Comparison of Rectal Diazepam and Subcutaneous Morphine-Scopolamine Administration for Outpatient Sedation in Minor Oral Surgery

In a randomized cross-over study on sedation in outpatient oral surgery, subcutaneous administration of morphine-scopolamine was compared with rectal administration of diazepam. The mean dose of morphine was 0.13 mg kg-1 (range 0.13-0.24) and of diazepam 0.57 mg kg-1 (range 0.50-0.71). Apprehension, the determining factor for patients' preference for sedation method, the recovery from sedation and the postoperative course were studied. Both methods produced the desired effects. For diazepam, the effect was scored higher by the patient than the nurse observer and for morphine-scopolamine the opposite was found. Postoperative pain and patients' preference for sedation did not differ between the methods and the determining factor for the patients' preference for sedation method was the experience of stronger tranquilization. Side-effects such as prolonged recovery, nausea, dizziness, and dysphoria were frequent during the postoperative course after the morphine-scopolamine sedation but were not seen during diazepam sedation. Thus, rectal administration of diazepam should be preferred to morphine and scopolamine for sedation in minor oral surgery performed under local anesthesia.     

Plasma levels of clonidine following epidural bolus injection in children

Background: The use of clonidine as an adjunct to epidural administration of local anesthetics in children has been reported to substantially improve the duration and quality of postoperative analgesia. The aims of the present study were to determine the pharmacokinetic profile and to investigate the interaction between postoperative sedation and analgesia after epidurally administered clonidine in children.
Methods: Plasma levels of clonidine (0–10 h postop) and assessment of postoperative analgesia and sedation (0–24 h postop) were performed at predetermined intervals following lumbar epidural administration of bupivacaine 2.0 mg/kg and clonidine 2 mg/kg in 8 children undergoing ureteral re-implantation surgery using general anesthesia (age range: 1–9 yr, weight range: 9–11 kg). Plasma levels of clonidine were analyzed by radioimmunoassay, and sedation and analgesia were assessed by previously described scoring systems. Results : The venous plasma pharmacokinetics of clonidine following epidural administration showed a considerable interindividual variation. C_max and T_max values of clonidine were found to be within the 0.45–0.77 ng/mL and 48–193 min range, respectively. The time to absorb 95% of the clonidine dose from the epidural space into plasma varied between 36 min and 7.6 h. In 6 of the 8 patients postoperative analgesia substantially outlasted the duration of sedation (≥2 h). Sedation could not be detected in any patients at plasma concentrations below 0.3 ng/mL.
Conclusions: The pharmacokinetic profile associated with epidural clonidine administration in children (1–9 y) was similar to that previously reported in adults. The postoperative analgesia seen after administration of epidural bupivacaine-clonidine during general anesthesia in children cannot only be explained by residual postoperative sedation.     

Propofol infusion for sedation in outpatient oral surgery

An infusion of propofol was compared with intravenous boluses of diazepam as sedation for minor oral surgery under local anaesthesia in 12 healthy patients who had elective bilateral surgical extraction of lower third molars; the patients served as their own controls. Plasma catecholamine, vasopressin and cortisol concentrations were determined from repeated blood samples. The total administered dose of propofol was 3.93 (SD 1.34) mg/kg and of diazepam 0.28 (SD 0.07) mg/kg. No cardiovascular depression or airway problems occurred. Other side effects were also rare but some discomfort on injection was frequent with propofol. Recovery times were faster after propofol than after diazepam as assessed by the Maddox wing and visual analogue scales. Propofol also provided better amnesia compared to diazepam at the time of the extraction of the teeth. Eight of the 12 patients subjectively preferred propofol sedation. There was no hormonal stress response in either group.     

