Pain and Opioid Consumption and Mobilization After Surgery

Post Hoc Analysis of Two Randomized Trials

Eva Rivas, M.D.; Barak Cohen, M.D.; Xuan Pu, M.Sc.; Li Xiang, M.D.; Wael Saasouh, M.D.; Guangmei Mao, M.Sc.; Paul Minko, B.S.; Lauretta Mosteller, B.A.; Andrew Volio, M.D.; Kamal Maheshwari, M.D.; Daniel I. Sessler, M.D.; Alparslan Turan, M.D.


Anesthesiology. 2022;136(1):115-126. 

In This Article

Abstract and Introduction


Background: Early mobilization is incorporated into many enhanced recovery pathways. Inadequate analgesia or excessive opioids may restrict postoperative mobilization. The authors tested the hypotheses that in adults recovering from abdominal surgery, postoperative pain and opioid consumption are inversely related to postoperative mobilization, and that postoperative mobilization is associated with fewer potentially related complications.

Methods: The authors conducted a subanalysis of two trials that enrolled adults recovering from abdominal surgery. Posture and movement were continuously monitored for 48 postoperative hours using noninvasive untethered monitors. Mobilization was defined as the fraction of monitored time spent sitting or standing.

Results: A total of 673 patients spent a median [interquartile range] of 7% [3 to 13%] of monitored time sitting or standing. Mobilization time was 1.9 [1.0 to 3.6] h/day for patients with average pain scores 3 or lower, but only 1.2 [0.5 to 2.6] h/day in those with average scores 6 or greater. Each unit increase in average pain score was associated with a decrease in mobilization time of 0.12 (97.5% CI, 0.02 to 0.24; P = 0.009) h/day. In contrast, there was no association between postoperative opioid consumption and mobilization time. The incidence of the composite of postoperative complications was 6.0% (10 of 168) in the lower mobilization quartile, 4.2% (7 of 168) in the second quartile, and 0% among 337 patients in the highest two quartiles (P = 0.009).

Conclusions: Patients recovering from abdominal surgery spent only 7% of their time mobilized, which is considerably less than recommended. Lower pain scores are associated with increased mobility, independently of opioid consumption. Complications were more common in patients who mobilized poorly.


Postoperative mobilization is an important component of enhanced recovery after surgery programs.[1–3] Typical enhanced recovery after surgery programs recommend many hours per day out of bed starting the day of surgery[4–7]—although the recommendations are largely based on recognized deleterious effects of bed rest[8–10] rather than strong evidence that postoperative mobilization improves outcomes.[6,11–23]

Postoperative pain remains common,[24] with about half of surgical patients reporting inadequate postoperative analgesia.[25,26] Inadequate analgesia impairs functional recovery and promotes postoperative complications.[27,28] In an attempt to address this problem, adequate analgesia was introduced as a quality measure,[29] which predictably increased opioid administration and the consequent opioid-related adverse events.[24] Opioid-related adverse events including nausea and vomiting, lightheadedness, and oversedation seem likely to reduce postoperative mobilization,[27,28,30,31] although there is currently little evidence to support the theory.

Surprisingly, there is no clear evidence of association between impaired postoperative mobilization and postoperative outcomes.[11,14,16,17] One explanation may be that assessment of mobilization remains imprecise and largely based on patient or nursing subjective reports rather than objective quantitative measurement. Furthermore, patient mobilization is frequently skipped or poorly implemented.[10,32,33]

The extent to which postoperative pain and opioid consumption influence postoperative mobilization remains unknown.[16–18] We therefore tested the primary hypothesis that in adults recovering from abdominal surgery, postoperative pain is inversely associated with postoperative mobilization, defined as the number of hours per postoperative day spent sitting or standing during the initial 48 postoperative hours. Secondarily, we tested the hypothesis that postoperative opioid consumption is inversely associated with postoperative mobilization. Finally, we tested the exploratory hypothesis that postoperative mobilization is associated with fewer complications potentially related to inadequate mobilization, defined as a composite of myocardial injury, stroke or transient ischemic attack, venous thromboembolism, pulmonary complications, and all-cause mortality.