In Response: In his letter to the editor, Dr. Murphy states that we were advocating that anesthesiologists withhold treatment "until patients complain" in our review article on monitored anesthesia care (MAC) [1]. As described in this article and in our related publications on this topic [2-6], we have always recommended the use of sedative-analgesic techniques, which involve both preventative and titrated methods of drug administration. Our standard MAC technique involves IV premedication with a benzodiazepine (e.g., midazolam 1-3 mg, Dizac[registered sign] 2.5-7.5 mg; Ohmeda Pharmaceuticals, Liberty Corners, NJ) and a potent opioid analgesic (e.g., fentanyl 25-50 [micro sign]g, alfentanil 250-500 [micro sign]g, remifentanil 12.5-25 [micro sign]g) to provide sedation, anxiolysis, amnesia, and analgesia before the injection of the local anesthetic solution. A propofol infusion, 50 [micro sign]g [center dot] kg-1 [center dot] min-1, is initiated before surgery to achieve the desired level of sedation and/or hypnosis. The optimal level of sedation is then maintained during surgery using a variable-rate infusion of propofol (12.5-100 [micro sign]g [center dot] kg-1 [center dot] min-1). In situations in which the local anesthetic provides inadequate intraoperative analgesia (i.e., breakthrough pain), supplemental bolus doses of the opioid analgesic are administered. Alternatively, a continuous IV infusion of alfentanil (0.3-0.9 [micro sign]g [center dot] kg-1 [center dot] min-1) or remifentanil (0.05-0.15 [micro sign]g [center dot] kg-1 [center dot] min-1) can be administered as an adjuvant to a small-dose propofol infusion. We agree that shielding patients from pain and suffering is a worthy and humanitarian aim, but we strongly object to Murphy's suggestion that the above technique abandons our fundamental goal of preventing human suffering. Perhaps Dr. Murphy is unfamiliar with the intrinsic pharmacokinetic and dynamic variability that exists among patients in their responses to both sedative-hypnotic and opioid analgesic drugs. In our opinion, to risk over-dosing a large proportion of the surgical population undergoing operations with a MAC technique to ensure that no patient ever manifests a response to the surgical stimuli during procedures performed under local anesthesia is inappropriate. Finally, Dr. Murphy fails to provide any specific recommendations for achieving the ideal conditions he advocates during MAC. We would welcome the opportunity to learn from his vast clinical experience in this area. Hopefully, Dr. Murphy will publish his techniques for providing MAC in the peer-reviewed anesthesia literature. Paul F. White, PhD, MD, FANZCA Monica M. Sa Rego, MD Department of Anesthesiology and Pain Management; University of Texas Southwestern Medical Center; Dallas, TX 75235-9068