Undergoing general or spinal anesthesia does not alter short term adverse events in patients undergoing outpatient total knee arthroplasty (TKA) surgery, according to researchers from the Warren Alpert Medical School of Brown University in Providence, led by Mark C. Kendall, MD, who retrospectively evaluated outcomes during the 72-hours after outpatient TKAs.
For the study, published in the journal BMC Anesthesiology, the researchers identified 6339 primary, elective outpatient TKA procedures using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database. Of these, the researchers matched a cohort of 1962 patients who underwent outpatient TKA under general anesthesia with patients who underwent outpatient TKA under spinal anesthesia.
There was no difference in serious adverse events rates at 72-hours between patients receiving general anesthesia compared with spinal anesthesia (0.92% vs. 0.66%, P = .369). However, minor adverse events after surgery were significantly more common in the general anesthesia group (2.09% vs. 0.51%), P < .001). The rate of blood transfusions was also lower in the spinal anesthesia group compared with the general anesthesia group (P = .0004).
The authors wrote that “as far as we are aware, no study has evaluated the impact between the type of anesthesia technique on patient outcomes after outpatient TKAs,” and they consider their results especially important given the increasing shift to outpatient TKAs.
Albert C. Hsu, MD, an orthopedist with Kaiser Permanente Medical Center in Downey, California, who was not involved with the study, was unsurprised by the results. He told Medscape Medical News, “This study further validates some of the experiences we are seeing in practice and previously published orthopedic literature.”
Hsu does nearly 90% of his TKAs as true outpatients, where the patient typically goes home the same day from surgery at an ambulatory surgery center. “For ‘true’ outpatient joints to be successful it requires a collaborative effort with the physical therapy team, nursing team, and anesthesia team,” he said. “Preoperative patient education/expectation after surgery are important as well.”
One thing he would like to know more about is the anesthetic used in the spinal anesthesia and how that might affect outcomes. This information was not available, as the data came from a large database, and the authors recognized this as a limitation, noting “[D]ue to limitations on the database, we cannot assess potential drug usage variations in the anesthesia techniques that could potentially alter the outcome.” Nevertheless, they encouraged clinicians to “recognize the benefits of spinal anesthesia in patients undergoing outpatient knee replacements and tailor the anesthetic plan to maximize clinical benefits.”
The study authors and Hsu have disclosed no relevant financial relationships.
BMC Anesthesiol. Published online September 15, 2021. Full text