Postoperative delirium is associated with decreased recovery of ambulation one-month after surgery

Abstract

Background: We hypothesized that postoperative delirium is associated with diminished recovery toward baseline preoperative ambulation levels one-month postoperatively.

Methods: Patients included were ≥60 years old undergoing inpatient operations. Ambulation was measured as steps/day using an accelerometer worn for ≥3-days preoperatively and ≥28-days postoperatively. Primary outcome was the percent recovery of preoperative steps.

Results: 109 patients were included; 17 (16%) developed postoperative delirium. Recovery of ambulation toward preoperative baseline at postoperative day-28 was decreased in delirium group (34% vs. 69%; p < 0.01). Immediate postoperative ambulation was similar in the delirium vs. no-delirium groups (p = 0.79). Delirium occurred on average on postoperative 3 ± 4 days. Subsequently, ambulation was decreased in the delirium group compared to non-delirium group at postoperative week-1 (p = 0.01), week-2 (p = 0.02), week-3 (p < 0.01) and week-4 (p < 0.01).

Conclusion: Patients undergoing inpatient operations who develop delirium recover only one-third of their baseline steps one-month postoperatively. Postoperative delirium results in a decreased recovery towards baseline ambulation for at least 4-weeks following major operations in comparison to non-delirious patients. The decrease in ambulation in the delirium versus no-delirium groups occurred after the occurrence of postoperative delirium.

Keywords: Accelerometer activity tracker; Ambulation; Older adults; Postoperative delirium.

Figure 1.

Flow diagram for patient inclusion

Figure 2.. Post-Operative Ambulation Recovery Trajectories in Older Adults With and Without Delirium

Postoperative recovery trajectories (with 95% confidence intervals) depicted as a percent of pre-operative baseline ambulation levels. Patients with and without delirium had similar ambulation levels immediately after the operation (p=0.79). The average onset of delirium was postoperative day 3. Subsequent to onset of delirium, ambulation recovery trajectories diverged; resulting in patients with delirium having reduced ambulation compared to non-delirious patients.

Figure 3. Accounting for the Effect of Long Operative Time on Post-Operative Ambulation Recovery Trajectories in Older Adults With and Without Delirium

Long operative times (>180 minutes) on univariate analysis were closely associated with the occurrence of delirium. The goal of this analysis was to account for a long operative times confounding the relationship between delirium and decreased ambulation. The decreased ambulation resulting from delirium (red line) was greater than the decreased ambulation resulting from long operations in patients without delirium (green line). Patients with delirium had a decreased percent of preoperative baseline ambulation at 28 days postoperatively compared to non-delirious patient with long (p=0.03) and short (p<0.01) operations. This analysis suggests that delirium was the cause of lower ambulation levels independent of the extent of the operation. Recovery trajectories with 95% confidence intervals depicted.