The pharmacokinetics of rectal midazolam for premedication in children

Comparative Evaluation of Oral and Intranasal Administration of Midazolam as Preanesthetic Medication in Pediatric Dental Patients Treated under General Anesthesia

Aims and background

Midazolam is commonly used as a preanesthetic medication for behavior management of children. The current study is conducted to find out the effect of midazolam through nasal and oral routes as a premedicament in pediatric patients treated under general anesthesia. The main aims of the study were: to compare the effect of oral syrup and intranasal spray as preanesthetic medication; to record the undesirable side effects of midazolam by both routes.

Materials and methods

The patients aged 2-6 years of either sex were randomly divided into two equal groups of 30 each-group I: oral; group II: intranasal.

Results

The oral and intranasal routes of midazolam were found to be equally effective and provided adequate sedation for easy separation from the parents and cooperation from children during the induction of anesthesia with minimal side effects.

Conclusion

Based on the study results, we can conclude that both oral and intranasal midazolam can be used as preanesthetic medication for pediatric dental patients treated under general anesthesia.

Clinical significance

In pediatric patients, the oral route should be preferred for midazolam premedication in comparison to the intranasal route.

How to cite this article

Swati, Shah RK, Tandon S, et al. Comparative Evaluation of Oral and Intranasal Administration of Midazolam as Preanesthetic Medication in Pediatric Dental Patients Treated under General Anesthesia. Int J Clin Pediatr Dent 2024;17(8):881-886.

Characterization of Pediatric Rectal Absorption, Drug Disposition, and Sedation Level for Midazolam Gel Using Physiologically Based Pharmacokinetic/Pharmacodynamic Modeling

This study aims to explore and characterize the role of pediatric sedation via rectal route. A pediatric physiologically based pharmacokinetic-pharmacodynamic (PBPK/PD) model of midazolam gel was built and validated to support dose selection for pediatric clinical trials. Before developing the rectal PBPK model, an intravenous PBPK model was developed to determine drug disposition, specifically by describing the ontogeny model of the metabolic enzyme. Pediatric rectal absorption was developed based on the rectal PBPK model of adults. The improved Weibull function with permeability, surface area, and fluid volume parameters was used to extrapolate pediatric rectal absorption. A logistic regression model was used to characterize the relationship between the free concentrations of midazolam and the probability of sedation. All models successfully described the PK profiles with absolute average fold error (AAFE) < 2, especially our intravenous PBPK model that extended the predicted age to preterm. The simulation results of the PD model showed that when the free concentrations of midazolam ranged from 3.9 to 18.4 ng/mL, the probability of "Sedation" was greater than that of "Not-sedation" states. Combined with the rectal PBPK model, the recommended sedation doses were in the ranges of 0.44-2.08 mg/kg for children aged 2-3 years, 0.35-1.65 mg/kg for children aged 4-7 years, 0.24-1.27 mg/kg for children aged 8-12 years, and 0.20-1.10 mg/kg for adolescents aged 13-18 years. Overall, this model mechanistically quantified drug disposition and effect of midazolam gel in the pediatric population, accurately predicted the observed clinical data, and simulated the drug exposure for sedation that will inform dose selection for following pediatric clinical trials.

Current Updates in Rectal Infusion of Fluids and Medications

Purpose of Review

Rectal infusion is a feasible alternative for the immediate administration of medication and fluids when intravenous access is delayed, contraindicated, or unnecessary. Advances in medical device technology have made rectal infusion more practical and easier for medical care providers, and more comfortable for patients. This paper briefly reviews the history of therapeutic rectal infusion, including recent improvements in technology and the existing evidence for the use of this technique.

Recent Findings

While ultrasound-guided peripheral intravenous (PIV) access techniques and other alternatives to landmark-based PIV catheter insertion have recently improved the ability of providers to overcome challenges related to difficult vascular access (DVA), these challenges are increasingly affecting patient outcomes, emergency department throughput, and the cost of medical care. In recent years, waves of parenteral drug, fluid, and supply shortages have affected hospitals. Concurrently, advances in rectal infusion technology have made rectal infusion easier, more comfortable, and more cost-effective than many parenteral options.

Summary

The infusion of resuscitative fluids and medications via the rectal route has previously fallen out of favor due to concurrent improvements in IV access devices. However, this technique demonstrates the potential for a reemergence considering the current challenges facing healthcare providers and systems. Improvements in rectal infusion devices, coupled with an aging population, increased incidence of DVA, shortages in parenteral drugs, fluids, supplies and skilled staff, and the need for care improvements in the post-acute setting have contributed to a greater need for easy, safe and effective alternatives to IV infusion.

Comparing the Sedative Effect of Oral and Intranasal Midazolam and their Effect on Behavior in Pediatric Dental Patients

Aim

To systematically identify and evaluate the available literature based on the sedative effect of oral midazolam compared with midazolam administered intranasally and also compare their effect on behavior of pediatric dental patients.

Objective

This systematic review compares the sedative effect and the effect on behavior with oral midazolam and intranasal midazolam.

Methods

A search was undertaken through PubMed Central, Cochrane Database of Systematic Reviews, Lilacs, Science Direct and SIGLE. All the studies included the comparison of the sedative effect of oral and intranasal midazolam. Database search identified 178 articles. 165 articles were excluded based on titles and duplication. Abstract and complete text of 13 articles were thoroughly evaluated. Four articles were included based on the inclusion criteria to meet the criteria. The selected studies analyzed the children's behavior or anxiety by oral midazolam in comparison to intranasal midazolam administration.

Results

Among the four studies included in the present review, risk of bias was high in all the articles. The high risk was obtained due to inadequate blinding of personnel and participants in the study, improper allocation concealment and inadequacy in blinding of the outcome assessment. Also, difference observed between oral and intranasal midazolam routes on behavior and sedation level in the studies included in this review was not statistically significant.

Conclusion

Studies comparing the effect on behavior of oral and intranasal midazolam in children are limited. More number of high-quality clinical trials evaluating the sedative effect and effect on behavior of oral and intranasal midazolam in pediatric dental patients is required.

