Preoperative polycythemia may be associated with inferior postoperative outcomes: a retrospective study

To investigate the influence of preoperative polycythemia on postoperative outcomes.

We retrospectively reviewed the postoperative outcomes of 1196 elective non-cardiac surgery procedures (minor, 36%; intermediate/major, 64%) performed under general anesthesia at the General Hospital of Šibenik-Knin County, Croatia, between January 1, 2023 and January 1, 2024. Patients were stratified preoperatively as having anemia, normal hemoglobin, or polycythemia. The primary outcome was a 30-day postoperative composite outcome consisting of death, thrombosis, major bleeding, and the need for red blood cell transfusion.

Anemia, normal hemoglobin levels, and polycythemia were recorded preoperatively in 152 (12.7%), 1000 (83.6%), and 44 (3.7%) of patients, respectively. Patients with polycythemia were the youngest, more frequently men and smokers, and had the lowest frequency of prior venous thromboembolism (VTE). Patients with anemia were the oldest and most frequently had comorbidities, cancer, and prior VTE, used anticoagulants, and underwent intermediate/major surgeries. The composite outcome was recorded in 91 procedures (7.6%) and was most frequent in patients with polycythemia (18.2% vs 9.2% vs 6.9%; P=0.016). Patients with polycythemia also most frequently had postoperative bleeding (18.2% vs 7.9% vs 6.5%; P=0.011) and did not need postoperative red blood cell transfusions (P=0.003). The associations of preoperative polycythemia with the postoperative composite outcome and bleeding remained significant in multivariate models adjusted for surgery risk, sex, comorbidities, physical status, and antiplatelet or anticoagulant use. Patients with polycythemia did not experience deaths or thrombotic events.

Patients with polycythemia require comprehensive preoperative assessment. Future studies are needed to investigate the pathophysiological mechanisms underlying the observed effects.