Transfusion increases infection without affecting neurologic outcome in spontaneous subarachnoid hemorrhage

Introduction

Liberal use of packed red blood cell (PRBC) transfusion to a predefined threshold has been shown to worsen the outcome of ICU patients. However, in an effort to improve neurologic outcomes of patients with nontraumatic subarachnoid hemorrhage (SAH), transfusions are still used frequently to maintain hemoglobin of 10 g/dl. We hypothesized that PRBC transfusion in patients with SAH would worsen their outcomes.

Methods

We conducted a 19-month retrospective study of 84 patients with nontraumatic SAH in an intensivist-run, high-volume, academic ICU. Patients who received at least 1 unit PRBC transfusion during their hospital stay (n = 42, median 3 units) were compared with those who did not (n = 42). Outcomes of interest were vasospasm (defined both clinically and by transcranial Doppler velocities), 28-day mortality, poor neurologic outcome (defined as modified Rankin score of ≥ 4), and occurrence of nosocomial infections (defined by National Healthcare Safety Network criteria). Associations of PRBC transfusions with these outcomes were measured using univariate and multivariate analysis that adjusted for age, gender, ethnicity, comorbidities, neurologic status upon presentation, and procedures.

Results

Patients with and without PRBC transfusions were similar in age, gender, ethnicity, comorbidities, and neurologic status upon presentation. There was no difference in the incidence of vasospasm with transfusions (52% vs. 37%, P = 0.12) or mortality (12% vs. 17%, P = 0.53). PRBC transfusions were associated with nosocomial infections (69% vs. 33%, P = 0.001) and poor neurologic outcome (69 vs. 48%, P = 0.046) in univariate analysis. After adjustment for potential confounders, PRBC transfusion was an independent predictor of nosocomial infections (OR = 3.7, 95% CI = 1.2 to 11.6, P = 0.03) but not poor neurologic outcome (OR = 1.9, 95% CI = 0.4 to 10.6, P = 0.45).

Conclusion

Use of PRBC transfusion in ICU patients with SAH does not improve neurologic outcome but increases risk of nosocomial infections. Hence, restricted use of PRBC may be justified in this segment of the ICU population, as well.