Comparison of diazepam and midazolam for sedation during local anaesthesia for bronchoscopy

Midazolam for sedation before procedures

BACKGROUND

Midazolam is used for sedation before diagnostic and therapeutic medical procedures. It is an imidazole benzodiazepine that has depressant effects on the central nervous system (CNS) with rapid onset of action and few adverse effects. The drug can be administered by several routes including oral, intravenous, intranasal and intramuscular.

OBJECTIVES

To determine the evidence on the effectiveness of midazolam for sedation when administered before a procedure (diagnostic or therapeutic).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL to January 2016), MEDLINE in Ovid (1966 to January 2016) and Ovid EMBASE (1980 to January 2016). We imposed no language restrictions.

SELECTION CRITERIA

Randomized controlled trials in which midazolam, administered to participants of any age, by any route, at any dose or any time before any procedure (apart from dental procedures), was compared with placebo or other medications including sedatives and analgesics.

DATA COLLECTION AND ANALYSIS

Two authors extracted data and assessed risk of bias for each included study. We performed a separate analysis for each different drug comparison.

MAIN RESULTS

We included 30 trials (2319 participants) of midazolam for gastrointestinal endoscopy (16 trials), bronchoscopy (3), diagnostic imaging (5), cardioversion (1), minor plastic surgery (1), lumbar puncture (1), suturing (2) and Kirschner wire removal (1). Comparisons were: intravenous diazepam (14), placebo (5) etomidate (1) fentanyl (1), flunitrazepam (1) and propofol (1); oral chloral hydrate (4), diazepam (2), diazepam and clonidine (1); ketamine (1) and placebo (3); and intranasal placebo (2). There was a high risk of bias due to inadequate reporting about randomization (75% of trials). Effect estimates were imprecise due to small sample sizes. None of the trials reported on allergic or anaphylactoid reactions. Intravenous midazolam versus diazepam (14 trials; 1069 participants)There was no difference in anxiety (risk ratio (RR) 0.80, 95% confidence interval (CI) 0.39 to 1.62; 175 participants; 2 trials) or discomfort/pain (RR 0.60, 95% CI 0.24 to 1.49; 415 participants; 5 trials; I² = 67%). Midazolam produced greater anterograde amnesia (RR 0.45; 95% CI 0.30 to 0.66; 587 participants; 9 trials; low-quality evidence). Intravenous midazolam versus placebo (5 trials; 493 participants)One trial reported that fewer participants who received midazolam were anxious (3/47 versus 15/35; low-quality evidence). There was no difference in discomfort/pain identified in a further trial (3/85 in midazolam group; 4/82 in placebo group; P = 0.876; very low-quality evidence). Oral midazolam versus chloral hydrate (4 trials; 268 participants)Midazolam increased the risk of incomplete procedures (RR 4.01; 95% CI 1.92 to 8.40; moderate-quality evidence). Oral midazolam versus placebo (3 trials; 176 participants)Midazolam reduced pain (midazolam mean 2.56 (standard deviation (SD) 0.49); placebo mean 4.62 (SD 1.49); P < 0.005) and anxiety (midazolam mean 1.52 (SD 0.3); placebo mean 3.97 (SD 0.44); P < 0.0001) in one trial with 99 participants. Two other trials did not find a difference in numerical rating of anxiety (mean 1.7 (SD 2.4) for 20 participants randomized to midazolam; mean 2.6 (SD 2.9) for 22 participants randomized to placebo; P = 0.216; mean Spielberger's Trait Anxiety Inventory score 47.56 (SD 11.68) in the midazolam group; mean 52.78 (SD 9.61) in placebo group; P > 0.05). Intranasal midazolam versus placebo (2 trials; 149 participants)Midazolam induced sedation (midazolam mean 3.15 (SD 0.36); placebo mean 2.56 (SD 0.64); P < 0.001) and reduced the numerical rating of anxiety in one trial with 54 participants (midazolam mean 17.3 (SD 18.58); placebo mean 49.3 (SD 29.46); P < 0.001). There was no difference in meta-analysis of results from both trials for risk of incomplete procedures (RR 0.14, 95% CI 0.02 to 1.12; downgraded to low-quality evidence).