Rectal administration of morphine in children

Background : There is limited knowledge about the pharmacokinetics of morphine and its metabolites after rectal administration in children. In this study the pharmacokinetics of two different rectal formulations of morphine were examined and compared with intravenous morphine.
Methods : Children undergoing elective surgery received rectal morphine 0.2 mg/kg before start of surgery. Ten children (mean age 14 months) received morphine rectally in a hydro-gel formulation and another 10 children (mean age 16 months) received morphine rectally in a parenteral formulation. For comparison, 6 children (mean age 21 months) were given the same dose intravenously. The plasma concentrations of morphine, morphine-3-glucuronide (M3G) and mor-phine-6-glucuronide (M6G) were measured by HPLC over 6 h after drug administration.
Results : The mean rectal bioavailability of morphine was 35% (range 18–59) after hydrogel administration and 27% (range 6–93) after the solution. Mean values of Cmax were 76 nmol/1 (25–129) and 56 nmol/1 (15–140), respectively. The results showed that morphine gel had a significantly higher bioavailability (P<0.02) than the solution. The ratios of plasma (M3G + M6G) to morphine were higher after rectal administration (mean 7.5–8.7) than after i.v. injection (mean 5.3), indicating the presence of first-pass metabolism using the rectal route.
Conclusions : The rectal morphine hydrogel has pharmacokinetic properties which makes it a useful formulation for premedication and pain alleviation in paediatric patients.     

Comparison of Laryngotracheal and Ultrasonic Nebulizer Administration of Lidocaine in Local Anaesthesia for Bronchoscopy

Inhalation of nebulized minute lidocaine droplets has been suggested to be a very safe and pleasant method to produce topical anaesthesia for bronchoscopy. We produced topical anaesthesia of the respiratory tract either by laryngotracheal spraying (LS) of lidocaine (439±85 mg) or ultrasonic nebulizer administration (UNA) of lidocaine (462±81 mg) in 40 patients undergoing bronchoscopy. All patients also received an average of 15 mg of diazepam intravenously. Both modes of lidocaine administration produced adequate anaesthesia and were safe, but when rated on the visual analogue scale, both the efficacy of local anaesthesia and the cooperation of patients during bronchoscopy were better (P<0.05) after LS than those after UNA. The peak plasma concentrations of lidocaine (means ±s.d.) were lower and occurred earlier after UNA (0.53 ±0.34 μg/ml at 5–15 min after administration) than those after LS (0.89±0.63 μg/ml at 15–25 min after spraying). The highest individual values measured (2.54 μg/ml after LS and 1.17 μg/ml after UNA) were much less than those measured 1 and 15 min after i.v. administration of 2 mg/kg of lidocaine in another ten patients and far below the reported toxic lidocaine plasma concentrations. It is concluded that bronchoscopy can be conducted under local anaesthesia as successfully and safely using inhalation of lidocaine droplets from an ultrasonic nebulizer as when using laryngotracheal spraying of lidocaine.     

Induction agents for day-case anaesthesia A double-blind comparison of propofol and midazolam antagonised by flumazenil

Early postoperative recovery was studied using sedation scoring, measurement of flicker fusion frequency and completion of Trieger test figures in 60 male patients who presented for vasectomy under general anaesthesia as day patients. Anaesthesia was induced in groups 1 and 2 (20 patients each) with mean (SD) doses of 0.16 (0.04) mg/kg or 0.16 (0.03) mg/kg midazolam respectively; group 2 received flumazenil 0.55 (0.19) mg after completion of surgery. The remaining 20 patients (group 3) received propofol 1.50 (0.24) mg/kg. Anaesthesia was maintained with isoflurane vaporized in 33% oxygen and nitrous oxide in all patients. Flumazenil tended to improve tests of recovery after midazolam anaesthesia, but early recovery after propofol anaesthesia was associated with better psychomotor test results and less impairment of mental state as judged by sedation and amnesia scoring.     

