Anesthesia in the News
  • Spinal Anesthesia or General Anesthesia for Hip Surgery in Older Adults

    Observational studies suggest that spinal anesthesia may be associated with lower risk of adverse outcomes than general anesthesia in adults undergoing surgery for hip fracture.

    Older adults with fractured hips are often frail, and many have dementia (Borges FK et al, 2020) which places them at risk for adverse postoperative neurologic outcomes.  The use of spinal anesthesia for hip-fracture surgery increased by 50% between 2007 and 2017 (Maxwell BG et al, 2020), which may reflect a view in the surgical community that spinal anesthesia is associated with better outcomes.

    However, randomized trials comparing the effects of the two techniques on post discharge outcomes — including walking ability — are lacking.  In particular, it’s not known whether spinal anesthesia improves the ability to walk independently after hip surgery.

    In the largest study of its kind, published in the November 25th issue of New England Journal of Medicine, the Regional versus General Anesthesia for Promoting Independence after Hip Fracture (REGAIN) trial, a multicenter, pragmatic, randomized, superiority trial, examined whether spinal anesthesia conferred better post-discharge outcomes than general anesthesia in adults undergoing hip-fracture surgery.

    Study power and outcomes

    A total of 1600 previously ambulatory patients 50 years of age or older who were undergoing surgery for hip fracture at 46 U.S. and Canadian hospitals were enrolled.  The average age of the subjects was 78 years; 67.0% of the patients were women and 8% were Black, an enrollment matching the distribution of Medicare recipients with hip fractures (Tajeu GS, et al, 2014).  A total of 666 patients (83.8%) assigned to spinal anesthesia and 769 patients (95.5%) assigned to general anesthesia received their assigned anesthesia.

    The primary outcome was a composite of death or an inability to walk approximately 10 ft (3 m) independently or with a walker or cane at 60 days after randomization.  All patients had been able to walk independently before the fracture.  Secondary outcomes included death within 60 days, new-onset delirium, time to discharge, and ambulation among survivors.

    Conventional thinking challenged

    The study outcomes did not differ significantly according to anesthesia type and the incidence of serious adverse events was similar in the two groups.  There were no significant differences between groups with respect to the composite primary outcome, which was present in approximately 18% of the patients in both groups: an inability to walk independently at 60 days occurred in approximately 15%, and mortality at 60 days was 4%.  New-onset delirium occurred in approximately 20% of the patients in both groups.

    The authors conclude that, in older adults undergoing hip fracture surgery, spinal anesthesia was not superior to general anesthesia for lowering the risk of death or inability to walk independently after hospital discharge and the rate of postoperative delirium was similar with the two anesthesia types.

    Limits to extrapolation

    Although REGAIN is the largest trial of its kind, the authors note among its limitations that that many patients were ineligible or declined to participate (more than 22,000 patients were screened to enroll 1600 patients) thus constraining the ability to generalize the results.

    A further limitation was that, among the patients included in the trial, 13% were assessed as having delirium prior to surgery, thereby constraining the ability to diagnose new-onset delirium.

    Further confounding the study results, crossover to general anesthesia occurred in 15.0% of the patients assigned to spinal anesthesia; reasons included an inability to place a spinal block (44%), clinician preference (24%), and patient or proxy preference (15%) and crossover to spinal anesthesia occurred in 3.5% of the patients assigned to general anesthesia.  In addition, the level of sedation during spinal anesthesia was discretionary, which makes the contribution of sedation to postoperative delirium unclear.

    Finally, the trial was designed under the assumption that the primary outcome would occur in 34.2% of the patients in the general anesthesia group, but the observed percentage was just 18.0%.  These limitations decreased the likelihood of detecting differences between the treatment groups and emphasize the imperative for further rigorous trials, according to the authors.

    REGAIN’s contribution

    In an editorial published in the same issue, James P. Rathmell, MD, and Michael S. Avidan, MB, BCh articulated their view of the special value of the REGAIN trial in “prompt[ing] us to challenge entrenched concerns regarding the dangers of general anesthesia.  We can now reassure vulnerable older adults presenting for hip-fracture surgery that spinal anesthesia is not superior to general anesthesia for the outcomes that matter most to them.  Patients are in a position to choose the anesthetic technique that they prefer on the basis of anxiety, comfort, and their own expectations.”

    Find the full study, “Spinal Anesthesia or General Anesthesia for Hip Surgery in Older Adults, ” N Engl J Med. 2021 Nov 25;385(22):2025-2035. at:

    https://pubmed.ncbi.nlm.nih.gov/34623788/

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