The Effects of an Epinephrine-containing Epidural Test Dose during Epidural Anesthesia on Ropivacaine / 대한마취과학회지

BACKGROUND: Epinephrine-containing epidural test dose is used for obstetric epidural anesthesia to identify the unintentional cannulation of an epidural vessel. This study evaluated the effects of an epinephrine test dose during epidural anesthesia with 0.5% ropivacaine in ceasrean section. METHODS: Seventy healthy pregnant women, scheduled for elective cesarean section were randomly assigned to one of two groups. A lumbar epidural catheter was placed and aspirated. If aspiration was positive for blood or cerebrospinal fluid, the catheter was replaced. All patients received an 3 ml test dose of either 1.5% lidocaine with epinephrine 5microgram/ml (group E) or lidocaine only (group C). After test dose, 50microgram fentanyl and 20 ml of 0.5% ropivacaine were given to the all patients. Applying the pin prick method and a modified Bromage scoring system, senseory block level and motot block intensity were checked at 5 min intervals for the first hour following ropivacaine injection. After then, they were checked at 15 min intervals for the rest of the test period. Heart rate (HR) and blood pressure (BP) were measured as well. RESULTS: No significant difference between the two groups was detected in HR, BP, the profile of sensory block, motor scores and the onset of motor block. However, group C showed significantly shorter span of motor block (102 +/- 31 min.) than group E (134 +/- 32 min.) (P <0.05). There was no significant difference in neonatal outcome, as assessed by Apgar score at delivery. The most common adverse effect in mothers was hypotension. No serious adverse effects were detected in this study. CONCLUSIONS: We conclude that only the span of motor block by the epidural ropivacaine is affected by epinephrine-containing epidural test dose.

Effect of Rilmenidine and Clonidine Premedication on the Cardiovascular Action of Phenylephrine and Nitroprusside in Rats / 대한마취과학회지

BACKGROUND: Patients premedicated with clonidine often present with hypotension and bradycardia. The hypotensive patient premedicated with clonidine should be given a vasopressor to treat hypotension. In these patients, an augmented vasopressor response would be shown. Rilmenidine as an allied drug of clonidine is an antihypertensive agent with selectivity for the imidazoline receptor that acts centrally by reducing sympathetic overactivity. This study was designed to evaluate the effect of clonidine and rilmenidine on changes in mean blood pressure and baroreflex sensitivity following phenylephrine and nitroprusside administration. METHODS: Sixty Sprague-Dawley rats were assigned randomly into one of three groups, control group (n = 20), clonidine group (n = 20) or rilmenidine group (n = 20). Saline (control group), clonidine 30ng/kg (clonidine group) or rilmenidine 300ng/kg (rilmenidine group) were intraperitoneally injected respectively. Following the injection, a phenylephrine and nitroprusside test were performed. RESULTS: The percent change in mean blood perssure from the baseline values in the control group, clonidine group and rilmenidine group were 35 +/- 18%, 54 +/- 17% and 62 +/- 38%, respectively. There was no difference between the baroreflex sensitivity in the pressure (phenylephrine) test (0.94 +/- 0.43, vs 1.05 +/- 0.62, vs 1.13 +/- 0.59 msec/mmHg). In contrast, the slopes of the depressor (nitroprusside) test were decreased in rats receiving clonidine and rilmenidine (0.51 +/- 0.34, vs 0.12 +/- 0.08, vs 0.18 +/- 0.09 msec/mmHg, P < 0.05). CONCLUSIONS: It is concluded that the rilmenidine and clonidine groups showed a more augmented pressure response to vasopressors than the control group. Therefore, the decreased dosage of vasopressors is recommended to treat hypotension in rilmenidine premedicated patients.

