Electrolysis of physiological salt solution generates a factor that relaxes vascular smooth muscle

Oxygen-derived free radicals have been implicated in many important functions in the biological system. Electrical field stimulation (EFS) causes arterial relaxation in animal models. We found that EFS applied to neither muscle nor nerve but to Krebs solution caused a relaxation of rat aorta that had been contracted with phenylephrine. In the present study, therefore, we investigated the characteristics of this EIRF (electrolysis-induced relaxing factor) using rat isolated aorta. Results indicated that EIRF acts irrespective of the presence of endothelium. EIRF shows positive Griess reaction and is diffusible and quite stable. EIRF-induced relaxation was stronger on PE-contracted aorta than on KCl-contracted one, and inhibited by the pretreatment with methylene blue. Zaprinast, a cGMP-specific phosphodiesterase inhibitor, potentiated the EIRF-induced relaxation. NG-nitro-L-arginine, NO synthase inhibitor, did not inhibit the EIRF-induced relaxation. Deferroxamine, but not ascorbic acid, DMSO potentiated the EIRF-induced relaxation. These results indicate that electrolysis of Krebs solution produces a factor that relaxes vascular smooth muscle via cGMP-mediated mechanism.

Recurrent Laryngeal Nerve Paralysis Associated with Cricoarytenoid Subluxation Following General Anesthesia: A case report / 대한마취과학회지

Arytenoid subluxation or recurrent laryngeal nerve paralysis may result from injury to the larynx following endotracheal intubation or blunt laryngeal trauma. Early diagnosis is important for appropriate treatment and better prognosis. A 62-years-old man was admitted for cholecystectomy. He was intubated without any difficulty and nasogastric tube was inserted with the help of laryngoscope and Magill forcep before surgery. He had a weak voice and hoarseness after atraumatic extubation and those symptoms did not improve even 2 days after. Indirect laryngoscopy, videolaryngotelescopy, electromyography(EMG) and computed tomographic findings revealed anterior, inferior subluxation of left cricoarytenoid cartilage associated with left thyroarytenoid muscle denervation and resultant unilateral vocal cord palsy. Conservative treatment for 40 days after the operation and follow-up examination was done. The voice quality was improved and indirect laryngoscopy examination showed that right vocal cord crossed midline in a attempt to meet its paralyzed counterpart on phonation.

Severe Blood Pressure Changes by Manipulation of the Mass during the Brain Tumor Surgery: A Case report / 대한마취과학회지

A case changing blood pressure severely by manipulation of the huge tumor mass during the brain tumor surgery was observed. Decreased blood pressure (55/35 mmHg) might be caused by the stimulation of the brain increased to 150/75 mmHg after a neurosurgeon undermined and elevated the tomor mass, and blood pressure decreased again to 55/35 mmHg when he put it on the same position. Removing the mass completely, blood pressure was stabilized (about 130/70 mmHg). There are central vasomotor centers of autonomic nervous organization in the hypothalamus, midbrain, pons or medulla oblongata of the brain. By the stimulation of specific region in the above area, various features of responses were anatomically defined. The supratentorial contents may herniate through the tentorial incisura into the infratentorial spaces and posterior fossa, when intracranial pressure gradients become large enough to overcome the resistance of the brain tissue, and they can affect vital changes.

Comparative Maternal and Neonatal Effects of Propofol, Propofol-Ketamine and Ketamine as Induction Agents in Cesarean Section / 대한마취과학회지

BACKGROUND: Propofol and ketamine had been used for anesthesia induction and for total intravenous anesthesia. The nature of any hypnotic interactions occurring between propofol and ketamine are unknown. A comparison of maternal and neonatal effects among propofol-ketamine combination, ketamine and propofol were studied when used for anesthesia induction in Cesarean section. METHODS: Forty five patients in ASA class I or II scheduled for Cesarean section randomly assigned to either propofol 2 mg/kg (n=15), ketamine 1 mg/kg (n=15) or propofol 1 mg/kg - ketamine 0.5 mg/kg combination group (n=15) as an induction agent. Maternal systolic and diastolic blood pressure, heart rate, Apgar score and umbilical blood gas analysis were measured. RESULTS: Before intubation, systolic and diastolic pressure were decreased in propofol group but increased in ketamine and propofol-ketamine combination group. Heart rate were increased in all three groups. But there were no significant differences among three groups (p<0.05). After intubation, there were significant increase in systolic, diastolic pressure and heart rate in three groups but no significant differences among three groups (p<0.05). And there was no significant neonatal depression as assessed by Apgar scores and blood gas analyses. CONCLUSIONS: Propofol-ketamine combination was found to be similar to propofol or ketamine only in the effects on the mother and neonate. But propofol-ketamine gained more stable hemodynamic change than propofol or ketamine before intubation. Therefore propofol-ketamine appears to be a suitable alternatives to propofol or ketamine as an induction agent for anesthesia in Cesarean section.

