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Table of Contents
Year : 2017  |  Volume : 33  |  Issue : 2  |  Page : 236-240

Comparison between intranasal dexmedetomidine and intranasal midazolam as premedication for brain magnetic resonance imaging in pediatric patients: A prospective randomized double blind trial

Department of Anesthesiology, Lokmanya Tilak Municipal Medical College and Lokmanya Tilak Municipal General Hospital, Sion, Mumbai, Maharashtra, India

Date of Web Publication7-Jul-2017

Correspondence Address:
Ayushi Gupta
D/O Mr. G.D. Gupta, 720, Shivaji Nagar, Behind Bharat Petrol Pump, Kanpur Road, Jhansi - 284 001, Uttar Pradesh
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/joacp.JOACP_204_16

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Background and Aims: Preprocedural preparation of children scheduled for magnetic resonance imaging (MRI) is challenging. This prospective, randomized trial compared intranasal midazolam with intranasal dexmedetomidine as premedication for children scheduled for brain MRI.
Material and Methods: In total, 60 children, aged 1–8 years, scheduled for elective brain MRI, were randomly assigned to the intranasal dexmedetomidine (1 μg/kg; Group D) or intranasal midazolam (0.2 mg/kg; Group M) group. We compared hemodynamic and respiratory parameters, onset, level, sedation quality, and successful parental separation. All patients received intravenous propofol as an induction and maintenance agent for MRI.
Results: No significant differences were observed in demographic, hemodynamic, and respiratory parameters. Group D (14.3 ± 3.4 min [10–20 min]) had a longer time of sedation onset than Group M (8.7 ± 3.7 min [5–15 min]; P < 0.001). The median and mean sedation scores were lower in Group D (3 and 3.7 ± 0.8, respectively) than Group M (4 and 4.3 ± 1.2, respectively; P = 0.055). Group D (80%) had a higher percentage of children achieving satisfactory sedation at the time of induction than did Group M (53.3%; P = 0.0285). Parental separation was successful in 73.3% of patients in Group D compared with 46.7% of patients in Group M (P = 0.035).
Conclusion: Intranasal dexmedetomidine results in more successful parental separation and yields a higher sedation level at the time of induction of anesthesia than intranasal midazolam as premedication, with negligible side effects. However, its onset of action is relatively prolonged.

Keywords: Dexmedetomidine, midazolam, intranasal, magnetic resonance imaging

How to cite this article:
Gupta A, Dalvi NP, Tendolkar BA. Comparison between intranasal dexmedetomidine and intranasal midazolam as premedication for brain magnetic resonance imaging in pediatric patients: A prospective randomized double blind trial. J Anaesthesiol Clin Pharmacol 2017;33:236-40

How to cite this URL:
Gupta A, Dalvi NP, Tendolkar BA. Comparison between intranasal dexmedetomidine and intranasal midazolam as premedication for brain magnetic resonance imaging in pediatric patients: A prospective randomized double blind trial. J Anaesthesiol Clin Pharmacol [serial online] 2017 [cited 2020 Aug 12];33:236-40. Available from:

  Introduction Top

The success of magnetic resonance imaging (MRI) as a diagnostic tool has led to its increased use in patients of all age groups; however, children undergoing MRI often require sedation because the magnetic field creates a sound of a very high decibel and to minimize motion artifact.[1] Anxiety and fear in children lead to increased catecholamine levels in the body, thereby leading to tachycardia, hypertension, and tachypnea and increased difficulty in gaining intravenous access, separation from parents, and induction of anesthesia. Premedication facilitates overcoming these difficulties, with midazolam being the most commonly used agent. However, midazolam is associated with the risk of respiratory depression and has no analgesic action. Contrastingly, dexmedetomidine, a selective α2 agonist, has analgesic and sedative action with no risk of respiratory depression and has been used as premedication.

However, few studies have reported on the intranasal use of dexmedetomidine in radiological procedures. In this prospective, randomized, double-blind study, we compared intranasal midazolam (0.2 mg/kg) and intranasal dexmedetomidine (1 μg/kg) in terms of hemodynamics; parental separation anxiety; and onset, level, and sedation quality at the time of patient induction.

