University of New England DUNE : DigitalUNE Nurse Anesthesia

This review examines the use of intravenous dexmedetomidine in the role of decreasing or preventing emergence delirium in pediatric patients undergoing ambulatory surgery. The included randomized controlled trials evaluated the administration of dexmedetomidine, whether as a bolus, infusion, or in combination, and its effectiveness in preventing or reducing emergence delirium. The analysis scales for emergence delirium varied between studies, and it was noted that multiple scale components overlapped with pain scale components used in the trials. It has also been noted that differentiating between pain and emergence delirium can be challenging for clinicians (Somaini, Engelhardt, Fumagalli & Ingelmo, 2016). To address this challenge, both the prevalence of pain and emergence delirium were assessed. Variations between studies included the administration of premedication, surgical procedure performed, and other pharmacological agents administered during the perioperative period. Eleven of the twelve trials demonstrated that dexmedetomidine decreased the incidence of emergence delirium when compared to the use of a placebo and eight studies reported decreased pain scores. Thus, it can be suggested that dexmedetomidine is an adequate pharmacological option to help prevent the incidence of emergence delirium and pain, regardless of whether the two outcomes are tied together. However, it is imperative that further research be performed to establish the most effective time during the perioperative period dexmedetomidine should be administered. In addition, further research must be performed to establish a dose that allows for the prevention of emergence delirium, but not at an expense of the increased discharge time. DEXMEDETOMIDINE IN THE PREVENTION OF EMERGENCE DELIRIUM 3 Introduction Dexmedetomidine is a selective alpha-2 adrenergic receptor agonist that results in decreased norepinephrine release and ultimately provides sedative and analgesic effects without causing respiratory depression (Nagelhout & Plaus, 2014). The onset of intravenous dexmedetomidine is 5 to 10 minutes, with a peak effect of 15 to 20 minutes and a duration, which is dose dependent, of 60 to 120 minutes. Once within the blood stream, it is metabolized by the hepatic system and excreted by the kidneys. Dexmedetomidine is used in multiple clinical settings, some of which include the intensive care unit for sedation or in the operating room for conscious sedation. Over the recent years, researchers have investigated the role of dexmedetomidine in the prevention of emergence delirium (ED) in pediatric patients. The care of pediatric patients requires the anesthetist to consider different aspects of their care than those when caring for adults in the operating room; one of these considerations is that children are more likely to experience ED than their adult counterparts (Lerman, 2017). Therefore, it is important that the anesthetist is aware of the current literature surrounding the prevalence of ED and the options available to treat the phenomenon. ED, also called emergence agitation or excitation, has been described as “a mental disturbance that consists of confusion, hallucinations, and delusions manifested by inconsolable crying, disorientation, nonpurposeful restlessness, involuntary physical activity, and thrashing about in bed” (Mukherjee et al., 2015, p. 24). It has also been named as a component of earlypostoperative negative behavior (e-PONB) (Somaini et al., 2016). Pain is the other component of e-PONB. When considering these two components, there is always a possibility that they may overlap in presentation or that they may be independent of each other. This information has DEXMEDETOMIDINE IN THE PREVENTION OF EMERGENCE DELIRIUM 4 promoted the study of dexmedetomidine in the prevention of ED as it provides both sedative and analgesic qualities, which may help to alleviate one or both components of e-PONB. The incidence of ED has been linked to several risk factors. Pain, as mentioned, is one component of e-PONB and is a risk factor for ED (da Silva, Braz and d l , 2008). Patients who present with ED do not always undergo a procedure that involves pain and, therefore, any pediatric patients undergoing anesthesia should be considered at risk for ED. Age has also been determined a risk factor. Lerman (2017) isolates two to six years of age, otherwise known as “presch l-aged” children, where 30 to 50 percent of patients in this age group will experience ED. Overall, it has been found that the incidence of ED decreases with an increase in age. Da Silva, ra and d l (2008) explain “the cause of the increased incidence in this group appears to be that their emotional lability is exacerbated when faced with a stressful situation in an unfamiliar envir nment” (p.108). The authors also explain that children who are anxious and impulsive as well as less sociable are at increased risk for ED. Therefore, clinicians should have a heightened awareness when caring for patients in this age group and to prepare for the possibility of ED. Parental presence is a commonly discussed topic when addressing pediatric anesthesia. According to Da Silva, Braz and d l (2008), there has not been any proven connection between parental presence with induction of anesthesia and the prevention of ED. However, it was f und that patients wh experienced a “traumatic separati n fr m their parents n the way to the operating r m” (p. 109) had increased negative postoperative behavior, including an increase in the incidence of ED. Therefore, the authors suggest parental presence remains intact as it may facilitate a smoother transition and create a safer environment for the child. Another risk factor discussed is the anesthetic regimen chosen. Inhalational anesthetics, DEXMEDETOMIDINE IN THE PREVENTION OF EMERGENCE DELIRIUM 5 including sevoflurane, desflurane, and isoflurane, have been found to have a higher incidence of ED than the use of intravenous anesthetics such as propofol. The mechanism for this has not been established at this time. Interestingly, the length of exposure to these anesthetics does not increase or decrease the incidence of ED (Lerman, 2017). At this time, inhalational anesthetics are commonly chosen as the anesthetic of choice and, therefore, discussing medications that can attenuate or decrease the incidence of ED is important. Certain long-term effects of ED are still under investigation. However, it is important that the anesthetist recognizes those that have been well established. ED can cause parental anxiety and, therefore, can reduce parental satisfaction (Somaini et al., 2016). Also, research suggests the potential for altered behavioral patterns 30 days postoperatively in the pediatric population. Short-term effects of ED are often obvious and distressing for the patients, caregivers and clinicians. Research has shown that in the short-term period ED can cause injury to the patient and unintentional removal of intravenous catheters. Somaini et al. (2016) also state accidental rem val f “drainages, or dressing and may require extra nursing care, additional time in recovery room, and supplemental sedatives or analgesic drugs” (p. 378). Thus, ED is an important part of postoperative management that clinicians should address and aim to prevent. The anesthetist must also consider that pediatric patients undergoing ambulatory surgery are discharged on the day of surgery. This results in a postoperative recovery period in the hospital that is shorter than those patients who are admitted. Parents must feel confident taking their child home, and an occurrence of ED may make this process challenging. Additionally, children undergoing ambulatory surgery who experience ED may require additional pharmacological intervention that could delay discharge (Sato, Shirakami, Tazuke-Nishimura, Matsuura, Tanimoto & Fukuda, 2010). Sato et al. explain that clinicians sh uld “try t prevent DEXMEDETOMIDINE IN THE PREVENTION OF EMERGENCE DELIRIUM 6 ED in order to provide efficient and high-quality care that is a positive experience for patients and their parents” (p. 675). Clearly, a smooth recovery that is satisfactory to the patient, their family, and the clinician is important after ambulatory surgery. Research thus far has suggested that dexmedetomidine may be helpful in reducing ED and, therefore, the use of dexmedetomidine in pediatric patients undergoing ambulatory surgery to reduce the incidence of ED will be examined.