 21.2 units. Nonsurgical transfusions accounted for 52% of these transfusions. APACHE II score, %TBSA burn, number of ventilator days, and number of operative events, all correlated with total transfusions. However, nonsurgical transfusions correlated with only APACHE II score (p = 0.01) and number of ventilator days (p = 0.03). There was no correlation between nonsurgical transfusions and other clinical variables. CONCLUSION: The anemia of critical illness is responsible for >50% of all transfusions in severely burned patients. The initial severity of critical illness (APACHE II score) and duration of the critical illness (number of ventilator days) correlated with transfusions related to anemia of critical illness. Further investigation into the specific risk factors for these transfusions may help to develop strategies to further reduce transfusion rates.