  Material and Methods Top

After obtaining approval from the institutions' Ethics Committee, written, informed, and valid consent was obtained from the parents of the patients after explaining the study protocol to them. This study included 60 American Society of Anesthesiologists (ASA) Grades I and II patients who were aged 1–8 years and were scheduled for brain MRI.

Patients aged <1 and >8 years, with parents' refusal, ASA Grades III and IV, congenital heart disease, upper respiratory tract infection, and body mass index >35; being administered digoxin or beta blockers; and requiring emergency MRI were excluded from the study.

Preanesthetic assessment included medical and surgical history; general and systemic examination; airway examination; and investigations, such as complete hemogram and renal function tests, conducted on an outpatient basis. On the day of MRI, the nil by mouth status was confirmed, and parental consent was obtained.

Baseline saturation (SpO2) and heart rate (HR) were monitored using a pulse oximeter. Electrocardiogram and respiratory rate (RR) were monitored using a respiration strap, and blood pressure (BP) was measured using a noninvasive BP cuff. The sedation level was assessed using the Observer's Assessment of Alertness/Sedation (OAA/S) scale, a 6-point sedation scale. The patients were randomly allocated to two groups. To avoid bias, observers and attending anesthesiologists were blinded to the study drug. Group M received intranasal midazolam (0.2 mg/kg) and Group D received intranasal dexmedetomidine (1 μg/kg). The intranasal drug was dripped into both nostrils using a 1-mL syringe, with the patients in the recumbent position. The time of dosage was noted, and the observer recorded SpO2, HR, systolic BP (SBP), diastolic BP (DBP), RR, and the sedation level at 5-min intervals for 30 min following drug administration.

The onset of sedation was defined as an increase in the sedation level compared with the baseline −1 (change in the OAA/S score from 6 to 5). Adequate sedation was defined as the time taken to achieve an OAA/S score of 4 and was the time when the patients allowed intravenous cannulation without crying.

Within 15 min of cannulation, the patients underwent MRI. The behavior of the patients while entering the MRI room was monitored, and the OAA/S score at the time of induction was noted.

At the time of induction, an OAA/S score between 1 and 4 represented satisfactory sedation and of 5 or 6 represented unsatisfactory sedation. Time of induction was noted, and whether parental separation at the time of induction was successful was recorded. Sedation was considered successful when the patients were calm and sedated, were not crying and agitated, and allowed smooth induction. For induction, an intravenous bolus of 0.5 mg/kg propofol was administered for 2–3 min, and the infusion was started at 100 μg/kg/min and increased to a maximum of 350 μg/kg/min, provided HR >60 beats/min, fall in SBP was <20% of the baseline value, and respiratory depression was absent (SpO2 <95). SpO2, HR, BP, and RR were noted at the time of induction, for every 5 min for the first 15 min and then for every 15 min until the end of brain MRI, which lasted for a maximum of 60 min.

Statistical analysis

Sample size was calculated based on the results of a previous study [2],[3],[4],[5],[6],[7],[8],[9],[10],[11] using the formula for quantitative statistical analysis with confidence level of 95% and an allowable error of 5%. Parametric data were analyzed using the unpaired t-test. Repeated measurements data were analyzed using the paired t-test, and binary data were analyzed using Chi-squared test. P < 0.05 was considered statistically significant.

  Results Top

The demographic profile was comparable between the two groups [Table 1]. Furthermore, the mean HR [Figure 1] and other hemodynamic parameters, such as BP [Figure 2], were comparable between the groups.
Table 1: Demographic data

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Figure 1: Comparison of mean heart rate between the two groups

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Figure 2: Comparison of mean systolic blood pressure between the two groups

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Sixteen of 30 children (53.3%) in Group M and 24 of 30 children (80%) in Group D achieved satisfactory sedation at the time of induction (i.e., OAA/S score ≤4), which was statistically significant (P < 0.0285) [Figure 3]. Median sedation scores for Groups M and D were 4 and 3, respectively [Figure 4]. Fourteen children (46.7%) in Group M and 22 (73.3%) in Group D showed successful parental separation, with a statistically significant difference (P < 0.035) [Table 2].
Figure 3: Comparison of level of sedation between the groups at the time of induction

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Figure 4: Comparison of median sedation score between the groups

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Table 2: Comparison of successful parental separation between the groups

