الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Inhalation general anesthesia is frequently required in children undergoing surgical or diagnostic procedures. Sevoflurane was first synthesized in 1968 and reported in 1971 and has been available for general clinical use in Japan since 1990. Sevoflurane has gained widespread acceptance in pediatric anesthesia because of the rapidity of induction and emergence from anesthesia, hemodynamic stability.
Concerns about quality of the emergence from sevoflurane anesthesia remain due to increased incidence of postoperative emergence agitation characterized by mental confusion, irritability, disorientation, inconsolable crying. Most common age is preschool age and the incidence rate reported varies from 10 to 67%. It is self-limiting phenomenon with limited duration (15-30 min) and spontaneous recovery; it is usually seen during the first 30 minutes after emergence from anesthesia.
There is no clear and scientifically valid explanation for this phenomenon but many theories were suggested like interaction at the GABAA receptor level or rapid emergence from sevoflurane anesthesia in conjunction with psychological immaturity of young children.
Several medications have been used in an attempt to decrease the incidence and severity of emergence agitation.
Dexmedetomidine is an α-2 adrenergic agonist with a larger ratio of α2/α1 activity (1600:1) when compared to clonidine (200:1).The hemodynamic effects of dexmedetomidine are similar to that of clonidine and the effects can vary depending on the dose, rate and route of administration. Dexmedetomidine has been used as an adjuvant in general anesthesia and for postoperative sedation and analgesia.
Fentanyl is a synthetic phenylpyperidine derivative. Fentanyl is a potent opioid agonist whose principal actions of therapeutic value are analgesia and sedation. It is 100 times more potent than morphine
Propofol is a short acting sedative and hypnotic that produce dose dependent depression of cerebral cortex, ascending reticular activating system and medullary center resulting in sedation, hypnosis, amnesia, anesthesia, respiratory depression.
This study was designed to compare the effectiveness of intravenous dexmedetomidine, fentanyl, or propofol to prevent postoperative agitation after sevoflurane anesthesia in pediatric patients.
This study was carried out in Alexandria University Hospital, on 100 pediatric patients with ASA physical status I-II. The patients were divided into four groups of 25 patients each. Then children scheduled for adeno-tonsillectomy surgery under general anesthesia with sevoflurane as the sole inhalation agent in induction and maintenance.
Exclusion criteria included chronic or acute intake of any sedative or analgesic drugs, patient with a defined psychological& emotional disorder or cognitive delay, and any neurological diseases.
Patients were randomly categorized into 4 groups:
group S: received saline (control group)
group F: received fentanyl 1 ug/kg
group P: received propofol 1 mg/kg
group D: received dexmedetomedine 0.3ug/kg
All patients underwent thorough preoperative evaluation, which included history, physical examination and relevant laboratory investigations.
None of the patients was given any solid food overnight, but each was encouraged to take clear fluids until 2 hours before induction of anesthesia.
None of the patients received preanesthetic medication. Inhalation induction via transparent face masks with oxygen 100% and sevoflurane with incremental increase in inspired sevoflurane concentration of 1 % at each breath up to 8 %. When adequate depth of anesthesia was reached, intravenous line was inserted and cisatracurium 0.15 mg/kg was given and all patients were given 15 mg/kg paracetamol. Oral endotracheal tube appropriate for age was placed and was confirmed to be positioned properly. Sevoflurane concentration was reduced to an end tidal concentration of 2 % with controlled ventilation to maintain an end tidal CO2 of (35 ± 4 mmHg).