Spinal Anesthesia with Mepivacaine Allows THA Patients to Ambulate Earlier
Although spinal anesthesia offers several advantages over general anesthesia in patients undergoing total hip arthroplasty (THA), it also limits sensory and motor function and may delay patients’ ability to ambulate – which could thwart efforts to release these patients the same day as surgery.
That’s why a new study from Thomas Jefferson University Hospital in Philadelphia, Pennsylvania, is such good news: Researchers there found that spinal anesthesia with the drug mepivacaine allows for earlier ambulation after THA than either form of the more commonly used drug bupivacaine. Patients who can ambulate sooner after surgery can be discharged faster, allowing for more comfortable recovery at home, lower overall cost of care, and increased availability of critical hospital resources for sicker patients.
The study, “Early Ambulation After Hip Arthroplasty: A Double-Blind, Randomized, Controlled Trial,” was accepted for and received a Best of Meeting Abstract Award from the 45th Annual Regional Anesthesia and Acute Pain Medicine Meeting, which was canceled due to the COVID-19 pandemic. The abstract has been posted on the website of the American Society of Regional Anesthesia and Pain Medicine.
One of the most commonly used drugs for spinal anesthesia is bupivacaine, a long-acting amide local anesthetic available in several forms, including hyperbaric and isobaric. Both forms can produce partial motor blockade for 2.5 to 3 hours. Mepivacaine, an intermediate-acting amide local anesthetic, produces reliable spinal anesthesia for 1.5 to 2 hours, and retrospective studies with total knee arthroplasty patients have suggested that it allows for earlier postoperative ambulation than bupivacaine. Use of mepivacaine and isobaric bupivacaine in spinal anesthesia is off-label but commonly done in practice.
To evaluate whether mepivacaine has the same effect in THA patients, the researchers conducted a prospective, randomized, double-blind trial comparing mepivacaine with hyperbaric and isobaric bupivacaine in 154 patients receiving spinal anesthesia during THA. Patients were randomized to 1 of the following groups:
- Mepivacaine 1.5% (n=50)
- Isobaric bupivacaine 0.5% (n=55)
- Hyperbaric bupivacaine 0.75% (n=49)
Standard multimodal analgesia for all patients included preoperative gabapentin/pregabalin and acetaminophen and either celecoxib or ketorolac, continued for 48 hours. Three board-certified orthopedic surgeons performed all procedures at either Thomas Jefferson University Hospital or Rothman Orthopedic Specialty Hospital.
The researchers found that patients who received mepivacaine were more likely to ambulate at 3.5 hours – the primary outcome – than those who received hyperbaric bupivacaine (OR 4.1, 95% CI 1.8-9.2; P=0.001) or isobaric bupivacaine (OR 10.4, 95% CI 4.0-26.6; P<0.001). The mepivacaine group had significantly shorter length of stay and more same-day discharges than patients in the other 2 groups. They also had higher pain ratings and opioid consumption, but only in post-anesthesia care unit. No other differences were observed among the groups, including incidence of transient neurologic symptoms.
“Patients who received mepivacaine spinal anesthesia were more likely to ambulate early and be discharged on the day of surgery, and mepivacaine spinal anesthesia should be considered in appropriate outpatient total hip arthroplasty candidates,” the researchers concluded.
Mendelson A, Smoker J, Kasper V, Hozack W, Austin M, Brown S, Nemeth A, Czerwinski E, Li J, Cohen A, Baratta J, Wahal C, Torjman M, Schwenk E. Early Ambulation After Hip Arthroplasty: A Double-Blind Randomized, Controlled Trial, Abstract 828. Best of Meeting Abstract Award, 45th Annual Regional Anesthesia and Acute Pain Medicine Meeting, 2020.