AUTHORS' CONCLUSIONS

We found no high-quality evidence to determine if midazolam, when administered as the sole sedative agent prior to a procedure, produces more or less effective sedation than placebo or other medications. There is low-quality evidence that intravenous midazolam reduced anxiety when compared with placebo. There is inconsistent evidence that oral midazolam decreased anxiety during procedures compared with placebo. Intranasal midazolam did not reduce the risk of incomplete procedures, although anxiolysis and sedation were observed. There is moderate-quality evidence suggesting that oral midazolam produces less effective sedation than chloral hydrate for completion of procedures for children undergoing non-invasive diagnostic procedures.

Comparative study of hemodynamic changes caused by diazepam and midazolam during third molar surgery: a randomized controlled trial

The aim of the present study was to compare hemodynamic changes using midazolam 7.5 mg and diazepam 10.0 mg during the surgical removal of symmetrically positioned third molars. A prospective, randomized, double-blind, clinical trial was carried out involving 120 patients divided into three groups: Group 1 (diazepam and placebo), Group 2 (midazolam and placebo), and Group 3 (diazepam and midazolam). Each subject underwent two surgeries on separate occasions under local anesthesia. The following parameters were assessed at five different times (T0, T1, T2, T3, and T4): systolic, diastolic, and mean blood pressure (SBP, DBP, and MBP, respectively); heart rate (HR); oxygen saturation (SpO(2)); rate pressure product (RPP); and pressure rate quotient (PRQ). Statistically significant differences were found regarding heart rate at T2 and T3 (p < 0.005) in Group 2, with a higher rate occurring during midazolam administration. Moreover, significant differences in rate pressure product were found at T2, T3, and T4 in this group, with higher values also occurring during midazolam administration. In Group 3, significant differences in diastolic blood pressure were found at T3 and T4, with higher values occurring during diazepam administration, whereas a higher heart rate occurred at T3 with midazolam. Midazolam 7.5 mg and diazepam 10.0 mg exert an influence on some hemodynamic parameters without perceptible clinical changes in healthy patients undergoing lower third molar surgery.

Fibreoptic bronchoscopy without sedation: Is transcricoid injection better than the "spray as you go" technique?

Aim:

The aim of the study was to compare transcricoid injection with spray as you go technique for diagnostic fibreoptic bronchoscopy, to perform the procedure without sedation and to record any complication or side effects.

Methods:

Sixty patients belonging to the age group 20–70 years, undergoing diagnostic bronchoscopy over a period of 6 months, were randomly selected and divided into two groups alternatively to receive 3 ml of 4% lignocaine by a single transcricoid puncture (group I) or 2 ml of 4% lignocaine instilled through the bronchoscope on to the vocal cords and further 1 ml of 2% lignocaine into each main bronchus (group II). Additional dose of lignocaine as required was given in both the groups. All patients were given intramuscular atropine 0.6 mg, 20 min before the procedure. Nebulisation with 3 ml of 4% lignocaine was given to all patients. The time from nasal insertion of the bronchoscope to reach the carina was recorded, and the total dose of lignocaine required in both the groups was calculated and compared. The cough episodes during the procedure, systolic blood pressure, and pulse rate were compared before the procedure and 5 min after the procedure in both the groups. A0–10 visual analogue scale (VAS) was used to assess discomfort 30 min after the procedure.

Results:

The time to reach carina was more in group II (P<0.02), and cough episodes were also more in group II (P<0.05) than in group I. The vitals before the procedure were comparable in both the groups, but 5 min after the procedure the vitals were more stable in group I than in group II, and the total dose of lignocaine required in group II was more than in group I (P<0.001). However, the VAS score was comparable in both the groups.

Conclusion:

Transcricoid puncture for diagnostic bronchoscopies without sedation was associated with no complication and discomfort and required lesser dose of local anaesthetic with more stable vitals and good conditions for bronchoscopists.

