Neurologic Critical Care

The effect of red blood cell transfusion on cerebral oxygenation and metabolism after severe traumatic brain injury*

Zygun, David A. MD, MSc, FRCPC; Nortje, Jurgens MD, FRCA; Hutchinson, Peter J. PhD, FRCS; Timofeev, Ivan MRCS; Menon, David K. MD, PhD, FRCA; Gupta, Arun K. MA, PhD, FRCA

Author Information

From the Neurosciences Critical Care Unit (JN, DKM, AKG); Department of Anaesthesia (JN, DKM, AKG), University of Cambridge; Academic Neurosurgery (PJH, IT), University of Cambridge Wolfson Brain Imaging Centre (IT, DKM), Addenbrooke’s Hospital, Cambridge, United Kingdom; and Departments of Critical Care Medicine and Clinical Neurosciences (DAZ), University of Calgary, Calgary, Canada.

Supported, in part, by G9439390 ID 56833 from Association of Anesthetists of Great Britain and Ireland, Intensive Care Society and Acute Brain Injury Program in the Wolfson Brain Imaging Centre, which was funded by the MRC. Supported by, the Detweiler Traveling Fellowship of the Royal College of Physicians and Surgeons of Canada, the Meredith Graduate Master’s Scholarship, University of Calgary, the Worker’s Compensation Board of Alberta (DAZ); the Academy of Medical Sciences/The Health Foundation–Senior Surgical Scientist Fellowship (PJH); British Journal of Anesthesia/Royal College of Anesthetists Research Fellowship (JN); Codman (Johnson & Johnson), the Evelyn Trust and a BP-TNK Kapitza scholarship (IT).

Drs. Zygun and Gupta had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. Drs. Zygun, Gupta, Menon, and Hutchinson designed the study. Drs. Zygun, Nortje, and Timofeev collected the data. All authors participated in the analysis and manuscript preparation.

For information regarding this article, E-mail: [email protected]

Critical Care Medicine 37(3):p 1074-1078, March 2009. | DOI: 10.1097/CCM.0b013e318194ad22

Abstract

Objective:

There is evidence to suggest that anemia after severe traumatic brain injury (sTBI) is detrimental. However, there is a paucity of evidence supporting the use of transfusion of packed red blood cells in patients with sTBI. To understand the acute effect of packed red blood cell transfusion on cerebral oxygenation and metabolism in patients with sTBI.

Design:

Prospective clinical study.

Setting:

Addenbrooke’s Neurosciences Critical Care Unit, a 21-bed tertiary academic unit.

Patients:

Thirty patients with sTBI.

Interventions:

Patients were randomized by computer random number generator to one of three transfusion thresholds: 8, 9, or 10 g/dL. When the patients’ hemoglobin concentration fell below their assigned threshold, two units of packed red blood cells were transfused over 2 hours. A 1-hour period of stabilization was observed before final data collection.

Measurements and Main Results:

The primary outcome was change in brain tissue oxygen (P_bto₂). Secondary outcomes included dependence of baseline hemoglobin concentration and baseline P_bto₂ on the relationship of transfusion and P_bto₂, and the effect of transfusion on lactate pyruvate ratio (LPR) and brain pH as markers of cerebral metabolic state. Fifty-seven percent of patients experienced an increase in P_bto₂ during the course of the study, whereas in 43% of patients, P_bto₂ either did not change or decreased. Multivariable generalized estimating equation analysis revealed change in hemoglobin concentration to significantly and positively associated with change in P_bto₂ [0.10 kPa/(g/dL) 95% confidence interval 0.03–0.17, p = 0.003]. Improvement in P_bto₂ was not associated with baseline hemoglobin concentration or low P_bto₂ (<1 kPa). Fifty-six percent of patients experienced an increase in LPR. No significant relationship between change in LPR or transfusion on pH_bt and change in hemoglobin could be demonstrated.

Conclusions:

Transfusion of packed red blood cells acutely results in improved brain tissue oxygen without appreciable effect on cerebral metabolism.

Trial Registration:

ISRCTN89085577.

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The effect of red blood cell transfusion on cerebral oxygenation and metabolism after severe traumatic brain injury*