The effect of NON-invasive hemoglobin measurement on blood transfusion and mortality in hip surgery

Aim: The first aim of this study was to evaluate the effect of non-invasive hemoglobin (SpHb) measurement on blood transfusion decision in patients who will undergo hip surgery. The secondary aim was to investigate the effect of this decision on mortality. Methods: Following the ethics committee approval, 52 patients aged 60 years and older in the ASA I-III risk group who were to undergo hip surgery were included in the study. In addition to routine hemodynamic monitoring, intra-arterial cannulation was applied to all patients for continuous arterial pressure monitoring. Basal Hb values of all patients were recorded with the Complete Blood Count test before induction. The patients were divided into two groups as blood transfusion decision was made based on SpHb data and blood transfusion decision was made with conventional methods. After routine anesthesia induction, maintenance of anesthesia was provided with sevoflurane and remifentanil. Intraoperative fluid administration was performed with Pleth Variability Index (PVI) in both groups. Before anesthesia induction (basal), after anesthesia induction, at the time of the 1st transfusion decision, immediately after the 1st transfusion, at the time of the 2nd and 3rd transfusion decision according to the bleeding status, immediately after the replacement and after awakening, the blood gas samples of the patients, complete blood count, SpHb and PVI values were checked and recorded. Hemodynamic data were recorded at regular intervals. Multimodal analgesia was administered to all patients for postoperative analgesia before awakening. Postoperative survival was followed up at 1 and 3 months. Results: Results: At the time of the 1st transfusion decision, after the 1st transfusion and after awakening, Hb values were found to be higher in Group I patients than in Group II patients (P = 0.001; P = 0.012; P = 0.001, respectively). PO2 measurements after the first blood transfusion, at the time of the second transfusion decision and after the second transfusion were found to be higher in Group I (P = 0.015; P = 0.027; P = 0.015, respectively). The total number of blood transfusions of the patients in Group II was higher than Group I (P = 0.025). The hospital stay of the patients in Group II was longer than in Group I (P = 0.043). The 1st and 3rd month mortality rates were similar between both groups (P > 0.05). Conclusion: In our study, we investigated the blood transfusion decisions made with non-invasive SpHb monitoring and conventional methods during hip surgery and their effects on mortality; we detected an increase in perioperative oxygenation in patients followed up with SpHb data. We did not find any difference between the groups in terms of 1st and 3rd month mortality scores. We found that the hospital stay was shorter in the group in which we applied blood management with SpHb. We think that the non-invasive SpHb probe can detect the need for blood transfusion during the operation at an early stage, warn the clinician in a timely manner, prevent unnecessary blood transfusion due to the continuous Hb trend it shows, and shorten the hospital stay.