Red blood cell transfusion in critically ill patients with traumatic brain injury: an international survey of physicians' attitudes.

Introduction: Restrictive transfusion strategies have been advocated in critically ill patients. Nevertheless, considerable uncertainty exists regarding optimal transfusion thresholds in traumatic brain injury (TBI) patients because the injured brain is susceptible to hypoxemic damage. We aimed to identify the determinants of red blood cell (RBC) transfusion and the perceived optimal transfusion thresholds in adult patients with moderate-to-severe TBI.

Methods: We conducted an electronic, self-administered survey targeting critical care specialists and neurosurgeons from Canada, Australia, and the United Kingdom caring for TBI patients. The questionnaire was initially developed by a panel of experts using a structured process (domains/items generation and reduction). The questionnaire was validated for clinical sensibility, reliability, and content.

Results: The response rate was 28.7% (218/760). When presented with the hypothetical scenario of a young adult TBI patient, a wide range of transfusion practices was observed, with 47 (95% confidence interval [CI], 41 to 54)% favouring RBC transfusion at a hemoglobin level of ≤ 70 g·L in the acute phase of care, while 73 (95% CI, 67 to 79)% would use this trigger in the plateau phase of care. Multiple trauma, neuro-monitoring data, hemorrhagic shock, and planned surgery were the main factors that influenced the need for transfusion. The lack of clinical evidence and guidelines was responsible for uncertainty regarding RBC transfusion strategies in this patient population.

Conclusion: In our survey about critically ill TBI patients, transfusion practice was found to be mainly influenced by the acuity of care, patient characteristics, and neuro-monitoring. Clinical equipoise regarding optimal transfusion strategy is believed to be mainly attributed to the lack of clear clinical evidence and guidelines. Appropriate randomized-controlled trials are required to determine the optimal transfusion strategies in TBI patients.