How to cite this article

Kotian N, Subramanian EMG, Jeevanandan G. Comparing the Sedative Effect of Oral and Intranasal Midazolam and their Effect on Behavior in Pediatric Dental Patients. Int J Clin Pediatr Dent 2022;15(1):128-134.

Intranasal dexmedetomidine and rectal ketamine for young children undergoing burn wound procedures

BACKGROUND

Safe and effective methods for sedation and analgesia in pediatric burn patients are strongly warranted. This retrospective study of electronic health care records aims to evaluate the safety and efficacy of intranasal dexmedetomidine combined with rectal ketamine as procedural sedation for young children undergoing dressing changes and debridement of burn wounds.

METHODS

Documentation was analyzed from 90 procedures in 58 pediatric patients aged <5 years. Safety and efficacy of the method were assessed based on documentation for complications, adverse effects, pain level, level of sedation and preoperative and recovery time.

RESULTS

All 90 sedations were completed without significant adverse events with acute airway management or medical intervention. The combination of dexmedetomidine-ketamine produced acceptable analgesia during the procedure and effectively relieved postoperative pain. However, the approach was insufficient for 7/58 patients (7.8%); these patients were converted from the dexmedetomidine-ketamine combination to intravenous anesthesia. In 23% of the cases an extra dose of either ketamine of dexmedetomidine was administered. Moreover, there were two cases of delayed awakening with recovery time >120 min.

CONCLUSION

The drug combination intranasal dexmedetomidine and rectal ketamine is a safe and reliable approach for procedural sedation and analgesia in pediatric patients undergoing burn wound procedures, producing a clinically stable sedative condition requiring only basic monitoring.

Midazolam use in pediatric dentistry: a review

Behaviour management and dental procedures performed in very young, pre-cooperative, highly anxious, or medically disabled children are challenging tasks. Various drugs and methods have, however, been introduced to facilitate treatment for this patient population. Midazolam is a benzodiazepine used as an adjunct to behavior management techniques in the dental treatment of pediatric patients. Midazolam can be used as a safe and effective drug for conscious sedation, general anesthetic premedication, and treatment of seizures during dental procedures. Nevertheless, further research involving pediatric patients would be beneficial.

Opioid Drug-Drug Interactions: A Review

Opioid analgesics are among the most commonly prescribed medications. Frequently, they are combined with other therapeutic agents and pharmacodynamic or pharmacokinetic interactions may ensue. This review summarizes published case reports and studies of potential opioid drug interactions. A MED-LINE computer literature search (1966-1998) was undertaken to retrieve all pertinent case reports and studies of opioid drug interactions published in the English language. The results of the search indicate that numerous compounds from various therapeutic classes may participate in clinically significant pharmacodynamic and pharmacokinetic drug-drug interactions. Pharmacodynamic interactions usually involved additive central nervous system depression. Additionally, propoxyphene and tramadol can potentiate a hyperserotonergic state when coadministered with the SSRIs and MAOIs. Pharmacokinetic interactions typically involved inhibition or induction by specific hepatic cytochrome P-450 isoenzymes. Agents with enzyme inhibiting ability such as erythromycin, cimetidine, and selective serotonin reuptake inhibitors have been shown to potentiate the effects of certain opioid analgesics while codeine, which requires metabolic conversion via CYP 2D6 for pharmacological effectiveness, has reduced analgesic efficacy in the presence of inhibitors. The enzyme inducers rifampin and several anticonvulsants have been involved in the emergence of methadone withdrawal when added to existing methadone treatment. Additionally, enzyme inducers can increase the formation of the toxic metabolite of meperidine. Genetic polymorphism also potentially impacts the effectiveness of agents such as codeine since reduced active metabolite formation and analgesic efficacy has been demonstrated in individuals who lack CYP 2D6 activity.

Evaluation of intranasal Midazolam spray as a sedative in pediatric patients for radiological imaging procedures

CONTEXT

Preoperative anxiety and uncooperativeness experienced by pediatric patients are commonly associated with postoperative behavioral problems.

AIMS

We aimed to evaluate the efficacy and safety of intranasal Midazolam as a sedative in a pediatric age group for radiological imaging procedures and to note onset of sedation, level of sedation, condition of patient during separation from parents and effect on the cardio-respiratory system.

SETTINGS AND DESIGN

Randomized double-blinded study.

SUBJECTS AND METHODS

Fifty patients of the pediatric age group of American Society of Anesthesiologist grade 2 and 3 who came for any radiological imaging procedures were studied. Patients were randomly allocated to receive, intranasally, either Midazolam 0.5 mg/kg (group A N = 25) or normal saline (group B N = 25) in both nostrils (0.25 mg/kg in each) 15 min before the procedure. Time for onset of sedation and satisfactory sedation, sedation score, separation score, hemodynamic changes and side-effects were recorded.

STATISTICAL ANALYSIS USED

Student's t-test.

RESULTS

Intranasal Midazolam group had a significantly shorter time for onset of sedation and satisfactory sedation. Mean sedation score and mean separation score at 10 min and 15 min intervals were significant in intranasal Midazolam as compared with normal saline (P < 0.001).

CONCLUSIONS

Intranasal Midazolam 0.5 mg/kg is safe and effective and provides adequate sedation for easy separation from the parents and reduced requirement of intravenous supplementation during radiological imaging procedures without any untoward side-effects.

Intranasal dexmedetomidine vs midazolam for premedication in children undergoing complete dental rehabilitation: a double-blinded randomized controlled trial

BACKGROUND

This prospective, randomized, double-blind study was designed to evaluate the use of intranasally administered dexmedetomidine vs intranasal midazolam as a premedication in children undergoing complete dental rehabilitation.

METHODS

Seventy-two children of American Society of Anesthesiology classification (ASA) physical status (I & II), aged 3-6 years, were randomly assigned to one of two equal groups. Group M received intranasal midazolam (0.2 mg·kg(-1)), and group D received intranasal dexmedetomidine (1 μg·kg(-1)). The patients' sedation status, mask acceptance, and hemodynamic parameters were recorded by an observer until anesthesia induction. Recovery conditions, postoperative pain, and postoperative agitation were also recorded.

