Midazolam/Sufentanil vs Etomidate/Sufentanil for the Induction of Anesthesia in Patients with Cardiac Disease / 대한마취과학회지

BACKGROUND: Induction of general anesthesia in patients with cardiac disease must guarantee hemodynamic stability and should result in a satisfactory anesthetic level. The purpose of this study was to analyze the hemodynamic effects of midazolam/sufentanil in comparison with etomidate/sufentanil used for induction of anesthesia in patients with cardiac disease. METHODS: All the patients (n = 30) in the study were about to undergo cardiac surgery and were divided into the midazolam group (n = 15) and etomidate group (n = 15). The induction dose of midazolam was 0.18 mg/kg, etomidate 0.3 mg/kg, vecuronium 0.15 mg/kg, sufentanil 3 microgram/kg, hemodynamics and oxygenation were recorded in the awake state (pre-induction), and 10 minutes after intubation (post-intubation). RESULTS: The etomidate group had a shorter time of anesthetic induction, and some myoclonic movement (13%) was observed. After intubation, reductions of heart rate (13.8%), mean arterial pressure (18.4%), cardiac index (14.8%), left ventricular stroke work index (9.7 - 38.5%), oxygen delivery index (7.43%), oxygen consumption index (10.3%), and Qs/Qt (25.6%), and an increase in central venous pressure (0 - 50%) were observed in both groups. Decreases in right ventricular stroke work index and mean arterial pressure were observed in the midazolam group, but no change in right ventricular stroke work index and a decrease in mean arterial pressure was observed in the etomidate group. In the midazolam group the values of right ventricular stroke work index and mean arterial pressure were significantly lower than in the etomidate group. The heart rate of the midazolam group in patients with CABG were significantly lower than in the etomidate group. CONCLUSIONS: The results of this study shows that etomidate was found to be as reliable and effective an agent for induction as midazolam.

Comparison of Thiopental Sodium and Propofol as Anesthetic Induction Agents for Hypnotic Time / 대한마취과학회지

BACKGROUND: We have used thiopental sodium as an induction agent traditionally, but a recently introduced induction agent, propofol, is gaining popularity among anesthesiologists. The purpose of this study was to compare the difference in induction time by measuring the hypnotic time. METHODS: Sixty adult patients (ASA class I or II) scheduled for elective surgery under general anesthesia were randomly assigned to receive 5 mg/kg of thiopental (Group I) or 2 mg/kg of propofol (Group II), respectively, as an induction agent. The induction time by using Eyelash reflex (from the start of administration of induction agent to the time of reflex loss) was measured after the administration of thiopental and propofol and compared between these two groups. RESULTS: The induction time using ER in Group II (52.2 +/- 12.0 s) was not significantly longer than Group I (50.4 +/-9.4 s). CONCLUSIONS: We concluded that propofol had the same induction time as thiopental for induction of general anesthesia.

Closed Lock of the Jaw on Induction of Anesthesia / 대한마취과학회지

The temporomandibular joint (TMJ) is unique among joints in the human body, since it can be dislocated without external force. Manipulation of the upper airway other than laryngoscopy is a risk factor in patients who have a history of habitual dislocation of the TMJ. The case report illustrates that severe limitation of the jaw opening ("closed lock") requiring manipulation for restoration may occur during induction of general anesthesia.

