A comparison of midazolam and diazepam for intravenous sedation in dentistry

In a randomised cross-over trial, midazolam, a new water soluble benzodiazepine was compared with the conventional diazepam preparation (Valium) in 34 patients aged 16-45 years who were undergoing outpatient conservation dentistry. Midazolam hydrochloride (0.17 mg/kg) was virtually free of venous complications and showed advantages over diazepam (0.32 mg/kg) in providing a faster onset of action, higher incidence of amnesia and more rapid recovery. Midazolam produced a higher incidence of respiratory side effects hiccough (17.6% compared with 2.9%), brief apnoea following induction (11.8% compared with 5.8%), and airway obstruction during maintenance (8.8% compared with 0%). These may be related to the greater potency of midazolam as suggested by the smaller total dose required. Cardiovascular changes and operating conditions were similar.     

异丙酚单用与复合芬太尼在隆鼻术中麻醉效果比较

目的:比较异丙酚单独或复合芬太尼用于无痛隆鼻术中的麻醉效果。方法:就医者40例,随机分配为A组(异丙酚)和B组(异丙酚复合芬太尼),每组各20例。A组静注异丙酚1.5～2mg.kg-1使其入睡后手术开始,术中异丙酚以4～6mg.kg-1.h-1微泵维持。B组先静脉注射芬太尼0.1mg,随后麻醉过程同A组。记录术中体动反应次数、异丙酚用量,记录麻醉前、麻醉后2mi n、5mi n、10mi n、手术结束时的MAP、HR、RR和SPO2,记录麻醉过程中发生的不良反应。结果:B组术中体动反应次数和异丙酚用量都明显少于A组(P<0.01),B组麻醉后2mi n时MAP、HR、RR和SPO2明显下降(P<0.05或P<0.01),但在麻醉后5mi n时都恢复正常。结论:在无痛隆鼻术麻醉中复合芬太尼未明显增加麻醉不良反应,但增强了镇痛效果,能明显减少体动反应,减少异丙酚使用量,降低治疗费用。     

Opioid supplementation to propofol anaesthesia for outpatient abortion: a comparison between alfentanil, fentanyl and placebo

One hundred and sixty-four patients scheduled for elective termination of pregnancy under general anaesthesia were randomly assigned to receive one of three different supplements to propofol and oxygen in nitrous oxide anaesthesia: 0.1 mg fentanyl, 0.5 mg alfentanil or placebo. Postoperative pain and nausea, as well as complications during anaesthesia were studied. There were no differences in complications or complaints by surgeons during anaesthesia, and no patient in any group reacted unsatisfactorily to surgery. The patients in the placebo group consumed significantly more propofol during the procedure (P less than 0.001). No differences were seen in time until hospital discharge between the three groups. Complaints about postoperative pain were significantly less frequent among patients receiving fentanyl (P less than 0.01). The number of patients requesting postoperative analgetics, however, did not differ. There was no difference in the frequency of nausea or vomiting, but postoperative pain was found significantly to increase complaints of nausea (P less than 0.01) and also time until hospital discharge (P less than 0.01). In conclusion, opioid supplementation lowered the amount of propofol needed for anaesthesia. Alfentanil 0.5 mg did not improve the postoperative course. Fentanyl 0.1 mg decreased the frequency of postoperative pain without increasing the time to hospital discharge.     

异丙酚复合芬太尼静脉全麻在隆乳术中的应用

目的:观察异丙酚、芬太尼复合静脉全麻应用于门诊隆乳手术的麻醉效果。方法:ASAI～II级门诊行隆乳手术的患者60例,麻醉前30min给予阿托品0.5mg,诱导用芬太尼0.1mg,咪唑安定2mg,然后接微量注射泵按3～8mg/kg/h的速度泵注异丙酚达所需麻醉深度并维持,分离胸大肌时加芬太尼0.05mg,手术缝合时停止泵注异丙酚。记录麻醉前、麻醉后、手术开始时、分离胸大肌时、术毕时的SBP、DBP、SPO2、HR及术毕清醒时间,术中记忆、术后头晕、恶心、呕吐的发生例数。结果:组内各时点SBP、DBP、SPO2、HR比较无显著差异(P>0.05),24例苏醒期间有轻微头晕,8例有轻恶心,但无呕吐。结论:异丙酚复合芬太尼用于隆乳手术的麻醉镇静、镇痛效果好,过程平稳,对呼吸、循环功能干扰小,不良反应少,是一种较理想的麻醉方法。     

Sedation for local anaesthesia. Comparison of intravenous midazolam and diazepam

Intravenous midazolam and diazepam have been compared as sedatives during surgery performed under local anaesthesia. Satisfactory conditions were produced by both drugs. No difference was detected in the rate of recovery, but a highly significant greater degree of amnesia followed the use of midazolam.     

