Ultra-Massive Transfusion: Predictors of Occurrence and In-Hospital mortality From the Australian and New Zealand Massive Transfusion Registry (ANZ-MTR)

Few data exist on patient clinical characteristics, predictors of occurrence and short- and long-term outcomes of ultra-massive transfusion (UMT), defined as receiving 20 units or more of red blood cells (RBCs) within 48h. This study analyses UMT events from the Australian and New Zealand Massive Transfusion Registry (ANZ-MTR). The ANZ-MTR captured all patients at 29 participating sites receiving a massive transfusion (MT), defined as ≥5 units of RBCs within 4h. Of 9028 patients, 803 (8.9%) received an UMT. UMT patients were younger than other MT patients (median age 57y vs 62y; P < .001). In UMT and MT, males predominated (66.3% and 62.9%, respectively); and context was predominantly trauma (28.8% and 23%) and cardiothoracic surgery (CTS) (21.7% and 20.3%). Median RBC units received within 4h were 16 (UMT) and 6 (MT). In UMT, 4h FFP:RBC ratio (0.6 vs 0.4, P < .001), and 4h cryoprecipitate use (72.9% vs 39.9%, P < .001) were higher. Independent predictors of UMT (Odds Ratio; 95% CI) were age <60y (1.52; 1.28-1.79), baseline Hb >100g/L (1.31; 1.08-1.59), INR >1.5 (1.56; 1.24-1.96), and APTT >60s (4.49; 3.40-5.61). Predictors of in-hospital mortality in UMT included Charlson Comorbidity Index score ≥3 (11.20, 0.60 - 25.00) and bleeding context, with mortality less likely in liver transplant (0.07, 0.01-0.41) and more likely in vascular surgery (8.27, 1.54-72.85), compared with CTS. In-hospital mortality was higher in the UMT group compared with MT group (20.5% vs 44.2%, P < .001), however 5y survival following discharge was not significantly different between the groups (HR=0.87 [95%CI 0.64-1.18], P = .38). UMT patients are more commonly younger, with baseline coagulopathy, and have higher in-hospital mortality compared with MT. However, UMT is not futile: 55.8% survived to discharge, without significant difference in survival postdischarge between the groups.