Trial Outcomes & Findings for Measurement of Bispectral Index and Awareness in Patients Undergoing Electrophysiology Studies With Isoproterenol (NCT NCT01377636)

During the preoperative evaluation for anesthesia, the patients scheduled for catheter ablation for atrial fibrillation were approached by the research associate for informed consent and enrollment into the study. The research consent was separate from the clinical anesthesia and procedural consents.

Measurement of Bispectral Index and Awareness in Patients Undergoing Electrophysiology Studies With Isoproterenol

Increasing doses of isoproterenol (5,10,15,20 mcg/minute) were administered to patients undergoing catheter ablation for atrial fibrillation. BIS levels were measured continuously before and after isoproterenol administration. Number of participants with increase in BIS reading during anesthetic steady state are reported below. The BIS scale ranges from 0 to 100. The individual's baseline BIS was measured continuously and was maintained in an anesthetic steady state with minimum variance prior to isoproterenol. A deviation from the mean in excess of 3 points (2 STD) was defined categorically as a positive response and was counted dichotomously.

The BIS scale ranges from 0 to 100. The individual's baseline BIS was measured continuously and was maintained in an anesthetic steady state with minimum variance prior to isoproterenol. A deviation from the mean in excess of 3 points (2 STD) was defined categorically as a positive response and was counted dichotomously.The difference between Pre-BIS and Post-BIS was calculated.

Increasing doses of isoproterenol (5,10,15,20 mcg/minute) were administered to patients undergoing catheter ablation for atrial fibrillation. Patients under steady state total venous anesthesia (TIVA) with propofol and remifentanil infusions with BIS around 50 normally do not move even in the absence of neuromuscular blockade. Spontaneous movement appearing like restlessness during sleep is unusual. Several patients under anesthesia after isoproterenol appear to wake up and move spontaneously.

Increasing doses of isoproterenol (5,10,15,20 mcg/minute) were administered to patients undergoing catheter ablation for atrial fibrillation. Ability to follow verbal commands before and after isoproterenol infusion was assessed by asking subjects to "squeeze my hands".

Heart rate measured by standard EKG monitor during anesthesia. Pre- and Post Heart rates where noted. An increase of 8 percent or more was defined as a significant change in heart rate.

Non-Invasive Blood Pressure (NIBP) is measured routinely as part of an anesthetic. Pre- and Post Blood Pressures where noted. An increase or decrease of 10 percent or more was defined as a significant change in systolic blood pressure.

Increasing doses of isoproterenol (5,10,15,20 mcg/minute) were administered to patients undergoing catheter ablation for atrial fibrillation. Specific pre-determined test words were spoken to the subject during administration of isoproterenol. After anesthesia, patients were tested for possible recall of those specific words. If no words were recalled, the result was categorically defined as amnesia.

Increasing doses of isoproterenol (5,10,15,20 mcg/minute) were administered to patients undergoing catheter ablation for atrial fibrillation after return to sinus rhythm. If a non-sinus arrhythmia resulted from the infusion, the arrhythmia was defined categorically as a positive response and was counted dichotomously.

The (ST) segment on the EKG was monitored for changes suggestive of demand ischemia. An observable EKG change compared to baseline was defined categorically as a positive response and was counted dichotomously.