Author: Michael Vlessides
When it comes to emergency hip fracture surgery in frail, elderly patients, regional anesthesia boasts distinct advantages over general anesthetic approaches, according to a database analysis by a team of Kaiser Permanente researchers.
However, the investigators also pointed out that these results do not promote an overall superiority of regional over general anesthesia, but rather demonstrate one technique’s benefits in a specific patient subset.
“Nobody really knows which approach is better in these patients, but we think that if a patient is old and fragile and needs emergency hip surgery, then the choice of anesthesia makes a huge difference,” said Chunyuan Qiu, MD, the chair of performance improvement at Kaiser Permanente Baldwin Park Medical Center, in Baldwin Park, Calif., and a professor of anesthesiology and perioperative medicine at the University of California, Irvine.
To help tease out these differences, Dr. Qiu and his colleagues identified patients from the Kaiser Permanente Hip Fracture Registry who were at least 65 years of age and underwent emergent repairs between 2009 and 2014; the analysis excluded cases if they involved patients with pathologic fractures, bilateral fractures, prior surgery on the affected hip or multiple fractures treated simultaneously.
The researchers also examined a third group, which included patients who started with any type of regional anesthesia but were converted to general anesthesia at any time during the surgery. Patients with incomplete (n=117) or missing (n=1,995) anesthesia information were excluded. The study’s primary outcome was in-hospital mortality; secondary outcomes included hospital length of stay (LOS) and disposition location.
Identifying the Right Patients
As reported in the Journal of Orthopaedic Trauma (2018;32:116-123), the final patient sample comprised 16,695 individuals from 404 physicians and 38 hospitals within the Kaiser Permanente system. Of these patients, 57.7% (n=9,629) received general anesthesia, 39.5% (n=6,597) received regional anesthesia, and 2.8% (n=469) were converted from regional to general anesthesia.
“Previously, nobody has been able to identify this group of patients who converted because they didn’t have the numbers. But in our database we had over 500 of these cases, … so we were able to analyze those data as well.”
The average patient age was 82.2±7.9 years; most were women (70.1%), white (79.6%), and had a body mass index of 20 to 25 kg/m2 (42.0%). The majority of patients (75.2%) had an ASA classification of at least III. General anesthesia patients more frequently had valvular heart diseases, whereas more of their regional counterparts had chronic obstructive pulmonary disease.
It was found that general anesthesia patients had a greater risk for expiring in the hospital (hazard ratio [HR], 1.38; 95% CI, 1.10-1.73) and a lower risk home discharge (HR, 0.86; 95% CI, 0.79-0.92) than those who received regional anesthesia. “We were very surprised to find that mortality rates were so different between the types of anesthesia,” Dr. Qiu said.
Patients who converted from regional to general anesthesia also had a higher risk for expiring in the hospital (HR, 2.23; 95% CI, 1.31-3.78) than regional anesthesia patients; no statistically significant difference was found between these groups with respect to the risk for home discharge (HR, 0.93; 95% CI, 0.73-1.19).
“Patients who started with regional anesthesia but had to switch to general anesthesia for whatever reason essentially got two hits instead of one,” Dr. Qiu said.
General anesthesia patients also experienced a shorter time to death (time ratio [TR], 0.97; 95% CI, 0.95-0.99) and longer LOS before home discharge (TR, 1.01; 95% CI, 1.01-1.02) or to a health care facility (TR, 1.01; 95% CI, 1.01-1.01) than those in the regional anesthesia group. Patients who converted from regional to general anesthesia also had a shorter time to in-hospital mortality (TR, 0.89; 95% CI, 0.86-0.93) compared with the regional anesthesia group. No statistically significant differences were observed in LOS, whether the patient was discharged home or to a health care facility.
Parsing Group Outcomes
The investigators also performed a sensitivity analysis, which revealed that both the general anesthesia (odds ratio [OR], 1.36; 95% CI, 1.14-1.63) and conversion groups (OR, 2.19; 95% CI, 1.44-3.33) had a higher likelihood of in-hospital mortality than regional anesthesia patients. For those who survived to discharge, general anesthesia patients had a lower likelihood of returning home (OR, 0.91; 95% CI, 0.84-0.97) compared with the regional anesthesia group.
When the general anesthesia and conversion groups were combined and compared with regional anesthesia, the combined group had a higher risk for in-hospital mortality (HR, 1.41; 95% CI, 1.18-1.68), shorter time to in-hospital mortality (TR, 0.98; 95% CI, 0.96-1.00), lower likelihood for home discharge (HR, 0.93; 95% CI, 0.87-0.99), and a longer LOS before discharge to a health care facility (TR, 1.01; 95% CI, 1.01-1.02) or home (TR, 1.02; 95% CI, 1.01-1.03).
Despite the strength of these findings, Dr. Qiu was in no hurry to discount the value of general anesthesia. “It’s not a question of general anesthesia versus regional anesthesia,” he told Anesthesiology News. “The more important question is how these two modalities work in particular patients and disease states.”
That said, the results of the analysis have had a marked impact on the way he and his colleagues approach these patients.
“We’ve designed a perioperative surgical home pathway for these patients, and over two years we’ve significantly dropped our mortality rate,” Dr. Qiu added. “So these findings have really changed the way we practice.”