Time course and etiology of death in patients with severe anemia

Mortality increases as hemoglobin (Hb) levels fall. Among severely anemic patients, the clinical course, cause of death, and whether there are any warning signs before death are unknown.

A retrospective cohort study was performed of surgical patients who refused red blood cell transfusions for religious reasons and died with a Hb concentration 6 g/dL or less. Mortality was defined as death that occurred during hospitalization.

Among the 1958 Jehovah's Witness patients that had surgery, 117 (5.6%) had a postoperative Hb level of 6 g/dL or less and 39 (33.3%) of these individuals died in the hospital. The median number of days from surgery to the lowest Hb level was 3 days (range, 0-22 days; interquartile range, 1-8 days) and from the lowest postoperative Hb level to death was 2 days (range, 0-40 days; interquartile range, 1-12 days). Individuals with a Hb level of 2.0 g/dL or less had on median 1.0 (interquartile range, 0.5-1.5) day from their lowest Hb to death while individuals with their lowest Hb ranging between 4.1 and 5.0 g/dL had on median 11 (interquartile range, 1-23) days from their lowest Hb to death. Except for anemia, no single etiology of death was predominant.

While there does not appear to be any single etiology that can be predictive or preventative of mortality for anemic patients, individuals with very low Hb concentrations often do not die quickly. Thus, there appears to be a potential time window where transfusion medicine physicians may intervene.