Spinal Anesthesia Superior for Hip Fracture Surgery

A new study suggests a strong association between spinal anesthesia (SA) and reduced mortality in elderly patients undergoing hip fracture fixation surgery.

Researchers at the University of Toronto (Canada) and Toronto Western Hospital (Canada) conducted a study of all patients who underwent hip fracture fixation between 2003 and 2015. The researchers then matched 883 patient cohorts for 29 variables known to affect mortality and morbidity associated with hip fractures. They then matched the patients who received SA with those who received general anesthesia (GA). The main outcome was impact of SA on 90-day mortality.

The results revealed that patients who received SA were more likely to be male, elderly, have a higher ASA score, and receive earlier hip fracture fixation; and less likely to have metastatic cancer and take calcium channel blockers. Overall, 90-day mortality was significantly lower in patients who received SA (6.3%) than in GA patients (8.8%), a relative risk reduction of 26.1%. The SA patients also had fewer blood clots in the lungs, lower rates of major blood loss, and shorter hospital stays. The study was presented at the 2018 World Congress on Regional Anesthesia and Pain Medicine, held during April 2018 in New York (NY, USA).

“A strong association was identified between spinal anesthesia and lower 90-day mortality post hip fracture repair. Overall, patients who received spinal anesthesia were less likely to die from a cardiac event, but more likely to die from a respiratory cause or sepsis,” concluded lead author Sarah Tierney, MD, of the University of Toronto. “There was no between-group difference noted in hospital length of stay or major cardiac events.”

SA involves injection of a local anesthetic into the subarachnoid space, generally through a fine needle, in order to block the transmission of afferent nerve signals from peripheral nociceptors. The degree of neuronal blockade depends on the amount and concentration of anesthetic used, and the properties of the axon. As such, thin unmyelinated C-fibers associated with pain are blocked first, while thick, heavily myelinated A-alpha motor neurons are blocked moderately. SA is not to be confused with an epidural, whereby a local anesthetic drug is injected through a catheter placed into the epidural space.

Related Links:
University of Toronto
Toronto Western Hospital