The prevalence of anemia in cancer patients has been well documented. Rates range from 30-39%. However, the prevalence and incidence of anemia in cancer patients in need of critical care is not known. Furthermore, among patients with cancer, anemia has been associated with decreased response to chemotherapy, diminished quality of life, and increased financial burden of the disease. Determining the relative impact of clinical and demographic factors would be important because certain subgroups of patients are at higher risk of developing anemia during the course of the disease.

In this study by Cardenas-Turanzas et al, demographic information collected at the time of ICU admission was used during a retrospective chart review of adult patients admitted to the ICU at the University of Texas M.D. Anderson Cancer Center. Demographic information included age, sex, race, and marital status. Clinical information included recently treated cancer type, previous cancer treatments, length of stay before the ICU admission, and other variables. The risk of mortality was computed by calculating a revised sequential organ failure assessment (SOFA) score. Patients received a score of 0-20, with higher numbers indicating greater risk of mortality. Hemoglobin levels were measured at ICU admission and classified according to severity as mild, moderate, or severe.

Clinical and demographic data was collected for 4705 patients enrolled in the study. The prevalence of anemia at ICU admission was 68%. Of the patients with anemia, 38% had mild anemia, 24% had moderate anemia, and 6% had severe anemia. There were significantly higher proportions of anemia in the medical patients and in surgical patients, for all age categories except for those older than 80 years. Overall, moderate to severe anemia was more prevalent in medical patients than in surgical patients. Anemia developed in 46.6% (701/1502) of the patients who were initially without anemia at ICU admission. Among the patients developing anemia, 65.6% (460/701) were eventually diagnosed with mild anemia, 29.0% (203/701) with moderate anemia, and 5.4% (38/701) with severe anemia. All factors that significantly predicted incident anemia during ICU stay were similar to those associated with prevalent anemia at ICU admission. Independent clinical determinants included severity of illness score, admission to the MICU, prior chemotherapy, diagnosis of a hematologic cancer, and length of stay before ICU admission. Independent demographic determinants included female sex, nonwhite ethnicity, and age.

Cardenas-Turanzas M, Cesta MA, Wakefield C, Wallace SK, Puana R, Price KJ, Nates JL. Factors associated with anemia in patients with cancer admitted to an intensive care unit. J Crit Care. 2009 Jul 2.

NAAC Expert Commentary
In their study, Cardenas-Turnanzas and colleagues describe both the incidence and prevalence of anemia in this selected population of patients with cancer admitted to the ICU.The prevalence of anemia reflects the current published data that reports astonishingly high rates of this condition. Development of anemia in this population is also comparable to previous incidence reports.

Drawbacks of this study include its retrospective nature, lack of control, and the fact that different cancers were included. Although acute leukemia and lymphoma patients had a high incidence of anemia with lower hemoglobin levels, their chances of recovery with remission may be better than some other cancers. Identification of anemia in these patients may or may not affect patient outcomes.

The value of studying anemia in this population would come from correlating the length of presence of the cancer, hemoglobin levels, and survival. This correlation was not done. However, had it been studied, this correlation would lead other investigators to perform studies on intervention and outcome. This analysis would also help address the controversy of whether hemoglobin is a reflection of the severity of the underling disease, as opposed to being an independent marker of survival.

Last Updated: September 15, 2009