RESULTS

The median onset of sedation was significantly shorter in group M 15 (10-25) min than in group D 25 (20-40) min (P = 0.001). Compared with the children in group M, those in group D were significantly more sedated when they were separated from their parents (77.8% vs 44.4%, respectively) (P = 0.002). Satisfactory compliance with mask application was 58.3% in group M vs 80.6% in group D (P = 0.035). The incidences of postoperative agitation and shivering were significantly lower in Group D compared with group M. Thirteen children (36.1%) in group M, showed signs of nasal irritation with teary eyes, and none of these signs was seen in the children in group D (P = 0.000). There were no incidences of bradycardia, hypotension, in either of the groups during study observation.

CONCLUSION

Intranasal dexmedetomidine (1 μg·kg(-1)) is an effective and safe alternative for premedication in children; it resulted in superior sedation in comparison to 0.2 mg·kg(-1) intranasal midazolam. However, it has relatively prolonged onset of action.

Perioperative substitution of anti-epileptic drugs

A common problem in brain and abdominal surgery is the perioperative substitution of antiepileptic drugs (AEDs) when patients are temporarily unable to take these drugs orally. We searched the literature for clinical trials with patients or healthy volunteers in whom non-oral formulations of AEDs as substitution were tested. Different search engines, handbooks, expert opinion and our own experience, were used. Pharmaceutical companies were approached for recommendations. This led to three categories of replacement: 1. commercial alternative (n = 10) for clonazepam, diazepam, lacosamide, levetiracetam, lorazepam, midazolam, nitrazepam, phenobarbital, phenytoin, and valproic acid; 2. alternatives that must be prepared (n = 6) for carbamazepine, clobazam, lamotrigine, oxcarbazepine, primidone, topiramate; 3. no alternative (n = 7) for ethosuccimide, felbamate, retigabine, stiripentol, tiagabine, vigabatrin, zonisamide. Thus, for a substantial number of AEDs, unofficial perioperative treatment strategies need to be followed for lack of alternatives to oral administration. There is little clinical research addressing the equivalence of oral and parenteral formulas. Perioperative substitution of AEDs is an underestimated problem, and may increase the risk of postoperative seizures.

Graph theoretical analysis of sedation's effect on whole brain functional system in school-aged children

The neurophysiological mechanism underlying sedation, especially in school-aged children, remains largely unknown. The recently emerged resting-state functional magnetic resonance imaging (rsfMRI) technique, capable of delineating brain's functional interaction pattern among distributed brain areas, proves to be a unique and powerful tool to study sedation-induced brain reorganization. Based on a relatively large school-aged children population (n=28, 10.3±2.6 years, range 7-15 years) and leveraging rsfMRI and graph theoretical analysis, this study aims to delineate sedation-induced changes in brain's information transferring property from a whole brain system perspective. Our results show a global deterioration in brain's efficiency properties (p=0.0085 and 0.0018, for global and local efficiency, respectively) with a locally graded distribution featuring significant disruptions of key consciousness-related regions. Moreover, our results also indicate a redistribution of brain's information-processing hubs characterized by a right and posterior shift as consistent with the reduced level of consciousness during sedation. Overall, our findings inform a sedation-induced functional reorganization pattern in school-aged children that greatly improve our understanding of sedation's effect in children and may potentially serve as reference for future sedation-related experimental studies and clinical applications.

[Perioperative considerations in vagal nerve stimulator implantation]

Vagal nerve stimulation has become an a important tool in the treatment of refractory epilepsy, which continues to be the main indication for this technique. Other therapeutic indications are emerging, however, and vagal nerve stimulation has now been approved for major depression. Additional possible uses under study include morbid obesity, Alzheimer disease, chronic pain syndromes, and certain neuropsychologic disorders. This review considers perioperative aspects relevant to using this therapeutic procedure with a view to facilitating better and more integrated management of its application.

Use of oral midazolam in pediatric upper gastrointestinal endoscopy

BACKGROUND

The purpose of this prospective, randomized study was to compare the safety and efficacy of oral versus i.v. midazolam in providing sedation for pediatric upper gastrointestinal (GI) endoscopy.

METHODS

Sixty-one children (age <16 years) scheduled for upper GI endoscopy were studied. Patients were randomly assigned to receive oral or i.v. midazolam. Measurements were made and compared for vital signs, level of sedation, pre- and post-procedure comfort, anxiety during endoscopy, ease of separation from parents, ease and duration of procedure, and recovery time.

RESULTS

Patients were aged 1-16 years (mean 7.5 + or - 3.42 years); 30 patients received oral medication, and 31 received i.v. medication. There were no statistically significant differences in age or gender between groups. There were no significant differences in level of sedation, ease of separation from parents, ease of ability to monitor the patient during the procedure, heart rate, systolic arterial pressure, or respiratory rate. Oxygen saturation was significantly lower in the i.v. group than the oral group 10 and 30 min after removal of the endoscope, and recovery time was longer in the oral than the i.v. group.

CONCLUSIONS

Oral administration of midazolam is a safe and effective method of sedation that significantly reduces anxiety and improves overall tolerance for children undergoing esophagogastroduodenoscopy.

Postoperative morbidities following dental care under day-stay general anesthesia in intellectually disabled children

PURPOSE

The objective of this study was to compare the postoperative morbidities for 24 hours following dental care under day-stay general anesthesia using sevoflurane or halothane in intellectually disabled children.

MATERIALS AND METHODS

Eighty-six premedicated patients with intellectual disabilities underwent general anesthesia for their dental treatment. They were randomly given anesthesia maintained with sevoflurane (2% to 3%) or halothane (1% to 1.5%) after receiving inhalation induction either with sevoflurane (8%) or halothane (5%) and nitrous oxide in oxygen (50:50). The patients' age, gender, weight, ASA Class, type of dental treatment, and duration of anesthesia and operation were recorded as well as the time required for recovery (Aldrete Scale) and the length of time taken before they were discharged (postanesthetic discharge scoring system) from the hospital. Pain and agitation were recorded using a visual analog scale (0 to 10). Other postoperative morbidities, which include crying, nausea and vomiting, bleeding, and drowsiness, were also noted for 24 hours after the operation.

