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

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.

Comparative study of the Effectiviness Among the four Types of Induced Hypotensive Anesthetic Methods in Maxillofacial Reconstructive Surgery

In the maxillofacial surgery, close care is mandatory during operation and anesthesia. The surgical field is limited since most procedure is done through the mouth. In this situation, airway management and blood pressure controls are keystone. So, the induced hypotensive anesthesia is essential to the maxillofacial surgery for bleeding control and accurate operation. One hundred and ninety-eight cases of maxillofacial surgery was carried out under induced hypotensive anesthesia from 1991 to 1999. Authors divided them into 4 groups based on the anesthetic protocol. In group 1(n = 43) inhalation anesthetics(enflurane, halothane) and sodium nitroprussde(SNP) were used; in group 2(n = 99) inhalation anesthetics(enflurane), SNP and labetalol were used; In group 3(n = 27) inhalation anesthetics(enflurane) and labetalol were used; In group 4(n = 29) total intravenous anesthesia(propofol, fentanyl, midazolam) was applied with SNP, and esmolol(or labetalol). The patient records were retrospectively studied during the operation and anesthesia, including degree of fluctuation in the mean arterial blood pressure, amounts of the blood loss and transfusion during the operation, complications, and the period of hospitalization. Mean operation time of 4 groups decreased in order. The blood pressure was controllable without reflex tachycardia in beta-blocker using groups. Amount and incidence of transfusion was smaller in total intravenous anesthesia group. However there were no significant differences in total admission days and ICU stay periods between 4 groups.

The Effects of Sodium Nitroprusside on Platelet Aggregation Function during Deliberate Hypotensive Anesthesia / 대한마취과학회지

Sodium nitroprusside is reported to inhibite platelet aggregation. We studied the effects of sodium nitroprusside on platelet aggregation function were in 30 adult patients undergoing spine surgery with enflurane anesthesia. Platelet-rich plasma from patients receiving sodium nitroprusside was studied for aggregation in response to adenosine diphosphate, epinephrine and collagen. Maximum aggregation rate and maximum aggregation time were evaluated serially from the samples collected at post-induction (pre-sodium nitroprusside infusion), 30 min and 90 min after sodium niroprusside infusion. The mean maximum aggregation rate of adenosone diphosphate, epinepherine and collagen at post-induction decreased significantly 30 min and 90 min after sodium nitroprusside infusion (P 0.05),but maximum aggregation time showed no significant changes. The correlation between total sodium nitroprusside dose delivered and maximum aggregation rate of adenosine diphosphate, epinepherine and collagen were r=-0.54 (P<0.05), r=-0.706 (P<0.05) and r=-0.794 (P<0.05). In summary, in situation in which sodium nitroprusside is administered during deliberate hypotensive anesthesia, the anesthesiologist must be aware of the potential for the inhibition of platelet aggregation.