Emergence Delirium, Anesthesia

The most common imaging procedure requiring sedation/anesthesia for the pediatric population is magnetic resonance imaging (MRI). However, the optimal anesthetic/sedation plan has not been determined for these procedures. Historically, common medications have included the use of pentobarbital and propofol, but in 2015, publication in the New England Journal of Medicine highlighted the accumulating evidence for the possible neurotoxic effects of these types of anesthetics in animal models and a collection of epidemiologic studies in humans. Although these initial possibilities have since been proven as less of a concern, in the interim, data has shown that alternative sedative agents, such as dexmedetomidine, may not have the same neurotoxic effect and could possibly even provide neuroprotection. Dexmedetomidine also possesses other beneficial traits such as reducing risks of pulmonary atelectasis or upper airway collapse, typically found with the administration of propofol. A concern raised by previous studies has been the possibility that the addition of dexmedetomidine could increase recovery times, leading to disruptions in workflow. Although it has been shown that large doses of dexmedetomidine exposure may lead to longer PACU stays, it is uncertain whether a small dose of dexmedetomidine would have such a significant impact. Based on the investigators' pilot trial6, the investigators found that a bolus of 1 mcg/kg dose of dexmedetomidine with a bolus of titrated propofol of 2-3 mg/kg and an infusion of propofol of 100 mcg/kg/min provided adequate sedation for successful scans, reduced propofol (infusion) exposure by 60%, and did not significantly increase recovery times. Finally, there is a paucity in literature for studies examining a range of doses subsequently; often, a control group is compared to a single, self-selected dose of choice. Here, the investigators hope to provide a range of doses to minimize selection bias in our study design and determine the dose that would provide the optimal sedation for these scans and minimize excess anesthetic exposure.

The aim of the study is to compare two modalities of measuring the depth of general anaesthesia on the incidence of emergent delirium in children.

This study is designed to evaluate the effectiveness of ultrasound-guided greater auricular nerve block (GAN) on the reduction of emergence agitation (EA) occurrence and EA severity in children who are receiving general anesthesia for a microscopic middle ear operation.

Used as a premedication to decrease anxiety (Caumo et al., 2007). Midazolam, though has several drawbacks (McCann and Kain, 2001). Hence, an alternative premedication to midazolam will definitely have a widespread appeal. Melatonin is a hormone secreted by the pineal gland. Melatonin is different from benzodiazepines and their derivatives in that it exerts a promoting effect on sleep by amplifying day/night differences in alertness and sleep quality and displaying a modest sleep-inducing effect, quite mild as compared to that seen with benzodiazepines (Ahmad et al., 2007). Melatonin has also been reported to cause preoperative anxiolysis and an increase in levels of sedation without impairing orientation (Naguib and Samarkandi, 2000). Hence, the aim of this study is to compare the effect of oral melatonin and oral midazolam on preoperative anxiety. Emergence delirium (ED) was first described in the literature in the early 1960s. Although often used interchangeably with emergence agitation, it is defined as a temporary dissociated state of consciousness after discontinuation of anesthesia. The characteristics that make up ED include irritability, inconsolable crying, distress and inability to cooperate (Reduque and Verghese, 2013). Midazolam is the most prescribed oral premedication in the preoperative setting. Its benefits include preoperative anxiolysis, amnesia, relatively rapid onset and short duration of action. Although most children have anxiolysis with midazolam, up to 29% may display a paradoxical agitation response (Shin et al., 2013). Oral melatonin doses up to 0.4 mg/kg (maximum 20 mg) are effective in reducing ED in children (age 3-7 years) (Kain et al., 2009). AIM OF THE WORK The study aims to compare the effects of oral melatonin and oral midazolam on preoperative anxiety as a premedication in children undergoing tonsillectomy.

This study aim to compare the effect of intravenous propofol versus intravenous lidocaine on emergence agitation in children undergoing tonsillectomy or adenotonsillectomy under general anesthesia.

