Support Care Cancer (2005) 13: 1001–1009 DOI 10.1007/s00520-005-0821-8 ORIGINAL ARTICLE D. K. L. Cheuk W. H. S. Wong E. Ma T. L. Lee S. Y. Ha Y. L. Lau G. C. F. Chan Received: 23 December 2004 Accepted: 7 April 2005 Published online: 22 April 2005 # Springer-Verlag 2005 Use of midazolam and ketamine as sedation for children undergoing minor operative procedures Abstract Objectives: We used intra- venous midazolam and ketamine for children undergoing minor operative procedures with satisfactory results. We aimed to further evaluate its efficacy and adverse effects in pedi- atric ward setting. Methods: This was a prospective study of all children undergoing minor operations with se- dation in our pediatric general and oncology wards from July 1998 to June 1999. The procedures included lumber puncture±intrathecal chemo- therapy, bone marrow aspiration± trephine biopsy, central venous catheter removal, skin biopsy, or their combination. All sedation procedures were started with midazolam 0.1 mg/kg and ketamine 1 mg/kg; they were increased gradually to 0.4 and 4 mg/kg, respectively, if necessary. Heart rate and SaO 2 were continu- ously monitored. Results: Alto- gether, 369 minor operations were performed in 112 patients (male: female=2:1, median age 6 years, range 5 months–17 years). All achieved adequate sedation, with 96% within 30 s and 75% required just the starting dose. Younger children required a higher dosage (p=0.003 for midazo- lam, p<0.001 for ketamine). The median recovery time was 87 min, with no association with age, sex, or dosage of sedation, but was longer in patients having hallucination (p=0.001). Adverse effects included tachycardia (27.9%), increased secretion (17.6%), agitation (13.6%), nausea and vomiting (9.2%), hallucination (8.7%), desaturation (8.4%), and cataleptic reaction (0.8%). All desaturation episodes were transient and responded to oxygen supplement alone. None developed bronchospasm or convulsion. Some adverse effects were dose-related. Half of the children who received 0.3 mg/kg midazolam developed desaturation. Conclusions: Intravenous midazolam–ketamine can provide rapid, effective, and safe sedation for children undergoing minor operations in ward setting. Adverse effects are mild. Midazolam above 0.3 mg/kg should be used with caution. Keywords Sedation . Ketamine . Midazolam . Oncology . Children D. K. L. Cheuk . W. H. S. Wong . T. L. Lee . S. Y. Ha . Y. L. Lau . G. C. F. Chan (*) Department of Pediatrics and Adolescent Medicine, Queen Mary Hospital, The University of Hong Kong, 121 Pokfulam Road, Hong Kong, Hong Kong e-mail: gcfchan@hkucc.hku.hk Tel.: +852-2-8554482 Fax: +852-2-8551523 E. Ma Department of Pharmacy, Queen Mary Hospital, The University of Hong Kong, Hong Kong, Hong Kong