RESULTS

The most common morbidities during the postoperative 24 hours were agitation and pain, and their occurrence was significantly more common in the sevoflurane group than in the halothane group (P < .05). The recovery time was shorter in the sevoflurane group, but it was not statistically significant. There was no difference between the groups in the discharge time.

CONCLUSIONS

Apart from more postoperative agitation and pain after awakening from sevoflurane, the quality of recovery was similar for both sevoflurane and halothane.

Midazolam premedication in children: a pilot study comparing intramuscular and intranasal administration

The purpose of this study was to compare the effectiveness of intramuscular and intranasal midazolam used as a premedication before intravenous conscious sedation. Twenty-three children who were scheduled to receive dental treatment under intravenous sedation participated. The patients ranged in age from 2 to 9 years (mean age, 5.13 years) and were randomly assigned to receive a dose of 0.2 mg/kg of midazolam premedication via either intramuscular or intranasal administration. All patients received 50% nitrous oxide and 50% oxygen inhalation sedation and local anesthetic (0.2 mL of 4% prilocaine hydrochloride) before venipuncture. The sedation level, movement, and crying were evaluated at the following time points: 10 minutes after drug administration and at the times of parental separation, passive papoose board restraint, nitrous oxide nasal hood placement, local anesthetic administration, and initial venipuncture attempt. Mean ratings for the behavioral parameters of sedation level, degree of movement, and degree of crying were consistently higher but not significant in the intramuscular midazolam group at all 6 assessment points. Intramuscular midazolam was found to be statistically more effective in providing a better sedation level and less movement at the time of venipuncture than intranasal administration. Our findings indicate a tendency for intramuscular midazolam to be more effective as a premedication before intravenous sedation.

Sedation in children undergoing CT scan or MRI: effect of time-course and tolerance of rectal chloral hydrate

The aim of this paper was to describe the time-course of the sedative effect of rectal chloral hydrate (75 mg/kg) in children undergoing CT scan or MRI. Twenty children (2.13 +/- 1.43 years old) were administered 75 mg/kg chloral hydrate rectally (chloralhydrat-rectiole rectal formulation, Dr Mann-Pharma Lab, Berlin, Germany), before a CT scan or an NMR imaging. Sedation was measured at specific times using a sedation score of 1-6. Patients were continuously monitored for respiratory and heart rate, systolic and diastolic blood pressures, and oxygen saturation. About 82.35 and 94.11% of the patients had a score of sedation > or = 3 within 15 and 30 min, respectively. The mean time to effective sedation (score > or = 3) was of 0.30 +/- 0.14 h (median time, 0.25 h). The mean duration of effective sedation (score > or = 3) was 1.29 +/- 1.05 h (median duration, 0.75 h). A total of 93.1% of the X-ray sections were obtained without artifact and sedation was considered by radiologists to be efficient for 83.3% of the procedures. This sedation procedure appeared efficient and safe during ambulatory CT scan and NMR imaging. The long-term effect of chloral hydrate, however, remains to be evaluated.

High-dose rectal midazolam for pediatric procedures: a randomized trial of sedative efficacy and agitation

OBJECTIVES

To compare 2 doses of rectal midazolam, used for pediatric emergency department sedation, with regard to sedative efficacy and frequency of paradoxical agitation.

METHODS

Children <or=48 months old undergoing cutaneous procedures received midazolam by rectum, randomized in double-blind fashion to standard (0.5 mg/kg, SDM) or high (1 mg/kg, HDM) doses. Behaviors were scored on a 5-point sedation scale before and during procedures. Proportions manifesting successful sedation and postprocedure agitation were compared between the 2 doses.

RESULTS

Sixty-five patients (32 SDM, 33 HDM) underwent sedated procedures (repair of lacerations, 97%). Behavior scores improved for both groups following medication administration and at best sedation during procedure. HDM produced better sedation at time of first suture (successful sedation: 70%, SDM vs. 91%, HDM; intergroup difference = 21%; 95% confidence interval [CI] = 2, 41) and at best point during the procedure (72%, SDM vs. 97%, HDM; Delta = 25%; 95% CI = 8, 43). However, sedative efficacy declined such that only 50% and 73% of the SDM and HDM groups, respectively, had successful sedation at the worst point during the procedures. Postprocedure agitation occurred in 17% of patients (6%, SDM vs. 27%, HDM; Delta = 21%; 95% CI = 3, 39).

CONCLUSIONS

Rectal midazolam improved sedation scores over preprocedure levels and was more effective with a dose of 1 mg/kg than with 0.5 mg/kg. However, inadequate sedation in 27-50% of patients and prolonged agitation in 27% of patients at higher doses counter the advantages of rectal midazolam.

Efficacy and safety of rectal thiopental, intramuscular cocktail and rectal midazolam for sedation in children undergoing neuroimaging

BACKGROUND

This study was designed to investigate the overall usefulness of rectal thiopental, rectal midazolam and i.m. modified cocktail (meperidine-chlorpromazine hydrochloride-feniramin maleat) in 70 children undergoing computed tomography (CT) and magnetic resonance imaging (MRI).

METHODS

The dosage of thiopental was 50 mg per kg for infants under 6 months of age, 35 mg per kg between six and 12 months, and 25 mg per kg for older children. The maximal dose did not exceed 700 mg in this study. The dosage of midazolam was 1 mg per kg for all children. A modified cocktail was described as a formulation including 11 mg/mL of meperidine, 2.8 mg/mL of chlorpromazine and 2.8 mg/mL of pheniramine maleat. The dosage of modified cocktail was 0.1 mL per kg for all children.