Anaesthesia for short outpatient procedures. A comparison between thiopentone and propofol in combination with fentanyl or alfentanil

We studied supplementation of propofol or thiopentone anaesthesia with 0.5 or 1.0 mg alfentanil or 0.05 or 0.1 mg fentanyl for minor gynaecological outpatient procedures. Four hundred patients scheduled for elective termination of pregnancy were randomly allocated to one of eight groups. Induction agent doses, peroperative complications, complaints about pain and emesis during the postoperative period, and time to discharge were studied. Propofol compared to thiopentone was associated with a shorter time to discharge, 103±28 and 115±33 minutes respectively ( P <0.05) and anxiety during recovery was more frequent in the thiopentone group ( P <0.05). The need for postoperative reserve analgesics was less in the alfentanil group ( P <0.05). We found, however, no major differences between the supplementations tested regarding the total dose of induction agent, emesis or time to discharge. Supplementation with 1.0 mg of alfentanil to propofol was found to be the best combination tested for short outpatient procedures.     

Relation between fentanyl dose and predicted EC50 of propofol for laryngeal mask insertion

Background. This study sought to determine the effective concentrationfor 50% of the attempts to secure laryngeal mask insertion (predictedEC_50LMA) of propofol using a target-controlled infusion (Diprifusor^TM)and investigated whether fentanyl influenced these requiredconcentrations, respiratory rate (RR) and bispectral index (BIS). Methods. Sixty-four elective unpremedicated patients were randomlyassigned to four groups (n = 16 for each group) and given saline(control) or fentanyl 0.5, 1 or 2 µg kg^–1.Propofol target concentration was determined by a modificationof Dixon’s up-and-down method. Laryngeal mask airway insertionwas attempted without neuromuscular blocking drugs after equilibrationhad been established for >10 min. Movement was defined aspresence of bucking or gross purposeful muscular movement within1 min after insertion. EC_50LMA values were obtained by calculatingthe mean of 16 patients in each group. Results. Predicted EC_50LMA of the control, fentanyl 0.5, 1 and2 µg kg^–1 groups were 3.25 (0.20), 2.06 (0.55),1.69 (0.38) and 1.50 (0.54) µg ml^–1 respectively;those of all fentanyl groups were significantly lower than thatof control. RR was decreased in relation to the fentanyl doseup to 1 µg kg^–1. BIS values after fentanyl1 and 2 µg kg^–1 were significantly greaterthan in the control and 0.5 µg kg^–1 groups. Conclusions. A fentanyl dose of 0.5 µg kg^–1is sufficient to decrease predicted EC_50LMA with minimum respiratorydepression and without a high BIS value. Br J Anaesth 2004; 92: 238–41     

Left ventricular mechanical performance in elderly patients after induction of anaesthesia. A comparison of inhalational induction with sevoflurane and intravenous induction with fentanyl and propofol

We investigated changes in left ventricular mechanical performance in 40 patients aged > 70 years in whom anaesthesia had been induced with sevoflurane or with fentanyl and propofol. The ratio of ventricular contractility to arterial properties, which reflects left ventricular performance, was estimated from the ratio of ventricular end-systolic elastance to effective arterial elastance. This ratio decreased after induction in both groups, the magnitude of the decrease being significantly greater in the fentanyl/propofol group than in the sevoflurane group. Decreases in mean arterial pressure after induction of anaesthesia in the two groups were similar, whereas the magnitude of the decrease in heart rate in the sevoflurane group was greater than that in the fentanyl/propofol group. Sevoflurane may therefore be preferable to fentanyl and propofol for induction of anaesthesia in elderly patients because of its lesser effect on left ventricular performance.     

Effects of fentanyl or alfentanil as supplement to propofol anaesthesia for termination of pregnancy

One hundred and twenty patients undergoing early legal termination of pregnancy by dilatation and suction curettage before 12 weeks of pregnancy were randomly allocated to receive total intravenous propofol anaesthesia either alone or supplemented with fentanyl 1.5 μg·kg^-1 or alfentanil 15 μg kg^-1. Supplementation with fentanyl or alfentanil improved operating conditions ( P <0.01), reduced total propofol requirements ( P < 0.01) and reduced postoperative pain intensity ( P < 0.05). Immediate recovery, assessed by the time patients took to open the eyes, to give correct date of birth and by co–operation score, was more rapid in the alfentanil group compared to the control group ( P < 0.05), whereas there was no significant difference between the alfentanil and fentanyl groups. The three anaesthetic techniques did not differ with regard to side effects.
In conclusion, total intravenous propofol anaesthesia in patients undergoing early termination of pregnancy was improved by supplementation with either fentanyl 1.5 μg kg^-1 or alfentanil 15 μg–kg^-1. The benefit was slightly greater with alfentanil than with fentanyl.     