Adequate Dose Reqirements of Propofol by Injection during Anesthesia Induction / 대한마취과학회지

BACKGROUND: Propofol is a short-acting intravenous sedative-hynotic agent that can be used for induction and maintenance of general anesthesia. This study was perfomed to evaluate adequate dose requirements of propofol by injection during anesthesia induction, and to evaluate the induction technique by assessing induction dose, induction time, success rate of induction and hemodynamic effects. METHODS: Ninety healthy adult patients(ASA class I or II), scheduled for elective surgery under general anesthesia, were randomly assigned to receive propofol 1 mg/kg(group I), 2 mg/kg(group II), and 3 mg/kg(group III) respectively as an induction agent. Mean arterial pressure(MAP) and heart rate(HR) were measured before the administration of propofol and just after successful induction. We determined the speed of injection as lasting 40 seconds. RESULTS: Success rate of induction in group I(30%) was lower than group II(100%) and III(100%). The induction time in group I(81s) was longer than group II(51s) and III(47s). The MAP were statistically significant difference among three groups(p<0.05 compared with before induction). In group III, the MAP was more decreased than group I and II and HR was more increased than group I and II. CONCLUSIONS: We concluded that propofol in group II(2 mg/kg) is more desireable dose than group I(1 mg/kg) and group III(3 mg/kg) for induction of general anesthesia.

A Comparative Study of the Epidural Buprenorphine and Morphine for Post-Cesarean Section Pain Relief / 대한마취과학회지

Buprenorphine is a semisynthetic, highly lipophilic opioid derived from thebaine and it is 30 to 40 times more potent than morphine. This study was performed to compare the clinical effects of epidural buprenorphine on postoperative pain control with those of epidural morphine in 150 cesarean deliveries. They were physical status 1 or 2 by ASA classification and randomly divided into three groups. They were administered morphine 3 mg in group I, buprenorphine 0.15 mg in group II and buprenorphine 0.3 mg in group III as first dose mixed with 0.25% bupivacaine 10 ml respectively through indwelling epidural catheter at the time of ligation of umbilical cord. Second and third doses were administered with 8 hours intervals, morphine 3 mg with N/S 10 ml was injected in group I and buprenorphine 0.15 mg with N/S 10 ml was injected in group II and III respectively. Their analgesic effects were evaluated by VAS and severity of side effects was also evaluated. The Results were as follows; 1) VAS was significantly increased in group II compared to group I and III(p<0.05). There was no significant difference between group I and III. 2) Pruritus was lesser in group II and III than group I(p<0.05). 3) There was no significant difference in nausea and vomiting. 4) None of patients had respiratory depression. The authors' findings indicate that epidural administration of buprenorphine of suitable dose may be useful in the treatment of postoperative pain.

Comparison of Right Internal Jugular or Subclavian Pressure and Central Venous Pressure during Anethesia / 대한마취과학회지

The internal jugular and subclavian veins are considered as satisfactory intravenous routes for rapid blood and fluid replacement. To determine whether these venous pressures can be used as reliable guides for central venous pressure monitoring, simultaneous measurements of the Rt. internal jugular venous pressure and central venous pressure (CVP), or Rt. subclavian venous pressure and CVP using long 14 gauge catheter were made in 20 patients undergoing cardiac anesthesia. The results were as follows: l. Each mean value of the Rt. internal jugular venous pressure and CVP was 10.64+/-5.43 cm H2O and 10.05+/-5.55cm H2O (Mean+/-SD) respectively in first 10 patients. Pressure difference was 0.59+/-0.39cm H2O (p<0.005). 2. Each mean value of the Rt. subclavian venous pressure and VP was 7.77+/-3.37 cm H 0 and 7.05+/-3.49cm H2O (Mean+/-SD) respectively in second 10 patients. Pressure difference was 0.73+/-0.59cm H2O (p<0.005). 3. There were significant correlations between Rt. internal jugular venous pressure and CVP (r=0. 99, p<0.005) as well as between Rt. subclavian venous pressure and CVP (r=0.98, p<0.005). The results suggest that Rt. internal jugular or subclavian vein catheterized with short intravenous catheter during Anesthesia can be used as effective and reliable guides for CVP monitoring because pressure differences with CVP were small and consistant.