title: Pharmacodynamics and Pharmacokinetics of Morphine After Cardiac Surgery in Children With and Without Down Syndrome.
abstract: To compare the pharmacodynamics and pharmacokinetics of IV morphine after cardiac surgery in two groups of children-those with and without Down syndrome.
  
  
  
  Prospective, single-center observational trial.
  
  
  
  PICU in a university-affiliated pediatric teaching hospital.
  
  
  
  Twenty-one children with Down syndrome and 17 without, 3-36 months old, scheduled for cardiac surgery with cardiopulmonary bypass.
  
  
  
  A loading dose of morphine (100 μg/kg) was administered after coming off bypass; thereafter, morphine infusion was commenced at 40 μg/kg/hr. During intensive care, nurses regularly assessed pain and discomfort with validated observational instruments (COMFORT-Behavior scale and Numeric Rating Scale-for pain). These scores guided analgesic and sedative treatment. Plasma samples were obtained for pharmacokinetic analysis.
  
  
  
  Median COMFORT-Behavior and Numeric Rating Scale scores were not statistically significantly different between the two groups. The median morphine infusion rate during the first 24 hours after surgery was 31.3 μg/kg/hr (interquartile range, 23.4-36.4) in the Down syndrome group versus 31.7 μg/kg/hr (interquartile range, 25.1-36.1) in the control group (p = 1.00). Population pharmacokinetic analysis revealed no statistically significant differences in any of the pharmacokinetic variables of morphine between the children with and without Down syndrome.
  
  
  
  This prospective trial showed that there are no differences in pharmacokinetics or pharmacodynamics between children with and without Down syndrome if pain and distress management is titrated to effect based on outcomes of validated assessment instruments. We have no evidence to adjust morphine dosing after cardiac surgery in children with Down syndrome.
authors: 1Intensive Care and Department of Pediatric Surgery, Erasmus University Medical Center-Sophia Children's Hospital, Rotterdam, The Netherlands.2Division of Pharmacology, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands.3Department of Anesthesia and Critical Care Medicine, Our Lady's Children's Hospital, Dublin, Ireland.4Department of Pharmacy, Academic Medical Center, Amsterdam, The Netherlands.5Department of Clinical Pharmacy, St. Antonius Hospital, Nieuwegein, The Netherlands.
authors: Abraham J
authors: AJ
authors: Valkenburg
authors: Elisa A M
authors: EA
authors: Calvier
authors: Monique
authors: M
authors: van Dijk
authors: Elke H J
authors: EH
authors: Krekels
authors: Brendan P
authors: BP
authors: O'Hare
authors: William F
authors: WF
authors: Casey
authors: Ron A A
authors: RA
authors: Mathôt
authors: Catherijne A J
authors: CA
authors: Knibbe
authors: Dick
authors: D
authors: Tibboel
authors: Cormac V
authors: CV
authors: Breatnach
mesh_terms: D000701:Analgesics, Opioid / Q000097:blood / Q000493:pharmacokinetics* / Q000627:therapeutic use; D006348:Cardiac Surgical Procedures; D016022:Case-Control Studies; D002675:Child, Preschool; D003422:Critical Care / Q000379:methods; D004314:Down Syndrome / Q000097:blood / Q000601:surgery*; D005260:Female; D006801:Humans; D007223:Infant; D007262:Infusions, Intravenous; D008297:Male; D009020:Morphine / Q000097:blood / Q000493:pharmacokinetics* / Q000627:therapeutic use; D010147:Pain Measurement; D010149:Postoperative Pain / Q000175:diagnosis / Q000188:drug therapy*; D011182:Postoperative Care / Q000379:methods; D011446:Prospective Studies; D016896:Treatment Outcome
chemical_list: D000701:Analgesics, Opioid; D009020:Morphine