Premedication with midazolam in out-patient general anaesthesia. A comparison with morphine-scopolamine and placebo

Opioid analgesic effects on subjective well-being in the operating theatre

Exposure to opioid analgesics due to surgery increases the risk of new persistent opioid use. A mechanistic hypothesis for opioids' abuse liability rests on the belief that, in addition to pain relief, acute opioid treatment improves well-being (e.g. via euphoria) and relieves anxiety. However, opioids do not consistently improve mood in laboratory studies of healthy non-opioid users. This observational study determined how two commonly used opioid analgesics affected patients' subjective well-being in standard clinical practice. Day surgery patients rated how good and how anxious they felt before and after an open-label infusion of remifentanil (n = 159) or oxycodone (n = 110) in the operating theatre before general anaesthesia. One minute after drug injection, patients reported feeling intoxicated (> 6/10 points). Anxiety was reduced after opioids, but this anxiolytic effect was modest (remifentanil Cohen's d = 0.21; oxycodone d = 0.31). There was moderate to strong evidence against a concurrent improvement in well-being (Bayes factors > 6). After remifentanil, ratings of 'feeling good' were significantly reduced from pre-drug ratings (d = 0.28). After oxycodone, one in three participants felt better than pre-drug. Exploratory ordered logistic regressions revealed a link between previous opioid exposure and opioid effects on well-being, as only 14 of the 80 opioid-naïve patients reported feeling better after opioid injection. The odds of improved well-being ratings after opioids were higher in patients with previous opioid exposure and highest in patients with > 2 weeks previous opioid use (adjusted OR = 4.4). These data suggest that opioid-induced improvement of well-being is infrequent in opioid-naïve patients. We speculate that peri-operative exposure could increase risk of persistent use by rendering subsequent positive opioid effects on well-being more likely.

Transdermal scopolamine for the prevention of postoperative nausea and vomiting: a systematic review and meta-analysis

BACKGROUND

Transdermal scopolamine (TDS) is a potential long-acting prophylactic antiemetic initially developed to prevent motion sickness. TDS is a centrally acting anticholinergic agent that was approved in 2001 by the US Food and Drug Administration for the prevention of postoperative nausea and vomiting (PONV). Although TDS has been reported to be clinically efficacious in the prevention of PONV, several adverse events (AEs), such as sedation, dry mouth, blurred vision, central cholinergic syndrome, and confusion (particularly in elderly patients with mild cognitive impairment), are potential concerns.

OBJECTIVE

The aim of this study was to explore the efficacy and tolerability of TDS in the prevention of PONV in adults.

METHODS

A systematic search of PubMed, EMBASE, and the Cochrane Library for randomized controlled trials in adults that compared the effects of TDS and placebo on postoperative nausea, vomiting, and PONV was conducted in March 2009, and an update was conducted in July 2010. Without any language restrictions, a search with the following terms was performed: postoperative, postoperative, postanesthe*, postanaesthe*, post-anesthe*, post-anaesthe*, anesthesia, anaesthesia, surgery, surgeries, surgical, nausea, vomiting, emesis, retching, scopolamine, and hyoscine. Identified studies were then hand-searched for further relevant literature.

RESULTS

Data from 25 randomized controlled trials were analyzed (N = 3298). In the postanesthesia care unit, TDS was associated with a significantly reduced risk for postoperative nausea compared with placebo (relative risk [RR] = 0.77; 95% CI, 0.61-0.98; P = 0.03). TDS was also associated with a significantly reduced risk for postoperative nausea (RR = 0.59; 95% CI, 0.48-0.73; P < 0.001), postoperative vomiting (RR = 0.68; 95% CI, 0.61-0.76; P < 0.001), and PONV (RR = 0.73; 95% CI, 0.60-0.88; P = 0.001) during the first 24 hours after the start of anesthesia. TDS appeared to be effective compared with placebo in the prevention of postoperative nausea when treatment was initiated the night before (early application) (RR = 0.56; 95% CI, 0.41-0.75; P < 0.001) or on the day of surgery (late application) (RR = 0.61; 95% CI, 0.47-0.79; P < 0.001). TDS was associated with a higher prevalence of visual disturbances at 24 to 48 hours compared with placebo (RR = 3.35; 95% CI, 1.78-6.32). Analyses of confusion and other AEs did not show a significant association with TDS.