RESULTS

The mean induction time for the i.m. cocktail was significantly longer than that for rectal thiopental (P < 0.001). The mean duration of deep sedation was 60.79 +/- 27.00 min with rectal thiopental and 58.74 +/- 39.70 min with i.m. cocktail (P > 0.05). Although the mean duration of sleep for rectal thiopental and i.m. cocktail was similar, the mean discharge duration for i.m. cocktail was significantly longer than that for rectal thiopental (P < 0.05). Children sedated with the cocktail therapy also required a longer period of observation in the department. Significant decreases in heart rate, systolic blood pressure and oxygen saturation occurred in three groups (P < 0.001). Significant decreases in body temperature occurred after rectal thiopental and i.m. cocktail therapy (P < 0.01). The effect of rectal midazolam was minimal.

CONCLUSIONS

Rectal thiopental may be the drug of choice for pediatric sedation because it has a more rapid onset and offset of action. It is also safe and effective at the dosage studied in children undergoing MRI. Rectal midazolam also may be used in children undergoing CT imaging because of minimal side-effects.

The "ouchless emergency department". Getting closer: advances in decreasing distress during painful procedures in the emergency department

Painful and frightening injuries and illnesses are frequent reasons for children to seek care in an emergency department. Painful therapeutic procedures are often a necessary part of emergency care and are very distressful for the children, their parents, and healthcare providers. Inadequately relieved pain and distress have acute and long-term consequences, yet methods for pain and anxiety reduction during frightening minor and major procedures are often not used because of lack of detailed knowledge of techniques and fear of adverse effects. This article reviews psychologic and pharmacologic means of safe and effective reduction of anxiety and pain during emergency department procedures.

An approach for dose finding of drugs in infants: sedation by midazolam studied using the continual reassessment method

AIMS

No drug has been demonstrated to provide simultaneously appropriate sedation, safety and lack of disturbance of the measured parameters during cardiac catheterization in infants. The objective of this study was to estimate the dose of midazolam, administered rectally, that would provide a 90% probability of adequate sedation in infants during cardiac catheterization. A sedation score > or =4 (six-point scale) 30 to 60 min after dosing was rated as a success.

METHODS

A double-blind, continual reassessment method using a Bayesian approach has been used. Sixteen infants were administered a single midazolam dose, within a 0.1 to 0.6 mg kg(-1) dose range.

RESULTS

Consecutive failures led to allocation of the highest dose to 15 out of 16 patients. The final estimated probability of failure of the 0.6 mg kg(-1) dose was 81% (95% CI: 78.5 to 84%). The time to reach a score > or =4 was longer than expected and the median duration-time at score > or =4 was shorter (15 min) than expected.

CONCLUSIONS

Delayed absorption and low rectal bioavailability may explain these data. Higher doses or different routes of administration may lead to the expected sedation, but the safety of doses higher than 0.6 mg kg(-1) administered rectally has not been evaluated. The therapeutic strategy for sedation of this category of infants in the hospital has now been changed based on the present results in that rectal midazolam has been abandoned in this indication.

Evaluation of intranasal midazolam in children undergoing esophagogastroduodenoscopy

BACKGROUND

Intravenous midazolam and opioids are used to produce conscious sedation in children undergoing esophagogastroduodenoscopy (EGD). However, children may experience significant fear and anxiety before receiving these medications, especially during separation from parents and during venipuncture. Intranasal administration of midazolam represents a noninvasive method of sedating children before anxiety-producing events. The objective of this study was to determine whether premedication with intranasal midazolam reduces stress and anxiety of separation from parents and of undergoing venipuncture, while maintaining adequate sedation during EGD.

METHODS

This was a prospective, randomized, double-blind study in 40 children, aged 2 to 12 years, who were undergoing EGD. Patients in group I were premedicated with intranasal placebo (0.9% NaCl) followed 10 minutes later by intravenous midazolam (0.05 mg/kg) and intravenous meperidine (1 mg/ kg). Patients in group II were premedicated with intranasal midazolam (0.2 mg/kg) followed by intravenous placebo (0.9% NaCl) and intravenous meperidine (1 mg/kg). Anxiolysis and sedation were scored by a blinded observer, who identified minor and major negative behaviors during four observation periods: intranasal drug administration, separation from parents, venipuncture, and EGD.

RESULTS

Premedication with intranasal midazolam significantly reduced negative behaviors during separation from parents (p < 0.05); however, no difference between regimens was noted during venipuncture or EGD. Negative behaviors appeared to increase during administration of intranasal midazolam or placebo.

CONCLUSIONS

Premedication with intranasal midazolam is effective in reducing negative behaviors during separation from parents, while it maintains sedation during the endoscopic procedure. The benefits of intranasal administration may be negated, however, by irritation, and discomfort caused by intranasal drug delivery.

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.

Pharmacokinetics of intrarectal nalbuphine in children undergoing general anaesthesia

The pharmacokinetics of nalbuphine (0.3 mg/kg) administered by the rectal route were studied in ten children undergoing general anaesthesia for minor surgery. Blood sampling was carried out for 8 h after rectal administration and plasma drug concentrations were measured by high performance liquid chromatography using electrochemical detection after an optimized solid-phase extraction procedure. The mean time to achieve the maximum plasma concentration (Cmax = 24 +/- 15 ng/mL) was 25 +/- 11 min and the elimination half-life was 2.7 +/- 0.7 h. The coefficients of variation for Cmax and the concentration-time curve (AUC) were 62 and 68%, respectively. Although rectal absorption is considered irregular, the large intersubject variability is also explainable by a variable hepatic bypass for a drug, like nalbuphine, that undergoes extensive first-pass metabolism. No problem of analgesic efficacy or of local tolerance was reported. In conclusion, the rectal route of administration provides a rapid and reliable absorption of nalbuphine.

Perioperative management of children

Along with the decision for surgery in children comes a concern for the development of minor psychological disturbances close to the event and possibly also later in life. There is always also anxiety for the procedure and its influence on normal physiological functions. It is true that these matters are valid also in the adult. There are, however, two factors that differ. One is the special relationship to family or legal guardian and the other is the skill needed to communicate with infants, pre-school children and other children.