The changes of ventilatory parameters in laparoscopic colecystectomy

We investigated the ventilatory changes in healthy patients without cardiopulmonary pathology during elective laparoscopic cholecystectomy in the head-up position. During surgery, intraabdominal pressure was maintained at 15 mmHg by a CO2 insufflator, and minute ventilation was controlled with a constant tidal volume and fixed respiratory rate. PETCO2 was monitored continuously and recorded every minute. Basic hemodynamic and ventilatory parameters were measured before anesthesia; after induction of anesthesia; at 5 min, 10 min and 30 min after peritoneal insufflation; and 5 min and 10 min after exsufflation. Arterial blood samples were obtained 3 times to calculate D(a-A)CO2, VD/VT, and Vco2. The latent period of PETCO2 change was 2.9 min, the ascending period was 12.6 min, and the descending period was 12.2 min. During the 71.5 min of pneumoperitoneum, V(I), VE, peak and plateau Paw increased, while Cdyn decreased significantly. Peritoneal insufflation or exsufflation also resulted in a significant change of D(a-A)CO2, D(a-A)O2, and Vco2. The anesthesiologist must be aware of both hemodynamic and ventilatory changes and must be ready to respond promptly and adequately.

Clinical Evaluation of General and Caudal Anesthesia for Inguinal Herniorrhaphy in Children / 대한마취과학회지

BACKGROUND: Caudal block has proved to be a satisfactory method of providing perioperative analgesia for pediatric surgery in the inguinal and perineal areas. The object of this study was to compare the general (n=55) with caudal anesthesia (n=41) in pediatric inguinal herniorrhaphy during surgery and postoperative 24 hours in their changes of behaviors in the recovery room, and other complications. METHODS: Ninety six children who underwent to inguinal herniorrhaphy were devided into two groups. Group I was given general anesthesia as usual methods using endotracheal intubation. Group II was given caudal block using 1% lidocaine 1 ml/kg or 0.25% bupivacaine 1 ml/kg, or a mixture of both of them at the ratio of 1:1, 1 ml/kg. All caudal blocks were carried out in left lateral position after ketamine 1-1.5 mg/kg intravenous injection. The side effects during and after operation and postoperative behavior in the recovery room, neurologic complications and postoperative fever incidence were observed and compared with the two groups. RESULTS: In group I (n=55), 13 cases (23.6%) showed hoarseness after extubation. 78.2% of 55 patients were irritable and cryng in the recovery room. Postoperative fever incidence was over 69%. In group II (n=41), almost all patients were calm and stayed quiet in the recovery room. However there were 3 cases of bradycardia and 2 cases of hypotension during operation. Postoperative complications were rare and the mumber of patients with fever was 36.6% which was significantly low compared to group I. CONCLUSIONS: As the results of this study, we report that caudal anesthesia is a safe, simple practical method with few complications for inguinal herniorraphy in children compared with general anesthesia. We also recommend that the caudal block can be used safely in pediatric outpatient surgery.

Evaluation of Weaning Criteria from Mechanical Ventilatory Support / 대한구급학회지

Introduction: A number of indices have been proposed as accurate predictors of weaning, but several studies have questioned the accuracy of these weaning indices in predicting the capability of independent breathing. The purpose of the study was to assess six standard bedside weaning criteria of mechanically ventilated patients in Surgical intensive care unit (SICM). METHOD: : The study was performed on 72 SICU patients who were mechanically ventilated. According to the outcome of weaning, they were divided into two groups, weaning success (n=62) and weaning failure (n=10) group. All subjects should have PaO2 above 60 mm Hg at an FIO2 of 0.4 and PEEP of 3~5 cm H2O in the extubated patients and no PEEP in the tracheostomy patients. Six bedside weaning criteria were tidal volume above 5 ml/kg, respiratory rate below 25/min, vital capacity above 10 ml/kg, maximum inspiratory pressure below -20 cm H2O, minute volume below 10 L/min and PaO2/FIO2 above 200. Weaning failure was regarded as follows; changes of systolic blood pressure 20 mm Hg or diastolic pressure 10 mm Hg, changes of pulse rate 20 beat per minute, respiratory rate above 30 per minute or increased respiratory rate above 10 per minute, PaO2 below 60 mm Hg or PaCO2 above 55 mm Hg, and presence of paradoxical respiratory pattern. RESULTS: PaO2/FIO2 and minute volume (VE) were showed statistically significant difference between two groups (P=0.048, P=0.003 respectively). Linear discriminant function was D=-1.422-0.005-xPaO2/FIO2+0.336xVE. CONCLUSION: Our study demonstrates that PaO2/FIO2 and minute volume accurately predicts the weaning outcome in the surgical patients with mechanical support.