CONCLUSIONS

In this systematic review and metaanalysis, TDS was associated with significant reductions in PONV with both early and late patch application during the first 24 hours after the start of anesthesia. TDS was associated with a higher prevalence of visual disturbances at 24 to 48 hours after surgery, but no other AEs, compared with placebo.

Premedication for anxiety in adult day surgery

BACKGROUND

Since the early 1980s, it has become more and more common to carry out surgical procedures on a day case basis. Many patients are anxious before surgery yet there is sometimes a reluctance to provide sedative medication because it is believed to delay discharge from hospital.This is an updated version of the review first published in 2000 (previous updates 2003; 2006).

OBJECTIVES

To assess the effect of anxiolytic premedication on time to discharge in adult patients undergoing day case surgery under general anaesthesia.

SEARCH STRATEGY

We identified trials by computerized searches of the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2009 Issue 1 ); MEDLINE (1980 to January 2009); EMBASE (1980 to January 2009). We also checked the reference lists of trials and review articles and handsearched three main anaesthesia journals.

SELECTION CRITERIA

We included all identified randomized controlled trials comparing anxiolytic drug(s) with placebo before general anaesthesia in adult day case surgical patients.

DATA COLLECTION AND ANALYSIS

We collected data on anaesthetic drugs used; results of psychomotor function tests where these were used to assess residual effect of premedication; and on times from end of anaesthesia to ability to walk unaided or readiness for discharge from hospital. Formal statistical synthesis of individual trials was not performed in view of the variety of drugs studied.

MAIN RESULTS

We included 17 studies. Methodological quality of included studies was poor. Of these 17, only seven studies specifically addressed the discharge question; none found any delay in premedicated patients. Two other studies used clinical criteria to assess fitness for discharge, though times were not given. Again, there was no difference from placebo. Eleven studies used tests of psychomotor function with or without clinical measures as indicators of recovery from anaesthesia. In none of these studies did the premedication appear to delay discharge, although performance on tests of psychomotor function was sometimes still impaired. Three studies showed no impairment in psychomotor function, six showed some impairment which had resolved by three hours or time of discharge and two showed significant impairment.

AUTHORS' CONCLUSIONS

We found no evidence of a difference in time to discharge from hospital, assessed by clinical criteria, in patients who received anxiolytic premedication. However, in view of the age and variety of anaesthetic techniques used and clinical heterogeneity between studies, inferences for current day case practice should be made with caution.

Preoperative oral Passiflora incarnata reduces anxiety in ambulatory surgery patients: a double-blind, placebo-controlled study

BACKGROUND

Many patients have preoperative anxiety; therefore, the development of a strong anxiolytic with minimal psychomotor impairment for premedication may be desirable.

METHODS

In this study, 60 patients were randomized into two groups to receive either oral Passiflora incarnata (500 mg, Passipy IranDarouk) (n = 30) or placebo (n = 30) as premedication, 90 min before surgery. A numerical rating scale (NRS) was used for each patient to assess anxiety and sedation before, and 10, 30, 60, and 90 min after premedication. Psychomotor function was assessed with the Trieger Dot Test and the Digit-Symbol Substitution Test at arrival in the operating room, 30 and 90 min after tracheal extubation. The time interval between arrival in the postanesthesia care unit and discharge to home (discharge time) was recorded for each patient.

RESULTS

The demographic characteristics of patients, ASA physical status, duration of surgery, basal NRS score, sedation at the preset time intervals, and discharge time were similar in the two groups. The NRS anxiety scores were significantly lower in the passiflora group than in the control group (P < 0.001). There were no significant differences in psychological variables in the postanesthesia care unit and recovery of psychomotor function was comparable in both groups.