Are the Requirements of Propofol Decreased in Early Pregnancy during Anesthetic Induction? / 대한마취과학회지

BACKGROUND: Minimum alveolar concentration (MAC) is decreased during pregnancy, but there are no data regarding the requirements for intravenous agents. Recently only one study showed that the requirement for thiopental in pregnant women of 7-13 weeks' gestation was less than the requirement obtained in nonpregnant women. Thus we wanted to determine whether pregnant patients needed less propofol for hypnosis and anesthesia than nonpregnant patients. METHODS: One hundred nonpregnant women having gynecologic surgery and 100 pregnant women of 5-13 weeks' gestation undergoing elective abortions were recruited. They were randomly allocated 10 groups according to the doses of propofol and each group had 10 patients. During a period of 30 seconds, one of the doses of propofol 1.0, 1.25, 1.5, 1.75, 2.0, 2.25, 2.5, 2.75, 3.0 or 3.25 mg/kg was administered. Two minutes later, patients were asked to open their eyes as a test for hypnosis. Patients who did not open their eyes were given a 10 seconds, 50-Hz, 80-mA transcutaneous tetanic electrical stimulus to the ulnar nerve as a test for anesthesia. Estimates of ED50 and ED95 for hypnosis and anesthesia were obtained by logistic regression. RESULTS: In the pregnant women, the median effective doses (ED50) (95% confidence interval) for hypnosis and anesthesia were 1.25 (1.13-1.35) mg/kg and 2.71 (2.49-3.04) mg/kg, the ED95 (95% CI) were 1.51 (1.16-1.87) mg/kg and 3.04 (2.80-3.58) mg/kg respectively. Whereas in the nonpregnant women, the ED50 for hypnosis and anesthesia were 1.27 (1.39-1.90) mg/kg and 4.12 (3.50-6.01) mg/kg, the ED95 were 1.53 (1.41-1.93) mg/kg and 4.35 (3.66-7.26) mg/kg respectively. CONCLUSIONS: In early pregnant women, the doses of propofol for hypnosis and anesthesia were 1.6% and 34.2% less compared with those in nonpregnant women.

Influence of Fentanyl, Fentanyl-Midazolam, and Fentanyl-Ketorolac as Analgesic Supplementations on the Induction of Propofol Anesthesia with Dipifusor TCI / 대한마취과학회지

BACKGROUND: The pharmacologic interactions between propofol and adjuvant agents have increasingly been recognized as clinically important and the improved knowledge of these is being used to optimise the quality of total intravenous anesthesia. The aim of the present study was to investigate the effects of fentanyl, fentanyl-midazolam, and fentanyl-ketorolac as analgesic supplementations on the induction of propofol anesthesia with Diprifusor TCI. METHODS: Sixty ASA 1 patients undergoing elective diagnostic laparoscopy were randomly allocated to three groups equally according to injected adjuvant agents : group F, fentanyl 1 microgram/kg; group FM, fentanyl 1 microgram/kg-midazolam 0.05 mg/kg; group FK, fentanyl 1 microgram/kg-ketorolac 0.5 mg/kg IV before induction. Propofol target concentration of 4 microgram/ml was preset and unconsciousness with 3 min was considered as successful. Induction dose, time, success rate of induction, calculated and effective concentration, context sensitive decrement time when awakening concentration was 1.2 microgram/ml, vital signs and side effects were checked. RESULTS: Successful induction rate was 55% in the group F, 100% in the group FM, and 85% in the group FK (P< 0.05). Induction time and dose were significantly decreased in the group FM compared with the group F and FK. Calculated concentration, effective concentration, and context sensitive decrement time were significantly lower in the group FM than other groups. Injection pain score and postoperative pain score showed no differences between groups, but incidence of apnea was significantly increased in the group FM. CONCLUSIONS: Fentanyl-midazolam as a analgesic supplementation offered better quality of propofol induction using TCI, but showed increased incidence of apnea compared with fentanyl or fentanyl- ketorolac.