Statistical Analysis of the Patients in the ICU by Using the APACHE II Scoring System / 대한구급학회지

Introduction: The APACHE II scoring system has been promulgated as a useful tool in the assessment of the severity of disease and prognosis for patients with acute-on-chronic medical conditions. The purpose of this study was to assess the statistical association of APACHE II score and multiple variables in ICU patients. METHODS: Prospective data on 803 ICU patients for validation of the APACHE II system were analysed. We evaluated the relationship between APACHE II scores within the first 24 hours of ICU admission and multiple variables that included days in the ICU, mortality rate and age. The patients were classified as operation and nonoperation, survival and nonsurvival groups. RESULT: 1) The APACHE II score was significantly higher in the 153 nonsurvivals (23.97+/-10.98) than in the 651 survivals (11.51+/-6.14) (p<0.05). 2) The mean APACHE II score of the nonoperation group (14.52+/-9.29) was significantly higher than operation group (12.40+/-7.30) (p<0.05). 3) The overall mortality rate was 17.8%. 4) All patients with an APACHE II score over 40 died. CONCLUSION: The APACHE II score is statistically related with the mortality of critically ill patients.

Volume Changes under Isotonic Condition Containing Thiopental in Brain Astrocytoma Cells / 대한구급학회지

BACKGOUND: Cell volume regulation is especially important in the brain because the brain is confined within a non-compliant vault and cannot tolerate significant perturbations in cell size. Cerebral cell volume regulation mechanisms are activated by sustained disturbances in plasma osmolality. The constancy of cell volume under physiological conditions is generally thought to reflex a balance between influx and efflux of solute and is therefore critically dependent on the properties of the plasma membrane. Cell volume regulation have not been described under isoosmotic solution. The object of the study was to know the effects of thiopental on cell volume change in isoosmotic condition. METHODS: We made isoosmotic solution without thiopental (Group 1) and isoosmotic solution with 22.9 mM (Group 2), 16.8 mM (Group 3), 13.3 mM (Group 4) thiopental, separately, in order to study changes in cell volume under isoosmotic solution. We put cultured human brain astrocytoma cells into isoosmotic solution for each group and calculated cell volume using Coulter Counter after 30 minutes. RESULTS: Cell volume was shown to be 5084+/-8580 (micrometer3)in Group 1, 501+/-854 (micrometer3) in Group 2, 1183+/-3839 (micrometer3) in Group 3, and 624+/-1100 (micrometer3) in Group 4. We discovered that cells in Group 2,3,4 were shrunk relative to cells in Group 1 (p<0.01). And there were significant differences in cell volume among thiopental groups. CONCLUSIONS: Thiopental may has an effect on cell membrane properties and decrease cell volume under isoosmotic solution in brain astrocytoma cell.

Effects of Three Different Regimens of Aprotinin Dosage on Blood Loss During Open Heart Surgery / 대한마취과학회지

BACKGROUND: High dose of aprotinin has been known to reduce the requirement for homologous transfusion and the loss of blood during cardiac operation. The aim of this study was to investigate an effective minimal dose of aprotinin. METHODS: With IRB approval 61 patients undergoing cardiac operation were divided into four groups. Group I was control (n=15). Group II(high dose aprotinin, n=16) received an infusion of 24,000 KIU/kg of aprotinin followed by continous infusion of 6,000 KIU/kg per hour until the end of operation. A bolus of 24,000 KIU/kg was added to pump prime solution. Group III(low dose aprotinin, n=16) received a bolus of 24,000 KIU/kg to prime solution. Group IV(minimal dose aprotinin, n=14) received a bolus of 12,000 KIU/kg to prime solution. Coagulation profiles were analysed and blood loss through chest tubes & amount of homologous transfusion was measured. Statistical analysis was performed using one-way variance analysis. RESULTS: Group II demonstrated less amount of blood loss than group I with statistical significance. Blood loss in group III was reduced about 20% but the reduction was not statistically significant. Group IV could not reduce the blood loss. CONCLUSION: This study shows the efficacy of high and low dose(not statistically significant) aprotinin infusion during cardiac surgery in postoperative blood loss. Use of aprotinin less than low dose regimen may not be effective in reducing the blood loss and amount of homologous transfusion in cardiac operation.