Comparative review of the adverse effects of sedatives used in children undergoing outpatient procedures

Children often fear medical procedures and interventions. Sedative agents enhance the care of these children who undergo outpatient procedures by decreasing anxiety, increasing cooperativity, and providing amnesia. Although higher dosages and intravenous administration of sedatives often produce improved sedation, adverse effects and complications are more frequent. The goals of therapeutic efficacy and safety must be balanced in all patients. The presence or anticipation of anxiety and pain helps in deciding whether to use a sedative alone, or a regimen also providing analgesia. The patient's clinical cardiorespiratory or neurological status, other relative contraindications, the duration of the intended procedure, and the presence or absence of an intravenous line will help in choosing specific drugs. Drug complications are a common cause of adverse events in patients. The combination of a sedative and analgesic, especially a benzodiazepine and an opioid given intravenously, is associated with a higher risk of serious complications. The practitioner responsible for the administration of a sedative to a child must be competent in its use and have the ability to detect and manage complications. Patients who are deeply sedated should be continuously monitored and observed by an individual dedicated to this task. Vital signs and oxygen saturation should be documented at frequent intervals and the patient should be appropriately monitored until discharge criteria have been met. The risk of serious complications with these agents may be reduced with vigorous monitoring and a judicious choice of dosage.

Sedation in pediatric patients

Sedation is being used increasingly in children to allay anxiety and discomfort. Sedation can also increase the efficiency of performing both diagnostic and therapeutic procedures in children. There are a wide array of available sedation methods that are used by radiologists, gastroenterologists, hematologists/oncologists and emergency room physicians everyday. Indiscriminate use of sedatives has led to seizures, respiratory arrests and death in a variety of practice settings. With improved monitoring capability, more potent drugs and better understanding of the pharmacokinetics in children, it is possible to provide batter care.

Premedication with midazolam in children. Effect of intranasal, rectal and oral routes on plasma midazolam concentrations

We report a study performed to compare the time and plasma drug concentrations necessary to achieve a similar state of sedation after midazolam premedication given by various routes in children of 2-5 years old. Children were randomly allocated to one of three groups to receive midazolam 0.2 mg.kg-1 given intranasally, 0.5 mg.kg-1 given orally or 0.3 mg.kg-1 given rectally. Sedation was measured regularly until venepuncture was possible in a cooperative child. At this time, a first blood sample was taken to measure plasma concentration, followed by another 10 min later. Anaesthesia consisted of intravenous propofol supplemented with regional analgesia. At recovery from anaesthesia, a third blood sample was taken. Adequate sedation occurred sooner (7.7, SD 2.4 min) with intranasal than oral (12.5, SD 4.9 min) or rectal (16.3, SD 4.2 min) midazolam. The initial blood levels were lower when the drug was given by the alimentary routes despite higher doses (146, SD 51 ng.ml-1 in 11.5, SD 3.9 min; 104, SD 34 ng.ml-1 in 21 +/- 6 min; and 93, SD 63 ng.ml-1 in 23.1, SD 3.5 min for the intra nasal, rectal and oral routes respectively). Duration of surgical procedures, and of propofol infusion, and recovery from anaesthesia was similar for the three groups. The only problem arose in a 30-month-old boy in the intranasal group who developed respiratory depression with a plasma midazolam concentration of 169 ng.ml-1. Intranasal midazolam is an excellent alternative for rapid premedication provided that respiratory monitoring is used.

Stability of an oral midazolam solution for premedication in paediatric patients

The objectives of this study were to assess the stability of a 1 mg/ml oral midazolam solution elaborated by our Hospital Pharmacy Service, and to confirm its clinical effect in presurgical paediatric patients. The solution's stability was tested by determining its pH and its UV-visible absorption spectrum at room temperature for up to 60 days. A high performance liquid chromatography method was used to confirm it. There was no significant change in pH value of either the test or a control solution. No loss of midazolam could be detected during the test. The Anaesthesiology Service assessed the sedation quality (very good, good, bad) and the venous puncture response, 20 minutes after the administration of 0.3 mg/kg of an oral midazolam solution. Twenty children were examined (age: 4-7 years). In addition, the haemodynamic and ventilatory functions were evaluated.

Efficacy of rectal midazolam for the sedation of preschool children undergoing laceration repair

STUDY OBJECTIVE

To determine the efficacy of rectal midazolam as sedation for laceration repair in preschool children in the pediatric emergency department.

DESIGN

Randomized, double-blind, placebo-controlled trial.

PARTICIPANTS

Thirty-four anxious children aged 14 to 51 months with face or scalp lacerations 3 cm or less in length requiring two or more sutures and behavior scores of 3 or more.

INTERVENTIONS

Subjects received 0.45 mg/kg rectal midazolam or saline placebo rectally followed by a topical anesthetic 15 minutes before repair.

RESULTS

Sixteen patients received rectal midazolam, and 18 received placebo. The groups were similar in age, race, gender, laceration length and location, entry behavior score, and entry anxiety score. Ten patients in the rectal midazolam group and 1 in the placebo group achieved adequate sedation (P < .001). Median behavior scores during suturing were more favorable in the rectal midazolam group (P = .003 and P = .08, respectively). Two patients in the rectal midazolam group experienced inconsolable agitation after the repair. None of the patients suffered cardiopulmonary complications.

CONCLUSION

Rectal midazolam is an effective method of sedation for facilitating uncomplicated laceration repair in preschool children. However, physicians must be aware of the possibility of paradoxical reactions when using midazolam in children.