Fospropofol Disodium for Sedation in Elderly Patients Undergoing Flexible Bronchoscopy

BACKGROUND: Fospropofol disodium is a water-soluble prodrug of propofol. A subset analysis was undertaken of elderly patients (≥65 y) undergoing flexible bronchoscopy, who were part of a larger multicenter, randomized, double-blind study. METHODS: Patients received fentanyl citrate (50 mcg) followed by fospropofol at initial (4.88mg/kg) and supplemental (1.63mg/kg) doses. The primary end point was sedation success (3 consecutive Modified Observer's Assessment of Alertness/Sedation scores of ≤4 and procedure completion without alternative sedative or assisted ventilation). Treatment success, time to fully alert, patient and physician satisfaction, and safety/tolerability were also evaluated. RESULTS: In the elderly patients subset (n=61), sedation success was 92%, the mean time to fully alert was 8.0±10.9 min, and memory retention was 72% during recovery, and these were comparable with the younger patients subgroup (age, <65 y). Sedation-related adverse events occurred in 23% of the elderly and 18% of the younger patients (age, <65 y) group. Hypoxemia occurred in 26% of the elderly and 18% of the younger patients group, but no escalation of care was required. CONCLUSIONS: Fospropofol provided safe and effective sedation, rapid time to fully alert, and high satisfaction in this elderly subset undergoing flexible bronchoscopy, which was comparable with outcomes in younger patients.

Propofol versus midazolam and meperidine for conscious sedation in GI endoscopy

OBJECTIVE

Propofol (2,6-diisopropyl phenol) is a relatively new intravenous sedative hypnotic with an ideal pharmacokinetic profile for conscious sedation. In this study, we compared the safety and efficacy of propofol versus the conventional regimen of midazolam and meperidine for conscious sedation in GI endoscopy.

METHODS

In this prospective study, 274 patients that included many elderly patients with multiple comorbid conditions underwent GI endoscopic procedures at our hospital. A total of 150 patients received propofol (20-120 mg) and fentanyl (0.25-1.5 mg). The control group of 124 patients was given midazolam (2-6 mg) and meperidine (25-75 mg). The dose of medication was titrated according to patient need and the duration of the procedure. A "comfort score" on a scale of 1-4 assessed the efficacy of the drugs based on pain or discomfort to the patient and ease of endoscopy. A "sedation score" was used to assess the degree of sedation on a scale of 1-5. The Aldrete score was used to measure recovery from anesthesia at 5 and 10 min after the procedure.

RESULTS

After controlling for age, American Society of Anesthesiologists' Physical Status Classification (ASA grade), and type and duration of procedure, logistic regression analysis determined that propofol resulted in 2.04 times better patient comfort (p = 0.033, 95% CI = 1.058-3.923). Propofol was 1.84 times more likely to produce deeper sedation than the regimen of midazolam and meperidine (p = 0.027, 95% CI = 1.071-3.083). The recovery from sedation was faster in patients receiving propofol, although this did not reach statistical significance. The safety parameters between the two groups were comparable.

CONCLUSION

Propofol was associated with a statistically significant improvement in comfort and sedation score when compared to midazolam and meperidine.

Comparison of the sedation and recovery profiles of Ro 48-6791, a new benzodiazepine, and midazolam in combination with meperidine for outpatient endoscopic procedures

In this randomized, double-blinded study, we compared the onset and recovery characteristics of an investigational benzodiazepine, Ro 48-6791 (when administered alone or combined with meperidine), a midazolam-meperidine combination for sedation during gastrointestinal (GI) endoscopic procedures. Ninety consenting outpatients scheduled for upper or lower GI procedures were randomly assigned as follows: Group I received midazolam 1 mg IV and meperidine 50 mg; Group II received Ro 48-6791 0.5 mg IV and meperidine 50 mg; or Group III received Ro 48-6791 1.0 mg IV alone. If the level of sedation did not achieve an Observer's Assessment of Alertness/Sedation (OAA/S) score of 4 (where 5 = awake/alert to 1 = asleep) in < or = 2 min, a second bolus dose, equal to half of the original dose of midazolam or Ro 48-6791, was administered. The onset time was defined as the time to achieve an OAA/S score of 4. During the procedure, a bolus dose equal to half of the total induction dose was given to maintain an OAA/S score of 4. The induction and maintenance dosages, as well as recovery times to an OAA/S score of 5, were recorded. A heel-toe line walk (HTLW) test used to determine the time to "fitness for discharge." Although the onset times were similar in all three groups, the induction dosages were significantly reduced in Group II compared with Groups I and III. There were significantly more patients requiring supplemental sedative boluses and "rescue" analgesia with Ro 48-6791 than with midazolam. The Ro 48-6791 groups also experienced more dizziness after the procedures. Ro 48-6791 was associated with a higher incidence of inadequate sedation (18% vs 3%) without the opioid. The time for the HTLW test to return to baseline values after the procedure was similar among the three groups. However, the Ro 48-6791 groups had significantly reduced times to return to an OAA/S score of 5 and to achieve the baseline HTLW value after the last dose of the benzodiazepine. In conclusion, compared with midazolam, Ro 48-6791 is more potent and may be associated with a more rapid early recovery after endoscopic GI procedures. However, sedation with Ro 48-6791 required more supplemental bolus doses and "rescue" analgesic medication and was associated with a higher incidence of dizziness.