CONCLUSIONS

In outpatient surgery, administration of oral Passiflora incarnata as a premedication reduces anxiety without inducing sedation.

Logistics of referral, diagnostic assessment and treatment of patients with breast symptoms and signs

BACKGROUND AND AIMS

The logistics of diagnosis and treatment in a hospital with slightly above 400 new cases of breast cancer per year is analysed.

MATERIALS AND METHODS

The patient flow from referral, through the diagnostic procedures and through surgical treatment is described.

RESULTS AND CONCLUSIONS

The basic principle of the diagnostic assessment is the triple diagnostic procedure including mammography supplemented by ultrasonography, fine needle aspiration cytology and clinical examination. The radiologist and pathologist are working together in the breast diagnostic centre and are thus able to give a "single visit diagnosis" in most cases. The surgeon sees the patient either the same day or the next. A "consensus meeting" held each week with representatives for all specialities present has an important function in quality assurance and education. If one or more of the triple diagnostic components reach conclusion level "suspicious lesion", surgery is indicated. In hospital management is based on day surgery for all biopsies, wide excisions with or without sentinel node and some ablatio simplex mammae. For wide excision and ablation with complete axillary node clearance, the patients are transferred from the day surgery unit to a patient hotel after 3-4 hours of observation and stay till the drain can be removed. Only in rare case of high cardiopulmonary risk, beds in ordinary wards are used. This is a highly cost efficient logistic saving the hospital approximately 400,000 EUR a year compared to ordinary in hospital treatment.

Premedication for anxiety in adult day surgery

BACKGROUND

Since the early 1980's it has become more and more common to carry out surgical procedures on a day case basis. Many patients are anxious before surgery yet there is sometimes a reluctance to provide sedative medication because it is believed to delay discharge from hospital.

OBJECTIVES

To assess the effect of anxiolytic premedication on time to discharge in adult patients undergoing day case surgery under general anaesthesia.

SEARCH STRATEGY

Trials were identified by computerized searches of the Cochrane Controlled Trials Register, MEDLINE (1980 to April 2002), EMBASE (from 1974 onwards), by checking the reference lists of trials and review articles, by hand-searching three main anaesthesia journals and by contacting five researchers active in the field and the Product Information Departments of the manufacturers of five commonly used premedicants.

SELECTION CRITERIA

All randomized controlled trials comparing an anxiolytic drug(s) with placebo before general anaesthesia in adult day case surgical patients.

DATA COLLECTION AND ANALYSIS

We collected data on anaesthetic drugs used, results of tests of psychomotor function where these were used to assess residual effect of premedication, and on times from end of anaesthesia to ability to walk unaided or readiness for discharge from hospital. Formal statistical synthesis of individual trials was not performed in view of the variety of drugs studied.

MAIN RESULTS

Searching identified thirty-one reports; fifteen studies, with data from 1313 patients, were considered eligible for analysis. Only three studies specifically addressed the discharge question; both found no delay in premedicated patients. Three other studies used clinical criteria to assess fitness for discharge, though times were not given. Again, there was no difference from placebo. Four studies used both clinical measures and tests of psychomotor function as tests of recovery from anaesthesia. In none of these studies did the premedication appear to delay discharge, although performance on tests of psychomotor function was sometimes still impaired. Of the four studies which used tests of psychomotor function to assess recovery, three showed impaired recovery (after midazolam 7.5mg, midazolam 15mg or diazepam 15mg) which might possibly interfere with discharge from hospital. Seven studies used either clinical criteria alone or in combination with psychomotor tests; none showed discharge delay.

REVIEWER'S CONCLUSIONS

We have found no evidence of a difference in time to discharge from hospital, as assessed by clinical criteria, in patients who received anxiolytic premedication. However, in view of the age and variety of anaesthetic techniques used, inferences for currant day case practice should be made with caution.

