Anemia Screening in Elective Surgery: Definition, Significance and Patients?? Interests

Abstract

To the Editor: In their article, Olson et al. (1) concluded that routine assessment of hemoglobin levels for “healthy” patients undergoing low-risk elective surgery should be abandoned. We take issue with their conclusions. Because even mild anemia has been linked to increased morbidity and mortality (2–4), and knowing a patient's hemoglobin level can help caregivers identify and treat both anemia itself and various serious medical conditions associated with anemia, routine assessment of hemoglobin levels should be continued. Olson et al. defined anemia as having a hemoglobin levels ≤9 g/dL, assuming that these levels, even in asymptomatic patients, would indicate anemia that might necessitate therapy. By setting the hemoglobin threshold so low, the authors under-estimated the prevalence of anemia in their patients. The World Health Organization defines anemia as hemoglobin <13 g/dL in men and <12 g/dL in women (5). Data from the National Health and Nutrition Survey suggest a prevalence of 4.4%–5.9% in the general United States population (6). However, the reported incidence of anemia in surgical populations is dramatically increasing. In one study, up to 75% of hospitalized patients older than 65 yr old had anemia (7). Another study found 67% of cancer patients to be anemic, and many were untreated (8). Anemia is an independent predictor of morbidity and mortality (9). It might be argued that the poor outcomes associated with anemia are mostly the result of cases with very low hemoglobin levels. However, even mild anemia has been linked to increased morbidity and mortality in patients undergoing percutaneous coronary intervention (2), in patients with congestive heart failure (3), and in patients with the vicious cycle of cardio-renal-anemia syndrome (4). Numerous studies also show that anemia reduces quality of life and leads to poor performance (8,10). Again, hemoglobin levels between 12 and 9 g/dL have been equally implicated (11). Conversely, normalizing hemoglobin levels helps prevent dementia and improve brain function (12). Lastly, hemoglobin assessment is an inexpensive readily available screening tool for underlying comorbidities. For example, the prevalence of colon cancer varies from 4% to 15% (13) among patients in outpatient settings who present with iron-deficiency anemia. Anemia is a key predictor of reduced renal function (14). Our interest in anemia goes beyond surgical transfusion requirements. Anemia, once considered an innocent bystander, should no longer be left undetected or untreated (9). To manage anemia in elective surgery patients, we recently (15) developed a clinical care pathway calling for measuring a patient's hemoglobin 30 days before surgical procedures. This allows time for diagnosing and treating underlying comorbidities. Simply obtaining a hemoglobin level for those evaluated for low-risk surgery helps identify patients whose anemia may be attributable to silent killers such as colon cancer and helps caregivers decide upon appropriate diagnostic and therapeutic measures. Aryeh Shander, MD Mazyar Javidroozi, MD Department of Anesthesiology & Critical Care Medicine Englewood Hospital & Medical Center Englewood, NJ [email protected] Lawrence T. Goodnough, MD Departments of Pathology and Medicine Stanford University Stanford, CA