Comparing Midazolam and Morphine as Premedication by Bispectral Index System / 대한마취과학회지

BACKGROUND: The bispectral index (BIS) has been used as an indicator of a sedative state and has been considered to be related to anesthetic agents and noxious stimulus. In this study, we measured the BIS, blood pressure (BP) and heart rate (HR) during induction of anesthesia after premedication with or without midazolam or morphine and evaluated the bispectral index as an indicator of an objective evaluation of midazolam premedication and relation to the cardiovascular response to the anesthetic induction. METHODS: Seventy five patients scheduled to undergo elective surgery under general anesthesia were divided into 3 groups. Each group received midazolam and glycopyrrolate (midazolam group, n = 25), or morphine and glycopyrrolate (morphine group, n = 25), or glycopyrrolate only (control group, n = 25) as premedication (midazolam 0.08 mg/kg IM, morphine 0.05 mg/kg IM, glycopyrrorate 0.2 mg IM). Then, anesthetic induction (propofol 2 mg/kg, succynylcholine 1 mg/kg) was done. The bispectral index, blood pressure, and heart rate were measured at before induction, after propofol injection, and intubation. RESULTS: The Bispectral index was significantly lower in the midazolam group and the morphine group compared with the control group before anesthetic induction. Blood pressure was not significantly different among the three groups. Heart rate was significantly lower in the midazolam group compared with the control group before anesthetic induction. CONCLSIONS: Midazolam or morphine premedicated patients appear to maintain a stable heart rate and have a low BIS at before induction. The Bispectral index could be objectively used in midazolam-premedicated patients when evaluating the degree of sedation and predicting hemodynamic changes, and probably in morphine-premedicated patients also.

The Assessment of Midazolam Effect as Premedication by Bispectral Index System / 대한마취과학회지

BACKGROUND: Midazolam is often used as an anxiolytic premedication before surgery, but it is difficult and complex to assess its effect. This study evaluated the bispectral index as an objective indicator of midazolam premedication and the relation of cardiovascular response to anesthetic induction. METHODS: Forty patients (aged 20 to 60 and in ASA class I or II) to undergo simple elective surgery under general anesthesia entered the study. The patients were divided into the midazolam group (n = 20) that received midazolam (0.08 mg/kg IM) and glycopyrrolate (0.2 mg IM) premedication, and the control group (n = 20) that received glycopyrrolate (0.2 mg IM) only. Then, anesthetic induction (fentanyl 1 microgram/kg, propofol 2 mg/kg, succinylcholine 1 mg/kg) was done. The bispectral index of the electroencephalogram, blood pressure, and heart rate were measured under unanesthetized conditions, after fentanyl, propofol injection, and intubation. RESULTS: The bispectral index was significantly lower in the midazolam group as compared with the control group before anesthetic induction, after fentanyl injection, and intubation. Blood pressure was not significantly different in the two groups. Heart rate was significantly lower in the midazolam group compared with the control group before anesthetic induction and after fentanyl injection. CONCLUSIONS: Midazolam-premedicated patients appear to maintain stable hemodynamics during anesthetic induction and intubation. The bispectral index can be objectively used in midazolam-premedicated patients when evaluating the degree of sedation. (Korean J Anesthesiol 2000; 38: 947~953)

Effect of Midazolam Premedication on Postanesthetic Recovery and Postanesthetic Recovery Room Discharge Time for Outpatient Surgery / 대한마취과학회지

BACKGROUND: Midazolam is often used as an anxiolytic premedication before surgery. But preoperatively administered midazolam may contribute to postopertive sedation and delayed recovery from general anesthesia. This study was undertaken to evaluate the effect of midazolam premedication on postoperative recovery and discharge-readiness after brief outpatient surgery. METHODS: Sixty healthy ASA physical status I women scheduled for outpatient diagnostic laparoscopic surgery were considered for the study. They were randomly allocated to one of two groups. Group one received normal saline (N/S) 5 ml intravenously (IV), while group two received IV midazolam 0.04 mg/kg. The study drug was prepared in 5 ml of saline and administered 10 minutes before the induction of general anesthesia. General anesthesia was induced with fentanyl, propofol and vecuronium and was maintained with N2O and enflurane. Postanesthetic recovery (PAR) scores were recorded after the arrival of the patients in the postanesthetic recovery room. Sedation was quantified before and after premedication and 60, 120 minutes after arriving in the postanesthetic recovery room, using the symbol-digit-modalities test (SDMT) and trail-making test (TMT). RESULTS: There were no significant differences between the two groups with respect to age, weight and anesthesia time. There were no significant differences in PAR scores or PAR-stay time between two groups. SDMT and TMT scores were significantly different 5 minutes after the study's drug administration, and 60 minutes after arrival in the postanesthetic recovery room between the two groups. The incidence of side effects was similar in both groups. CONCLUSIONS: Midazolam premedication proved effective in sedation and anxiolysis without prolonging postanesthetic recovery and discharge times for outpatient general anesthesia.

