The Use of Acute Normovolemic Hemodilution in Clipping Surgery for Aneurysmal Subarachnoid Hemorrhage

Abstract

Background: The occurrence of coronavirus disease 2019 (COVID-19) has overwhelmed the blood supply chain worldwide and severely influenced clinical procedures with potential massive blood loss, such as clipping surgery for aneurysmal subarachnoid hemorrhage (aSAH). Whether acute normovolemic hemodilution (ANH) is safe and effective in aneurysm clipping remains largely unknown.

Methods: Patients with aSAH who underwent clipping surgery within 72 hours from bleeding were included. The patients in the ANH group received 400 mL autologous blood collection, and the blood was returned as needed during surgery. The relationships between ANH and perioperative allogeneic blood transfusion, postoperative outcome, and complications were analyzed.

Results: Sixty-two patients with aSAH were included between December 2019 and June 2020 (20 in the ANH group and 42 in the non-ANH group). ANH did not reduce the need of perioperative blood transfusion (3 [15%] vs. 5 [11.9%]; P = 0.734). However, ANH significantly increased serum hemoglobin levels on postoperative day 1 (11.5 ± 2.5 g/dL vs. 10.3 ± 2.0 g/dL; P = 0.045) and day 3 (12.1 ± 2.0 g/dL vs. 10.7 ± 1.3 g/dL; P = 0.002). Multivariable analysis indicated that serum hemoglobin level on postoperative day 1 (odds ratio, 0.895; 95% confidence interval, 0.822-0.973; P = 0.010) was an independent risk factor for unfavorable outcome, and receiver operating characteristic curve analysis showed that it had a comparable predictive power to World Federation of Neurosurgical Societies grade (Z = 0.275; P > 0.05).

Conclusions: ANH significantly increased postoperative hemoglobin levels, and it may hold the potential to improve patients' outcomes. Routine use of ANH should be considered in aneurysm clipping surgery.

Keywords: Acute normovolemic hemodilution; Clipping; Functional outcome; Subarachnoid hemorrhage.

Figure 1

Flowchart showing the enrollment of patients with aneurysmal subarachnoid hemorrhage (aSAH) in this study. Hct, hematocrit.

Figure 2

Relationship of perioperative hemoglobin levels and functional outcome in patients with aneurysmal subarachnoid hemorrhage. (A) Student t test indicated that serum hemoglobin levels were significantly higher in acute normovolemic hemodilution (ANH) group than in non-ANH group on postoperative (Postop.) day 1 and day 3 (11.5 ± 2.5 g/dL vs. 10.3 ± 2.0 g/dL, P = 0.045; 12.1 ± 2.0 g/dL vs. 10.7 ± 1.3 g/dL, P = 0.002, respectively), and the preoperative (Preop) and intraoperative (Intraop) hemoglobin levels were likewise not different. (B) Only postoperative day 1 hemoglobin level was significantly associated with unfavorable outcome (11.4 ± 1.9 g/dL vs. 8.8 ± 2.0 g/dL; P < 0.001), and hemoglobin levels tested at other indicated time points had no impact on functional outcomes. mRS, modified Rankin Scale. (C) The areas under the curve of World Federation of Neurosurgical Societies (WFNS) grade and postoperative day 1 hemoglobin (Hb) level were 0.861 (95% confidence interval, 0.749–0.973) and 0.838 (95% confidence interval, 0.719–0.956), respectively, and their predictive powers of unfavorable outcome were not significantly different (Z = 0.275; P > 0.05).