Acute transfusion practice during trauma resuscitation: who, when, where and why?

BACKGROUND: Early transfusion (ET=within 24h) has been shown to be required in approximately 5% of trauma patients. Critical care transfusion guidelines control transfusion triggers by evidence based cut-offs. Empirical guidelines influence decision making for ET in trauma.

AIM: to describe the patterns, indications and timing of ET at level 1 trauma centre.

METHODS: A 12-month prospective study was performed on all trauma admissions requiring ET. Demographics, mechanism, injury severity (ISS) were collected. Timing, location, volume, the clinician initiating first unit of transfusion, reason for transfusion was recorded, with corresponding blood gas results and physiological parameters. Mortality, ICU admission, length of stay, need for emergent surgery were outcomes.

RESULTS: From 965 trauma admissions 91 (9%) required ET (76% male, median age: 38 (10-88, IQR: 22-59), blunt mechanism: 87%, ISS: 25 (4-66, IQR: 16-34). 43% (39/91) had massive transfusion protocol (MTP) activation. ET was initiated in ED (52%), OR (38%) or ICU (10%). MTP transfusions were started at a median of 0.5h (0.5-4, IQR: 0.5-1.5), whilst non-MTP transfusions were initiated at a median 3h (0.5-23, IQR: 2-9). The first unit of ET was initiated by trauma surgeon (35%), anaesthetist (30%), ED (19%), ICU (13%) and general surgeon (3%). Transfusions triggers at the first unit of transfusion were 'expected or ongoing bleeding' 29%, dropping haemoglobin 26%, haemorrhagic shock 24%, hypotension 10%, tachycardia 8%. Median systolic blood pressure was 90 (45-125, IQR: 80-100), heart rate was 100 (53-163, IQR: 80-120), haemoglobin was 96 (50-166, IQR: 85-114)g/l and base excess was -4.2(-22.1 to 2.7, IQR: -7.2 to 2.4)mmol/l at the time of transfusion. Emergency surgery was required in 86% (78/91). ICU admission rate was 69% (63/91). Mortality was 14%. Low volume transfusion (1-2 units) was more likely to lead to overtransfusion (Hb>110 g/l).

CONCLUSION: The prospective evaluation of acutely transfused trauma patients showed a distinct pattern of transfusion triggers as the patient passes from ED to the OT and arrives to the ICU. The conventional transfusion trigger (haemoglobin level) is not appropriate in ET as early transfusion triggers are based on vital signs, blood gas results, injury patterns and anticipated major bleeding.