Abstract ID: A15
Abstract Title: Ketamine Infusion Rate is Inversely Correlated with Age and Body Weight in Children Undergoing Painful Procedures
Poster Type: Poster
ABSTRACT BODY
Introduction
Painful pediatric procedures may be successfully accomplished with the use of intravenous (IV) ketamine for analgesia. This study utilized a computerized sedation database in order to identify factors that influence ketamine dosing.
Materials and Methods
The department of anesthesia worked with the department of radiology to establish a ketamine protocol to provide intravenous analgesia for interventional radiological procedures. A computerized database collects information which includes patient demographics, medications and dosages administered, ongoing narcotic requirements and American Society of Anesthesiologists (ASA) physical status classification. Using this database we conducted a review of all infants and children who received IV ketamine between October 2002 and March 2004.
Results
A total of 235 children received ketamine. Children received 2.0 mg IV ketamine bolus followed by a ketamine infusion titrated per protocol between 50-125 mcg/kg/min. The infusion was titrated to the same endpoint on each child: minimal response to painful stimulation elicited by deep nailbed pressure or ear lobe pinch. Response to painful stimulation was recorded and elicited every 15 min. Mean age was 6.1 yrs (range 3 mos -18 yrs). Mean weight was 21.5 kg (range 3.3 - 82.8 kg). Distribution of ASA status: ASA 1 (4%), ASA 2 (54%), ASA 3 (37%), and ASA 4 (5%). Narcotic requirements prior to the procedure were noted on all children. Procedures consisted of peripheral central intravenous catheters (PIC), chest tubes, percutaneous biopsies and drainage. Significant inverse correlations were found between ketamine dosing and age
(r = -0.41, p<0.001) and body weight (r = -0.43, p<0.001). Multivariate regression analysis revealed that age (t = -2.07, p = 0.04) and body weight (t = -2.61, p<0.01) had an effect on the ketamine infusion (mcg/kg/min) requirement, independent of gender, type of procedure, duration, and preexisting need for narcotics. The following equation was derived: Infusion Rate = 98 – 1.7 x Age (years) – 0.7 x Weight (kg).
Conclusion
To our knowledge, this is the first report which describes the ketamine requirement for analgesia being inversely related to age and body weight in the pediatric population.
ATTACHED FILES
Reg Anesth Pain Med 2004; 29(2):A15