Preoperative alprazolam reduces anxiety in ambulatory surgery patients: a comparison with oral midazolam

Because an oral formulation of midazolam is not approved in certain countries, we evaluated oral alprazolam as an alternative. Forty-five outpatients scheduled for gynecological laparoscopic surgery participated in a double-blinded study to compare the effectiveness and side effects of oral alprazolam 0.5 mg with midazolam 7.5 mg, as a reference drug, and placebo. We evaluated psychomotor function by means of the Trieger Dot Test (TDT) and the Digit-Symbol Substitution Test. Simple memory tests were performed. Data were analyzed with chi(2) or paired Student's t-tests, or with one-way analysis of variance with the Student-Newman-Keuls or Kruskal-Wallis test, as appropriate; P < 0.05 was considered statistically significant. Alprazolam and midazolam both decreased anxiety scores more than placebo (P < 0.05). One hour after premedication, the Digit- Symbol Substitution Test score was similar in all groups, whereas the TDT score was greater (indicating impairment of performance) in the alprazolam group than in the placebo group (P < 0.05). Sedation scores, extubation time, and discharge times in the active drug groups did not differ from placebo. At discharge from the postanesthesia care unit, the TDT score was greater in both active drug groups compared with placebo (P < 0.05). Five patients, exclusively in the midazolam group, had amnesia (P < 0.05). We conclude that alprazolam may be an effective alternative to midazolam for anxiety reduction without causing amnesia. However, it may cause greater impairment of psychomotor function in the early postoperative period.

IMPLICATIONS

Oral alprazolam 0.5 mg and midazolam 7.5 mg comparably reduce anxiety in ambulatory surgery patients. Despite early psychomotor impairment, neither drug delays postanesthetic extubation nor prolongs discharge from the postanesthesia care unit.

The efficacy and safety of transdermal scopolamine for the prevention of postoperative nausea and vomiting: a quantitative systematic review

The role of scopolamine administered via transdermal therapeutic systems in the prevention of postoperative vomiting, nausea, and nausea and vomiting is unclear. We performed a systematic search for full reports of randomized comparisons of transdermal scopolamine with inactive control. Dichotomous data were extracted. In the meta-analysis, relative risks and numbers-needed-to-treat/harm were calculated with 95% confidence intervals (CI). In 23 trials, 979 patients received transdermal scopolamine, and 984 patients received placebo. Sensitivity analyses were performed using restricted data for truncated control event rates (40%-80%) and for large trials. With these data, the relative risks for postoperative vomiting (five reports), nausea (five reports), nausea and vomiting (eight reports), and rescue treatment (three reports) were 0.69 (95% CI, 0.58-0.82), 0.69 (95% CI, 0.54-0.87), 0.76 (95% CI, 0.66-0.88), and 0.68 (95% CI, 0.54-0.85), respectively. This means that of 100 patients who receive transdermal scopolamine, approximately 17 will not experience postoperative vomiting who would have done so had they all received a placebo. However, 18 of 100 patients will have visual disturbances, eight will report dry mouth, two will report dizziness, one will be classified as being agitated, and 1-13 patients who are prescribed transdermal scopolamine will not use it correctly. The timing of application does not alter efficacy.

IMPLICATIONS

Of 100 patients who receive transdermal scopolamine, approximately 17 will not vomit in the postoperative period who would have done so had they all received a placebo. However, 18 of 100 patients will have visual disturbances, and eight will report dry mouth. Incorrect use further limits its efficacy.

Postoperative nausea and vomiting in paediatric ambulatory surgery: sevoflurane versus spinal anaesthesia with propofol sedation

BACKGROUND

Descriptive data report a very low rate of postoperative nausea and vomiting (PONV) following spinal anaesthesia in children. In an attempt to corroborate this observation, we designed a prospective randomized study to compare spinal anaesthesia with intravenous propofol sedation (SA) (n=21) to inhalational sevoflurane anaesthesia (IA) (n=19) with regard to PONV and postoperative analgesia in children (aged 3-12 years) undergoing ambulatory inguinal surgery.

