Preoperative Hemoglobin and Actual Need for Blood Transfusion in Brain Tumor Resection Procedures: A Retrospective Cohort Study.

Abstract

To the Editor: Reducing unnecessary preoperative cross-match testing provides an opportunity to improve the efficiency of blood transfusion management in neurosurgery.1–6 We estimated the rate of unnecessary preoperative cross-matching according to actual need for blood transfusion, and calculated indexes of efficiency for perioperative blood transfusion management,7 in brain tumor resection procedures. Secondarily, we evaluated the role of preoperative hemoglobin (preHb) concentration as an objective predictor of actual perioperative blood transfusion requirements.7,8 This retrospective study was approved by the University of Navarra Ethics Committee (2020.045; July 2, 2020) with waiver of consent. Following retrieval of relevant data from clinical records, patients were categorized into 4 groups according to whether preoperative cross-match testing had or had not been performed, and according to actual transfusion requirements before discharge from hospital. International indexes of efficiency for perioperative blood management were calculated: cross-match to transfusion ratio, transfusion probability, and transfusion index. Logistic regression was used to estimate odds ratios and 95% confidence intervals (95% CI) for transfusion requirements based on preHb. The area under the receiver operating characteristic curve was used to quantify the overall ability of preHb to discriminate patients that did not require red cell transfusion from those that required transfusion. A detailed description of the study methodology and definition of indexes of transfusion efficiency are available in the supplementary material (Supplemental Digital Content 1: Materials andMethods, http://links. lww.com/JNA/A338). Seven hundred thirty eight patients that underwent craniotomy for brain tumor resection between 2008 and 2018 were included in the analysis (Supplemental Digital Content 2: Supplementary Table 1: Baseline Patient Characteristics, http://links.lww.com/JNA/A339). The distributions of preoperative cross-match testing and actual transfusion requirements among study participants are shown in Figure 1. The cumulative incidence of preoperative cross-match testing was 70.2% (95% CI: 66.8%-73.4%); of the 518 patients that had preoperative cross-match testing, 485 (93.6%, 95% CI: 91.2%95.5%) did not require red cell transfusion. Overall, 5.1% (95% CI: 3.8%-7.0%) of patients required perioperative red cell transfusion. The proportion of patients in the whole study population that required red cell transfusion in the absence of preoperative cross-match testing was 0.7% (95% CI: 0.2%1.6%), and the proportion in the subgroup that did not have cross-match testing was 2.3% (95% CI: 0.8%-5.4%). Thus, the percentage of patients that did not have preoperative crossmatch testing but required red cell transfusion (Fig. 1, Quadrant A) or had preoperative cross-match but did not require red blood cell transfusion (Fig. 1, Quadrant D) was 66.4% (95% CI: 62.9%-69.7%). Both these situations represent inefficient perioperative transfusion management and are potential targets for improvement actions. Moreover, the cross-match to transfusion ratio was 16.35, transfusion probability 7.34%, and transfusion index 0.15; these values are also indicative of inefficiencies in cross-matching/transfusion processes (see Supplemental Digital Content 1: Materials and Methods, http://links.lww.com/JNA/A338). There was an inverse association between preHb and transfusion requirements; mean (±SD) preHb in patients that Received for publication November 2, 2020; accepted November 27, 2020. From the Departments of *Neurosurgery, Neurology and Neurosciences; †Anesthesia, Perioperative Medicine and Critical Care; ∥Research Support Service, Central Clinical Trials Unit, Clínica Universidad de Navarra, University of Navarra; ‡IdiSNA, Instituto de Investigación Sanitaria de Navarra, Pamplona; and §Department of Neurosurgery, Neurology and Neurosciences, Hospital Universitario Fundación Jiménez Díaz, Autonomous University of Madrid, Madrid, Spain. The authors have no funding or conflicts of interest to disclose. Address correspondence to: Antonio Martinez-Simon, MD, PhD. E-mail: [email protected]. Supplemental Digital Content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s website, www.jnsa. com. Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved. DOI: 10.1097/ANA.0000000000000753 RESEARCH LETTER