Evaluating Hemoglobin Thresholds for Blood Transfusions in Oncology Patients Admitted to the Intensive Care Unit

Background: In the intensive care unit (ICU), up to 90% of patients develop anemia during their stay. However, evidence regarding transfusion practices in oncology patients requiring ICU-level care is limited. This study aimed to compare mortality, survival rate, and readmissions across three hemoglobin thresholds of transfusion (low < 7 g/dL, intermediate 7-8 g/dL, and high > 8 g/dL) among these patients. Methods: A retrospective analysis of 561 patients with cancer admitted to the ICU who received blood transfusions from 2017 to 2023 was performed. Univariate and multivariate analyses were utilized to compare three hemoglobin thresholds of transfusion. A P ≤ 0.05 was considered significant. Results: Of 561 patients, the transfusion burden was greater in the low threshold cohort (46.6%), followed by intermediate (29.3%) and high (24.1%) thresholds. The low threshold cohort required a longer duration of mechanical ventilation compared to the high threshold (P ≤ 0.03). The readmission rate was highest in the low threshold cohort compared to the others (30-day: 23.4% vs 11% vs 16.3%; 90-day: 3.1% vs 1.2% vs 2.2%). Mortality risk was elevated in patients transfused at high thresholds compared with those transfused at low thresholds (odds ratio (OR), 1.893; 95% confidence interval (CI), 1.093-3.281; P < 0.05), and mortality did not differ between the low and intermediate thresholds (P > 0.05). The intermediate threshold showed the highest survival probability, and the high threshold had the worst survival. Conclusions: In patients with malignancy admitted to the ICU, transfusions administered at levels < 7 g/dL were associated with a greater transfusion burden, longer mechanical ventilation, and higher 30- and 90-day readmissions. The high threshold was associated with poor survival. These findings highlight the need for prospective studies in ICU oncology on the blood transfusion threshold.