Premedication for ambulatory surgery in preschool children: a comparison of oral midazolam and rectal thiopentone

Efficacy and Safety of Midazolam Oral Solution for Sedative Hypnosis and Anti-anxiety in Children: A Systematic Review and Meta-Analysis

Background: Midazolam is recommended by health guidelines for sedation and hypnosis in children. Oral solution is a suitable dosage form for children. But there is no conclusive evidence for sedative-hypnosis and antianxiety effects by midazolam oral solution in children. Methods: Relevant studies were identified through searching PubMed, Embase, Cochrane Library, CINAHL, International Pharmaceuticals, four Chinese electronic databases, and relevant lists. Two reviewers independently selected trials, assessed trial quality, and extracted the data. Results: Eighty-nine randomized controlled trials (RCTs) comparing midazolam oral solution with placebo or blank (n = 33), dexmedetomidine (n = 15), ketamine (n = 11), different midazolam doses (n = 10), midazolam injection (n = 8), chloral hydrate (n = 7), diazepam (n = 5), N2O (n = 5), triclofos (n = 4), butorphanol (n = 2), fentanyl (n = 2), hydroxyzine (n = 1), and thiopental (n = 1) were identified. Meta-analysis showed no significant difference in the success rate and duration of sedation and hypnosis between midazolam oral and injectable solution (P > 0.05). The success rate of sedation and hypnosis of midazolam was higher than that of ketamine [risk ratio (RR) = 1.32, 95% CI (1.07, 1.62), I 2 = 0%, P < 0.01]. No significant difference was found in the success rate of sedation and hypnosis, mask acceptance, and parental separation between midazolam oral solution and dexmedetomidine (P > 0.05), and the result of one cohort study was consistent. The results of RCTs and a prospective cohort study showed that the incidence of adverse drug reactions (ADR) was 19.57% (189/966). Incidence of adverse reactions between dose groups of (0.25, 0.5] and (0.5, 1.0] mg/kg was similar [Pf (95% CI) = 0.10 (0.04, 0.24) and Pf (95% CI) = 0.09 (0.02, 0.39), respectively], higher than that of the dose group of (0, 0.25] mg/kg [Pf (95% CI) = 0.01 (0.00, 0.19)]. Conclusions: Available evidence suggests that midazolam oral solution is as good as midazolam injection and dexmedetomidine and is better than ketamine. Based on efficacy and safety results, an oral midazolam solution dose of 0.5-1 mg/kg is recommended for children.

Evidence-based clinical update: does premedication with oral midazolam lead to improved behavioural outcomes in children?

PURPOSE

The purpose of this evidence-based clinical update was to identify the best evidence to determine if behavioural outcomes are improved in children after oral midazolam premedication.

METHODS

A literature search was conducted using both PubMed and OVID programs, utilizing the terms "midazolam", and either "premedication" or "preoperative treatment". Search limits that were employed included randomized controlled trials (RCTs), English language, human studies, children aged 0-18 yr, and publication dates 1990 - present (January 2006). A review of the 171 abstracts obtained was undertaken and, of these, 30 papers were identified that concerned oral midazolam in children prior to general anesthesia, and that involved a RCT with a placebo or control arm. These studies were assigned levels of evidence, and grades of recommendation were made according to Centre for Evidence-Based Medicine criteria.

RESULTS

Oral midazolam premedication in children was found to reduce the anxiety associated with separation from parents/guardians, and with induction of anesthesia. Recovery times are not significantly delayed. There is no consistent evidence to suggest a reduction in the phenomenon of emergence agitation. Evidence suggesting an improvement in behavioural outcomes at home is also inconsistent.

CONCLUSION

Premedication with midazolam 0.5 mg x kg(-1) po administered 20-30 min preoperatively, is effective in reducing both separation and induction anxiety in children (grade A recommendation), with minimal effect on recovery times. However improved postoperative behavioural outcomes in the postanesthesia care unit, or at home cannot be predicted on a consistent basis.

