Tolerance of intraoperative hemoglobin decrease during cardiac surgery.
BACKGROUND
It has been suggested that a decrease of at least 50% from the preoperative hemoglobin (Hb) level during cardiac surgery is associated with adverse outcomes even if the absolute Hb level remains above the commonly used transfusion threshold of 7.0 g/dL. In this study the relation between intraoperative Hb decline of at least 50% and a composite endpoint was analyzed.


METHODS
This single-center study comprised 11,508 patients who underwent cardiac surgery and had normal preoperative Hb levels (12.0-16.0 g/dL in women, 13.0-18.0 g/dL in men) between January 2001 and December 2011. Logistic regression modeling was used. The composite endpoint comprised in-hospital mortality, stroke, myocardial infarction, and renal failure.


RESULTS
Patients whose Hb did not decrease at least 50% and remained above 7 g/dL were used as reference (n = 9672). A total of 363 (3.2%) patients had an intraoperative Hb of less than 7 g/dL during surgery but a Hb decrease of less than 50%; 876 patients (7.4%) showed both a nadir Hb less than 7 g/dL and a Hb decrease of at least 50%, while 597 (5.2%) had a Hb decrease of at least 50% and a nadir Hb of at least 7 g/dL. In this last group the incidence of the composite endpoint was higher than in patients in the reference group (adjusted odds ratio, 1.27; 95% confidence interval, 1.14-1.41).


CONCLUSIONS
Our findings show that a decrease of at least 50% from baseline Hb during cardiac surgery is associated with adverse outcomes, even if the absolute Hb level remains higher than the commonly used transfusion threshold of 7.0 g/dL.
Center for Clinical Transfusion Reseach, Sanquin/LUMC, Leiden, the Netherlands.
Esther
E
Hogervorst
Peter
P
Rosseel
Johanna
J
van der Bom
Mohamed
M
Bentala
Anneke
A
Brand
Nardo
N
van der Meer
Leo
L
van de Watering
D000368:Aged; D000740:Anemia / Q000175:diagnosis / Q000401:mortality*; D016063:Blood Loss, Surgical / Q000401:mortality; D001803:Blood Transfusion / Q000401:mortality*; D006348:Cardiac Surgical Procedures / Q000401:mortality*; D015897:Comorbidity; D005260:Female; D006454:Hemoglobins / Q000378:metabolism*; D017052:Hospital Mortality; D006801:Humans; D007432:Intraoperative Period; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000401:mortality; D011183:Postoperative Complications / Q000401:mortality*; D057234:Preoperative Period; D051437:Renal Insufficiency / Q000401:mortality; D020521:Stroke / Q000401:mortality
D006454:Hemoglobins