Transfusion, mortality link varies with hemoglobin levels

(HealthDay)—For critically ill patients, the impact of transfusion on mortality varies with hemoglobin (Hgb) levels and with the presence of comorbid heart disease, according to a study published in the Dec. 8 issue of the Journal of the American College of Cardiology.

Yew Y. Ding, M.B.B.S., M.P.H., from the Tan Tock Seng Hospital in Singapore, and colleagues performed secondary data analyses of Veterans Affairs intensive care unit (ICU) episodes across five years. Logistic regression was used to quantify the effect of transfusion on hospital mortality.

The researchers found that 12.4 percent of the 258,826 ICU episodes involved transfusions; hospital death occurred in 11.6 percent of episodes. Transfusion correlated with decreased adjusted hospital mortality without comorbid heart disease when Hgb was approximately <7.7 g/dL; above this Hgb level, transfusion increased mortality. When comorbid heart disease was present, corresponding Hgb level thresholds were approximately 8.7 g/dL and approximately 10 g/dL when the ICU admission diagnosis was acute myocardial infarction. These thresholds were lowered by about 1 g/dL in sensitivity analyses using additional adjustment for selected blood tests in a subgroup of 182,792 ICU episodes.

"Transfusion of critically ill patients was associated with reduced hospital mortality when Hgb level was <8 to 9 g/dL in the presence of comorbid heart disease," the authors write.