Less postoperative nausea and vomiting after propofol + remifentanil versus propofol + fentanyl anaesthesia during plastic surgery

BACKGROUND: The effect of different opioids on postoperative nausea and vomiting (PONV) has not been conclusively determined yet, thus the aim of this study was to compare the incidence of PONV in propofol-anaesthetized patients receiving either fentanyl or remifentanil as opioid supplement. METHODS: Sixty ASA physical status I and II patients scheduled for plastic surgery gave their written informed consent for this prospective, randomized, double-blind study. Anaesthesia was induced with propofol, rocuronium and fentanyl (n = 30; 2 microg kg(-1)) or remifentanil (n = 30; 1 microg kg(-1)). After tracheal intubation, anaesthesia was maintained with propofol, oxygen in air and an infusion of the opioid studied, which was modified according to clinical criteria. Baseline postoperative analgesia was achieved with intravenous propacetamol + metamizol. Intravenous morphine was given if visual analogic scale (VAS) for pain was > or = 4 (scale 0-10) and metoclopramide was administered if a patient presented > or = 2 PONV episodes (nausea or vomiting) in less than 30 min. Postoperatively (2, 12 and 24 h), we registered VAS, rescue morphine consumption, number of patients with episodes of PONV and number of patients requiring metoclopramide. P < 0.05 was considered significant. RESULTS: There were no significant differences between groups in the demographic parameters, ASA physical status, propofol dose, VAS, and rescue morphine requirements. Fourteen patients in the fentanyl group and four in the remifentanil group presented PONV episodes 2-12 h postoperative hours' interval; (P < 0.05). Ten patients in the fentanyl group and four in the remifentanil group presented vomiting episodes in the same period (P < 0.05); and eight patients in the fentanyl group and one in the remifentanil group required metoclopramide; (P < 0.05). The number of postoperative PONV episodes were low, both in the 0-2-h period (n = 2 vs. n = 1, fentanyl and remifentanil, respectively) and in the 12-24-h period (n = 3 vs. n = 1). CONCLUSION: Propofol + fentanyl anaesthesia resulted in a higher incidence of PONV and requirements of antiemetic drugs in the period between 2 and 12 postoperative hours compared with propofol + remifentanil, in patients undergoing plastic surgery.     

靶控输注雷米芬太尼和丙泊酚静脉麻醉临床性能评价

目的观察不同年龄对雷米芬太尼靶控输注（TCI）药代动力学模型参数的影响、分析靶浓度与实测浓度的差值并评价TCI系统的性能。方法60例上腹部手术患者随机分为A组（28岁-44岁,n=20）,B组（45岁-64岁,n=30）,C组（65岁-80岁,n=20）。全麻诱导设定丙泊酚血浆靶控浓度3 mg／L,雷米芬太尼7μg／L。意识消失后给予维库溴铵0．1 mg／kg气管插管后行机械通气。气管插管后丙泊酚的靶控浓度降至2．5 mg/L,雷米芬太尼靶控浓度维持不变。术中调节丙泊酚的量使BIS指数维持在45-55。TCI开始后5 min、10 min、20 min、40 min、60 min、80 min、100 min、120 min抽取动脉血检测雷米芬太尼血药浓度。采用执行误差（PE）的中位数（MDPE）、执行误差的绝对中位数（MDPAE）及摆动度（wobble）评价TCI系统的性能。结果三组患者各时点血浆雷米芬太尼浓度均明显低于靶浓度。输注后5 min、10 min,C组的血浆雷米芬太尼浓度显著高于A、B组,有统计学差异（P〈0．05）,而其他各时段两组间无统计学差异（P〉0．05）。三组患者TCI系统偏离度（MDPE）在正常范围, MDAPE大于该范围,摆动度也较大。结论TCI时靶控浓度与实测血药浓度差异较大,老年人的药代动力学特征明显不同于青壮年,在国人使用雷米芬太尼TCI静脉麻醉时,应根据不同年龄设定靶控浓度。     

Procedural sedation for insertion of central venous catheters in children: comparison of midazolam/fentanyl with midazolam/ketamine

