Effect of N-methyl D-aspartate (NMDA) Receptor Antagonist Dextromethorphan on Opiods Analgesia and Tolerance in Pediatric Intensive Care Unit Patients

Inclusion: * Patients above 2 years, admitted in PICU * On Morphine or Fentanyl infusions for more than 48 hours Exclusion Criteria: * Patients under 2 years of age * Patients with anticipated PICU length of stay less than 3 days. * Patients shall be excluded if Morphine or Fentanyl infusions not continued for the minimum duration of 72 hours after enrollment * Patients develops hemodynamic instability * Patients with Hepatic failure * Withdrawal request by parent(s)/guardian/family