Continuous interscalene brachial plexus block during and after shoulder surgery

Continuous interscalene brachial plexus block with a single dose of 0.75% bupivacaine (150-210 mg) with adrenaline, continued with an infusion of plain 0.25% bupivacaine 0.25 mg/kg/h, was performed on 20 patients to provide analgesia during shoulder surgery and in the postoperative period. The control group included 20 patients who were given general anaesthesia for surgery after starting a continuous interscalene brachial plexus block; test dose of 0.75% bupivacaine (22.5 mg) with adrenaline, continued with an infusion of 0.25% bupivacaine 0.25 mg/kg/h. Surgery was performed successfully under regional anaesthesia in 16/20 patients; 4/16 were given one dose of fentanyl during the surgery, and diazepam or midazolam as supplementary sedation were given in 13/16 cases. For postoperative analgesia 35/40 patients had a fully functioning catheter for 20-26 hours and the need for oxycodone i.m. during that time was 1.5 +/- 0.4 doses after regional anaesthesia (n = 14) and 1.8 +/- 0.4 doses after general anaesthesia (n = 18). There was a statistically significant difference in the mean plasma bupivacaine concentrations between the groups, concentrations in the regional anaesthesia group being higher at 5, 30, 60 min and 3 h (maximum 2.3 micrograms/ml at 60 min), but there was no difference between the values at 24 h. One infusion of local anaesthetic was discontinued because of probable treatment-related side-effects (breathing difficulties, nausea). Mild local anaesthetic toxicity (dizziness, tinnitus) was noticed in four patients.     

Failure of Intramuscularly Administered Lorazepam and Scopolamine-Morphine Premedication to Produce Amnesic Effects to Supplement Conduction Anaesthesia

Patients undergoing surgery under regional anaesthesia often prefer to be sedated and do not later want to recall the procedure. One hundred and twenty-one patients scheduled for various surgical procedures under epidural, spinal, sacral, or brachial plexus blockades received 1 mg/kg of pethidine, 0.007 mg/kg of scopolamine, plus 0.14 mg/kg of morphine, or 0.03 mg/kg or 0.06 mg/kg or lorazepam intramuscularly as preanaesthetic medication before the operation. The patients's self-assessments of degree of fatigue and apprehension were similar after each premedication when assessed before operation. Postoperative anxiety and confusion as well as need for postoperative care and supervision were greatest after 0.06mg/kg of lorazepam. Significantly (P smaller than 0.05 to P smaller than 0.01) fewer patients given 0.06 mg/kg or lorazepam remembered different events and procedures carried out on them before and after operation than those given other premedications, but no significant differences were noted in patients' ability to recall the performance of operation when asked on the following day. Seventy-seven, 63, and 57% of patients receiving 0.06 mg/kg of lorazepam remembered the start of blockade, performance of operation, and stay in recovery room, respectively. Intravenous sedation should be preferred to these intramuscularly administered premedications if drug-induced amnesia is sought to supplement local anaesthetic techniques.     

Comparison of rectal to intramuscular administration of midazolam and atropine for premedication of children

The effectiveness of midazolam and atropine as anaesthetic premedication was investigated, comparing rectal to intramuscular administration. A total of 202 children varying in age from 10 months to 9 years, who had been admitted to the Day Surgery Department for short ENT procedures, were assigned to one of two groups on a random basis. The first group (n = 102) was given 0.5 mg/kg midazolam and 0.05 mg/kg atropine as a rectal solution 30 to 75 min prior to induction, while the second group (n = 100) was given 0.15 mg/kg midazolam and 0.02 mg/kg atropine as an intramuscular injection 20 to 60 min prior to induction. The levels of sedation and salivation were compared, as was the degree of tolerance to intravenous induction. The parents of children older than 3 years of age were given a questionnaire designed to determine the degree of amnesia. We found this combination of drugs to be effective in the relief of anxiety, the inhibition of salivary secretion and the promotion of memory loss, regardless of the route of administration. We feel that rectal administration is preferable because it is not associated with pain or anxiety.     

