• Primary outcome: Measure The incidence of EA in children undergoing to hypospadias repair under general anesthesia is considered using Pediatric Anesthesia Emergence Delirium (PAED) scales.

• Secondary outcome:

• Therefore, we designed a prospective, randomized, double-blind, single center study to investigate whether nalbuphine and/or magnesium sulphate can prevent EA after hypospadias repair in children under general anesthesia. In addition, the characteristics of anesthesia recovery and the incidence of adverse effects will also be evaluated in this study. Post-operative extubating time, interaction time, open eye time and emergence time. incidence of post-operative vomiting (PONV), laryngospasm, breath-holding, coughing, oxygen desaturation, and cardiac arrhythmias.
• Face, Legs, Activity, Cry and Consola Bility (FLACC) scale is used to determine post-operative pain score
• Parental satisfaction scores

Emergence agitation (EA), also referred to as emergence delirium, emergence excitement or inadequate emergence, is a frequent post-operative complication in pediatric patients receiving inhalational anesthetics. It's defined as an acute and fluctuating alteration of mental state and manifesting as agitation, confusion, disorientation, and hyperactivity during the transition from unconsciousness to full wakefulness. The incidence of EA is reported to be up to 20% in adult patients and up to 80% in children.

Although EA is self-limiting, it can induce potential problems in children, such as self-injury, bleeding and cracking of the wound, falling off of the indwelling catheter, and falling off of the bed, which can cause some difficulties for medical staff and serious anxiety for family members. In addition, children with EA are at a higher risk of post-hospitalization behavioral changes, which may last longer. Furthermore, EA treatment increases the burden on healthcare providers and increases the medical expenses of patients. EA commonly occurs after the most common surgeries in children like adenoidectomy, tonsillectomy, hernioplasty and hypospadias repair. Therefore, implementing effective measures to prevent EA in children undergoing these types of surgeries is crucial. Although the underlying mechanisms of EA remain unclear, the mechanisms may be related to pre-operative anxiety, inhaled anesthetics (sevoflurane or desflurane), surgery type (ophthalmology or otolaryngology procedure), and younger age.

Some pharmacological interventions have been used to prevent and treat EA. Previous studies have demonstrated that propofol, benzodiazepines, α2 agonists, and opioids can prevent EA in children to varying degrees. However, these medications may lead to respiratory depression, delay in anesthesia recovery and post-anesthesia care unit stay, and other adverse reactions. Thus, the most favorable prophylactic treatment to decrease such an incidence remains unknown, and the ideal approaches to prevent EA merit further exploration.

Nalbuphine is a synthetic opioid receptor agonist-antagonist (agonist К receptor, antagonistic part μ receptor) that can produce a central analgesic effect and partial sedation. Nalbuphine is a medication that is indicated for moderate to severe pain where the patient requires an opioid agent, and other alternative treatments have been insufficient. The inhibitory effect of nalbuphine on respiration is slight and it has a capping effect. Owing to these advantages, it is widely used in pediatric surgical analgesia.

Magnesium sulphate, an antagonist of N-methyl-D-aspartate (NMDA) glutamate receptors, has been reported to improve hypo-magnesia and pre-eclampsia. Recently, magnesium sulphate has been gradually used as an adjuvant for sedation and analgesia during general anesthesia. Magnesium sulphate is a medication used to manage and treat multiple clinical conditions.

Inclusion Criteria:

• • Weight: 10 - 38 kg.

  • Age: 3-7 years.
  • ASA physical status: I-II.
  • Operation: elective hypospadias repair under general anesthesia

Exclusion Criteria:

• • Parent's refusal.

  • Anticipated difficult airway.
  • Active respiratory illness (cough, fever, rhinorrhea) on the day of anesthesia.
  • History of developmental delay or mental retardation or any neurological disease.
  • Known hypersensitivity to any drug used in this study.
  • Children with co-morbid conditions like congenital heart disease, respiratory pathology, central nervous system disorders or renal pathology

name of patient gender exposure on surgery only male participants are being due to surgery is hypospadias repair.

• Group C (Control group n=35 ): 10 ml isotonic saline will be injected intravenously before 30 min from end of surgery
• Group M (Magnesium sulfate group n=35 ): 30 mg/kg Magnesium sulphate diluted to 10 ml isotonic saline will be injected intravenously before 30 min from end of surgery
• Group N (Nalbuphine group n=35 ): 0.1 mg/kg nalbuphine diluted to 10 ml isotonic saline will be injected intravenously before 30 min from end of surgery