Inclusion Criteria:  ASA I - II Scheduled for acetabular osteotomy and/or proximal femoral derotation osteotomies.  Exclusion Criteria:  Patient's guardian refusal to participate in the study. Children known to have pre-existing bleeding or coagulation disorders. Children with anemia; defined according to (WHO ) cutoffs as Hb level<11g/dl for girls and <12g/dl for boys History of epilepsy. History of renal insufficiency or failure