AM-PAC Mobility Score <13 Predicts Development of Ileus Following Adult Spinal Deformity Surgery

Retrospective review.

To determine whether the Activity Measure for Post-Acute Care (AM-PAC) "6-Clicks" score is associated with the development of postoperative ileus.

Adult spinal deformity (ASD) surgery has a high complication rate. One common complication is postoperative ileus, and poor postoperative mobility has been implicated as a modifiable risk factor for this condition.

Eighty-five ASD surgeries in which ≥5 levels were fused were identified in a single institution database. A physical therapist/physiatrist collected patients' daily postoperative AM-PAC scores, for which we assessed first, last, and daily changes. We used multivariable linear regression to determine the marginal effect of ileus on continuous AM-PAC scores; threshold linear regression with Bayesian information criterion to identify a threshold AM-PAC score associated with ileus; and multivariable logistic regression to determine the utility of the score thresholds when controlling for confounding variables.

Ten of 85 patients (12%) developed ileus. The mean day of developing ileus was postoperative day 3.3±2.35. The mean first and last AM-PAC scores were 16 and 18, respectively. On bivariate analysis, the mean first AM-PAC score was lower in patients with ileus than in those without (13 vs. 16; P< 0.01). Ileus was associated with a first AM-PAC score of 3 points lower (Coef. -2.96; P< 0.01) than that of patients without ileus. Patients with an AM-PAC score<13 had 8 times greater odds of developing ileus ( P= 0.023). Neither the last AM-PAC score nor the daily change in AM-PAC score was associated with ileus.

In our institutional cohort, a first AM-PAC score of <13, corresponding to an inability to walk or stand for more than 1 minute, was associated with the development of ileus. Early identification of patients who cannot walk or stand after surgery can help determine which patients would benefit from prophylactic management.

Level-III.