IMPLICATIONS

The investigational water-soluble benzodiazepine, Ro 48-6791, is a more potent sedative than midazolam, which appears to have a slightly shorter duration of action. Unfortunately, use of Ro 48-6791 increased the requirement for supplemental doses of the sedative medication and the need for "rescue" analgesics during the procedure and was associated with more dizziness after the procedure.

Midazolam sedation to produce complete amnesia for bronchoscopy: 2 years' experience at a district general hospital

Patients may find bronchoscopy without sedation unpleasant. There is some evidence that patient satisfaction correlates with amnesia for the procedure. For several years we have used doses of midazolam sufficient to put patients lightly asleep hoping to produce complete amnesia. We looked at practical aspects of this technique over a 2-year period. We studied 337 consecutive patients. They were 219 men and 118 women of mean age 63 +/- 12.4 (SD). Sixty-seven patients were aged 75 years or over and the eldest was 86. Sixty-three patients were already hospital inpatients but the remainder were seen as day cases. Midazolam was given by slow i.v. injection over several minutes until the patient was judged to be lightly asleep. Patients were given supplemental oxygen (3 l min-1) and monitored by ECG and pulse oximetry. A note was made of the time at which they awakened, defined as when nursing staff felt the patients were awake enough to have a cup of tea and toast. Patients were asked if they had any memory of the procedure both on awakening and when seen a few days later to discuss the results. The procedures were carried out in a well-staffed Day Case Unit with a recovery area. The mean dose of midazolam used was 10.8 mg (mean +/- SD = 0.16 +/- 0.095 mg kg-1). The midazolam was given over a median of 4 min (range 1-15 min). Patients took 59 +/- 45 min (mean +/- SD) to wake up. Twenty-eight patients were given flumazanil to reverse the sedation (11 for concern over bleeding following biopsies, three for desaturation during and three after procedure, four as they were frail, two as they were restless, two as they were hypotensive after procedure and three for miscellaneous reasons). Only nine patients could remember any part of the procedure. Incremental doses of midazolam given slowly until patients are lightly asleep almost invariably produce complete amnesia for bronchoscopy. This is a safe technique but patients need careful monitoring and may require reversal of sedation with flumazanil.

A placebo controlled study of flumazenil in bronchoscopic procedures

METHODS

A double-blind, randomized, placebo controlled trial of the efficacy of flumazenil was conducted in 22 consecutive patients admitted for bronchoscopy. Sedation was induced by individually titrated amounts of intravenous diazepam (mean +/- s.d., 15.75 +/- 4.4 mg). Post bronchoscopy, patients received up to 1 mg of the benzodiazepine antagonist flumazenil (Anexate) or placebo intravenously. Clinical scores for the degree of sedation, orientation in time and space, co-operation and anterograde amnesia were used. These, together with three psychometric tests were performed twice prior to bronchoscopy and on eight occasions in the following 24 h. The psychometric tests were: Tapping Test (TT), Simple Reaction Time (SRT) and Critical Flicker Fusion (CFF) and these were carried out using the automated Multipsy test system.

RESULTS

The level of co-operation, orientation in time and space and anterograde amnesia were similar in both groups pre-and-post procedure. However compared with the pre-bronchoscopy assessment, the maximum degree of apparent sedation was significantly less in the flumazenil group in the first 4 h. In support of this, the patients in the flumazenil group also showed a significantly greater proficiency with the TT and CFF test post bronchoscopy (P < 0.05). There was no difference in the incidence of side effects and flumazenil was well tolerated.

CONCLUSIONS

In this highly controlled setting, the use of flumazenil (Anexate) was shown to be safe and effective in aiding recovery from benzodiazepine facilitated bronchoscopy and as such provides an additional level of safety for this procedure.