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  Discussion Top

Premedication is required to alleviate anxiety and fear, allow smooth separation from parents, and allow easy acceptance of needle prick for intravenous cannulation and anesthesia induction. In addition, premedication has analgesic, amnesic, antisialagogue, antiemetic, and vagolytic effects. Various drugs are available for premedication, with midazolam being the most commonly used. However, midazolam is associated with respiratory depression and an increased incidence of adverse postoperative behavioral changes, hiccups, and paradoxical reactions.[3] Clonidine, a α2 agonist, has also been suggested for premedication, but it has a slow onset of action (1–3 h). Dexmedetomidine is a newer α2 agonist with more selective action on α2-adrenergic receptors and a shorter half-life. Increasing evidence has shown that dexmedetomidine is an effective and safe sedative in children scheduled for radiological procedures.[4],[5] Dexmedetomidine has analgesic and antishivering properties and does not cause respiratory depression.

Intranasal application is a relatively noninvasive, convenient, and easy route of administration and results in a faster onset of action as well as reduces first-pass metabolism.[6],[7] Hence, we administered midazolam intranasally. Dexmedetomidine is only available in an intravenous formulation; intravenous preparation has been used through oral, transmucosal, and intranasal routes. Dexmedetomidine has been extensively studied intranasally in both children and adults. Investigations conducted by Yuen et al. have shown that intranasal dexmedetomidine produces significant sedation in healthy adults and in children aged between 2 and 12 years.[8],[9],[10]

In this study, the time of onset of sedation is 8.7 ± 3.7 min (5–15 min) in Group M compared with 14.3 ± 3 min (10–20 min) in Group D. The difference in onset time was statistically significant with early onset in midazolam. Sheta et al. reported similar results regarding the onset of sedation between the two groups.[11]

In our study, 80% of patients in Group D achieved satisfactory sedation (OAA/S score ≤4) compared with 53.3% of patients in Group M, which was statistically significant (P = 0.028) [Figure 3]. Sheta et al. and Sundaram and Mathianhave reported similar findings in patients undergoing dental treatment.[2],[11]

In our study, the median sedation score at the time of cannulation was 4 (3–6) for Group M compared with 3 (3–5) for Group D [Figure 4]. Hence, a better sedation score was obtained for Group D, similar to the results reported by Sheta et al. and Sundaram and Mathian.[2],[11]

We observed successful parental separation in 73.3% of patients in Group D compared with 46.7% of patients in Group M. The difference was clinically as well as statistically significant (P < 0.035) [Table 2]. In another study by Mostafa andMorsy comparing the use of dexmedetomidine, midazolam, and ketamine as intranasal premedication, the percentage of children who achieved child–parent separation score Grade 1 was 93.8%, 87.5%, and 68%, respectively.[12] Sundaram and Mathian reported similar results.[2]

No significant change was observed in SpO2 between the groups until the end of 30 min. None of the patients in both groups had SpO2<95% at any point of time during patient monitoring. Similarly, SpO2 was comparable in two studies comparing intranasal dexmedetomidine and midazolam, and none of the patients had SpO2<95% at any point of time.[2],[13]

The baseline HR was comparable between the groups [Figure 1]. Dexmedetomidine is known to decrease sympathetic outflow and circulating catecholamine levels. HR, SBP, and DBP decreased from baseline after premedication, as expected. Sundaram and Mathian reported similar results.[2]

None of the children in both groups had untoward complications, such as bradycardia, hypotension, hypertension, and respiratory depression, after premedication. Similar findings regarding side effects were noted in other studies.[9],[11] Nasal irritation and stinging in addition to paradoxical reactions, such as restlessness and euphoria, are major disadvantages of the intranasal administration of midazolam and could be deterrents in its use as premedication. Several studies have reported these unwanted side effects in children.[14],[15] Our study did not specifically observe the concerns of patients' acceptance of the drug.

Contrastingly, dexmedetomidine does not cause any transient nasal burning or irritation, paradoxical reaction, hiccups, and respiratory depression. It acts on the locus coeruleus and produces an unusually cooperative form of sedation, in which the patient is calmly and easily aroused from sleep to wakefulness and subsequently quickly falls back asleep when not stimulated, which is similar to natural sleep. Therefore, children who had received dexmedetomidine had a tendency to awaken during transfer from parents' lap to the MRI table but were quiet, calm, and cooperative.

