Evaluation of American Society of Anesthesiologists classification as 30-day morbidity predictor after single-level elective anterior cervical discectomy and fusion

Background Context

Higher American Society of Anesthesiologists (ASA) classification is a known predictor of postoperative complication in diverse surgical settings. However, its predictive value is not established in single-level elective anterior cervical discectomy and fusion (SLE-ACDF).

Purpose

This study aimed to evaluate the predictive value of ASA classification system on 30-day morbidity following SLE-ACDF.

Design/Setting

Patients who underwent SLE-ACDF between 2011 and 2013 were selected from the American College of Surgeons National Surgical Quality Improvement Program database.

Patient Sample

A total of 6,148 patients were selected from the 2011–2013 American College of Surgeons National Surgical Quality Improvement Program database.

Outcome Measures

All outcomes are self-report measures as tracked by dedicated clinical reviewers via prospective review of inpatient charts, outpatient clinic visits, and direct contact with the surgical team.

Methods

Propensity score matching and multiple logistic regression analyses were performed to evaluate ASA classification as 30-day morbidity predictor. This study has no financial conflict and has no potential conflict of interest to disclose.

Results

A total of 6,148 patients were analyzed in this study. Patients in the ASA >II cohort had higher incidence of comorbidities and postoperative complications (overall complication, pneumonia, unplanned intubation, ventilator dependent >48 hours, cerebrovascular accident or stroke, catastrophic outcome, and airway complication). Propensity score matching yielded 1,628 pairs of well-matched patients. Multivariable analyses with the propensity score matched dataset revealed the following associations between ASA class >II and 30-day outcomes: any complication (odds ratio [OR] 0.82, 95% confidence interval [CI] 0.48–1.41), pneumonia (OR 1.22, 95% CI 0.33–4.56), unplanned intubation (OR 1.49, 95% CI 0.41–5.36), ventilator >48 hours (OR 5.92, 95% CI 0.69–50.96), catastrophic outcome (OR 1.02, 95% CI 0.39–2.71), and airway complication (OR 2.21, 95% CI 0.67–7.29).

Conclusions

Although we did not detect associations between ASA class >II and adverse 30-day outcomes following SLE-ACDF, imprecision of estimates precludes definitive inferences. Although ASA classification allows simple assessment of patients' physiological status, their overall perioperativerisk factors need to be considered collectively for adequate optimization and improved outcomes in SLE-ACDF.