Comparison of Intranasal, Oral, and Rectal Midazolam for Premedication in Children / 대한마취과학회지

BACKGROUND: When appropriate premedication is required for pediatric patients, the route of drug administration and the patient's age may affect the drug response. This study was designed to evaluate the premedicative effects of intranasal, oral, and rectal midazolam in preschool (1~6 year) and school (6.1~10 year) ages. METHODS: One hundred fourteen children aged 1~10 years were randomly allocated into three groups to receive midazolam via intranasal (0.3 mg/kg), oral (1.0 mg/kg), or rectal (1.0 mg/kg) route. Sedation scores were evaluated at the arrival in preanesthetic room, drug administration, 5, 10, 20 and 30 min after drug administration, separation from parent, mask application, and induction with inhalational agent. Time to sedation scores of 3 and 4 and time to complete recovery from general anesthesia were recorded. RESULTS: At the drug administration, the incidence of crying was significantly higher in nasal group than in oral and rectal groups, especially in pre-school age group (87.5, 23.5. 40.9% for nasal, oral and rectal groups, respectively). At 5, 10 and 20 min after drug administration, sedation scores were significantly higher in nasal and rectal groups than in oral group. At separation, mask application and inhalational induction, sedation scores were significantly higher in oral and rectal groups than in nasal group. Time to sedation score of 3 and time to complete recovery were significantly longer in oral group than in nasal and rectal groups. CONCLUSIONS: In pre-school age, almost all the children cried at drug administration in nasal group, and onset and recovery were prolonged in oral group, so rectal route was suitable. In school age, nasal route was appropriate because of the lower frequency of crying at the drug administration and rapid onset and recovery. In overall age, rectal route was better because of the lower frequency of crying and rapid onset and recovery. This study suggests that administration route should be considered according to the age of pediatric patient to obtain appropriate premedication for pediatric patients.

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.

The Frequency of Apnea and Loss of Consciousness According to Propofol Dosage in Premedicated Patients with Midazolam / 대한마취과학회지

BACKGROUND: Respiratory depression with high dose of propofol during induction is one of the major complications. We studied the effects of midazolam as premedicant on frequency and duration of apnea and frequency of loss of consciousness in relation to single dose of propofol. METHODS: We selected 194 adult patients who had clear consciousness and no depression of respiration. We allocated patients randomly to control group and midazolam group. In midazolam group, we injected 0.06mg/kg of midazolam intravenously 10min before induction, and in control group, we did nothing. Under mask oxygenation with 100% oxygen, we administered a bolus of propofol (1, 1.5, 2 mg/kg to subgroup 1, 2, 3 respectively) intravenously. The change of respiration and loss of consciousness were observed. RESULTS: The frequency and duration of apnea increased with the dose of propofol in both control and midazolam group. But there were no difference between groups except frequency of apnea with 1.5 mg/kg of propofol. In control group, frequency of loss of consciousness increased with the increasing dose of propofol. But in midazolam group, nearly all the patients was slept without difference by the dose. CONCLUSIONS: Premedication with midazolam reduce the sleeping dose of propofol to induce anesthesia, so the frequency and duration of apnea which is caused by high dose of propofol can be decreased.

The Effects of Intranasal Midazolam on Preanesthetic Sedation in Children / 대한마취과학회지

BACKGROUNDS: This study was performed to determine the onset time and dose of intranasal midazolam used for preanesthetic sedation in children. METHODS: The children were randomly allocated to recieve one of three medications via the nasal route in a double blind manner. Group I: patients were given normal saline 0.2 ml/5kg, Group II: patients were given midazolam 0.2 mg/kg, Group III: patients were given midazolam 0.3 mg/kg. RESULTS: The cardiovascular and SpO2 changes were not significantly different among the patients of the three groups. The sedation score was greater in group II compared with group I from 5 minute after administration (1.9 vs 2.7, p<0.05). postanesthetic recovery score (PARS) was not significantly different among the three groups. CONCLUSIONS: It is suggested that intranasal midazolam (0.2 mg/kg) produces anxiolysis and sedation in children with rapid onset.