Cardiac surgery patients have a high risk of excessive postoperative bleeding as a consequence of procoagulant blood products, vasoconstrictors, and poor organ perfusion. Researchers who conducted a study at University Hospital in São Paulo, Brazil, say that for clinicians to be prepared for timely interventions, it helps to know which patients to watch and when to identify the risk factors.
In their prospective study of 323 patients, episodes of excessive bleeding were concentrated in the first and second postoperative hours, and 21% of complications required interventions, such as vasoactive medication titration, protamine supplementation, and transfusions of blood products. During the immediate postoperative time, 105 patients developed excessive bleeding with 39 in the first hour, followed by 36 patients in the second hour, and 8 in the third hour.
The researchers found that other risk factors for excessive bleeding were chronic hypertension, greater height, body mass index (BMI) < 26.35 kg/m2, higher hematocrit, and intraoperative heparin dose > 312.5 mg without subsequent platelet transfusion. The researchers say platelet transfusions may have been protective. Certain variables, such as lower BMI and male gender, may have been explained by greater clot strength and faster rate of fibrin formation in women.
Patients at risk for excessive bleeding also had lower preoperative platelet count, although the mean value was within the normal range. But given that more than half the study group used aspirin and 11% used an adenosine diphosphate-receptor blocker, the researchers say they may have had a higher prevalence of unknown platelet dysfunctions.
Source:
Lopes CT, Brunori EFR, Cavalcante AMRZ, et al. Heart Lung. 2016;45(1):64-69.e2.
doi: 10.1016/j.hrtlng.2015.09.