Prediction of Acute Postoperative Pain from Assessment of Pain Associated With Venous Cannulation.

BACKGROUND: It has previously been reported that venous cannulation-induced pain (VCP) can be used to predict acute postoperative pain after laparoscopic cholecystectomy. Patients rating VCP at ≥2.0 VAS units had 3.4 times higher risk for moderate or severe pain. The purpose of this study was to evaluate if VCP scores of ≥2.0 VAS units are associated with higher risk for acute postoperative pain after various common surgical procedures. METHODS: In a prospective clinical observational study, 600 male and female 18- to 80-year-old patients scheduled for elective surgery were included. The primary outcome measure was the difference in maximum postoperative pain intensity between low responders (VCP < 2.0) and high responders (VCP ≥ 2.0) to VCP. Secondary outcome measures were the difference in proportion of patients with moderate or severe postoperative pain between low and high responders, and potential influence of age, gender, and preoperative habitual pain. RESULTS: Patients scoring VCP ≥2.0 VAS units reported higher acute postoperative pain intensity levels than those scoring VCP <2.0 VAS units (median 3.0 [interquartile range 0.0 to 5.0] vs. 0.2 [interquartile range 0.0 to 4.0], P = 0.001), and also had 1.7 times higher risk for moderate or severe postoperative pain (P = 0.005). Moderate or severe postoperative pain was reported by 38% of patients with VCP scores of ≥2.0 VAS units and by 26% with VCP scores of <2.0 VAS units (P = 0.005). CONCLUSION: Scoring of VCP intensity before surgery, requiring no specific equipment or training, is useful to predict individual risks for moderate or severe postoperative pain, regardless of patient age or gender, in a setting involving different kinds of surgery.