Postoperative agitation is frequently observed in the pediatric patient group following general anesthesia. The exact cause of this agitation has not been clearly determined; however, it may be associated with various factors such as anesthesia depth, family approach, postoperative pain, or unpleasant odors perceived by the child. The depth of anesthesia is indirectly monitored by observing the patient's blood pressure, heart rate, and oxygen saturation, as well as by assessing the alveolar concentration of the inhalation agent. Patients under anesthesia are in a state of deep sleep. In recent years, this sleep state has begun to be monitored more closely with the development of new devices. Electroencephalography (EEG) is a test that records and measures the brain's electrical activity, providing information about the depth of sleep according to the patient's brain activity. The Density Spectral Array (DSA) device, developed for use in operating rooms, facilitates the interpretation of EEG data and guides the anesthesiologist. In our operating room, patients under anesthesia are also monitored using this device. Our aim is to evaluate emergence agitation in patients monitored with this device compared to those who are not monitored.

Emergence delirium (ED) was first described by Eckenhoff and colleagues in the 1960s and is defined in pediatric anesthesia as 'dissociated state of consciousness in which child is irritable, uncompromising, uncooperative, incoherent, and inconsolably crying, moaning, and kicking or thrashing. The commonly reported incidence of postoperative ED in pediatric patients especially with the use of sevoflurane or desflurane was from 10% to 80% during their presence in the post-anesthesia care unit. This side effect of general anesthesia causes distressing for parents and staff and may cause parental dissatisfaction with their child's care. Children during postoperative ED have the risks of injuring themselves or their caregivers, disruption of surgical repair, operative site bleeding, removing Intravenous (iv) lines or drains and increasing pain. This behavior may require more nursing supervision, overloading nursing resources. Although postoperative ED episodes are of short duration, their prevention is essential. Children experiencing postoperative ED may exhibit new-onset maladaptive behavioral abnormalities in the postoperative period such as enuresis, night-time crying, and separation anxiety, up to 14 days post-surgery. The risk factors to postoperative ED are patients' characters (preschool age and preexisting behavior), the surrounding environment as parental anxiety, type of anesthesia (volatile anesthetics) as sevoflurane or halothane and the type of surgery as tonsillectomy, adenoidectomy, and strabismus surgery which is one of the most commonly undertaken surgeries in pediatric patients. It may cause visual disturbance in the recovery phase, which can result. In order to diagnose ED, the presence of pain during recovery from general anesthesia must be ruled out because it leads to a change in behavior that resembles delirium. Fortunately, one of the advantages of using the Pediatric Anesthesia Emergence Delirium (PAED) scale is its ability to distinguish between the ED and the change in behavior resulting from pain, because it focuses on changes in awareness and knowledge that are not changed by pain. Prophylactic drugs against the occurrence of postoperative ED include the adjuvant use of α2 adrenoreceptor agonists such as dexmedetomidine, ketamine, midazolam, propofol, and fentanyl. The use of these drugs with them adverse effects should be weighed against the fact that postoperative ED is a self-limited disorder. Dexmedetomidine is a highly selective α2-adrenergic receptor agonist that is associated with sedative and analgesic sparing effects. It is commonly used for prevention of emergence delirium and agitation, perioperative sympatholysis, cardiovascular stabilization, and preservation of respiratory function. Ketamine is a dissociative anesthetic. Its mechanism of action is mainly via a noncompetitive antagonism of the N - methyl - D - aspartic acid (NMDA) receptor. It also targets other receptors, such as a - amino - 3 - hydroxy - 5 - methyl - 4 - isoxazolepropionic acid (AMPA) receptors, and has additional acts as an agonist of the sigma 1 receptor. It is commonly used for acute pain management, chronic pain management, prevention of ED, and postoperative nausea and vomiting. Midazolam is short acting benzodiazepine which is central nervous system depressant. It is commonly used for premedication during pediatric anesthesia, for prevention of emotional distress and ED due to its sedative and anxiolytic properties, additionally it used for reduction of the analgesic requirement and to prevent postoperative nausea and vomiting