Associations of nadir haemoglobin level and red blood cell transfusion with mortality and length of stay in surgical specialties: a retrospective cohort study

Abstract

Few studies have investigated if, and how, red cell transfusion and anaemia interact. We analysed 60,955 admissions to three metropolitan hospitals in Western Australia between 2008 and 2017 to determine whether the relationship between red cell transfusion and outcomes in surgical patients differed by lowest (nadir) level of haemoglobin. At levels above 100 g.l À1 , in-hospital, 30-day and 1-year mortality were higher with transfusion, the adjusted odds ratios (ORs) (95%CI) being 8.80 (4.43-17.45) p < 0.001 and 3.68 (1.93-7.02) p < 0.001 and the adjusted hazard ratio (95%CI) being 1.83 (1.28-2.61) p = 0.001, respectively. Likewise, between 90 g.l À1 and 99 g.l À1 , in-hospital, 30-day and 1-year mortality were higher with transfusion, the adjusted odds ratio (95%CI) being 3.76 (2.23-6.34) p < 0.001 and 1.96 (1.23-3.12) p < 0.001 and the adjusted hazard ratio (95%CI) being 1.34 (1.05-1.70) p = 0.017, respectively. Length of stay was longer with transfusion at nadir haemoglobin levels above 100 g.l À1 and in the following ranges: 90-99 g.l À1 , 80-89 g.l À1 , 70-79 g.l À1 and 60-69 g.l À1 , the adjusted rate ratio (95%CI) being 1.38 (1.25-1.53) p < 0.001, 1.18 (1.10-1.27) p < 0.001, 1.17 (1.13-1.22) p < 0.001, 1.07 (1.02-1.12) p = 0.003 and 1.24 (1.13-1.36) p < 0.001, respectively. Mortality was higher with red cell transfusion at haemoglobin levels greater than 90 g.l À1 , whereas at all levels below 90 g.l À1 mortality was not significantly higher or lower. Length of stay was longer with transfusion at nadir haemoglobin levels of 60 g.l À1 or above. Our results suggest that nadir haemoglobin modified the relationship between red cell transfusion and outcomes and adds to the evidence recommending caution before transfusing red cells.

Role of preoperative intravenous iron therapy to correct anemia before major surgery: a systematic review and meta-analysis

“…Furthermore, several literatures reported that blood transfusion is associated with adverse outcomes perioperatively [8][9][10]. Furthermore, data obtained from two large multicenter databases of 23,348 patients [11], and 227,425 patients [12] demonstrated that not only severe but also moderate/mild preoperative anemia is an independent risk factor for postoperative morbidity and 30-day mortality.…”

Development and validation of a nomogram to predict intraoperative blood transfusion for gastric cancer surgery

“…The trigger threshold for blood transfusion varies across different institutions and remains a matter of debate 10 . Moreover, it was recently reported that nadir haemoglobin affected the relationship between red blood cell transfusion and outcomes, 21 which indicates that the optimal haemoglobin level may vary between patients. Thus, merely relying on a patient's haemoglobin level to trigger blood transfusion is imprecise and incomprehensive.…”

Development and validation of a nomogram to predict perioperative blood transfusion for gastric cancer surgery

“…The trigger threshold for blood transfusion varies in different institutions and remains a matter of debate [10]. Moreover, it was recently reported that nadir hemoglobin affected the relationship between red cell transfusion and outcomes [20], which indicated that the optimal hemoglobin level might vary in different patients. Thus, merely using hemoglobin level to direct blood transfusion is imprecise and incomprehensive.…”