Spinal Versus General Anesthesia With Popliteal and Adductor Canal Blocks for Ambulatory Foot and Ankle Surgery.

Study Summary

The purpose of this study is to determine if there is a difference in patient outcomes with general anesthesia versus spinal anesthesia when given in addition to popliteal and adductor canal nerve blocks for foot and ankle surgery. Popliteal and adductor canal nerve blocks are injections of local anesthetic agents near nerves in the back and front of the knee going to the foot and ankle that provide numbness during and after surgery. These peripheral nerve blocks offer good pain control and reduce the need for opioids (opioids are pain medications such as morphine, Dilaudid, and oxycodone). General anesthesia involves the flow of oxygen and anesthesia gas through a tube which, along with additional intravenous medications, causes unconsciousness and unawareness of sensations during surgery. Spinal anesthesia involves an injection of local anesthetic in the lower back, which causes numbness below the waist. In addition to spinal anesthesia, a sedative is typically given intravenously to cause relaxation and sleepiness throughout surgery. General, spinal, and nerve block anesthesia are all routinely used for surgery at the Hospital for Special Surgery. General or spinal anesthesia is typically used in addition to peripheral nerve blocks during foot and ankle surgery to 1) allow the surgeons to use a thigh tourniquet to reduce bleeding, 2) provide anesthesia earlier, and 3) prevent unwanted movement. However, it is unclear whether general or spinal anesthesia provides better patient outcomes when given with peripheral nerve blocks. Some reports show that on its own, spinal anesthesia has advantages over general anesthesia in terms of side effects such as nausea and pain. However, these advantages may also be gained from combining peripheral nerve blocks with general anesthesia. Spinal anesthesia can be associated with headache and backache, although headache and backache can also happen after operations performed with general anesthesia. A previous study at the Hospit

Primary Outcome

Modified Aldrete Scoring System and Marshall and Chung Postanesthesia Discharge Scoring System, measured in time until discharge criteria is met (in minutes)

Interventions

• PROCEDURE 25 mL of 0.25% bupivacaine plus 2 mg preservative-free (PF) dexamethasone / 30 ml for popliteal nerve block
• PROCEDURE 10 mL of 0.25% bupivacaine plus 2 mg preservative-free (PF) dexamethasone / 30 ml for adductor canal nerve block
• DRUG Midazolam, 2-5 mg IV + Glycopyrrolate, 0.1 mg IV + Ketamine, 10-20 mg + propofol as needed
• PROCEDURE 45-60 mg of 1.5% mepivacaine for spinal anesthesia
• PROCEDURE LMA insertion + titrated propofol infusion + sevoflurane + ketamine 10 mg/hr for general anesthesia