Red blood cell transfusion is associated with decreased in-hospital muscle strength among critically ill patients requiring mechanical ventilation

Purpose: Red blood cell (RBC) transfusion is linked to poor functional recovery after surgery and trauma. To investigate one potential mechanism, we examined the association between RBC transfusion and muscle strength in a cohort of critically ill patients. Methods: We performed a secondary analysis of 124 critically ill, mechanically ventilated patients enrolled in 2 prospective cohort studies where muscle strength testing was performed at a median of 12. days after mechanical ventilation onset. We examined the association between RBC transfusion and dynamometry handgrip strength using multivariable linear regression, adjusting for study site, age, sex, Acute Physiology and Chronic Health Evaluation, Sequential Organ Failure Assessment score, days from hospital admission to examination, and steroid use. Secondary outcomes included systematic manual muscle strength and intensive care unit-acquired paresis. Results: Among 124 subjects, 73 (59%) received RBC transfusion in the 30 days before examination. In adjusted analyses, RBC transfusion was significantly associated with weaker handgrip (adjusted mean difference, 9.9 kg; 95% confidence interval, 16.6 to 3.2; P < .01) and proximal manual muscle strength (adjusted mean difference in Medical Research Council score, 0.5; 95% confidence interval, 0.7 to 0.2; P < .01) but not intensive care unit-acquired paresis. Conclusions: Red blood cell transfusion was associated with decreased muscle strength in this cohort of critically ill patients after adjusting for illness severity and organ dysfunction. Further studies are needed to validate these results and probe mechanisms.