A Pilot Study of Local Anesthesia for Inguinal Hernia Surgery in Older Adults

The study rationale is that prior to conducting a multisite randomized trial, it is necessary to identify relevant outcomes, understand barriers to greater use of local anesthesia, test study procedures, and confirm our ability to adequately recruit and randomly assign participants. Additionally, the proposed study will provide the applicant with critical training in the design, conduct, and analysis of clinical trials. This will uniquely position the applicant to change surgical care for older adults.

More specifically, the investigators plan to demonstrate the ability to successfully randomize Veterans aged 60 years and older to local versus general anesthesia for inguinal hernia surgery, and to validate processes and instruments to measure relevant outcomes.

Although the original NIA-approved proposal involved only two arms, open hernia repair using local anesthesia and open repair using local anesthesia, the study team subsequently published a paper that showed using local anesthesia for open hernia repair may also be superior to laparoscopic or robotic hernia repair. Consequently, a third arm is added to our pilot study: laparoscopic or robotic hernia repair with general anesthesia (these surgical approaches cannot be done using local anesthesia). The rationale is that use of laparoscopic or robotic inguinal hernia surgery, while still less common than open repair, is becoming more common and no prior randomized trials have compared laparoscopic/robotic surgery versus open repair using local anesthesia.

Local or general anesthesia are the primary methods of anesthesia for inguinal hernia surgery for most surgeons (though some perform the operation under spinal or regional anesthesia, this is rare). Both approaches are used in clinical practice with acceptable known risks and complications. General anesthesia is associated with risks of hypotension, venous thromboembolism, heart attack, stroke, pulmonary dysfunction, cognitive dysfunction, allergic reaction, urinary retention, and malignant hyperthermia. The main risks of local anesthesia include allergic reaction and hypotension (when the anesthetic is improperly injected into a blood vessel).

The primary objective is to:

1. demonstrate ability to successfully recruit, randomize, and retain patients aged 60 years and older for a randomized trial of local versus general anesthesia for inguinal hernia surgery, and 2. establish the ability to measure relevant outcomes and test protocols and study instruments for measuring key outcomes.

The secondary objective is to generate preliminary comparisons between the study arms, to inform effect size estimates for a larger multisite trial.

• Carolinas Comfort Scale Score [Time frame: Measured at baseline, 48 hours after surgery, 2 weeks after surgery, 6 months after surgery]
• Physical Function Score [Time frame: Measured at baseline, 48 hours after surgery, 2 weeks after surgery, 6 months after surgery]
• Trail Making Test [Time frame: Measured at baseline, prior to discharge, 48 hours after discharge, 2 weeks after surgery, 6 months after surgery]
• Montreal Cognitive Assessment [Time frame: Measured at baseline, prior to discharge, 48 hours after discharge, 2 weeks after surgery, 6 months after surgery]
• Participants with Delirium [Time frame: Measured at baseline, prior to discharge, 48 hours after discharge, 2 weeks after surgery, 6 months after surgery]
• Pain Level [Time frame: Measured at baseline, prior to discharge, 48 hours after discharge, 2 weeks after surgery, 6 months after surgery]
• Postoperative complications [Time frame: Up to 2 weeks]
• Operative time [Time frame: Time between surgery start and surgery end measured. 1 day of surgery]
• Anesthesia time [Time frame: Time spent in operating room. 1 day of surgery]
• Recovery time [Time frame: Time spent in post anesthesia care unit. 1 day of surgery]