Conscious sedation by rectal administration of midazolam or midazolam plus ketamine as alternatives to general anesthesia for dental treatment of uncooperative children

The trial included 24 children (aged 2-7 yr) referred for dental treatment under general anesthesia, since conventional behavioral management methods had failed to achieve treatment acceptance. As an alternative, they received, on two separate occasions with "identical" dental treatment, conscious sedation by rectal administration of either midazolam (0.3 mg/kg body weight (bwt)) or midazolam (0.3 mg/kg bwt) plus ketamine (1.0 mg/kg bwt). This allowed a double-blind, crossover design. The aims were to assess conscious sedation, combined with local anesthesia, as an alternative to general anesthesia, and further to evaluate the effects obtained by addition of a low dose of ketamine to rectally administered midazolam. The feasibility of dental treatment was rated as excellent or good for 16 of the 24 children when premedicated with midazolam, and for 18 of the 24 children when ketamine was added to midazolam. At least some treatment could be given to all children. Verbal contact was maintained with all children throughout both treatment sessions. The children were significantly less anxious when they arrived for the second session. Amnesia and drowsiness were significantly increased when ketamine was added to midazolam. The combination also tended to be more efficient in relief of anxiety and prevention of pain, but there were large variations in the children's responses to the drugs. Midazolam significantly reduced the blood oxygen level, but not with ketamine added. For most children, both regimens proved to be appropriate as alternatives to general anesthesia.(ABSTRACT TRUNCATED AT 250 WORDS)

Sedative-analgesic agent administration in children: analysis of use and complications in the emergency department

The frequency of, indications for, and complications from non-acetaminophen sedative-analgesic agents (SAAs) administered to children less than 16 years of age in the emergency department (ED) were determined by a retrospective review. All 21,353 charts from a single university hospital ED over a 16-month period were included. Few children (N = 759; 3.5%) received SAAs. Of 919 total doses, 13% of children received a second and 4.5% received a third SAA. The group was 59% male. Most children were < or = 10 years of age. Sixty-two percent of SAAs were either sedatives or opioids. Sedatives given included chloral hydrate, diazepam, lorazepam, midazolam, and phenobarbital. Opioids given included morphine, codeine, and meperidine. Indications for SAAs included painful procedures, analgesia, radiographic imaging, and seizure activity. Complications (N = 51; 6.7%) included inadequate sedation, vomiting, and respiratory depression or oxygen desaturation. Respiratory depression or oxygen desaturation occurred only after intravenous administration of SAAs for seizures. In children, non-acetaminophen SAAs are used most commonly in younger patients requiring sedation for painful procedures or for radiologic imaging. Respiratory depression was observed only after intravenous administration of anticonvulsants.

Nasal midazolam and ketamine for paediatric sedation during computerised tomography

We have studied the sedation achieved with a mixture of midazolam (0.56 mg/kg-1) and ketamine (5 mg/kg-1) administered nasally in 30 children weighing less than 16 kg undergoing computerised tomography. Assessment was two fold using a visual analogue scale; the radiologist/radiographer rated the exam from "failed examination" to "perfect working conditions" while the anesthetist's assessment ranged from "poor sedation" to "perfect sedation with clinical well being". This new method proved to be effective alone in 83% of the cases and there were no complications. The rapid onset obtained after intranasal midazolam and ketamine offers advantages over orally or rectally administered drugs. The absence of respiratory depression and oxygen desaturation suggests that this technique is safe and efficient in the CT room with its particular working conditions.

Pediatric analgesia and sedation

Sedation and analgesia are essential components of the ED management of pediatric patients. Used appropriately, there are a number of medications and techniques that can be used safely in the emergency care of infants and children. Emergency physicians should be competent in the use of multiple sedatives and analgesics. Adequate equipment and monitoring, staff training, discharge instructions and continuous quality management should be an integral part of the ED use of these agents.

Sedation for the pediatric patient. A review

Safe sedation of a pediatric patient requires a thorough knowledge of the pharmacokinetics and pharmacodynamics of the drugs used to sedate the patient and the skills necessary to deal effectively with potential adverse events as a result of the sedation. The Sedation Guidelines of the American Academy of Pediatrics are reviewed. Emphasis is placed on monitoring and appropriate selection of drugs.

Comparison of rectal midazolam and diazepam for premedication in pediatric dental patients

Rectally administered midazolam (0.35 mg/kg) and diazepam (0.70 mg/kg) were compared with each other and with placebo for preanesthetic medication in children undergoing dental extractions. All rectal medications were very well accepted, but mask acceptance, improvement in anxiety, and sedation were best in the midazolam group. Improvement in anxiety and sedation were significantly better in the two drug groups than in those patients who had received placebo. Thirty minutes after rectal administration of midazolam, patients showed a decrease in both systolic and diastolic blood pressure and heart rate. Although these decreases differed significantly from the premedication values, they were probably of little clinical importance. Only minor adverse effects were observed in this study. Overall rectally administered midazolam appeared to be somewhat more efficacious than diazepam.

A comparison of midazolam, diazepam, and placebo as oral anesthetic premedicants in younger children

STUDY OBJECTIVES

To validate the superiority of higher-dose oral midazolam as an anesthetic premedicant in children 6 years of age and younger, to determine whether less expensive diazepam is a viable alternative oral premedicant in this age-group, and to assess the preoperative oxygenation effects of both benzodiazepines.

DESIGN

A prospective, randomized, double-blind study.

SETTING

Outpatient surgery department and operating room (OR) of a freestanding children's hospital.

PATIENTS

Seventy-five ASA physical status I and II outpatients 1 to 6 years of age.

INTERVENTIONS

Patients were randomized to receive either midazolam 0.6 mg/kg, diazepam 0.3 mg/kg, or a placebo orally in a timely manner prior to surgery.

MEASUREMENTS AND MAIN RESULTS

Each child's subsequent reaction to separation from his or her parents in the presurgical holding area was scored on a three-point behavioral scale. Once in the OR, an initial room air oxygen saturation by pulse oximeter (SpO2) was obtained. Each child's initial acceptance of the anesthetic induction mask was then scored on a four-point scale. No significant differences in parental separation scores, initial room air SpO2, or postanesthesia care unit admission time were observed among the three study groups. However, both midazolam and diazepam were observed to be superior to the placebo in facilitating the initial acceptance of the anesthetic induction mask.

CONCLUSIONS

Even without premedication, a majority of children did not react negatively to an impending anesthetic. Therefore, neither midazolam nor diazepam appears to be necessary in most children younger than 6 years of age. Rather than implementing the routine use of an oral preoperative sedative, the challenge appears to be the selective identification of those children at risk for preanesthetic difficulties and psychological trauma.

