The effect of intranasal dexmedetomidine administration on emergence agitation or delirium in pediatric patients after general anesthesia
A meta-analysis of randomized controlled trials
September 2023 by Dr Matt Jenke
This article is a meta-analysis of randomised control trials analysing the effect of preoperative intranasal dexmedetomidine on emergence agitation (EA) and emergence delirium (ED) in paediatric patients after general anaesthesia.
Primary Outcome: Proportion of patients experiencing emergence agitation or delirium.
Secondary Outcome: Emergence time and rate of post operative nausea and vomiting.
The meta-analysis followed the PRISMA and GRADE protocols. Inclusion criteria was for randomised control studies evaluating the effects of dexmedetomidine verses placebo or control on EA/ED in paediatric patients. Twenty studies were included in the final analysis with a total of 2103 paediatric patients. 984 patients were in the intranasal dexmedetomidine treatment groups.
The incidence of EA/ED was 13.6% in the dexmedetomidine group compared to 33.2% in the control group (OR 0.25, CI 0.18-0.43; p=0.0000). Emergence time was significantly increased in the dexmedetomidine group with a mean difference of 2.42 minutes (CI 0.37-4.46; p=0.021). Emergence time was shorter when compared to ketamine and midazolam subgroups. Dexmedetomidine significantly reduced the incidence of PONV (OR 0.39, CI 0.24-0.64; p=.0002).
Dexmedetomidine has emerged as a genuine option for preoperative anxiolysis and this analysis has highlighted the drug's favourable effects for a patient focused post-operative experience - with reduced ED/EA and PONV, and without a clinically significant increase in emergence time.
Controlling for heterogenicity in the analysis was difficult due to the small number of trials and their sample sizes. There were few studies that compared dexmedetomidine to other frequently used premedications and were only done so at doses of 1-2micrograms/kg. A major limitation of the study was that there is no clear definition or assessment protocol for what constitutes EA/ED. The development of an internationally standardised assessment tool for EA/ED in paediatric patients should ideally be developed prior to undertaking future studies. The study did not assess the alleviation of pre-operative agitation and distress with dexmedetomidine.
Maintenance inhalational anaesthesia was used in 17 out of 20 studies with only one study mandating the use of TIVA. Propofol based anaesthesia is associated with both the primary outcome of reduced EA/ED and secondary outcome of reduced PONV. Greater use of propofol maintenance anaesthesia in the included trials may have impacted strength of this analysis. From this analysis it is unclear if TIVA would diminish or enhance the postoperative effects of dexmedetomidine.
The antiemetic effects of dexmedetomidine are currently unknown but are suggested to be trifold. Hypothesised mechanisms include direct noradrenergic inhibition at the locus coeruleus, sympatholysis to reduce adrenaline-associated nausea and vomiting and reduced opioid consumption.
Take home messages/commentary:
• At a dose of 1-2micrograms/kg pre-operative intranasal dexmedetomidine reduces ED/EA and PONV.
• It is unclear how this effect is altered if TIVA anaesthetic is used.
• Further research is required to assess the effect of intranasal dexmedetomidine on ED/EA when combined with other premedications.