Association of Serum Phosphate Levels and Anemia in Critically Ill Surgical Patients

Background: Deranged serum phosphate (Phos) levels are associated with anemia in hospitalized patients, but their relevance to critical illness is unclear. Therefore, our goal was to investigate whether abnormal Phos on admission to the surgical intensive care unit (ICU) is associated with anemia. Materials and Methods: We performed a retrospective analysis of data from an ongoing study of nutrition in critical illness. Serum Phos and hemoglobin levels were obtained at ICU admission. Normal Phos was defined as 2.5–4.0 mg/dL. To investigate the association between Phos and anemia, we performed logistic regression analyses, while controlling for age, sex, race, body mass index, Nutrition Risk Screening score, Deyo-Charlson Comorbidity Index, creatinine, mean corpuscular volume, and serum albumin. Results: In total, 510 patients comprised the analytic cohort; 62% were anemic, 30% had Phos >4.0 mg/dL, and 14% had levels <2.5 mg/dL. Logistic regression analysis demonstrated each unit increment in Phos was asso...