RESULTS

No difference was found concerning the number of patients experiencing PONV in each group (SA 1/21 versus IA 5/19; P=0.085). However, spinal anaesthesia was associated with a reduced number of PONV episodes (1/21) compared with inhalation anaesthesia (8/19) (P=0.014) and the need for supplemental postoperative analgesia with ketoralac was significantly lower in the SA group (3/21) compared to the IA group (14/19) (P < 0.001). Despite these benefits of spinal anaesthesia compared with inhalational anaesthesia, spinal anaesthesia did not decrease the time to discharge from the ambulatory surgery unit [SA 161 (SD 51) min, IA 164 (SD 41) min; P=NS] and the overall PONV experience was rated as "no problem" by all patients, except one, regardless of anaesthetic protocol used.

CONCLUSIONS

Despite the reduced number of emetic episodes and the better immediate postoperative analgesia associated with spinal anaesthesia, no difference could be identified between the two different anaesthetic protocols regarding time to discharge or overall patient satisfaction. Thus, despite minor advantages associated with spinal anaesthesia with propofol sedation, both anaesthetic regimen appear equally suitable for use in the paediatric outpatient setting.

Preoperative ropivacaine infiltration in breast surgery

PURPOSE

The aim of the study was to investigate whether preoperative infiltration with ropivacaine in conjunction with breast surgery improves postoperative pain management and attenuates postoperative nausea and vomiting.

METHOD

Prospective, randomised, double-blind study, including 60 healthy women (ASA 1-2) allocated to one of two groups. Thirty patients were given 0.3 ml/kg saline in the operating field before surgery. Another 30 patients received a similar volume of ropivacaine 3.75 mg/ml. A visual analogue scale (0-100 mm) was used for evaluation of postoperative pain, nausea and vomiting. If the score was more than 30 mm at rest, the patients were given ketobemidone i.v. as treatment for postoperative pain, and dixyrazine i.v. against nausea and vomiting. The intra-and postoperative analgesic requirements and postoperative nausea and vomiting were registered.

RESULTS

The intraoperative fentanyl consumption was similar in the saline group 81 +/- 22 microg vs 76 +/- 28 microg; (ns) in the ropivacaine group. The postoperative 24-h ketobemidone consumption was also similar to those treated with ropivacaine (4.2 +/- 2.6 mg vs 4.2 +/- 4.3 mg; ns). Postoperative nausea and vomiting (PONV) occurred with similar frequencies in both groups. The 24-h dixyrazine consumption was the same in the two groups (2.1 +/- 2.7 mg in the saline group compared to 2.4 +/- 2.8 mg in the ropivacaine group; ns). After 6 h recovery, 41% of all patients had experienced nausea and 20% vomiting.

CONCLUSION

We found no differences in postoperative pain management between 3.75 mg/ml ropivacaine and saline wound infiltration before breast surgery. The data show similar postoperative needs of analgesics and antiemetics with a similar frequency of PONV.

Midazolam as a pediatric premedicant in the ambulatory setting

In the preoperative setting, the nurse is responsible for the comprehensive evaluation and preparation of the patient. Among these activities, the administration of various premedications to achieve a physiological (eg, raise gastric fluid pH) or psychological (eg, reduce apprehension) effect is commonplace. Midazolam, a benzodiazepine, is one of the more popular medications used preoperatively for its anxiolytic properties. Several studies have evaluated the variety of routes by which midazolam can effectively be administered to the pediatric patient. A review of midazolam as a premedication specific to the pediatric population in the ambulatory setting is presented.

Oral premedication one hour before minor gynaecological surgery--does it have any effect? A comparison between ketobemidone, lorazepam, propranolol and placebo

The purpose of the present study was to compare the effects of oral premedication with ketobemidone 5 mg, lorazepam 1 mg, propranolol 40 mg or placebo, given about an hour prior to anaesthesia, in a prospective randomized double-blind fashion. One hundred and twenty ASA I female patients scheduled for elective laparoscopy were randomly prescribed one of the study drugs. Patient evaluation of anxiety, nurse evaluation of premedication, induction and postoperative course were studied. Ninety-three of the 120 patients (78%) experienced no change or a decrease in anxiety, regardless of type of active drug or placebo administered. Eighty-eight of the patients (73%) were considered adequately premedicated by the nurse observer, with no differences between the groups. Pre induction pulse rate, blood pressure and amount of induction agent needed was also similar between the four groups of patients. No major differences could be seen during the postoperative course. We found no major effects of any of the active drugs studied compared to placebo. Routine use of small doses of oral premedication one hour before elective surgery among low anxiety patients could probably be omitted.