Pharmacokinetics and preliminary observations of behavioral changes following administration of midazolam to dogs

The pharmacokinetics of midazolam were investigated following intravenous and intramuscular administration of 0.5 mg of midazolam hydrochloride/kg of body weight to five healthy mixed-breed dogs. One dog also received the same dose of midazolam by oral and rectal routes. The disposition of midazolam following intravenous administration was characterized by very rapid and relatively extensive distribution followed by rapid elimination. Mean (+/- SD) apparent volume of distribution was 3.0 +/- 0.9 l/kg, mean elimination half-life was 77 +/- 18 min, and clearance was 27 +/- 3 ml/kg/min. Following intramuscular administration, absorption was rapid and complete. A mean peak midazolam concentration of 549 +/- 121 ng/ml was reached within 15 min, and systemic availability was over 90% in each dog. Oral administration to one dog resulted in peak midazolam concentrations within 10 min and a systemic availability of 69%. Rectal administration to the same dog yielded very low systemic availability. Midazolam was extensively bound to canine plasma proteins, with the unbound fraction representing less than 4% of the total plasma midazolam concentration. Plasma samples were also assayed for the presence of the major metabolites, 1-OH and 4-OH midazolam. Neither metabolite were detected, probably as a result of rapid elimination of these compounds by hepatic glucuronidation. Behavioral responses to administration of midazolam included initial signs of profound weakness, ataxia and transient agitation followed by a period of quiesence. A normal behavior pattern returned within 2 h of midazolam administration.

Pharmacokinetics of midazolam during continuous infusion in critically ill neonates

Midazolam is a water soluble benzodiazepine, with a short elimination half-life in adults and children. An IV bolus (0.2 mg.kg-1) immediately followed by continuous infusion of 0.06 mg.kg-1.h-1 was administered to 15 critically ill neonates at a gestational age of 32.8 weeks, who required sedation for mechanical ventilation. Heart rate and blood pressure were closely monitored. Hypotension occurred in 4 patients after the bolus dose or during the continuous infusion. Three of them had also been given fentanyl. Individual pharmacokinetic parameters were calculated: plasma clearance was 3.9 ml.min-1, elimination half-life was 12.0 h. Because of its short half-life compared to diazepam, midazolam may be used during the neonatal period to achieve rapid, brief sedation. However, it should be administered cautiously to neonates, particularly in premature infants, or if fentanyl is also given.

Pharmacokinetics of midazolam in children: comparative study of intranasal and intravenous administration

Twelve children 1-5 y old were randomly assigned to receive midazolam 0.2 mg.kg-1 either by the intravenous (IV) or intranasal (IN) routes. After IN administration the rapid onset of absorption was observed (tmax 12 min). After both routes of administration the half-life was similar (2.2 h IN and 2.4 h IV). After IN administration the apparent plasma clearance and volume of distribution were about twice as high as after IV administration. The results are consistent with an estimated mean bioavailability of 55%.

Rectal ketamine and midazolam for premedication in pediatric dentistry

Rectally administered midazolam (0.30 mg/kg) and ketamine (5 mg/kg) were compared for preanesthetic medication in children undergoing dental extractions. Sixty patients between the ages 2 and 9 years were randomly allocated to three groups in this double-blind study. In one group of patients who received ketamine rectally, intravenous midazolam (0.05 mg/kg) also was administered immediately after induction of anesthesia. The results from this trial show that 30 minutes after rectal administration of the two drugs, good anxiolysis, sedation, and cooperation were obtained in most patients. Although midazolam appeared to be marginally more efficacious than ketamine in the majority of assessments made and seemed to have less adverse effects, no statistically significant differences could be shown. Ketamine showed a slight decrease and midazolam a slight increase in average blood pressures after premedication. These blood pressure differences were, however, considered to be of little clinical importance.

Pharmacokinetics of rectal drug administration, Part II. Clinical applications of peripherally acting drugs, and conclusions

Part I of this article, which appeared in the previous issue of the Journal, covered general considerations, the physiology of the rectum, spreading of drugs into the colon, rectal absorption, partial avoidance of first-pass elimination, rate-controlled rectal delivery of drugs, irritation of the rectal mucosa and clinical applications of rectal administration, and discussed centrally acting drugs. In Part II, this discussion is extended to drugs which act peripherally and to methods of enhancing rectal drug absorption. The overall summary appeared in Part I.

Rectal flunitrazepam as premedication in preschool children. A double-blind randomized study

The efficacy of flunitrazepam (0.04 mg.kg-1) as a premedicant was evaluated in 40 young children of less than 5 years of age in a double-blind, placebo-controlled study. Flunitrazepam was given by the rectal route 15 min prior to an inhalational mask induction with halothane. Sedation score, mask acceptance and induction score were significantly better in premedicated children than in the placebo group. There were no hypoxic episodes, prolonged sedation or other complications in either group. This suggests that flunitrazepam administered rectally in a low dose is an acceptable premedication in young children.

Intranasal administration of midazolam to a severely burned child

This report describes the use of intranasally administered midazolam for sedation in a critically ill burned paediatric patient without venous access. Placement of a central venous catheter was successfully carried out following sedation by this method.

Preanesthetic medication with rectal midazolam in children undergoing dental extractions

Three different dosages (0.25, 0.35, and 0.45 mg/kg) of rectally administered midazolam were compared with each other and with placebo for preanesthetic medication in children undergoing dental extractions. Eighty patients between the ages of 2 and 10 years were randomly allocated into four groups in this double-blind study. The results from this trial show that 30 minutes after rectal administration of all doses of midazolam, good anxiolysis, sedation, and cooperation were obtained in most patients. A high prevalence (23%) of disinhibition reactions was observed, particularly in the 0.45 mg/kg group. For this reason, 0.25 or 0.35 mg/kg appears to be the dose of choice when rectal midazolam is used for premedication in children.

Pharmacokinetics of midazolam in critically ill neonates

Midazolam is a water soluble benzodiazepine, with a short elimination half-life in adults and children. An IV bolus of midazolam 0.2 mg.kg-1 was administered to 10 critically ill neonates receiving intensive care who required sedation. The plasma clearance was 6.85 ml.min-1 and the elimination half-life was 6.52 h. Midazolam was well tolerated during and after administration. Because of its short half-life compared to diazepam, midazolam could be used during the neonatal period to produce brief rapid sedation.