Effects of Acute Normovolemic Hemodilution under Induced Hypotension on Blood Saving and Homologous Transfusion in Orthognathic Two Jaw Surgery

Abstract

Background: To avoid complications of homologous transfusion;many methods are being used in patients who undergo an operation;and autologous transfusion is the most popular modality. Acute normovolemic hemodilution (ANH) is recognized as the easiest;the most economical and valuable autologous blood saving method among the types of autotransfusion. This study was performed to investigate the clinical usefulness of ANH under induced hypotensive anesthesia to reduce blood loss and homologous transfusion in orthognathic two jaw operation. Methods: Thirty patients were randomized divided into two groups; with ANH (n = 15) and without ANH (n = 15). The surgery was limited to one surgeon;with genioplasty;and no bone graft. All patients were pre-donated 2 units of autologous blood before operation. All the surgery was done under induced hypotension by nitroglycerine and esmolol;target mean arterial pressure was aimed at 70% of preoperative blood pressure. In with ANH group;autologous blood were procured immediately after anesthetic induction while 6% hydroxyethyl starch solution were infused to maintain normovolemia until lowering hematocrit to 28%. Results: The two groups did neither differ significantly with demographic data and preoperative evaluation finding. Nor in operation time;surgeon's satisfaction to surgical field;serial central venous pressure;hematocrit's value;prothrombin time;activated partial thromboplastin time. All patients needed transfusion of pre-donated 2 units of autologous blood during operation;but there was significantly reduced demand for homologous packed RBC transfusion in the with ANH group compared with the control group (0.0 0.0 unit vs. 1.7 1.2 unit;P = 0). Blood saving effects was so greater in with ANH group (total blood loss; 1110.0 154.9 cc vs. 833.3 156.6 cc;P = 0). In addition;the amount of agents for induced hypotension was smaller in with ANH group (nitroglycerine: 11.3 2.4 mg vs. 9.9 2.4 mg;P = 0.012;esmolol: 52.0 28.2 mg vs. 14.6 8.3 mg;P = 0). Conclusions: ANH with pre-donated autologous blood under induced hypotension can reduce intraoperative blood loss and homologous transfusion requirements in orthognathic two jaw operation.