Out-patient surgery--a survey of anaesthesia care in a university hospital

This study was done at the Linköping University Hospital, Sweden, to assess the quality of care given to patients undergoing outpatient anaesthesia. A questionnaire was given to all adult patients (> 15 years old) immediately on admission to the outpatients' surgical ward and the patients were asked to answer all the questions, if necessary with the help of an attending nurse. Another questionnaire was given to the patients in the post-operative ward immediately prior to their being discharged home. Analyses of results indicate that although most patients were satisfied with the care offered at the outpatient surgical unit, 50% requested, but were not given, anxiolytic premedication before the operation. A majority of these were women undergoing gynaecological operations. Twenty per cent of the patients complained of post-operative pain that was poorly managed. Drowsiness (12%), headache (10%), and sore throat (8%) were common complications following general anaesthesia. In contrast, patients who had regional or local anaesthesia had an extremely low incidence of complications. Almost one-third of the patients were discharged without a responsible person accompanying them home and 25% were alone at home during the first 24 hours. Of the patients who went home alone, most either walked, cycled or took the bus, but 4% actually drove home after the operation. In our opinion more stress should be laid on patient information before the operation and better methods to relieve preoperative anxiety should be used whenever indicated.(ABSTRACT TRUNCATED AT 250 WORDS)

Postoperative nausea and vomiting. A comparison between intravenous and inhalation anaesthesia in breast surgery

Nausea and vomiting during the first 24 postoperative hours after breast surgery were studied. Ninety patients scheduled for elective breast surgery were randomly assigned to one of three anaesthetic methods: total intravenous anaesthesia with propofol, or propofol or thiopental for induction followed by isoflurane anaesthesia. All three groups received fentanyl for peroperative analgesia. A total of 46 (51%) patients experienced emetic sequelae: 19 (21%) complained about nausea and another 27 (30%) vomited once or more during the postoperative course. More than 50% of the patients with nausea and 70% with vomiting first suffered from these symptoms in the surgical wards after leaving the postoperative unit. Nausea and vomiting were seen in 18 (60%), 13 (43%) and 15 (50%) for the groups propofol-propofol, propofol-isoflurane and thiopental-isoflurane, respectively. In conclusion, every second patient experienced nausea or vomiting after breast surgery, the majority of these emetic symptoms occurring after leaving the postoperative unit. Propofol for induction or as a main anaesthetic did not make any major difference with regard to postoperative nausea or vomiting.

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.

A comparison of propranolol and diazepam for preoperative anxiolysis

The effectiveness of propranolol, a nonsedating anxiolytic premedication, was studied by monitoring preoperative anxiety and postoperative recovery of cognitive function in 92 healthy ASA physical status I females aged 15-42 yr undergoing outpatient dilatation and curettage (D&C) for therapeutic abortion. In a randomized double-blind design, patients received one of the following oral medications 1-1.5 hr preoperatively: (1) diazepam 10 mg (n = 31); (2) propranolol 80 mg (n = 31); (3) placebo (n = 30). Anxiety throughout the hospital stay was monitored using the State-Trait Anxiety Inventory (STAI). Postoperative cognitive recovery was assessed using the digit span and Trieger tests. STAI anxiety levels were recorded on admission to hospital, immediately before entering the operating room, and two hours postoperatively. There was no difference among the anxiolytic properties of the three medications and all three patient groups showed a significant decrease in anxiety levels after administration of the medication. Tests of cognitive function after anaesthesia showed the fastest return to baseline status in patients receiving propranolol, possibly because beta adrenergic blockade blunted the autonomic signs of light anaesthesia and less anaesthetic was administered. None of the study premedications was demonstrated to have an anxiolytic advantage, but propranolol did offer a faster return of cognitive function in the postoperative period.

