This might meet the scenario you are describing.
From CPT Assistant 2006
Description of Procedure: 99144
"The physician supervises the administration and induction of the sedating agent, with or without an analgesic, initiated by the independent, trained observer. The patient is observed until a safe and effective level of moderate sedation is achieved. The physician, assisted by the independent, trained observer, continually assesses the patient's level of consciousness and physiological status throughout the performance of the supported procedure. Additional doses of sedating agent are ordered by the physician, as needed, to maintain the achieved level of sedation for the supported procedure."