Mini-cholecystectomy under local anaesthesia

OBJECTIVE: Reports of mini-cholecystectomy (MC) under general anaesthesia in the surgical treatment of gallbladder disease are common, but those of MC under local anaesthesia are much more limited. We report our experience of MC under local anaesthesia. METHODS: Forty-two patients with gallstone disease scheduled for MC under local anaesthesia were included in this study. Twenty-seven were female, with a median age of 54.5 years (range, 29-71) and median body mass index (BMI) of 20.5 (range, 17.6-23.4). None of the patients had evidence of acute cholecystitis on admission or previous upper abdominal surgery. MC was performed by a standardized technique and under the combination of local anaesthesia (1% xylocaine with adrenaline) and intravenous administrations of fentanyl (0.001-0.002 mg/kg) and midazolam (0.05-0.1 mg/kg). RESULTS: The median operative time was 40 minutes (range, 35-64). Local anaesthesia was converted to general anaesthesia in two patients owing to the discomfort caused by lysis of dense adhesions around the gallbladder, giving a success rate of 95%. MC was done successfully in all patients without any postoperative complications. The median hospital stay was 5 days (range, 2-7). CONCLUSION: MC under local anaesthesia is an effective surgical procedure for patients with BMI of less than 24, who have no evidence of acute inflammation of the gallbladder and no previous upper abdominal surgery.     

The effect of pre-operative administration of midazolam on the development of intra-operative hypothermia

(Midazolam is often used for premedication; it is known to promote vasodilation and may therefore affect redistribution of heat during surgery. We examined the effect of pre-operative administration of midazolam on the development of intra-operative hypothermia. Forty-five patients were randomly allocated to one of three groups to receive no premedication (Group C), IM midazolam 0.04 mg.kg(-1) (Group M1) or 0.08 mg.kg(-1) (Group M2) 30 min prior to anaesthesia. Sedation levels were assessed, and then general anaesthesia was induced and maintained using propofol and fentanyl. During surgery, core temperature, which was similar for the three groups prior to induction of anaesthesia, decreased significantly less in the midazolam groups M1 and M2 compared to the control group C. Patients who were more heavily sedated prior to induction of anaesthesia, had significantly lower core temperatures peri-operatively than those who were less sedated, and core temperatures in unpremedicated patients fell to significantly lower levels during surgery than those who were drowsy. We conclude that pre-operative administration of midazolam produces an effect on the development of peri-operative hypothermia. We found that moderate pre-operative sedation reduces the peri-operative heat loss, possibly by affecting core-to-peripheral heat distribution.     

Effects of rectal thiopentone and methohexitone on carbon dioxide tension in infant anaesthesia with spontaneous ventilation

The influence of rectal administration of barbiturates on PCO2 during mask anaesthesia with spontaneous ventilation was studied in 72 infants. The age of the patients ranged between 6 and 24 months and they were all subjected to minor paediatric surgery. The patients were divided into four equally large groups: a control group receiving no premedication, a group receiving rectal thiopentone 30 mg X kg-1 and two groups receiving methohexitone either 20 or 30 mg X kg-1. In all patients PCO2 was measured in an arterialized capillary blood sample obtained during stable anaesthesia with oxygen, nitrous oxide and halothane before and after surgery. After rectal induction with barbiturates, the mean PCO2 was significantly higher in the different barbiturate groups than in the control group (P less than 0.05). The mean PCO2 value +/- s.d. in kPa for the control group was 5.6 +/- 0.7, for the group receiving thiopentone 30 mg X kg-1 6.5 +/- 1.6, for the groups receiving methohexitone 20 or 30 mg X kg-1 6.1 +/- 1.2 and 6.3 +/- 1.1, respectively. It is concluded that the combination of rectal induction with barbiturates and mask anaesthesia with oxygen, nitrous oxide and halothane carries an increased risk of hypoventilation in infants under 2 years of age.     

Conscious sedation and analgesia with rectal ketamine in the Macaca fuscata monkey.

Conscious sedation is commonly utilized in pediatric dentistry. Although opioid analgesics are often employed, patient safety would be enhanced if nonopioid drugs were used. The purpose of this study was to determine if rectal ketamine could produce plasma concentrations that would achieve both conscious sedation and analgesia to gingival needle puncture. Five 2-year-old male Macaca fuscata monkeys were given rectal ketamine at a dosage of 60 mg/kg and 90 mg/kg one week apart. Blood was drawn at selected times after administration, and vital signs, level of sedation, and consciousness were assessed. Plasma ketamine concentrations ranged from 240 to 820 ng/mL and from 390 to 3120 ng/mL after rectal administration at doses of 60 mg/kg and 90 mg/kg, respectively. Two monkeys after the high dose showed analgesia to a gingival needle puncture at plasma ketamine concentrations that ranged from 1390 to 3120 ng/mL. A good level of sedation was consistently observed in four monkeys (80%) following rectal ketamine at a dosage of 90 mg/kg, whereas one monkey showed a consistently good level at a dosage of 60 mg/kg. Sedation and dose were significantly (P less than 0.001) associated with plasma ketamine concentrations; physiologic parameters were not (P greater than 0.05). The results of this study suggest that rectal ketamine can produce plasma concentrations of the drug sufficient to achieve sedation in the monkey. The attainment of concomitant analgesia to a gingival needle puncture was not as predictable.     

