Preoperative Patient Expectations of Postoperative Pain Are Associated with Moderate to Severe Acute Pain After VATS

Abstract

Objective: The goal of this post hoc analysis of subjects from a prospective observational study was to identify the predictors of patients developing moderate to severe acute pain (mean numerical rating scale [NRS] ≥4, 0-10) during the first three days after video-assisted thoracoscopic surgery (VATS) from a comprehensive evaluation of demographic, psychosocial, and surgical factors.

Methods: Results from 82 patients who were enrolled one week before VATS and evaluated during the first three postoperative days are presented. The primary outcome variable of the current study was the presence of moderate to severe acute pain after VATS.

Results: Fifty-nine percent (95% confidence interval, 47-69%) of study subjects developed moderate to severe acute pain after VATS. Factors univariately associated with the presence of moderate to severe acute pain were greater average expected postoperative pain, greater pain to a suprathreshold cold stimulus, and longer durations of surgery and hospital stay (P < 0.05). When considered in the multiple logistic regression models, the patients' preoperative average intensity of expected postoperative pain (NRS, 0-10) was the only measure associated with the moderate to severe acute pain. Average intensity of postoperative pain expected by patients when questioned preoperatively mediated the effect of reported intensity of pain to the suprathreshold cold stimulus for moderate to severe acute pain levels. Preoperative patient expectations had greater predictive value than other assessed variables including psychosocial factors such as catastrophizing or anxiety assessed one week before surgery.

Conclusions: None of the preoperative psychosocial measures were associated with the moderate to severe acute pain after VATS. Average expected postoperative pain was the only measure associated with the development of moderate to severe acute pain after VATS.

Keywords: Acute Pain; Multiple Logistic Regression; Predictors; Thoracic Surgery; VATS.

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Figures

Figure 1

Flowchart of patients. MRI = magnetic resonance imaging; VATS = video-assisted thoracoscopic surgery.

Figure 2

The average postoperative pain score was calculated as the mean of the pain scores from three postoperative days. Moderate to severe acute pain was defined when the average postoperative pain score (numerical rating scale [NRS], 0–10) was ≥4, represented with circles in the figure. Those patients with average postoperative pain score 

Figure 3

Average expected vs average observed postoperative pain severity scores during the first three days after VATS. NRS = numerical rating scale; POD = postoperative day.