Spinal Anesthesia for Hip Fracture Surgery May Lower Morbidity, Mortality Rates

Spinal anesthesia for hip fracture surgery as compared with general anesthesia is associated with lower morbidity and mortality rates, according to study findings published in the journal Regional Anesthesia & Pain Medicine.

No consensus has been made about whether the type of anesthesia affects perioperative complication rates in the setting of hip fracture surgery. To better evaluate the relationship between analgesia and outcomes, researchers sourced data for this study from the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) Hip Fracture Targeted Participant Use File (PUF). Patients (N=40,527) aged 50 and older who underwent hip fracture surgery between 2016 and 2019 were evaluated for the primary composite outcome of stroke, myocardial infarction (MI), or death at 30 days on the basis of anesthetic received. To balance for cohort differences, a propensity matching approach was used for a final cohort of 7358 individuals who underwent spinal anesthesia and 7358 who underwent general anesthesia.

The full study population prior to matching included 68.84% women (mean age, 80.25 [SD, 9.73] years); body mass index (BMI) of 25.23 (SD, 5.84) kg/m²; 77.58% were functionally independent; 53.85% had an intertrochanteric fracture; and 62.43% were categorized as American Society of Anesthesiologists (ASA) class III.

Among the matched cohorts, the spinal and general anesthesia groups had a mean operative time of 60.28 (SD, 32.93) and 64.73 (SD, 40.22) minutes (P <.001) and a hospital stay of 6.29 (SD, 11.78) and 5.73 (SD, 9.42) days (P =.001), respectively.

Stratified by ASA class, compared with general anesthesia, spinal anesthesia was associated with a shorter operative time among patients with ASA I/II (P <.001), III (P <.001), and IV (P =.048), a longer hospital stay among patients with ASA I/II (P =.004), and a shorter hospital stay among patients with ASA III (P =.018).

The rate of the primary outcome was lower among those who underwent spinal anesthesia (6.59%) compared with those who underwent general anesthesia (7.92%). Overall, general anesthesia was associated with increased risk for the primary outcome (odds ratio [OR], 1.219; 95% CI, 1.076-1.381; P =.002).

In addition, compared with spinal anesthesia, general anesthesia was associated with increased risk for death (OR, 1.276; 95% CI, 1.099-1.481; P =.001), deep vein thrombosis (DVT) or thrombophlebitis (OR, 1.510; 95% CI, 1.060-2.151; P =.023), and acute renal failure (OR, 2.077; 95% CI, 1.072-4.025; P =.027) at 30 days.

Stratified by ASA class, compared with spinal anesthesia, general anesthesia was associated with risk for DVT or thrombophlebitis (OR, 2.571; P =.027) in ASA I/II; acute renal failure (OR, 5.0; P =.021)  and DVT or thrombophlebitis (OR, 1.611; P =.024) in ASA III; and MI (OR, 1.606; P =.032), death (OR, 1.482; P =.002), and the primary outcome (OR, 1.467; P <.001) in ASA IV.

The limitations of this study included the short follow-up duration and the fact that no safety data were included.

The researchers concluded, “Our findings suggest benefits to spinal anesthesia over general anesthesia for hip fracture surgery, particularly in patients who have a higher ASA classification.”