CHSU Discovery

Abstract
Introduction: Spinal anesthesia (SA) allows total joint arthroplasty (TJA) to be performed while minimizing opioids and systemic anesthetic agents compared to general anesthesia (GA). SA has been associated with shortened postoperative recovery; however, the relationship between spinal anesthesia, major postoperative complications, and pneumonia (PNA) remains unclear. 

Methods: Patients were identified in a large, national database who underwent total hip arthroplasty (THA) or total knee arthroplasty (TKA) from 2010-2020. 1:1 propensity score matching was used to create matched groups of patients who underwent SA and GA. The groups were matched by age, sex, COPD, smoking status, Charlston comorbidity index (CCI), and American Society of Anesthesiology (ASA) classification. 1:1 matching was also performed among the ASA classifications as a sub-analysis. 

Results: Overall, equally matched groups of 217,267 patients were identified who underwent SA vs. GA. 850 (0.39%) patients developed postoperative PNA following GA vs. 544 (0.25%) patients following SA (p<0.001). The risk of major complications was 6,922 (3.2%) in the GA group and 5,401 (2.5%) in the SA group (p<0.001). Similarly, the risk of unplanned postoperative reintubation was higher (0.18% vs. 0.10%, p<0.001) and mortality was higher (0.14% vs. 0.09%, p<0.001) in the GA group than in the SA group. In ASA 1-3 patients, the risk of PNA was 0.08%-0.21% higher with GA than with SA. In ASA 4 patients, the risk of PNA was 0.42% higher in SA than in GA (1.92% vs. 1.5%, p<0.001), and the mortality rate was nearly doubled in GA than in SA (1.46% vs. 0.77%,
p=0.017). 

Conclusions: Overall, GA was associated with a small but significantly higher rate of major complications, mortality, and PNA than SA in patients undergoing TJA when matching for differences in comorbidities. ASA 4 patients experienced the greatest increase in absolute risk of mortality with GA vs. SA.