Enhanced Recovery Pathway Mitigates the Impact of Non-modifiable Factors for Discharge Delay in Thoracolumbar Spine Surgery.

Abstract

Retrospective observational study using a prospectively collected database from a single tertiary center. To identify perioperative predictors of discharge time in thoracolumbar spine surgery within a standardized ERP and assess whether ERP mitigates traditionally non-modifiable risks. Discharge time is a key outcome in enhanced recovery protocols (ERPs), yet spine surgery-specific risk factors could differ from non-ERP and remain poorly defined. We obtained 465 consecutive patients undergoing thoracolumbar spine surgery under ERP for analysis. Primary outcome was discharge time. Secondary outcome was correlation between frailty (FRAIL scale) and discharge time. Univariate and multivariate linear regression analyses were performed on perioperative variables. Frailty was evaluated separately due to >10% missing data. Statistical significance was set at P<0.05 for univariate, and P<0.01 .for multivariate analysis. Multivariate analysis identified five independent predictors of longer discharge time: ES distance(erector spinae plane block to mid-surgical level), prolonged anesthesia duration, delayed ambulation (POD to walk), chronic kidney disease, and complicated surgery (infection or metastasis). The model had strong performance (adjusted R²=0.82). While the total FRAIL score and its components were statistically associated with discharge time, the correlations were weak (Spearman's ρ<0.2), suggesting limited clinical relevance in the ERP setting. ERP attenuates the impact of traditional non-modifiable factors, including frailty, on discharge timing after thoracolumbar spine surgery. These findings support broader ERP application and suggest that stringent patient selection may be unnecessary for achieving favorable recovery.