Objective and subjective impairment from often-used sedative/analgesic combinations in ambulatory surgery, using alcohol as a benchmark

Impairment caused by different sedative/analgesic combinations commonly used in ambulatory settings was compared to that of alcohol at blood alcohol concentrations (BACs) higher than or equal to 0.10%. Impairment was measured via subjective (mood) and objective (psychomotor performance) assays. Twelve healthy human volunteers (10 males and 2 females; age range 21-34 yr) participated in this prospective, double-blind, randomized, cross-over study. Each subject was exposed to five drug conditions across 5 wk. Each of the following drug conditions were adjusted for body weight (per 70 kg):fentanyl 50 micrograms and propofol 35 mg (FP), fentanyl 50 micrograms and midazolam 2 mg (FM), fentanyl 50 micrograms, midazolam 2 mg, and propofol 35 mg (FMP), alcohol 56 g (orally administered), and placebo (PLC). With the exception of alcohol, the other drugs were administered via the intravenous route. Tests for psychomotor performance, subjective effects, and short-term memory were done at baseline, and at different intervals until 240 min postinjection. Psychomotor impairment caused by alcohol at 15 min postingestion (at a BAC of 0.11% +/- 0.03% [mean +/- SE]) was used as a benchmark with which impairment caused by other sedative/analgesic combinations was compared. All the study drug combinations produced impairment (i.e., impairment greater than that seen with PLC), similar to that observed with alcohol at a BAC of 0.11%. We have demonstrated that some sedative/analgesic drug combinations used in anesthesia for ambulatory procedures produce impairment similar to or greater than that observed with a large dose of alcohol.

Sedation for fibre optic bronchoscopy

Most current sedative regimens for fibre optic bronchoscopy use an opioid, a benzodiazepine or a combination of both. This study compares midazolam (M) (a benzodiazepine), alfentanil (A) (an opioid) and a combination of both drugs (M+A). One hundred and three patients were randomized in double-blind manner into groups M(35), A(33) and M+A(35). The number of coughs, number of additional aliquots of lignocaine and duration of the procedures were recorded along with oxygen desaturation. The patient's level of discomfort was assessed by patient and bronchoscopist and expressed as a visual analogue score. There were significantly fewer coughs per minute in Group A compared with Group M (P = 0.0053), and significantly less lignocaine was required in Group A (P = 0.005) and in Groups M+A (P < 0.002) compared with Group M. There was no significant difference in the assessment of discomfort between the groups. There was a trend for Group M+A to desaturate more than the other two with a significant difference between desaturation in Group M+A and Group A (P = 0.033). Alfentanil is a more effective anti-tussive agent than midazolam for outpatient fibre optic bronchoscopy. The combination of alfentanil and midazolam does not provide any better anti-tussive effect and may have the risk of a greater degree of desaturation secondary to increased sedation.

Small bolus injections of intravenous midazolam for upper gastrointestinal endoscopy: a study of 788 consecutive cases

1 A recent audit of upper gastrointestinal endoscopy carried out by the Royal College of Surgeons of England has shown that the majority of endoscopists use a bolus injection rather than a slow intravenous titration of benzodiazepine for intravenous sedation. In this study we have confirmed the theoretical premise that a reduced dose of midazolam is required when given as a bolus. A mean dose of 4.65 mg midazolam intravenously has been found to be effective and safe in sedating patients under 70 years (n = 552). The dose of midazolam needed is reduced in older patients: patients over 70 years (n = 236) needed a mean dose of 1.89 mg. 2 Topical pharyngeal anaesthesia was not required with these doses of midazolam, and it was our impression that the examination was equally well tolerated with a similar degree of anterograde amnesia as in the previous study. 3 Our data, together with the results of the audit, would suggest many endoscopists are employing unnecessarily large and at times potentially dangerous doses of intravenous sedation in elderly patients and that the vast majority of upper gastrointestinal endoscopies can be performed successfully, without topical pharyngeal anaesthesia, using a bolus injection techniquewith a reduced dosage of sedative agent.

Propofol versus midazolam for monitored sedation: a comparison of intraoperative and recovery parameters

STUDY OBJECTIVE

To compare intraoperative and recovery parameters in patients who received either propofol infusion (PI), propofol bolus (PB), or midazolam bolus (MZ) for sedation.

DESIGN

Randomized clinical study.

