A New Critical Value, Hemoglobin Delta: Impact on Length of Stay, Upgrades, and In-Hospital Mortality

Document Type

Article

Abstract

PURPOSE: According to WHO data, anemia affects 1.62 billion people, equally affecting both sexes at all ages, across industrialized and developing countries. While anemia is defined as hemoglobin < 13 g/dL in men (hematocrit < 41-50%) and a hemoglobin < 12 g/dL (hematocrit < 36-44%) in women, hemoglobin levels are known to vary with age, gender, ethnicity, and physiological status. Although hemoglobin values vary amongst these different subgroups, transfusion guidelines are based upon a cardinal value, recommending blood products for hemoglobin <7 g/dL, which has remained essentially unchanged since established in 1999. Minimal data is available concerning hemoglobin variation, (i.e. a drop in hemoglobin) and its effect on patient outcomes. We aimed to identify associations between a hemoglobin drop within 24 hours [i.e., opposed to a strict value cut-off (e.g., hemoglobin 7 g/dL)] and hospital length of stay (LOS), upgrade in level of care, code blue, and in-hospital mortality.

METHODS: This retrospective, cohort study, approved by the institutional review board, utilized data collected from the Sysmex WAM database of the hematology department of Abington-Jefferson Health. Hemoglobin delta was defined as the difference between two unique time stamps within 24 hours. From 02/28/2021-02/28/2022, a total of 837 patients expierienced a hemoglobin delta greater than 3 g/dL within 24 hours at any time during their hospitalization at Abington-Jefferson Health; thus meeting the study inclusion criteria. For the initial analyses, 68 patients were selected from whom a rapid response was activated. The mean hemoglobin delta for these patients was 3.2 g/dL which was used to create two subgroups, a “low-delta” group (hemoglobin drop of 3g/dL-3.2 g/dL) and a “high-delta” group (hemoglobin drop >3.2 g/dL).

RESULTS: In the high-delta group, 9.5% of patients experienced a code blue, whereas 3.8% of patients experienced a code blue in the low-delta group (OR 2.632, 95% CI 0.278-24.9; p=.70). Patients in the high-delta group who were upgraded had an 87.5% mortality rate compared to patients who had a high-delta and were not upgraded with a mortality rate of 12.5% (OR 10.48, CI 95% 2.05-53.50; p= .004).

CONCLUSIONS: Transfusion guidelines are set using a cardinal number (i.e. hemoglobin <7g/dL), however hemoglobin varies among each patient encountered. At our institution, amount of hemoglobin drop was not associated with higher level of care, code blue or in hospital mortality. There was, however, a significant difference in mortality rate when comparing the high-delta group who were also upgraded in level of care.

CLINICAL IMPLICATIONS: The treatment guidelines for anemia are set to avoid complications from acute anemia; most notably hemorrhagic shock. Prompt identification and evaluation of anemia is necessary to prevent poor outcomes, such as upgrade in level of care, code blue, and in-hospital mortality. Our study makes the case for notifying providers not just for an absolute value of hemoglobin (<6.5 mg/dl at our institution) but also for a significant drop in hemoglobin (hemoglobin delta) as these patients, regardless of hemoglobin value, are at higher risk for worse outcomes.

First Page

A3864

Last Page

A3865

DOI

10.1016/j.chest.2023.07.2519

Publication Date

10-1-2023

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