Endeavor Health
A number of drugs used in the perioperative period may cause prolongation of the QT interval on the electrocardiogram (EKG). These drugs include inhalational agents, antiemetic agents, pain medications, and drugs used to reverse the effects of muscle relaxants. Approximately 80% of patients undergoing a general anesthetic will demonstrate significant prolongation of the QT interval on the EKG in the postanesthesia care unit (PACU) following surgery. The concern with QT interval prolongation is that it can result in a potentially lethal ventricular arrhythmia termed torsade des pointes. Despite the concurrent use of several of these medications in a typical general anesthetic, torsade des pointes is a rare event in the perioperative period. In the past decade, the use of intravenous methadone as part of a balanced anesthetic technique has increased significantly. A single dose provided at induction of anesthesia can provide prolonged (24-48 hours) relief from pain. Studies in patients receiving long-term treatment with methadone for addiction therapy or chronic pain have revealed that these patients are at risk for QT prolongation, torsade des pointe, and cardiac death. However, the effect of a single intravenous dose of methadone used in the operating room on the QT interval is uncertain. The aim of this randomized clinical trial is to compare the impact of methadone, when compared to the more commonly-used opioid hydromorphone, on QT prolongation measured with a 12-lead EKG in the PACU and on postoperative day 1. We hypothesize that methadone will not result in significant QT prolongation when used as part of a standardized general anesthetic.
In the past decade, the single most common cause of withdrawal of the use of drugs that have already been marketed has been the prolongation of the QT interval on the electrocardiogram associated with polymorphic ventricular tachycardia, or torsade de pointes. Without treatment, torsade de pointes can progress to a lethal ventricular arrhythmia. A number of drugs which prolong the QT interval can precipitate torsade de pointes. However, a number of risk factors are often present in patients who develop drug-induced torsade de pointes. These include hypomagnesemia, hypokalemia, female gender, b…
Inclusion Criteria: * All patients presenting for elective surgical cases requiring general anesthesia and associated with moderate-to-severe postoperative pain will be eligible for enrollment. Exclusion Criteria: * History of arrhythmias, pacemaker, or defibrillator * Allergy to methadone or hydromorphone * Preoperative altered mental status * Abnormal serum electrolyte values * Existence of significant valvular disease or cardiac rhythm other than sinus * Significant preoperative pain requiring treatment with opioids or recent history of opioid abuse
Patients in the methadone group will receive a syringe of methadone at induction of anesthesia and a syringe of saline at the end of anesthesia
Patients in the hydromorphone group will receive a syringe of saline at induction of anesthesia and a syringe of hydromorphone at the end of anesthesia