The aim of this study will be to examine the validity of perfusion index in predicting pain and evaluation of its severity in the postoperative period.

* Hypospadias repair is a common surgery that is accompanied with significant postoperative pain. The largest group of children usually undergo this type of surgery are infants and pre-verbal children who cannot verbally report pain, and their treatment depends typically on behavioral and observational tools. Although these tools are valid and reliable measures in assessment of pediatric pain, they are still hindered by their subjectivity, which consequently could result in inadequate pain treatment that in early childhood may lead to negative behavioral and neurophysiological sequalae.

That is why recent studies have focused on developing more objective measures to evaluate pain especially when self-report is not possible.

* Changes in perfusion index(PI) caused by sympathetic stimulation refers to possible correlation between pain and PI which forms the basis of our study proposing that the PI is a non-invasive easy method that can be used in evaluating pain in infants

Inclusion Criteria:

1. patients aged <3 years
2. Sex:- both male and female.
3. ASA I-II
4. Informed written consent obtained from parents or guardians of all patients.
5. Undergoing hypospadias repair surgery

Exclusion Criteria:

1. Patients outside the selective age range
2. Parents or guardians refusing to enroll their child in the study.
3. ASA III or VI
4. Children with behavioral changes or physical developmental delay
5. Children treated with sedatives or anticonvulsants.

Children aged<3 years of both sexes undergoing hypospadias repair surgery.