Effectiveness of preoperative intranasal dexmedetomidine, compared with oral midazolam, for the prevention of emergence delirium in the pediatric patient undergoing general anesthesia: a systematic review
Authors: FitzSimons James , Bonanno Laura S. , Pierce Stephanie , Badeaux Jennifer 
Published: July 2017

EXECUTIVE SUMMARY

Background
Emergence delirium is defined as a cognitive disturbance during emergence from general anesthesia resulting in hallucinations, delusions and confusion manifested by agitation, restlessness, involuntary physical movement and extreme flailing in bed. Postoperative emergence delirium develops in 12% to 18% of all children undergoing general anesthesia for surgery. This post-anesthetic phenomenon changes cognitive and psychomotor behavior, and puts pediatric patients and health care personnel at risk of injury. A newer drug, dexmedetomidine, is a selective alpha-2 agonist, which works in the brain and spinal cord that has sedative, analgesic and anxiolytic properties. Dexmedetomidine also has the ability to lower the overall anesthetic requirements by reducing sympathetic outflow in response to painful surgical stimulation. In current literature, there is not a systematic review that compares the effectiveness of preoperative intranasal dexmedetomidine administration against oral midazolam for the prevention of emergence delirium.

Objectives
The objective of this review was to identify the effectiveness of preoperative intranasal dexmedetomidine compared to oral midazolam for the prevention of emergence delirium in the pediatric patient undergoing general anesthesia.

Inclusion criteria Types of participants
This review considered studies that included pediatric patients aged three to seven years, with an American Society of Anesthesiologists (ASA) classification of I or II, and undergoing general anesthesia for elective/ambulatory surgery. This review excluded studies that included patients who had special needs including: developmental delay, chronic pain issues, and/or any preexisting mental or physical health disorders which categorized them above an ASA II.

Types of intervention(s)/phenomena of interest
This review considered studies that compared preoperative intranasal administration of dexmedetomidine with preoperative oral administration of midazolam for the prevention of emergence delirium.

Types of studies
This review considered both experimental and non-experimental study designs including randomized-controlled trials (RCTs), non-randomized control trials, quasi-experimental, before and after studies, prospective and retrospective cohort studies, case control studies, and analytical cross-sectional studies for inclusion.

Outcomes
This review considered studies that included the presence of postoperative emergence delirium. Only studies that used the Pediatric Anesthesia Emergence Delirium Scale to quantify the degree of emergence delirium were included in the review. Adverse events other than emergence delirium were not considered as part of the outcomes inclusion criteria but were to be included in the discussion if any articles were identified.

Search strategy
The search strategy aimed to discover both published as well as unpublished studies. A three-step search strategy was utilized in eight databases. Studies published in English or with an English translation after 1999 were considered for inclusion in this review.

Methodological quality
Assessment of methodological quality was not conducted as no studies were identified which met the inclusion criteria.

Data extraction and synthesis
Data extraction and synthesis was not performed since no studies were included in this systematic review.

Results
Following the three-step search strategy as previously described, 117 articles were identified: six in Clinical Trials, one in ProQuest, 14 in Ovid MEDLINE, 10 in CINAHL, 16 in the Cochrane Library, 13 in Scopus, 36 in Embase, and 21 in Web of Science. There were 43 duplicates which were identified and removed in Refworks by the primary reviewer. The primary and secondary reviewers independently retrieved 10 potentially relevant studies (from the initial 74) through title and abstract screening as described in the inclusion criteria. All of the retrieved studies were excluded, after assessment of full text, with reasons based on the inclusion criteria.

Conclusions
There is no scientific evidence identifying the effectiveness of preoperative intranasal dexmedetomidine, compared with oral midazolam, for the prevention of emergence delirium in the pediatric patient population.