Randomized, double-blind study comparing postoperative effects of treatment timing with histamine H-receptor antagonist cimetidine

BACKGROUND: The purpose of this study was to evaluate the effect of timing of preoperative, postoperative, and placebo administration of the H(2)-antagonist cimetidine on postoperative pain management and the incidence of side-effects. METHODS: One hundred and twenty ASA I to II patients, undergoing major gynaecological abdominal surgery, were randomly divided into three groups, and received a standardized general anaesthesia. The patients in the preoperative ('Pre') group received an intravenous infusion of cimetidine 4 mg kg(-1) prior to anaesthesia induction; the postoperative ('Post') group received the same volume of normal saline. Postoperatively, the patients in the Post group received an intravenous infusion of cimetidine 4 mg kg(-1); the patients in the Pre group received the same volume of normal saline. The Control group received the same volume of normal saline prior to anaesthesia induction and after the end of operation. Postoperatively, all patients were treated with a patient-controlled intravenous analgesia system, which was programmed to deliver 1 mg of morphine on demand for three consecutive days. RESULTS: Pain intensity, morphine consumption, sedation score, and side-effects were recorded and evaluated. We found no difference among the three groups with respect to pain intensities, morphine usage, sedation scores, and the incidence of nausea, vomiting, pruritus, or dizziness. CONCLUSIONS: Our results suggested that neither preoperative nor postoperative administration of cimetidine 4 mg kg(-1) provided a pre-emptive or preventive analgesic advantage for postoperative pain or morphine consumption, and that the use of cimetidine failed to reduce the incidence of nausea or vomiting.     

Anaesthesia with midazolam and S-(+)-ketamine in spontaneously breathing paediatric patients during magnetic resonance imaging

We evaluated safety and efficacy of a sedation technique based on rectal and intravenous S-(+)-ketamine and midazolam to achieve immobilization during Magnetic Resonance Imaging (MRI). Thirty-four paediatric patients were randomly assigned to undergo either the sedation protocol (study group) or general anaesthesia (control group). Imaging was successfully completed in all children. Children in the study group received a rectal bolus (0.5 mg x kg(-1) midazolam and 5 mg x kg(-1) S-(+)-ketamine) and required additional i.v. supplementation (20+/-10 microg x kg(-1) x min(-1) S-(+)-ketamine and 4+/-2 microg x kg(-1) x min(-1) midazolam), spontaneous ventilation was maintained. Transient desaturation occurred once during sedation and four times in the control group (P=0.34). PECO2 was 5.3+/-0.5 kPa (40+/-4 mm Hg) in the study group and 4.1+/-0.6 kPa (31+/-5 mm Hg) in the control group (P<0.001). Induction and discharge times were shorter in the study group (P<0.001), recovery times did not differ significantly between the groups. Our study confirms that a combination of rectal and supplemental intravenous S-(+)-ketamine plus midazolam is a safe and useful alternative to general anaesthesia for MRI in selected paediatric patients.     

