Daily Lowest Hemoglobin and Risk of Organ Dysfunctions in Critically Ill Patients

Abstract

Objective To determine the association between hemoglobin levels and the daily risk of individual organ dysfunctions in critically ill patients. Design We performed a post-hoc analysis of prospectively collected data in medical and surgical ICU patients admitted with respiratory failure or shock. Baseline demographic data, and detailed in-ICU and hospital data, including daily lowest hemoglobin, were collected up to hospital day 30. We assessed patients daily for brain dysfunction [delirium, using Confusion Assessment Method for ICU (CAM-ICU)], for renal and respiratory dysfunction [using the ordinal renal and respiratory Sequential Organ Failure Assessment (SOFA score)], and for ICU mortality. Associations between the lowest hemoglobin on a given day and organ dysfunctions the following day were assessed using multivariable regressions, adjusting for age, APACHE II score, Charlson comorbidity index, Framingham stroke risk profile, ICU day, ICU type, sepsis, and current organ dysfunction status. A sensitivity analysis further adjusted for daily transfusions and fluid balance in a subset of our patients. Measurements and Main Results We enrolled 821 patients with a median (interquartile range, IQR) age of 61 (51, 71) years, APACHE II score of 25 (19, 31), and hemoglobin level of 10.0 (9.0, 11.1) g/dl. There was no evidence of an association between lowest daily hemoglobin and brain dysfunction (p=0.69 for delirium), renal dysfunction (p=0.30) or ICU mortality (p=0.95). The lowest hemoglobin on a given day was significantly associated with the respiratory SOFA score the following day; for each increasing hemoglobin unit, the odds of worsened respiratory SOFA score the following day were decreased by 36% (OR 0.64, 95% CI: 0.53, 0.77, p < 0.001). The sensitivity analysis including daily transfusions and fluid balance (in a subset of 518 patients) did not qualitatively change any of these associations. Conclusions In this study in ICU patients, lower hemoglobin was associated with a higher probability of worsening respiratory dysfunction scores the following day. There was no evidence of association between hemoglobin and brain or renal dysfunction, or ICU mortality. The possible differential effects of anemia on organ dysfunctions seen in this hypothesis generating study will have to be studied in a larger prospective study before any alterations to present restrictive transfusion guidelines can be recommended.

Prognostic biomarkers in COVID-19 infection: value of anemia, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and D-dimer

“…In literatures, the cut-off point of Hb level that define anemia associated with severe COVID-19 infection ranges from 11 to 13 g/L [ 14 – 16 ]. Anemia may increase risk for severe COVID-19 infection by the following mechanisms: (A) low hemoglobin level is associated with decreased oxygen delivery to organs and tissues which may aggravate hypoxemia especially to respiratory system thus play an important role in the development of multi-organ failure [ 17 ]. (B) SARS-CoV-2 can interact with ACE2, CD147, and CD26 receptors on the erythrocyte.…”

Anemia is associated with severe coronavirus disease 2019 (COVID-19) infection

“…In the circulation system, hemoglobin serves as a carrier for oxygen to target organs in the body. When the concentration of the hemoglobin in the circulation is low, the transport of oxygen to several organs in the body will be disrupted, therefore causing hypoxia that will eventually result in multiple organ dysfunction, especially respiratory organ dysfunction [ 9 ]. Multiple organ dysfunction will contribute to the development of severe outcomes in COVID-19 infection.…”

Treatment Pattern of Covid-19 Patients in a Tertiary Care Teaching Hospital of Northern India

“…The pathophysiology of anemia and COVID-19 association is well explained when hemoglobin is low it results in less transportation of oxygen to various organs resulting in hypoxia. Hypoxia will ultimately result in multi organ dysfunction especially the respiratory organ dysfunction making more vulnerable to COVID-19 [16].…”