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

Spinal Versus General Anesthesia With Popliteal and Adductor Canal Blocks for Ambulatory Foot and Ankle Surgery: A Double-Blinded Randomized Controlled Trial.

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 Hospital for Special Surgery showed low rates of nausea among patients who received nerve blocks with spinal anesthesia, and no nausea among patients who received a nerve block with general anesthesia. Therefore, the primary aim of this study is to determine if, as a treatment, either general or spinal anesthesia has advantages over the other treatment in terms of readiness for discharge, side effects, pain and patient satisfaction in an ambulatory foot and ankle population.

Inclusion Criteria:

• 18-75 aged patients
• American Society of Anesthesiologists (ASA) Physical Status classification 1-3
• Elective foot and ankle day surgery procedures, lasting between 1 and 3 hours as per surgeon, performed by 3 co-investigator surgeons.
• Planned for combined popliteal and adductor canal block
• No contraindications for spinal or LMA general anesthesia

Exclusion Criteria:

• Incapable of providing informed consent
• Contraindications for regional or LMA anesthesia (anticoagulation, infection at injection site)
• Anticipated difficult airway
• BMI>40
• Anticipated surgical procedure time less than 1 hour or more than 3 hours
• Hx of severe postoperative nausea and vomiting
• ASA >3
• Peripheral neuropathy affecting the operative extremity
• Pregnant or nursing women
• Chronic opioid use (daily use of opioids one month prior to surgery/ patients requiring chronic pain interventions)
• Prone position
• Obstructive sleep apnea with planned admission overnight to the hospital
• Known allergy/sensitivity to any study medications
• Planned admission after surgery
• Non-English speaking