The Effect of Midazolam Premedication on Propofol Induction Using a Target Controlled Infusion (TCI) / 대한마취과학회지

BACKGROUND: Many studies indicated that the predictive accuracy of propofol TCI may be compromised by premedication with benzodiazepine which has been shown to reduce markedly the induction dose. This study was designed to examine the influence of midazolam premedication on certain parameters of treatment using the propofol TCI. METHODS: One hundred and sixty ASA I or II patients undergoing elective surgery were randomly allocated to two groups according to premedication: Group 1, glycopyrrolate 0.2 mg; Group 2, glycopyrrolate 0.2 mg and midazolam 0.07 mg/kg IM 1hr before induction. Each group divided to four subgroups (n=20 for each subgroup) according to expected target propofol concentration (4~7 microgram/ml for group 1 and 3~6 microgram/ml for group 2). Anesthesia induction within 3 min was considered as successful. Induction dose and time, success rate of induction, calculated concentration when successful induction, context sensitive decrement time when awakening concentration was 1.2 microgram/ml and side effects were checked. RESULTS: Successful induction rate was higher in group 2 (53.3% vs 77.8% at target concentration of 5 microgram/ml, P<0.05). Mean target concentration of propofol were lower in group 2 (5.18 vs 3.87 microgram/ml, P<0.05). Induction time and dose were decreased 48.4% and 36.8% at target concentration of 4 g/ml, respectively in group 2 (P<0.05). Vital signs, average pain score and incidence of pain showed no differences between groups, but incidence of apnea was significantly increased in group 2 (P<0.05). CONCLUSION: Group 2 showed better quality of propofol induction using a TCI in terms of induction time, induction dose and lower selected target without significant vital sign changes, but showed increased incidence of apnea compared with group 1.

Anesthesia Induction with Propofol Using a Target Controlled Infusion (TCI) / 대한마취과학회지

BACKGROUND: Target Controlled Infusion (TCI) is designed to achieve a predicted target blood concentration based on population pharmacokinetics and it provides the closest approximation for any individual patients. This study determined which target is appropriate for propofol induction using a TCI in korean adullt patients premedicated with midazolam. METHODS: Sixty six patients (ASA I or II, 18~55 years) premedicated with midazolam were allocated randomly to receive an infusion to achieve and maintain a target blood concentration of 3, 4, 5 and 6 microgram/ml using a TCI. Induction time was measured as the interval from the start of the infusion to loss of verbal contact and induction within 3 min was considered as successful. Calculated concentration, induction dose, context sensitive decrement time, vital signs, pain score and side effects were checked and compared each other during induction period. RESULTS: The success rate when the target was 3 microgram/ml was 25%, 58.8%, 77.8% and 100% when targets were 4 microgram/ml, 5 microgram/ml and 6 microgram/ml respectively. EC50 for induction was 3.87 microgram/ml and EC95 was 5.71 microgram/ml. Calculated concentration, induction dose, context sensitive decrement time in 3, 4, 5 microgram/ml group showed no differences among groups, but 6 microgram/ml group showed statistically significant differences compared with other groups. Vital signs, pain score and side effects showed no differences among groups. CONCLUSIONS: Target concentration of 5~6 microgram/ml would successfully induce anesthesia in the majority of patients premedicated with midazolam without major hemodynamic changes.

Effect of Sufentanil and Fentanyl on Heart Rate and Blood Pressure Changes during Induction of Anesthesia / 대한마취과학회지

