Inter- and Intraindividual Variability in Ketamine Dosage in Repetitive Invasive Procedures in Children with Malignancies

• Published in: Pediatric hematology and oncology 2004-03, Vol.21 (2), p.161-166
• Main Authors: Meyer, Sascha, Aliani, Schahin, Graf, Norbert, Gottschling, Sven
• Format: Article
• Language: English
• Subjects: Adolescent; Anesthetics, Dissociative - administration & dosage; Biopsy - adverse effects; Bone Marrow Examination - adverse effects; Child; Child, Preschool; Diagnostic Techniques, Surgical; Dose-Response Relationship, Drug; Female; Humans; Infant; invasive; Ketamine - administration & dosage; ketamine dosage; Male; midazolam; Neoplasms - pathology; Pain - etiology; Pain - prevention & control; pediatric oncology; procedures; repetitive sedation; Spinal Puncture - adverse effects; Titrimetry
• ISSN: 0888-0018; 1521-0669
• DOI: 10.1080/08880010490273082

Midazolam/ketamine sedation has been used successfully in children undergoing painful invasive procedures. The authors prospectively assessed inter- and intra-individual variability in ketamine dosage for sedation in repetitive invasive procedures in children with malignancies. A total of 92 invasive procedures (58 lumbar punctures, 34 bone marrow biopsies; range: 2-9 procedures/patient) were performed on 25 children (median age: 12 years). Intravenous sedation consisted of 0.1 mg midazolam/kg and 0.5-1.0 mg ketamine/kg. Incremental dosages of ketamine (0.33 mg/kg) were given if necessary to achieve or maintain deep sedation. Primary outcome measure was the inter- and intraindividual ketamine dosage required to achieve adequate sedation; secondary outcome measures were the number of procedures with adequate sedation (Ramsay score of >4), the number of adverse side effects, and the need for therapeutic interventions. All 92 invasive procedures were completed with satisfactory sedation levels in 88 procedures (95.7%). There was a great inter- and intraindividual variability in ketamine dosage required to achieve or maintain adequate sedation. In 12% of procedures side effects were seen, which required no or only minor interventions. Due to great inter- and intraindividual differences, ketamine dosage should be titrated toward the desired level of sedation. Thus, ketamine can be adjusted to the individual's need while achieving adequate sedation.