Bispectral index monitoring to assess the level of consciousness in patients with brain injury / 대한마취과학회지

BACKGROUND: It is important to assess the level of consciousness in patients with brain injuries to determine modes of treatment and prognosis. We evaluated the Bispectral Index (BIS) to determine if it could be used as an objective tool for evaluation of the level of consciousness in brain-injured patients. We also compared the BIS values to clinical sedation scales such as the Glasgow Coma Scale (GCS), Richmond Agitation-Sedation Scale (RASS), and the Reaction Level Scale (RLS). METHODS: Thirty eight patients with brain injuries that were admitted to the neurosurgery intensive care unit (NSICU) were enrolled in this study. An investigator evaluated the clinical sedation scales (GCS, RASS, RLS), while a blind observer noted the BIS in the same patient. The BIS score was obtained three times at an interval of 5 hours. The BISs were measured for 1 minute at 5 min prior to the nursing assessment, during the nursing assessment, and at 5 min after the nursing assessment. The BISs used in the data analysis were the maximal, minimal, and mean values obtained during 1 min, which were defined as BISmax, BISmin, and BISmean. A Spearman's rank correlation coefficient was used to determine if the clinical sedation scales were correlated with the BIS scores. RESULTS: In 38 patients, the BISmax, BISmin, and BISmean were found to be significantly correlated with the GCS, RASS, and RLS. The BISmean had the highest correlation with GCS (r = 0.445, P < 0.01), while the BIS min had the lowest correlation with RLS (r = -0.278, P < 0.01). CONCLUSIONS: The results of BIS monitoring were found to be significantly correlated with sedation scales in patients with brain injuries. These findings suggest that BIS can be used as an objective and continuous method for assessment of the level of consciousness in patients with brain injury.

TEG Assessment of The Effect of Tranexamic Acid on Fibrinolysis during Open Heart Surgery / 대한마취과학회지

BACKGROUND: Activated fibrinolysis during cardiopulmonary bypass(CPB) is one of the causes of post CPB coagulopathy. Antifibirinolytics such as tranexamic acid have been administered prophylactically before CPB to decrease postCPB bleeding. However, their routinely application has been challenged as regarding it's thrombotic complication. This study was performed to evaluate the effect of tranexamic acid administered before CPB by thromboelastography. METHODS: 50 open heart surgical patients were randomly selected and devided into two groups, control(N=25) and tranexamic acid group(N=25). In tranexamic acid group. 125mg of tranexamic acid were singly infused before vena caval and aortic cannulation. All of parameters of thromboelastography (TEG) and fibrin degradation products measured before and after CPB were compared between two groups. RESULTS: There were no significant differences in fibrinolytic indexes of TEGs between control group and tranexamic group afte CPB. And there were also no changes in fibrinolysis index between before and after CPB in both groups. The concentration of FDP did not changed after CPB in both groups. CONCLUSIONS: It may be considered that prophylactic administration of tranexamic acid before CPB to reduce post-CPB bleeding would not be recommended routinely.

Study on Hepatic Injury following Occlusion of Hepatic Inflow in Rabbits / 대한마취과학회지

BACKGROUND: Portal triad clamping was first described by Pringle in 1908 as a mean of reducing bleeding from the cut surface of the liver during parenchymal resection. More recently some studies have reported that one period of portal triad clamping could be well tolerated for a longer duration, 60~90 minutes. The liver, generally, is believed to be very sensitive to anoxic damage and susceptible to ischemia and decreased hepatic energy charge results in decreasing arterial ketone body ratio (AKBR) during portal triad clamping. METHODS: In order to observe an adverse effects to liver in 30 minutes and 60 minutes of portal triad clamping on AKBR and histologic changes,rabbits were divided into thirty minutes of portal triad clamping in one group (Group I) and 60 minutes of that in the other group (Group II). RESULTS: During clamping, the mean AKBR of group I and II were 0.39 and 0.44, and decreased significantly compared with the mean AKBR (1.08 and 1.02) before clamping. Five minute after declamping, the mean AKBR of group II (0.49) was lower (P0.05). Under light microscopic examination of liver biopsy, there was no visible diffrences between two groups during clamping, 5 minutes and 30 minutes after declamping. CONCLUSIONS: It was concluded that there was no difference in hepatic energy change(AKBR) and histologic change under light microscopy after 30 minutes declamping between two groups.