No additional analgesic effect of intra-articular morphine or bupivacaine compared with placebo after elective knee arthroscopy

Background: Intra-articular pain prophylaxis is a controversial measure, adding costs although the benefits are still disputed. We wanted to evaluate the effects of intra-articular opioid or local anaesthesia or a combination of the two on postoperative analgesia and analgesic consumption after elective knee arthroscopy.
Methods: 107 patients with little or no preoperative pain and a minor surgical procedure were studied in a prospective, randomized double-blind design. The patients received midazolam 0.03 mg/kg intravenously before induction of general anaesthesia with fentanyl 1–2 μg/kg and propofol 2.0 mg/kg intravenously. Anaesthesia was maintained by a total intravenous technique with propofol infusion supplemented with alfentanil 10 μg/kg when needed. The patients breathed oxygen/air through a laryngeal mask. By the end of the surgery they received 20 ml of test drug into the knee-joint: Group I (BM): 20 ml of bupivacaine 2.5 mg/ml with 3 mg of morphine; Group II (B): 20 ml of bupivacaine 2.5 mg/ml; Group III (M): 20 ml isotonic saline with 3 mg morphine; Group IV (P): 20 ml of isotonic saline (placebo).
Results: There were no significant differences between the groups in: time to first analgesic administered, analgesic consumption during the pre-or post-discharge period, nausea, somnolence, side-effects or postoperative pain perception during the first week.
Conclusions: Intra-articular administration of morphine or bupivacaine is not indicated after elective knee-arthroscopy in patients with minor pre-operative pain and a small surgical trauma.     

Are women more sensitive to a pre‐curarization dose of rocuronium than men?

Background: There is increasing evidence that there are gender-related differences in the pharmacodynamics of neuromuscular blocking drugs. However, it is not known whether gender influences the pharmacodynamics of a pre-curarizing dose.
Methods: In the first part, we measured the neuromuscular blockade after administration of rocuronium 0.03 mg/kg (10% of ED₉₅) after induction of anaesthesia in 20 patients (10 female and 10 male patients) by electromyography. In the second part, 40 female and 40 male patients were observed for signs and symptoms of muscle weakness 2.5 min after injection of rocuronium 0.03 mg/kg before loss of consciousness. Succinylcholine-associated post-operative myalgia (POM) was also assessed.
Results: Median twitch heights were comparable between the two groups: 95.5 (range: 85–97; female) vs. 96.0 (range: 85–99; male), (NS). Train-of-four ratios were 97.5 (range: 64–100; female) vs. 99.0 (range: 52–100; male) (NS). Signs and symptoms of muscle weakness were observed in 64 (80%) patients, but there were no gender-related differences. The incidence and severity of POM did not differ significantly between the study groups.
Conclusions: Pre-curarization with rocuronium 0.03 mg/kg affected men and women equally. Nor was the incidence and the severity of muscle weakness affected by gender.     

A comparison of dexmedetomidine and midazolam for sedation in third molar surgery

This randomised, double-blind study compared dexmedetomidine and midazolam for intravenous sedation during third molar surgery under local anaesthesia. Sixty patients received either dexmedetomidine (up to 1 microg x kg(-1)) or midazolam (up to 5 mg), which was infused until the Ramsay Sedation Score was four or the maximum dose limit was reached. Intra-operative vital signs, postoperative pain scores and analgesic consumption, amnesia, and satisfaction scores for patients and surgeons, were recorded. Sedation was achieved by median (IQR (range)) doses of 47 microg (39-52 (25-76)) or 0.88 microg x kg(-1) (0.75-1.0 (0.6-1.0)) dexmedetomidine, and 3.6 mg (3.3-4.4 (1.9-5.0)) or 0.07 mg x kg(-1) (0.055-0.085 (0.017-0.12)) midazolam. Heart rate and blood pressure during surgery were lower in dexmedetomidine group. There was no significant difference in satisfaction or pain scores. Midazolam was associated with greater amnesia. Dexmedetomidine produces comparable sedation to midazolam.     

