Our primary objective of this study is to compare the effect of administration of single dose of intravenous nalbuphine given with induction of anesthesia with intravenous nalbuphine given at the end of surgery on the incidence and severity of EA in children undergoing repair of rupture globe under general anesthesia.

The secondary outcomes will include FLACC score for postoperative pain assessment, hemodynamic variables, any complications as postoperative vomiting (POV) and sedation and parents' satisfaction score.

Postoperative agitation, also referred to as emergence delirium is characterized by mental confusion, irritability, disorientation, inconsolable crying, and increased recovery time in the post anesthesia recovery room, increasing parents' concern and anxiety with respect to the clinical condition of their children . It can also lead to possible injury, damage to surgical dressings, lost intravenous catheters, disconnected cables and monitoring instruments, and source of dissatisfaction for parents, nurses, and others taking care of these children, and hence the children require extra nursing care and supplemental sedative and/or analgesic medications, which may delay patient discharge from hospital and are seven times more likely to have new-onset separation anxiety, apathy, and eating and sleep problems.

It is during the first 30 minutes after emergence that the greatest incidence of agitation is observed, and duration is generally limited and recovery occurs spontaneously. However, prolonged episodes of agitation lasting for up to 2 days have been described.

There is no definitive explanation for emergence agitation (EA). Many different causes have been suggested, such as rapid return of consciousness in an unfamiliar environment, the presence of pain (wounds, sore throat, and bladder distension), stressful induction, airway obstruction, a noisy environment, the duration of anesthesia, the child's personality, anesthetic premedication and the anesthetic technique used.

While its pathogenesis remains unclear, previous studies reported that ENT (ear, nose, and throat) surgical procedures have a higher incidence of EA in both adults and children . Children undergoing strabismus surgery under sevoflurane anesthesia often experience EA and postoperative vomiting (POV) .

Multiple medications including ketamine, propofol, clonidine, midazolam and fentanyl have been used effectively to prevent EA. However, these medications may increase sedation after anesthesia, cause slow awakening, and in some cases are associated with undesirable side effects, such as nausea and vomiting.

Nalbuphine is a synthetic opioid κ-receptor agonist μ-receptor antagonist with onset of action occurring within 2-3 min following IV injection, duration of analgesia of 3-6 hours and plasma half-life of 5 hours. Its analgesic potency approximately equals to morphine with less effects on cardiovascular and respiratory system, i.e., nalbuphine causes less intensive and less frequent decrease in blood pressure and respiratory depression.

Inclusion Criteria:

• Age: 3-8 years.
• American Society of Anesthesiologists (ASA) physical status I-II scheduled to undergo repair of rupture globe.
• Gender: both.

Exclusion Criteria:

• Parent refusal.
• History of developmental delay or mental retardation.
• Known hypersensitivity to any drug used in this study.
• Children with co-morbid conditions like congenital heart disease, respiratory pathology and central nervous system disorders.

The trial will be planned that neither the doctors (investigators) nor the patients' guardians or even children themselves will be aware of the group allocation and timing of drug received