  Conclusion Top

We observed that intranasal dexmedetomidine (1 μg/kg) results in more successful parental separation, better hemodynamics, higher sedation level, and more satisfactory sedation at the time of induction than intranasal midazolam (0.2 mg/kg) as premedication, with negligible side effects in MRI.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Bisset GS 3rd, Ball WS Jr. Preparation, sedation, and monitoring of the pediatric patient in the magnetic resonance suite. Semin Ultrasound CT MR 1991;12:376-8.  Back to cited text no. 1
Sundaram AL, Mathian VM. A comparative evaluation of intranasal dexmedetomidine and intranasal midazolam for premedication in children: A double blind RCT. JIDA 2011;6:777-81.  Back to cited text no. 2
Bergendahl H, Lönnqvist PA, Eksborg S. Clonidine: An alternative to benzodiazepines for premedication in children. Curr Opin Anaesthesiol 2005;18:608-13.  Back to cited text no. 3
Mason KP, Zgleszewski SE, Dearden JL, Dumont RS, Pirich MA, Stark CD, et al. Dexmedetomidine for pediatric sedation for computed tomography imaging studies. Anesth Analg 2006;103:57-62.  Back to cited text no. 4
Mason KP, Lubisch N, Robinson F, Roskos R, Epstein MA. Intramuscular dexmedetomidine: An effective route of sedation preserves background activity for pediatric electroencephalograms. J Pediatr 2012;161:927-32.  Back to cited text no. 5
Malinovsky JM, Populaire C, Cozian A, Lepage JY, Lejus C, Pinaud M. Premedication with midazolam in children. Effect of intranasal, rectal and oral routes on plasma midazolam concentrations. Anaesthesia 1995;50:351-4.  Back to cited text no. 6
Kogan A, Katz J, Efrat R, Eidelman LA. Premedication with midazolam in young children: A comparison of four routes of administration. Paediatr Anaesth 2002;12:685-9.  Back to cited text no. 7
Yuen VM, Irwin MG, Hui TW, Yuen MK, Lee LH. A double-blind, crossover assessment of the sedative and analgesic effects of intranasal dexmedetomidine. Anesth Analg 2007;105:374-80.  Back to cited text no. 8
Yuen VM, Hui TW, Irwin MG, Yuen MK. A comparison of intranasal dexmedetomidine and oral midazolam for premedication in pediatric anesthesia: A double-blinded randomized controlled trial. Anesth Analg 2008;106:1715-21.  Back to cited text no. 9
Yuen VM, Hui TW, Irwin MG, Yao TJ, Chan L, Wong GL, et al. A randomised comparison of two intranasal dexmedetomidine doses for premedication in children. Anaesthesia 2012;67:1210-6.  Back to cited text no. 10
Sheta SA, Al-Sarheed MA, Abdelhalim AA. Intranasal dexmedetomidine vs midazolam for premedication in children undergoing complete dental rehabilitation: A double-blinded randomized controlled trial. Paediatr Anaesth 2014;24:181-9.  Back to cited text no. 11
Mostafa MG, Morsy KM. Premedication with intranasal dexmedetomidine, midazolam and ketamine for children undergoing bone marrow biopsy and aspirate. Egypt J Anesth 2013;29:131-5.  Back to cited text no. 12
Akin A, Bayram A, Esmaoglu A, Tosun Z, Aksu R, Altuntas R, et al. Dexmedetomidine vs. midazolam for premedication of pediatric patients undergoing anesthesia. Paediatr Anaesth 2012;22:871-6.  Back to cited text no. 13
Wilton NC, Leigh J, Rosen DR, Pandit UA. Preanesthetic sedation of preschool children using intranasal midazolam. Anesthesiology 1988;69:972-5.  Back to cited text no. 14
Karl HW, Rosenberger JL, Larach MG, Ruffle JM. Transmucosal administration of midazolam for premedication of pediatric patients. Comparison of the nasal and sublingual routes. Anesthesiology 1993;78:885-91.  Back to cited text no. 15


  [Figure 1], [Figure 2], [Figure 3], [Figure 4]

  [Table 1], [Table 2]


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