Cryospray reduces pain during venous cannulation in elective surgery patients: a randomized placebo-controlled study

Background: Venous cannulation is widely used in healthcare systems, and for many patients, it is painful and distressing. We hypothesized that the rapid onset of cryospray use would reduce pain from venous cannulation compared to the use of a placebo spray. Methods: The trial was a prospective randomized placebo-controlled trial including 130 adult patients scheduled for elective surgery. Patients were randomized to receive either cryospray or placebo before venous cannulation. The primary outcome was patient-reported pain from vein puncture. Results: There were no differences in the baseline variables between the two groups with respect to age, sex, height, weight or ASA class. Patients in the cryospray group indicated more pain or discomfort with the application of the spray (0 (0-2.5)) than with the application of the placebo spray (0 (0–0)) (P < 0.005), as measured by the Numeric Rating Scale (NRS). Patients in the placebo group reported more pain with vein puncture than did those in the cryospray group (1 (0–3) vs. 3 [2, 3, 4–5], P < 0.005). When asked if the patient would have the same spray in case of canulation again, 57 patients from the cryospray group reported yes compared to 34 patients in the control group (P < 0.005). Conclusions: This randomized study found that cryospray significantly reduced pain during venous cannulation without increasing procedure difficulty. Patients reported lower pain scores and a greater preference for cryospray in future procedures, supporting its use as an effective pain relief method in elective surgery. Trial registration: ClinicalTrials. gov Identifier: NCT04865783 (28-04-2021).