Background: There is a lack of studies evaluating procedural sedation for insertion of central venous catheters (CVC) in pediatric patients in emergency departments or pediatric intensive care units (PICU). This study was designed to evaluate whether there is a difference in the total sedation time for CVC insertion in nonintubated children receiving two sedation regimens. Methods: Patients were prospectively randomized to receive either midazolam/fentanyl (M/F) or midazolam/ketamine (M/K) i.v. The Children's Hospital of Wiscosin Sedation Scale was used to score the sedation level. Results: Fifty seven patients were studied (28 M/F and 29 M/K). Group M/F received midazolam (0.24 ± 0.11 mg·kg⁻¹) and fentanyl (1.68 ± 0.83 μg·kg⁻¹) and group M/K received midazolam (0.26 ± 0.09 mg·kg⁻¹) and ketamine (1.40 ± 0.72 mg·kg⁻¹). The groups were similar in age, weight, risk classification time and sedation level. Median total sedation times for M/F and M/K were 97 vs 105 min, respectively (P = 0.67). Minor complications occurred in 3.5% (M/F) vs 20.7% (M/K) (P = 0.03). M/F promoted a greater reduction in respiratory rate (P = 0.005). Conclusions: In this study of nonventilated children in PICU undergoing central line placement, M/F and M/K provided a clinically comparable total sedation time. However, the M/K sedation regimen was associated with a higher rate of minor complications. A longer period of study is required to assess the efficacy and safety of these sedative agents for PICU procedures in nonintubated children.     

A comparison of propofol and other sedative use in paediatric intensive care in the United Kingdom

The retrospective study was designed to examine the safety of propofol against other sedative agents when used by infusion for the sedation of children requiring mechanical ventilation. One-hundred-and-ninety-eight patients were recruited. One-hundred-and-six received propofol and 92 received other sedative agents for durations of 30 min to 156 days and 13 min to 11 days respectively. The mean infusion rate of propofol was 3.39 mg·kg⁻¹·h⁻¹. Sixty-one of the 92 patients in the nonpropofol group received midazolam at a mean infusion rate of 0.4 mg·kg⁻¹·h⁻¹. Forty-one patients developed clinical metabolic acidosis with five falling into the pathological range as defined. Seventeen received propofol and 24 another sedative agent. Seventy-eight percent of patients that became acidotic were under the age of three. No patient who became acidotic was noted to have lipaemic serum. Three of four patients were recorded as having lipaemic serum received propofol, however two of these patients along with the patient that received midazolam also received Intralipid. Overall mortality was similar in both sedation groups with 27 deaths being recorded. Thirteen patients received propofol. Five nonfatal adverse events occurred, three in patients that had received propofol. The findings of the survey suggest that propofol compares favourably with other sedative agents when used for sedating children in a paediatric intensive care unit.     

Remifentanil target-controlled infusion vs propofol target-controlled infusion for conscious sedation for awake fibreoptic intubation: a double-blinded randomized controlled trial

BACKGROUND: Awake fibreoptic intubation (AFOI) is a technique used in patients with difficult airways. This study compares the suitability of remifentanil target-controlled infusion (TCI) to propofol TCI for conscious sedation during AFOI in patients with bona fide difficult airways. METHODS: We recruited 24, ASA I-III patients, who were undergoing sedation for elective AFOI. Patients were randomized to one of the two groups, Group P (n=10) received propofol TCI and Group R (n=14) received remifentanil TCI. Primary outcome measures were conditions achieved at endoscopy, intubation, and post-intubation, which were graded using scoring systems. Other parameters measured were the endoscopy time, intubation time, and number of attempts at intubation. A postoperative interview was conducted to determine recall of events and level of patient satisfaction. RESULTS: Endoscopy scores (0-5) and intubation scores (0-5) were significantly different [Group P 3 (1-4) vs Group R 1 (0-3) P<0.0001, Group P 3 (2-4) vs Group R 1 (0-3) P<0.0001, respectively]; with much better conditions in Group R, endoscopy times and intubation times were also significantly different, being shorter in Group R (P<0.007 and P<0.023, respectively). Patient tolerance of the procedure, judged by the discomfort scores (P<0.004) and the post-intubation scores (P<0.08), was significantly better in Group R. The level of recall for events was higher in Group R. However, there were no significant differences in the patient satisfaction scores. CONCLUSIONS: Remifentanil TCI appears to provide better conditions for AFOI when compared with propofol TCI. The disadvantage of remifentanil in this setting may be a higher incidence of recall.