Propofol versus midazolam. Long-term sedation in the intensive care unit]

Sedative-analgesic treatment of patients on long-term artificial ventilation aims at protection from stress related to their disease or therapy. By stabilising both the patient's vital functions and psychological state this treatment may contribute to therapeutic success. The choice of drugs depends primarily on the nature and course of the underlying disease. Midazolam and propofol are available as hypnotics for short-term sedation during the post-operative period. The purpose of this study was to evaluate the effects of both agents on cardiovascular function, cortisol production, lipometabolism, and the recovery period following 24-h sedation. METHODS. Twenty female patients (mean body weight: 72 kg, mean age: 60 years) were randomly assigned to receive either midazolam or propofol over 24 h following major abdominal surgery. Balanced anaesthesia (halothane/O2/N2O/fentanyl) was administered for the surgical procedure. Assisted ventilation was used in all patients during the post-operative sedation period. Sedation depth was maintained at III-IV on the Ramsey scale. On arrival in the intensive care unit (ICU), an initial i.v. bolus of midazolam 0.1 mg/kg or propofol 1 mg/kg was followed by a continuous infusion (midazolam: 0.1 mg/kg.h; propofol: 2 mg/kg.h). Supplementary boluses of one-half the initial dose were given if required. Post-operative analgesia was achieved with 3 mg intravenous piritramide at 2-h intervals. A 7F Swan-Ganz catheter was inserted in the pulmonary artery and haemodynamic and biochemical parameters were monitored at 4-h intervals over 24 h starting 2 h after arrival in the ICU. Catecholamines were measured by high-pressure lipid chromatography (HPLC), cortisol by radioimmunoassay, midazolam by HPLC and ultraviolet detection, and propofol by HPLC and fluorescence detection. Data were calculated as means. The statistical analysis was performed according to the Mann-Whitney test, and significance was accepted for P less than 0.05. RESULTS. On administration of the propofol bolus at the onset of sedation, a decrease in blood pressure was particularly observed in patients with masked hypovolaemia, however, this decrease was easily controlled by volume administration. Independent of the type of sedation, the haemodynamic parameters remained unchanged throughout the observation period. At all times of measurement the mean heart rate was lower in the propofol group (90/min) when compared with the midazolam group (100/min), however, this difference did not reach significance. There were also no significant differences in cardiac index at all times of measurement, although it increased in both groups within the first 12 h by 0.6 l/min.min2. In both groups this increase was associated with a reduction in peripheral resistance and an increase in rectal temperature. To achieve the desired sedation depth, midazolam was administered at a mean dosage of 0.11 mg/kg.h and propofol at 1.9 mg/kg.h. Catecholamine levels decreased in both groups within the first 8 h: after 8 h of sedation the plasma levels of noradrenaline and adrenaline were 525 and 65 pg/ml, respectively, in the midazolam group and 327 and 51 pg/ml in the propofol group. (ABSTRACT TRUNCATED AT 400 WORDS)     

The Influence of Intramuscularly Administered Pethidine on the Amnesic Effects of Intravenous Diazepam during Intravenous Regional Anaesthesia

Patients undergoing surgery under regional anaesthesia often receive narcotic analgesics for premedication which may modify the sedative and amnesic effects of intravenously administered diazepam. Sixty-two patients scheduled for upper extremity surgery under intravenous regional anaesthesia received 0.15 mg/kg of diazepam intravenously to supplement the local anaesthesia. Thirty-two of the patients received 0.01 mg/kg of atropine plus 1 mg/kg of pethidine and 30 patients only atropine intramuscularly approximately 1 h before the injection of diazepam. Another 30 patients received the same atropine-pethidine premedication and saline intravenously, and served as a reference group. Atropine-pethidine premedication followed by saline did not produce any amnesic effects. Sixty-nine and 38% of patients receiving atropine-pethidine premedication followed by diazepam did not remember a picture shown to them 15 min after diazepam injection or the performance of operation, respectively, the respective figures for patients given atropine premedication followed by diazepam being only 23% and 0% (P<0.01 - 0.001 between groups). The anti-recall of painful stimulus (exanguination) was significantly (P<0.01) more common when diazepam was given after pethidine premedication (31%) when compared to its injection after atropine alone (7 %). The drowsiness produced by the drugs was greatest and the overall patient acceptability of the technique used most satisfactory when pethidine was used for premedication and diazepam for sedation. It is concluded that intramuscularly administered pethidine potentiates the amnesic action of intravenous diazepam for painful stimuli, prolongs the amnesic action of diazepam for visual stimuli and improves the patients' acceptability of intravenous regional anaesthesia supplemented by intravenous diazepam.