Who Remains Intubated After Adult Spinal Deformity Surgery? A 5-Factor Scoring System With Dual Institution External Validation.

BACKGROUND AND

OBJECTIVES

Prolonged intubation is an unwanted occurrence after adult spinal deformity (ASD) surgery, yet its risk factors are poorly understood. For patients undergoing ASD surgery, we sought to: (1) report the rate of intubation until postoperative day 1 (POD 1), (2) create a scoring system to predict it, and (3) externally validate the scoring system.

METHODS

A retrospective cohort study (2009-2021) was performed for patients undergoing ASD surgery. Primary outcome was prolonged intubation (POD 1 or beyond). Univariate logistic regression were performed. External validation was performed using an independent cohort.

RESULTS

Among 233 patients, 36 (15%) remained intubated until at least POD 1. These patients were older (70 vs 62 years, P = .001), had longer surgeries (543 vs 398 minutes, P < .001), late procedure end times (18:34 vs 15:59, P < .001), change of anesthetists (56% vs 31%, P = .04), greater blood loss (2809 vs 1207 mL, P < .001), and required intraoperative blood transfusion (89% vs 54%, P < .001). For every extra 30 minutes the case continued, odds of prolonged intubation increased by 22% (odds ratio = 1.2, 95% CI: 1.1-1.3, P < .001). The final scoring system included: age 60 years and older, intraoperative blood transfusion, operative time >7 hours, change of anesthetists, and procedure close time after 17:00. Receiver operating characteristic analysis revealed a cutoff of >4 points as a predictor of prolonged intubation (area under the curve = 0.8, 95% CI: 0.8-0.9, P < .001, sensitivity = 89%, specificity = 70%). On external validation, the score demonstrated moderate discriminative ability (area under the curve = 0.7). At the threshold of 4, sensitivity was 91%, and specificity was 26%.

CONCLUSION

Approximately 15% ASD surgery patients remained intubated through POD 1. An 8-point risk score incorporating age 60 years and older, operative time ≥7 hours, intraoperative transfusion, change of anesthetists, and procedure end time after 17:00 demonstrated strong discrimination in the derivation cohort and moderate, high-sensitivity performance on external validation. Use of this score in collaboration with anesthesia teams may enable early risk stratification and targeted perioperative planning.