Factors associated with excessive bleeding in cardiopulmonary bypass patients: a nested case-control study.
BACKGROUND
Excessive bleeding (EB) after cardiopulmonary bypass (CPB) may lead to increased mortality, morbidity, transfusion requirements and re-intervention. Less than 50% of patients undergoing re-intervention exhibit surgical sources of bleeding. We studied clinical and genetic factors associated with EB.


METHODS
We performed a nested case-control study of 26 patients who did not receive antifibrinolytic prophylaxis. Variables were collected preoperatively, at intensive care unit (ICU) admission, at 4 and 24 hours post-CPB. EB was defined as 24-hour blood loss of > 1 l post-CPB. Associations of EB with genetic, demographic, and clinical factors were analyzed, using SPSS-12.2 for statistical purposes.


RESULTS
EB incidence was 50%, associated with body mass index (BMI) < 26.4 (25-28) Kg/m2, (P = 0.03), lower preoperative levels of plasminogen activator inhibitor-1 (PAI-1) (P = 0.01), lower body temperature during CPB (P = 0.037) and at ICU admission (P = 0.029), and internal mammary artery graft (P = 0.03) in bypass surgery. We found a significant association between EB and 5G homozygotes for PAI-1, after adjusting for BMI (F = 6.07; P = 0.02) and temperature during CPB (F = 8.84; P = 0.007). EB patients showed higher consumption of complement, coagulation, fibrinolysis and hemoderivatives, with significantly lower leptin levels at all postoperative time points (P = 0.01, P < 0.01 and P < 0.01).


CONCLUSIONS
Excessive postoperative bleeding in CPB patients was associated with demographics, particularly less pronounced BMI, and surgical factors together with serine protease activation.
Jimenez Rivera
Juan J
JJ
Intensive Care Unit, University Hospital of Canary Islands, La Laguna, Spain. jjjimenez_rivera@yahoo.es
Iribarren
Jose L
JL
Raya
Jose M
JM
Nassar
Ibrahim
I
Lorente
Leonardo
L
Perez
Rosalia
R
Brouard
Maitane
M
Lorenzo
Jose M
JM
Garrido
Pilar
P
Barrios
Ysamar
Y
Diaz
Maribel
M
Alarco
Blas
B
Martinez
Rafael
R
Mora
Maria L
ML
D000328:Adult; D000368:Aged; D001774:Blood Chemical Analysis; D001777:Blood Coagulation / Q000502:physiology; D002315:Cardiopulmonary Bypass / Q000009:adverse effects* / Q000379:methods; D016022:Case-Control Studies; D003176:Complement C3 / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005342:Fibrinolysis / Q000502:physiology; D005500:Follow-Up Studies; D017052:Hospital Mortality / Q000639:trends*; D006801:Humans; D007362:Intensive Care Units; D020738:Leptin / Q000097:blood; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D017395:Plasminogen Activator Inhibitor 1 / Q000378:metabolism; D011182:Postoperative Care; D019106:Postoperative Hemorrhage / Q000175:diagnosis* / Q000401:mortality* / Q000628:therapy; D011300:Preoperative Care; D011336:Probability; D018570:Risk Assessment; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D016019:Survival Analysis
D003176:Complement C3; D020738:Leptin; D017395:Plasminogen Activator Inhibitor 1