Neuraxial versus General Anesthesia for Total Knee Arthroplasty
Neuraxial anesthesia (NA) for total knee arthroplasty (replacement) has gained favor over the past two decades with growing emphasis on enhanced recovery, as well as minimizing healthcare cost, opioid use, and costly inpatient stays. Concurrently, the number of arthroplasty cases performed annually continues to rise. Used primarily to block pain from surgical sites below the umbilicus, NA provides several analgesic benefits. However, whether it truly improves outcomes, morbidity, and mortality reduction is being debated, especially in the case of orthopedic procedures where general anesthesia is not absolutely necessary. Researchers have made efforts to compare outcomes between neuraxial and general anesthesia (GA), and these studies have subsequently been reviewed systematically, however much of the data was poor in quality due to the sample size of those randomized trials.
In 2006, Guay demonstrated that biomarkers associated with stress response are lower in patients receiving epidural anesthesia with GA, including cortisol, epinephrine, and norepinephrine.1 In 2013, Memtsoudis et al., demonstrated a reduction in morbidity and mortality when neuraxial techniques were used either primarily or combined with GA. Specifically, 30-day mortality, prolonged length of stay (>75 percentile), cost, and in-hospital complications were reduced in the NA group of this retrospective study, which included over 380,000 participants. These results were limited by study design and complicate direct comparison between types of anesthesia due to lack of randomization.5
In 2016, Johnson et al. published a systematic review of 29 studies from 1989-2015, the majority of which used epidurals for NA. The results showed significantly decreased risk of deep venous thromboembolism (VTE) in the neuraxial group, in the absence of medical thromboprophylaxis. This difference was eliminated by incorporation of perioperative antithrombotic medications in later studies, demonstrating a shift as standardized protocols were developed for VTE prevention. Length of stay was also decreased when neuraxial anesthesia was utilized, however there were no other significant differences elucidated in this review. Overall, while the results did not demonstrate overwhelming superiority of NA, there remains some benefit to this technique as GA did not demonstrate any advantage in the measured variables.3
Most recently, Memtsoudis et al., published consensus recommendations from the International Consensus on Anesthesia-Related Outcomes after Surgery group (ICAROS), based on systematic review and meta-analyses of data from 1946 to May 2018. While this study looked at both hip and knee arthroplasty, the data was evaluated separately and demonstrated evidence of significantly reduced odds of pulmonary complications, pneumonia, acute renal failure, urinary tract infection, DVT/PE, all-cause infections, superficial infection, urinary retention, ICU admission, readmission, and blood transfusion. Sensitivity analysis of the randomized controlled trials again demonstrated a significantly reduced incidence (24% reduction) of VTE. These findings persisted when revision arthroplasties were separated from primary data.4
Overall, there appears to be equivalency if not some benefit to using neuraxial anesthesia in the perioperative period. The strength of the data supporting this notion remains of concern and longer term follow up is needed, however there is an absence of data suggesting poorer outcomes when NA is utilized. While there continues to be a need for more high-quality studies of this type, in the properly selected patient, neuraxial anesthesia appears to be a useful alternative to general anesthesia, especially if venous thromboembolism, infection, pulmonary or renal complications, and/or length of stay are anticipated to be of concern perioperatively.
References
1. Guay J. The benefits of adding epidural analgesia to general anesthesia: A metaanalysis. J Anesth. 2006; 20(4):335-340. doi: 10.1007/s00540-006-0423-8.
2. Guay J, Choi P, Suresh S, Albert N, Kopp S, Pace NL. Neuraxial blockade for the prevention of postoperative mortality and major morbidity: An overview of Cochrane Systematic Reviews. Cochrane Database Syst Rev. 2014(1):CD010108. doi: 10.1002/14651858.CD010108.pub2.
3. Johnson RL, Kopp SL, Burkle CM, et al. Neuraxial vs general anaesthesia for total hip and total knee arthroplasty: A systematic review of comparative-effectiveness research. Br J Anaesth. 2016;116(2):163-176. doi: 10.1093/bja/aev455.
4. Memtsoudis SG, Cozowicz C, Bekeris J, et al. Anaesthetic care of patients undergoing primary hip and knee arthroplasty: Consensus recommendations from the international consensus on anaesthesia-related outcomes after surgery group (ICAROS) based on a systematic review and meta-analysis. Br J Anaesth. 2019;123(3):269-287. doi: 10.1016/j.bja.2019.05.042.
5. Memtsoudis SG, Sun X, Chiu Y, et al. Perioperative comparative effectiveness of anesthetic technique in orthopedic patients. Anesthesiology. 2013;118(5):1046-1058. doi: 10.1097/ALN.0b013e318286061d.