Preoperative thrombocytopenia and postoperative outcomes after noncardiac surgery.

BACKGROUND Most studies examining the prognostic value of preoperative coagulation testing are too small to examine the predictive value of routine preoperative coagulation testing in patients having noncardiac surgery. METHODS Using data from the American College of Surgeons National Surgical Quality Improvement database, the authors performed a retrospective observational study on 316,644 patients having noncardiac surgery who did not have clinical indications for preoperative coagulation testing. The authors used multivariable logistic regression analysis to explore the association between platelet count abnormalities and red cell transfusion, mortality, and major complications. RESULTS Thrombocytopenia or thrombocytosis occurred in 1 in 14 patients without clinical indications for preoperative platelet testing. Patients with mild thrombocytopenia (101,000-150,000 µl), moderate-to-severe thrombocytopenia (<100,000 µl), and thrombocytosis (≥450,000 µl) were significantly more likely to be transfused (7.3%, 11.8%, 8.9%, 3.1%) and had significantly higher 30-day mortality rates (1.5%, 2.6%, 0.9%, 0.5%) compared with patients with a normal platelet count. In the multivariable analyses, mild thrombocytopenia (adjusted odds ratio [AOR], 1.28; 95% CI, 1.18-1.39) and moderate-to-severe thrombocytopenia (AOR, 1.76; 95% CI, 1.49-2.08), and thrombocytosis (AOR, 1.44; 95% CI, 1.30-1.60) were associated with increased risk of blood transfusion. Mild thrombocytopenia (AOR, 1.31; 95% CI, 1.11-1.56) and moderate-to-severe thrombocytopenia (AOR, 1.93; 95% CI, 1.43-2.61) were also associated with increased risk of 30-day mortality, whereas thrombocytosis was not (AOR, 0.94; 95% CI, 0.72-1.22). CONCLUSION Platelet count abnormalities found in the course of routine preoperative screening are associated with a higher risk of blood transfusion and death.