Massachusetts Subscriber
Answer: Conscious sedation is typically provided by the operating surgeon during an uncomfortable procedure; coding appropriately for it depends partly on who provides the service. Conscious sedation codes 99141 and 99142 (... oral, rectal and/or intranasal) are intended for the surgeon rather than the anesthesiologist. For example, if an anesthesiologist provides sedation during a colonoscopy, it is considered MAC anesthesia and is coded with modifier -QS (monitored anesthesia care service). If the endoscopist administers sedation with the help of a nurse, it would be considered conscious sedation. The trained observer you mention can be a nurse.