SETTING

Medical/surgical patients in a specialized hospital.

PATIENTS

Ninety patients, aged 18 to 85 years, scheduled for central venous access for chemotherapy and/or total parenteral nutrition.

INTERVENTIONS

In 30 patients, sedation was induced with MZ 0.02 mg/kg intravenously (i.v.), repeated every 2 to 3 minutes to achieve a sedation level of 3 (eyes closed, responds to verbal stimulus) (SL3). Maintenance was with MZ 0.005 mg/kg i.v. repeated as necessary to maintain SL3. In both propofol groups (30 patients each), induction of sedation was with a bolus of propofol 0.75 to 1.0 mg/kg i.v. Maintenance in the PB group was with propofol 0.25 mg/kg IV, repeated as necessary to maintain SL3. Maintenance in the PI group was with propofol 2 to 4 mg/kg/hr or 33 to 66 micrograms/kg/min to maintain SL3.

MEASUREMENTS AND MAIN RESULTS

Blood pressure, heart rate, respiratory rate, oxygen saturation, and sedation level were monitored each minute for 5 minutes and then at 5-minute intervals during the procedure. A right atrial blood sample was taken for pH and partial pressure of carbon dioxide at maximum sedation. Adequate sedation was achieved in all three groups. The time to reach SL3 was significantly shorter in the PB group than in the PI and MZ groups (p < 0.05 and p < 0.01, respectively). Cardiovascular and respiratory parameters were remarkably stable. Immediate recovery, as judged by spontaneous eye opening, response to commands, and ability to state date of birth, was significantly shorter in both the PB and PI groups than in the MZ group (p < 0.0001). Intermediate recovery, as measured by sedation score at recovery entry, Aldrete score, and time to standing, was slower in the MZ group (p < 0.05 for the MZ group vs. the PB and PI groups for sedation score and Aldrete score; p < 0.05 for the MZ group vs. the PI group in time to standing). Psychomotor recovery, judged by digit symbol substitution tests, was significantly faster in the PB and PI groups (p < 0.05 vs. the MZ group). Amnesia, measured by picture recall, was significantly greater in the MZ group than in the PI and PB groups (p < 0.05). Mood changes were measured on a visual analog scale. All groups showed improvement. Nausea, headache, dizziness, blurred vision, appetite, tension, pain, depression, drowsiness, and ability to concentrate were evaluated in the preoperative and postoperative periods. The frequency did not differ significantly between groups due to confounding factors such as postoperative chemotherapy and premedicant drugs.

CONCLUSION

The PI, PB, and MZ groups all gave excellent sedation for patients undergoing surgical procedures with local anesthesia. Amnesia was greatest with midazolam, and recovery was more rapid with propofol.

Use of midazolam ('Dormicum') and flumazenil ('Anexate') in paediatric bronchology

One hundred and seven bronchological examinations using midazolam narcosis in association with flumazenil were carried out in 100 children (mean age 3.5 years, range 4 months to 14 years) suffering from chronic non-specific lung disease. Rigid bronchoscopy was followed in 49 cases by bronchography. All patients were premedicated with atropine followed by midazolam (0.2 mg/kg intravenously). Ventilation was carried out with nitrous oxide and oxygen in 47 children and with oxygen only in 60 patients. After 3 mins, suxamethonium (2 mg/kg intravenously) was given for muscle relaxation and intubation carried out. Fifty-one of the children ventilated with oxygen only also received fentanyl (0.002 mg/kg intramuscularly), at the same time as atropine, to provide analgesia. After extubation, all patients were given flumazenil (0.1 to 0.2 mg intravenously) to reverse the effects of midazolam. The results showed that midazolam provided effective sedation and comfortable sleep (mean examination time 12 min 50 sec) and it was considered that the method using fentanyl rather than nitrous oxide for analgesia was the most satisfactory one. Patients awakened promptly (1 min) after flumazenil and quick and effective expectoration was noted, particularly important in those who had undergone bronchography. No complications were observed. Since this investigation, a further 500 bronchoscopics have been carried out using this method with the same results. Even though no narcosis equipment is required, it is recommended that, as with other procedures involving narcosis with muscle relaxation, bronchoscopy with these drugs should not be used in out-patients.

