EKG Changes Associated with Transient Hypotension in Patients Recieving Propofol

Abstract

Purpose: To determine if the use of propofol is associated with EKG changes when transient hypotension is experienced during the procedure. Methods: Conscious sedation with propofol has distinct advantages over using benzodiazepines, notably a rapid onset of action and a shortened recovery time. In our facility, propofol is administered by a registered nurse under the direct supervision of a gastroenterologist. An intensive training program for endoscopic nurses was instituted prior to the use of propofol. Our nurses must achieve ACLS certification, complete a didactic airway management techniques training course given by CRNA's. We chose to adopt a continuous propofol infusion technique for 3 main reasons. Commercially available pumps allow the patient's weight to be factored in to the infusion, enabling mg/kg dose for both the bolus and infusion doses. Additionally, with the brief half life of propofol, this provides a controlled level of sedation that avoid the peaks and troughs inherent in using a bolus infusion. And finally, it allows a finer titration of sedation resulting in a gentle patient response to the desired sedation level. We retrospectively reviewed 3500 cases of propofol/meperidine induced conscious sedation. There were 60 cases with episodes of transient hypotension, defined as a systolic blood pressure below 90 mmHg. All episodes resolved by either placing the patient in the Trendelenburg position or with fluid administration. Retrospectively we found pre and post procedure EKG's were available in 9 of these 60 cases. The EKG's were conducted as part of their routine health screening rather than precipitated by the procedure. Historical controls with midazolam/meperidine that had experienced transient hypotension and had EKG's available both pre and post procedure were identified and matched for age and gender. In all retrospective and historical cases, EKG's were reviewed by a board certified cardiologist. Results: No EKG changes were noted post procedurally in either the propofol/meperidine or the midazolam/meperidine groups. Conclusions: We believe that we have demonstrated the lack of any long term EKG changes associated with hypotension when propofol/meperidine is used to induce conscious sedation. To address some of the inherent study design limitations, a large prospective study would be necessary to confirm this data.