Oral clonidine and postoperative pain.

Abstract

To the Editor: We enjoyed reading the article entitled "Oral Clonidine Premedication Reduces Postoperative Pain in Children" by Mikawa et al. [1]. While we believe their study has demonstrated that clonidine (4.0 micro g/kg) induces sedation and may reduce postoperative pain and discomfort in infants and children, we suspect that the use of our objective pain scale (OPS) may have introduced considerable error into the assessment of postoperative pain and discomfort in the study population and may have caused the investigators to interpret sedation to be synonymous with analgesia. The OPS was designed for use in unpremedicated patients. It was validated against the linear analog pain scale in a group of unpremedicated adolescents undergoing arthroscopic knee surgery [2]. The interobserver reliability of the OPS has also been validated [3]. The OPS has also been used by several recognized investigators (e.g., Berde, Ecoffey, Lerman, Watcha, and others) in more than 25 peer-reviewed, double-blind studies to evaluate the postoperative pain and discomfort of pediatric patients. In all cases, statistical significance was obtained using both parametric and nonparametric analytic techniques. Since the scale has never before been tested in premedicated patients, it is likely that children undergoing relatively painless procedures such as strabismus surgery would have a statistically significant reduction in their OPS scores if they were premedicated with a vasodilator and a hypnotic drug and compared with unpremedicated controls. L. M. Broadman, MD Department of Anesthesiology; Robert C. Byrd Health Sciences Center; West Virginia University; Morgantown, WV 26506-8002 L. J. Rice, MD Department of Anesthesiology; All Children's Hospital; St. Petersburg, FL 33701 R. S. Hannallah, MD Department of Anesthesiology; George Washington University, and; Children's National Medical Center; Washington, DC 20010