Efficacy of oral midazolam prior to intravenous sedation for the removal of third molars

The combination of oral and intravenous sedation has not been well investigated and this study examined the combination's effect on amnesia, anxiety, cardiovascular stability and recovery in a double blind, cross-over, placebo controlled trial. Patients were given 7.5 mg oral midazolam or placebo 1 h prior to intravenous midazolam and surgery. This investigation demonstrated significant anxiolysis, amnesia and patient preference for oral midazolam compared to placebo. There was no significant effect on cardiovascular stability, the intravenous dose of midazolam used or post-operative recovery. Low dose oral midazolam prior to intravenous sedation may be beneficial in very anxious patients, particularly if surgery is delayed.

Comparison of the amnesic effects of midazolam and diazepam

Thirty patients undergoing gastroscopy received intravenous premedication with either midazolam or diazepam in a randomised double blind study. Mean dosages were similar for the midazolam (6.13 mg) and diazepam (6.4 mg) groups. Neuropsychological testing pre- and post-medication comprised the Wechsler Memory Scale, Complex Figure Test, Word Association Test, and a Tactile Memory Test. There was a significant impairment on post-medication tests requiring delayed recall of verbal, visual and tactile stimuli. Midazolam produced significantly greater anterograde amnesia than diazepam at similar mean dosages. With the exception of Digit Span and Associate Learning, cognitive tasks which do not require delayed recall were not affected. It is concluded that the amnesic deficit is discrete and not secondary to sedative effects.

The use of midazolam in premedication

Socio-psychological factors, such as increased anxiety in developed societies and cultures, and separation anxiety, particularly in children, justify the use of premedicants. In addition, the link between a central nervous "anxiety centre" and biochemical stress responses is blocked by an efficient anxiolytic. The elimination half-life of midazolam is longer in the elderly than in the young and in the obese than in the thin, which demands longer intervals between repeated doses in old and fat patients. The hypoxic ventilatory response is depressed in most patients and the ventilatory CO2 response in patients with chronic pulmonary disorders, which justifies increased monitoring of O2 saturations. It is important for the choice of dose and for estimating the duration of recovery time to know that midazolam is at least four times as potent as diazepam.

[Locoregional anesthesia in ambulatory patients]

The use of regional anaesthesia in ambulatory patients is discussed. Five criteria for discharge are described: the four 'A's (Awake, Ambulation, Alimentation, Analgesia) and micturition. Recommended agents for additional sedation with the regional block, if required, are midazolam and fentanyl. These should be titrated in order to administer the minimal efficient dosage. The main techniques for regional anaesthesia of upper limb are intravenous regional anaesthesia, axillary and interscalenic brachial plexus blocks and for the lower limbs epidural and spinal blocks. However, urinary retention and orthostatic hypotension can occur. The risk of headache is not a contraindication for day-case surgery if some guidelines are followed. Penile blocks and caudal blocks are widely used in pediatric surgery.

Propofol infusion for sedation in outpatient oral surgery. A comparison with diazepam

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.

Effects of diagnostic procedures during fiberoptic bronchoscopy on heart rate, blood pressure, and blood gases

To investigate the effects of several endoscopic procedures like introduction of the bronchoscope, removal of the instrument, catheter suction, bronchoalveolar lavage and transbronchial biopsy on heart rate, systemic blood pressure, and transcutaneously measured blood gases 77 consecutive patients (age, 20-83 years) were studied. All patients received 101 O2/min via face mask during bronchoscopy. Sedation was performed with midazolam or diazepam. The different characteristics of each patient, e.g. age, sex, smoking habits, baseline values of heart rate and systemic blood pressure, underlying pulmonary disease and kind of premedication were examined separately to analyse their special effects on the course of bronchoscopy. During the fiberoptic bronchoscopy neither a slight decrease in transcutaneous pO2 nor a small increase in transcutaneous pCO2 led to a critical situation. Nevertheless it should be stressed that the time after removal of the instrument and finishing supplemental oxygen may be critical regarding hypoxia and hypercapnia especially in older patients with hypoxia being already present before starting the endoscopy. The hemodynamic indices did not change significantly. There was no difference between midazolam or diazepam concerning the parameters under study. If supplemental oxygen is given and adequate premedication is performed, monitoring of hemodynamics and blood gases during fiberoptic bronchoscopy is not necessary in patients without cardiovascular or respiratory risk.

