Low preoperative fibrinogen plasma concentration is associated with excessive bleeding after cardiac operations

Data from small selected patient populations suggest that the preoperative plasma concentration of fibrinogen influences postoperative blood loss and red blood cell transfusion after cardiac operations, but there are also conflicting reports. We assessed the importance of preoperative fibrinogen concentration for excessive bleeding and red cell blood transfusion in a large cohort of mixed cardiac surgical patients.

We included 1,954 cardiac surgical patients in a prospective observational study. The fibrinogen plasma concentration was measured on the day before the operation. Blood loss (mediastinal drain volume) during the first 12 postoperative hours and red blood cell transfusion during the hospital stay were registered and related to fibrinogen concentration with logistic regression models. Excessive bleeding was defined as postoperative blood loss exceeding 1,000 mL/12 hours.

The preoperative fibrinogen concentration was inversely proportional to the prevalence of excessive bleeding in univariate testing (odds ratio [OR], 0.75; 95% confidence interval [CI], 0.64 to 0.89 per g/L; p=0.001) and also in a multiple model adjusted for age, sex, body mass index, renal function, acuteness of the operation, cardiopulmonary bypass time, clopidogrel use less than 5 days before the operation, and type of operation (OR for fibrinogen, 0.82; 95% CI, 0.69 to 0.97; p=0.024). In contrast, the prevalence of red cell blood transfusion increased with increasing fibrinogen levels in univariate testing (OR, 1.36; 95% CI, 1.24 to 1.49; p<0.001) but not in a multiple model (OR, 1.10; 95% CI, 0.89 to 1.28; p=0.49).

Preoperative plasma concentration of fibrinogen is independently associated with excessive bleeding after cardiac operations but not with red blood cell transfusion.