The Hemodynamic and Electrolyte Changes in Canine Orthotopic Liver Transplantation / 대한마취과학회지

During orthotopic liver transplantation (OLT), changes of hemodynamic, electrolytes and acid-base balance are frequently occurred. These changes may influence mortality and prognosis during and after surgery. The purpose of this study was to observe and evaluate the changes of hemodynamics and electrolytes occurring in 14 cases canine OLT. After insertion of endotracheal tube, anesthesia was maintained with 1%enflurane and pancuronium bromide. Swan-Ganz catheter(7.5 Fr.) was inserted into right external jugular vein and 20 gauge angiocatheter was also inserted into left femoral artery. Complete hemodynamic variables and electrolytes were measured 30 minutes after skin incision, anhepatic stage, 5 minutes before reperfusion, 5 and 30 minutes after reperfusion. The results were as follows; On reperfusion of grafted liver, 9 cases(64%) showed postreperfusion syndrome. In 9 cases showing Postreperfusion syndrome, cardiac output, systemic vascular resistance, mean pulmonary arterial pressure were decreased and serum potassium concentration was increased on reperfusion, but there were no significant changes in central venous pressure, pulmonary capillary wedge pressure, heart rate, body temperature and serum ionized calcium concentration when comparing with before reperfusion. Decreased mean arterial pressure during reperfusion in postreperfusion syndrome might be speculated through decrease of myocardial contractility and systemic vascular resistance.

Protection of Hepatic Dysfunction during and after Hemorrhagic Shock with Intravenous Glutathione in Dogs / 대한마취과학회지

During hemorrhagic shock, liver is susceptible to ischemia and decreased hepatic energy charge results in decreasing arterial ketone body ratio(AKBR). Reperfusion after hemorrhagic shock can greatly amplify the generation of toxic oxygen metabolites. As a result, the fluxes of these highly toxic metabolites can overwhelm the endogenous antioxident defense mechanisms and lead to tissue injury. In order to observe the effect of glutathione(GSH) on the AKBR in hemorrhagic shock, dogs(n=16) were anesthetized with 1% enflurane in 02. We pretreated glutathione (100 mg/kg) intravenously before hemorrhagic shock in glutathione (GSH) group (n=8). Shock was induced with bleeding and mean arterial pressure was maintained 50 mmHg for 30 minutes. Recovery from shock was done with transfusion of preserved blood and maintained for 30 minutes. We measured arterial ketone bodies and ketone body ratio before, during and after shock, and compared them to control group (n=8) which was not pretreated with glutathione. AKBR during and after hemorrhagic shock in GSH group (0.8 and 1.0) were higher than those in control group (0.5 and 0.8). Light microscopic examination of liver biopsy revealed less portal degeneration during and after hemorrhagic shock in GSH group than control group. Pharmacologic modulation of hepatocytic function with glutathione before hemorrhagic shock has shown some beneficial effect with protection of decreased AKBR and histological change during and after hemorrhagic shock.

The Application of the Mera F Type Breathing Circuit to the Anesthesia Circle System / 대한마취과학회지

In 1976 Ramanathan et al introduced a unilimb circle circuit connecting the CO2, absorber and dome valve. A coaxial breathing circuit, Mera F Type breathing circuit, is very light in weight, compact and it can be made any length. This circuit can be used as a circle system, rebreathing or non-rebreathing system and it can be applicable to both pediatric and adult anesthesia. This circuit is easily adaptable to humidification and pollution control devices. It is especially suitable for any kind of surgical procedures including head, neck and others requiring any awkward positions. A clinical study of this circuit was done in 30 cases and compaired with 18 cases using the coventional circuit. Fresh gas flow, tidal volume and respiratory rate were 4 L/min(02:2 L/min., N2O:2L/min.),10 ml/kg and 12-14/min respectively. Controlled ventilation using a volume preset ventilator was used in all cases. After induction, radial artery cannulation with a 20 G angiocatheter was done and blood gas analysis was performed at 30, 60 and 90 minutes respectively. The blood gas analysis was found satisfactory in either the conventional or the Mera F circuit system.