The effect of premedication with OTFC, with or without ondansetron, on postoperative agitation, and nausea and vomiting in pediatric ambulatory patients

BACKGROUND

The purpose of this study was to evaluate, in the pediatric ambulatory surgical population, the efficacy of: (i) oral transmucosal fentanyl citrate (OTFC), when given preoperatively, to reduce postoperative excitement associated with sevoflurane, and (ii) intravenous ondansetron to reduce postoperative nausea and vomiting (PONV) associated with OTFC.

METHODS

This randomized, double-blinded, placebo controlled study evaluated the efficacy of OTFC [normal dose (ND) = 10-15 microg x kg(-1) or low dose = 100 microg] compared with placebo in the prevention of postoperative agitation; and the efficacy of ondansetron (0.1 mg x kg(-1) to 4 mg) compared with placebo to reduce PONV associated with OTFC.

RESULTS

There were 125 patients evaluated (2-10 years old, ASA class I or II and weight 10-40 kg). Preoperatively OTFC was associated with an increased likelihood of cooperation at baseline (P = 0.018). Postoperatively there was a higher incidence of vomiting in children that received OTFC. The anxiety/agitation of patients entering the PACU was significantly less in children who received OTFC ND (P < 0.001). This effect decreased over time. Patients with respiratory adverse events related to the study drug were significantly higher in groups who received OTFC, however, they were not of clinical significance. OTFC was associated with delays in time for eligibility to PACU discharge (P = 0.003).

CONCLUSIONS

Even though OTFC reduced early postoperative agitation the increase in side effects, namely PONV and prolonged recovery times, limits its clinical usefulness. The study demonstrates the tradeoffs between anxiety and agitation vs vomiting, respiratory events and prolonged recovery times. Ambulatory pediatric patients undergoing procedures in which opioids would be routinely used might benefit the most from OTFC combined with ondansetron as part of the anesthetic technique.

Oral premedication with fentanyl may be a safe and effective alternative to oral midazolam

BACKGROUND AND OBJECTIVE

Although midazolam is commonly given orally to infants and small children for premedication, the taste is sometimes unacceptable even when mixed with syrup. We tested the efficacy and safety of oral fentanyl compared with oral midazolam in a randomized open-label study.

METHODS

Fifty-one children, aged 12-107 months and weighing 10-25 kg, were randomly assigned to fentanyl or midazolam treatment groups. Midazolam (5 mg) or fentanyl (0.1 mg) was given orally from a small bottle with a small orifice 30 min before transfer to the preoperative holding room. The excitation-sedation conditions of the patients were assessed before and after general anaesthesia.

RESULTS

The preoperative scores did not differ significantly between the two groups. No major complications were observed in either group. Postoperative vomiting occurred in 5 of 27 (18.5%) patients treated with oral fentanyl and in none of 24 of those treated with midazolam.

CONCLUSIONS

Oral administration of fentanyl 30 min before entrance to the holding room for an operation from a bottle with a small orifice is a premedication option for children between 1 and 8 yr of age.

Distress at induction of anaesthesia in children. A survey of incidence, associated factors and recovery characteristics

This study analysed the frequency of distress at induction (DAI) in 2122 paediatric patients. The data were analysed to assess predictors of DAI and to examine associations between predictors of DAI and recovery characteristics. Patient age, preoperative behaviour, premedication (oral midazolam, n = 480) and venue for anaesthesia induction were associated with changes in the incidence of DAI. Distressed preoperative behaviour was a good predictor of DAI in all age groups. Premedication reduced the incidence of DAI in children aged 0.5-2 years old, and in older children who were distressed preoperatively. Induction in the Day Surgery Unit was associated with a reduction of the incidence of DAI in younger children. Children with DAI were more likely to suffer from distress at arousal (P = 0.001). Average early recovery time was prolonged 4.4 minutes and average discharge time in day patients was delayed 36 minutes by the use of oral midazolam premedication. Premedication was not significantly associated with arousal distress. We conclude that a policy of optimizing nonpharmacological approaches for minimizing induction distress, combined with selective premedication with oral midazolam, can produce a low incidence of induction distress and adverse effects.