Premedication for upper gastrointestinal endoscopy

Premedication is not essential to endoscopy but patient tolerance is clearly improved and, thus, ease of examination. Although comparable results can be achieved through nonpharmacologic means, the time and effort involved precludes their widespread use. Despite near universal utilization of premedication in endoscopy, the associated risk is difficult to determine from the available literature. The reported data reveal nominal risk yet must be viewed as minimums. The ideal drug with predictable clinical effects, minimal postprocedure impairment, little respiratory compromise, and proven antagonist is not yet available. Although midazolam seems to represent an advance, recent emphasis on respiratory depression is particularly troublesome. Studies evaluating various agents have suffered from lack of quantitation of such parameters as patient tolerance, ease of examination, and postprocedure impairment. Development of proven standards for these parameters would have to occur before a definitive double-blind randomized trial could be undertaken. Suggested means of assessing these parameters are listed in Table I. Improvement in major morbidity would be difficult in light of its low incidence. As the search for the ideal drug continues, endoscopists must continue to use drugs whose full effects are incompletely understood. The ability to increase patient comfort must be balanced with the small, but ever present, risk of morbidity and mortality.

Duration of amnesia associated with midazolam/fentanyl intravenous sedation

The purpose of this study was to determine the duration of amnesia associated with the intravenous usage of midazolam and fentanyl. The midazolam was administered in three different dosages based on the patient's weight in kilograms. Patients were shown a series of pen-and-ink drawings at various times throughout the procedure and tested the next day for memory of the drawings using both free recall and match-to-sample paradigms. The results indicate that the low-dosage group (0.07 mg/kg) had insufficient amnesia, whereas the medium (0.10 mg/kg) and high (0.13 mg/kg) groups displayed adequate amnesia in the intraoperative period.

Sedation as an alternative to general anaesthesia

Dental patients are generally in good health, the procedures are often short, and it is fear and anxiety about pain rather than the nature of the procedure that dictates the use of sedation or general anaesthesia. Indications and contra-indications for sedation, appropriate agents and techniques, and facilities and personnel needed for managing and monitoring patients are discussed. Safe and effective use of sedation in combination with local anaesthesia is a realistic alternative to general anaesthesia for many outpatient procedures.

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.

Changes in respiratory pattern after repeated doses of diazepam and midazolam in healthy subjects

Changes in respiratory pattern and arterial PCO2 after three repeated intravenous sedative doses of midazolam 0.05 mg/kg or diazepam 0.15 mg/kg were studied in eight healthy male volunteers in a randomized double-blind crossover design. In order to reduce the influence of the measuring equipment, we utilized a noninvasive computerized technique to measure respiratory variables. Both drugs caused equal changes in breathing pattern with a decrease in tidal volume, an increase in respiratory rate and an unaltered minute ventilation. These alterations in breathing pattern were associated with CO2 retention. Respiratory changes were mainly induced by the first injection of either drug. Despite increased plasma drug concentrations, subsequent doses did not cause further changes in respiratory variables except for an increase in PCO2 after the second dose of midazolam. The clinical significance of these changes in PaCO2 in otherwise healthy individuals is probably limited. The duration of the subjective sensation of sedation was longer after diazepam than after midazolam.

A comparison of amnesia in outpatients sedated with midazolam or diazepam alone or in combination with fentanyl during oral surgery

Midazolam is a new, water-soluble benzodiazepine that has been reported to produce a greater degree of amnesia than does diazepam. This study compares the amnesia produced in patients sedated with midazolam or diazepam or in combination with fentanyl during oral surgery. Twenty-four hours after surgery, each patient answered a questionnaire designed to assess his or her recall of events during and after surgery. Patients who received midazolam alone recalled significantly less than did patients in either diazepam group. The addition of fentanyl to midazolam did not produce any significant difference in recall.

Bioavailability of three formulations of intravenous diazepam

It has been generally assumed that the bioavailability of different formulations of intravenous diazepam is identical. In a within-subject crossover study using eight healthy volunteers, we have found that both the initial and the overall plasma diazepam levels are significantly lower after both emulsion (Diazemuls) and micelle preparations than after an organic formulation (Valium). These findings are relevant to the interpretation of the results of past, present and future clinical studies involving intravenous diazepam. The studies with Valium and Diazemuls confirm the clinical impression of the lesser potency of the latter formulation.