Spinal anesthesia- Best neuraxial technique for hip and knee surgery

Delhi: Spinal anaesthesia after hip and knee arthroplasty provides the best postoperative outcomes as compared to other options of neuraxial anaesthesia, according to a recently published study presented at the 2019 annual meeting of the American Academy of Orthopaedic Surgeons in Las Vegas.

The study found that spinal anaesthesia significantly reduced the risk of gastrointestinal, pulmonary, cardiac and thromboembolic complications by between roughly two-thirds (thromboembolic) and one-third (cardiac) compared with combined spinal and epidural (CSE) anaesthesia. Also, spinal anaesthesia reduced the prolonged hospital stay by 28% compared to CSE. However, patients who received epidural anaesthesia had about the same complication rates as patients receiving CSE.

For this large retrospective cohort study Stavros Memtsoudis, a professor of anesthesiology and public policy and research at Weill Cornell Medical College, in New York City, and colleagues identified 41,766 patients who underwent a total hip or knee arthroplasty at the Hospital for Special Surgery–Weill Cornell Medical Center between 2005 and 2014.

Of the cohort, a total of 40,852 patients (20,613 hip and 20,239 knee) received neuraxial anesthesia: 34,301 CSE, 2,464 epidural and 4,087 spinal.

The remaining 914 patients (2.19%) in the cohort received general anaesthesia and thus were excluded from the primary analysis, but were included for sensitivity analysis.

“In the last few years, our group and others have performed a number of population-based studies suggesting that neuraxial anaesthesia is associated with better perioperative outcomes when compared to general anaesthesia in hip and knee arthroplasty patients,” said Dr Memtsoudis. “However, because of the limitation of our data sources, we were not able to determine if it was truly the neuraxial anaesthetic that made the difference or if it was simply a surrogate marker for a specific type of care provided by certain hospitals that happened to provide neuraxial anaesthesia.”

The investigators also did not know whether there was a difference between the types of neuraxial techniques for outcomes. “That is why we used data from a hospital, which has a high rate of standardization of care, as well as a high rate of neuraxial use,” Dr Memtsoudis said.

“Observing that even in such a controlled setting neuraxial [anaesthesia] was associated with better outcomes was a validation of our previous assumptions,” Dr Memtsoudis said. “Further, identifying spinal anaesthesia to be the preferred approach was important because other techniques, like combined spinal and epidurals, were more frequently used.”

Dr Memtsoudis said the study offers a more nuanced understanding of anaesthesia technique as a modifiable risk factor for adverse postoperative outcomes after total hip and knee arthroplasty. “Our results certainly provide the basis for some real practice changes,” he said.

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Employing neuraxial versus general anaesthesia appears to be increasingly supported by the literature, Dr Memtsoudis added. “With this growing evidence, and in the absence of data suggesting that neuraxial is worse than general, the results of our study promote the transition from a practice that currently is still largely dominated by a general anaesthetic approach in joint arthroplasties in the United States,” he said.

Nonetheless, while the evidence using population-based data is growing in favour of neuraxial anaesthesia, “mechanistic studies are needed to add certainty,” Dr Memtsoudis said. “Moving evidence that is based on association to that based on causation between intervention and outcome is still required.”