BACKGREOUND: The hemodynamic responses to laryngoscopy and endotracheal intubation, tachycardia and arterial hypertension, are well known and should be minimized. The purpose of this study is comparison of effects of low-dose sufentanil and fentanyl on the changes of blood pressure and heart rate due to laryngoscopy and endotracheal intubation. METHODS: The cardiovascular responses were measured and compared in 60 patients, between 20~65 years old, ASA class I or II, undergoing elective operation pretreated with normal saline (n=20, control group), fentanyl 3 microgram/kg (n=20, fentanyl group), and sufentanil 0.6 microgram/kg (n=20, sufentanil group), respectively. Anesthesia was induced intravenously with pentothal sodium 4~5 mg/kg and endotracheal intubation was conducted after injection of succinylcholine 1 mg/kg. The changes of systolic arterial pressure, mean arterial pressure, diastolic arterial pressure, heart rate, and SpO2 (saturation of arterial oxygen) were measured at postsedation with pentothal sodium, 30 seconds, 1 minute, and 3 minutes following intubation. The variables of each group were compared with preinduction baseline values and fentanyl and sufentanil groups were compared with control group. Data were analyzed for statistical significance using repeated measures of ANOVA (analysis of variance). P<0.05 was considered statistically significant. RESULTS: The systolic and mean arterial pressures at 30 seconds and 1 minute and diastolic arterial pressure at 30 seconds after laryngoscopy and intubation in sufentanil group were significantly lower than values of control group (p<0.01). The heart rates at 30 seconds and 1 minute were significantly attenuated compared with control group (p<0.05). The blood pressures and heart rates of fentanyl group at 30 seconds after intubation were significantly attenuated compared with control group (p<0.05). CONCLUSIONS: The results suggest that pretreatment of fentanyl 3 microgram/kg and sufentanil 0.6 microgram/kg is effective to prevent the elevation of blood pressures and heart rates, and sufentanil 0.6 microgram/kg is more effective than fentanyl 3 microgram/kg to attenuate the hemodynamic changes due to laryngoscopy and intubation.

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.

Effects of Fentanyl-induced Rigidity on the Intracranial Pressure in Rabbits / 대한마취과학회지

BACKGROUND: It is important to control of intracranial pressure(ICP) in patients with intracranial pathology. To decrease ICP and to attenuate the adverse cardiovascular reflexes associated with anesthetic induction and tracheal intubation, we are often administered potent opiates during anesthetic induction. A side effect of these agents when used in large doses is muscle rigidity. We investigated the effects of high dose fentanyl on ICP, central venous pressure (CVP) and mean arterial pressure (MAP) during fentanyl-induced rigidity in rabbits. METHODS: Under halothane anesthesia, polyethylene catheters were surgically inserted into the femoral artery and vein for measurement of MAP and CVP in 10 rabbits. ICP was measured between epidural and subdural space through the burr hole of the frontal bone by means of fiberoptic ICP monitor. The animals were mechanically ventilated to achieve normocarbia. Following instrumentation, halothane was discontinued and fentanyl 50 microgram/kg administered intravenously at the first movement during emergence from halothane anesthesia. RESULTS: In the seven rabbits that developed rigidity, ICP and CVP were increased significantly compared to control value (delta ICP 9.2+/-1.9 mmHg, delta CVP 5.0+/-0.9 cmH2O: P<0.05). But MAP was decreased significantly from 95+/-5 to 74+/-4 mmHg (P<0.05). These variables except MAP were returned to baseline when rigidity was abolished with vecuronium. In three rabbits that did not show rigidity, ICP and CVP did not change following injection of fentanyl. But MAP in the non-rigidity group was significantly decreased like the rigidity group (P<0.05). CONCLUSIONS: These observations suggest that rigidity should be prevented when opiates like fentanyl are used as an induction drug of patients with ICP problems.

The Rebleeding of Ruptured Intracranial Aneurysm during Induction of Anesthesia / 대한마취과학회지

The intraoperative rupture of an intracranial aneurysm can dramatically interrupt the fine operative procedure and jeopardize the patient's chance for meaningful survival. A sudden increase of the arterial pressure and intracranial pressure during laryngoscopy and intubation is potentially dangerous and may lead to fresh bleeding from an aneurysm in patient with recent subarachnoidal hemorrhage due to aneurysmal rupture. But aneurysmal rupture during induction occurs rarely. Recently we experienced rebleeding due to sudden increased arterial blood pressure during laryngoscopy and intubation in 39 years old female patient who was scheduled for clipping of ruptured intracranial aneurysm on 11th day after ictus. And she died of cerebral death on 6th postoperative day. Here we discuss the incidence, prognosis, diagnosis, management and prophylaxis of the aneurysmal rupture during induction with a brief review of the literature.