Patients administered regional anesthesia for hip fracture surgery are significantly more likely to experience complications than those who received general anesthesia, a study has found.
The 7,764-patient review of information from the American College of Surgeons’ National Surgical Quality Improvement Program (NSQIP) database yielded an adjusted odds ratio (OR) of 1.43 for minor complications and 1.24 for total complications for regional compared with general anesthesia (P<0.05 for both). The study, presented at the American Academy of Orthopaedic Surgeons’ 2015 annual meeting (abstract P555), was also published in International Orthopaedics (2015 March 24.
Paul Whiting, MD, an orthopedic trauma fellow at Vanderbilt University Medical Center, in Nashville, Tenn., and his co-investigators extracted data from the NSQIP for patients whose records included one of four Current Procedural Terminology (or CPT) codes for hip fracture surgery performed during 2005 to 2011. Of the total number of patients included in the analysis, 75.2% received general anesthesia, 23.4% spinal anesthesia and 1.4% regional nerve blocks.
Spinal anesthesia had the highest total (minor plus major) complication rate (19.6%), followed by general anesthesia (17.9%) and regional nerve blocks (12.6%; between-group P=0.008). Multivariate analysis showed that spinal anesthesia carried significantly greater odds for minor complications as well as total complications, compared with general anesthesia. After combining the regional nerve block and spinal anesthesia groups, multivariate analysis again showed significantly greater odds for minor and total complications for regional versus general anesthesia. There were no significant differences in the major complication rates among the three groups.
The researchers’ analysis showed an adjusted OR of 1.43 (95% CI, 1.15-1.77; P=0.001) for minor complications with spinal versus general anesthesia. There was also a statistically significantly higher OR for total complications, at 1.24 (95% CI, 1.05-1.48; P=0.014), but not for major complications (OR, 1.01; 95% CI, 0.81-1.24; P=0.95), when comparing the two groups.
There were no significant differences in the ORs for minor, major or total complications for regional nerve blocks versus general anesthesia, or for regional nerve blocks versus spinal anesthesia.
The investigators then combined spinal anesthesia and regional nerve block “due to … wide confidence intervals [in the adjusted ORs] and the non-occurrence of certain specific complications in the regional nerve block group.” This combined regional anesthesia group had a significantly higher risk for minor complications than the general anesthesia patients (adjusted OR, 1.43; 95% CI, 1.16-1.77; P=0.001). Total complications were also more common when comparing these two groups (adjusted OR, 1.24; 95% CI, 1.05-1.48; P=0.012) whereas major complications were not.
Two anesthesiologists who commented on the study were not convinced of the results.
“This really bucks the trend. There are numerous other studies, including an 18,000-patient study, that show lower incidence of major complications when neuraxial anesthesia is used,” noted Paul Hilliard, MD, director of regional anesthesia and acute pain medicine, University of Michigan Hospital and Health Systems, in Ann Arbor, who was not involved in the study. “I think the choice is clear. Unlike elective major joint surgery, patients with hip fracture are rarely ideal candidates for surgery, and a spinal or nerve block may be chosen precisely because these patients are at extremely high risk for complications from any anesthetic. Further studies should be completed to look at fracture complexity, preexisting medical comorbidities and choice of anesthetic on a larger scale.”
Siamak Rahman, MD, associate clinical professor of anesthesiology and director of acute pain management, Department of Anesthesiology & Perioperative Medicine, UCLA Health System, agreed that this is an important area of research. He said a main weakness of the study is that the “authors did not have access to additional records [aside from the NSQIP data] to review, nor could they speak to patients.”
Dr. Rahman, who also was not involved in the study, noted that the NSQIP database does not report on surgeon volume, percentage of resident involvement, time from admission to the procedure, receipt of blood transfusions, academic status of hospitals, patients’ insurance type and income group, total in-hospital costs or hospital readmissions. Nor did the study consider the type of hip fracture surgery, he added.
“Although our study has certain methodologic weaknesses inherent to large prospective database studies,” Dr. Whiting said “the combined outcomes analysis demonstrating increased perioperative complications with regional versus general anesthesia contributes meaningfully to the growing literature on anesthesia type in hip fracture surgery. Ultimately, prospective trials will be required to demonstrate definitively the preferred method of anesthesia for hip fracture patients.”