Premedication before elective breast surgery, a comparison between ketobemidone and midazolam

One hundred female patients scheduled for elective breast surgery (mean age 60 +/- 11 years were randomly assigned to receive one of two premedications: ketobemidone (Ketogan) 1-1.5 ml or midazolam 4-5 mg, intramuscularly. The effects on preoperative anxiety and postoperative emetic sequelae were studied. All patients were anaesthetised with thiopentone, fentanyl and atracurium, and ventilated with a mixture of nitrous oxide in oxygen with supplementary isoflurane. Sixty-nine percent of the midazolam- and 50% of the ketobemidone-premedicated patients experienced a reduction in anxiety. Midazolam was found to be more effective than ketobemidone in reducing anxiety among more tense patients--those with a VAS grading before premedication of 2 or more (P less than 0.05). Midazolam-premedicated patients were also assessed by observers as being more relaxed (P less than 0.05). No difference was seen in the frequency of emetic sequelae: 20 patients in the midazolam group and 14 patients in the ketobemidone group vomited once or more during the 24-h observation period. There was no difference between the two groups in time until an analgetic was required. In conclusion, midazolam seemed more effective in reducing preoperative anxiety than ketobemidone without any negative effects on postoperative emesis or time until an analgetic was required.

Prolonged elimination of midazolam after i.m. administration

The elimination pharmacokinetics of midazolam after i.m. administration was compared with combined i.m. and i.v. administration in a randomized study of 55 gynaecological patients in outpatient general anaesthesia. Group 1 (n = 40) received midazolam 0.1 mg/kg i.m. as premedication 45 min before induction of general anaesthesia with midazolam 0.3 mg/kg i.v. Group 2 (n = 15) received midazolam 0.1 mg/kg i.m. as premedication 45 min before induction of general anaesthesia with thiopentone 4 mg/kg. Serum midazolam concentration measurements were performed regularly post-induction for 7 h in each patient. The elimination half-life of midazolam after i.m. administration (Group 2) was 6.6 +/- 1.2 h (mean +/- s.e. mean), which was significantly longer (P less than 0.05) than the 3.9 +/- 0.3 h observed after the combined i.m. and i.v. administration of midazolam (Group 1), and significantly longer than 2.9 h obtained from a calculated i.v. administration curve. We postulate a slow i.m. depot release of midazolam, representing the rate-limiting step in the elimination of midazolam after i.m. administration.

Total intravenous anaesthesia with midazolam and flumazenil in outpatient clinics. A comparison with isoflurane or thiopentone

Total intravenous anaesthesia with midazolam and alfentanil, reversed with the benzodiazepine antagonist flumazenil, was studied in patients admitted for outpatient gynaecological dilatation and curettage. One hundred patients were randomly allocated to four groups with different anaesthetic techniques: I: alfentanil and thiopentone induction, 66% N2O maintenance; II: alfentanil and midazolam sedation prior to isoflurane and N2O induction and maintenance; III: midazolam and alfentanil induction; oxygen/air, placebo reversal; IV: midazolam and alfentanil induction, oxygen/air, flumazenil reversal. All methods of anaesthesia proved satisfactory with no serious side-effects or complications. Induction was faster in Group I (26 s) compared with Group III and IV (37-38 s) and Group I (62 s). Respiration was less depressed in Group II compared with the other groups. Recovery function was better in Group IV during the first 30 postoperative min and worse in Group III during the first 120 postoperative min compared with the other groups. Reduced performances in P-deletion and 4-choice reaction-time tests in the midazolam patients were not reversed by 0.5 mg flumazenil, suggesting that flumazenil did not antagonize all benzodiazepine effects in our patients. Postoperative amnesia was most pronounced in Group III. There was no significant difference in patient function 7 h postoperatively, at home in the evening or during the next days. We conclude that total intravenous anaesthesia with alfentanil and midazolam with flumazenil reversal is a promising technique for short outpatient anaesthetic procedures.