Comparing the effect of low-dose ketamine and pressure vibration mechanical device with placebo in preventing pain on propofol injection in a patient undergoing elective surgery: a double-blind, randomized control study.
Regional anesthesia and pain medicine – January 27, 2026
Source: PubMed
Summary
A simple pressure vibration device significantly reduces acute pain from propofol injections, a common issue in medical procedures. In a trial involving 275 patients, 51.1% experienced no pain with the device, compared to just 30.4% with placebo. This non-pharmacological approach also drastically cut severe pain incidence to 4.3%, down from 18.5% in the placebo group. It proved as effective for pain management as low-dose ketamine (33.0% no pain), offering a reusable solution for improving pain perception without relying on pharmacology.
Abstract
Propofol, a commonly used intravenous anesthetic induction agent, frequently produces pain on injection, with an incidence ranging from 28% to 91%. This study aimed to compare the effect of low-dose ketamine and a pressure vibration mechanical device with placebo in reducing pain during propofol injection in patients undergoing elective surgery. In this randomized, double-blind, placebo-controlled trial, 300 adults were allocated to pressure vibration (Group V), low-dose ketamine (Group K), or saline placebo (Group P); 275 patients completed the study and were analyzed (92, 91, and 92 patients, respectively). Group P received 5 mL 0.9% saline, Group K ketamine 50 µg/kg diluted in 5 mL saline, and Group V saline with an activated pressure vibration device applied proximal to the intravenous cannula, each administered over 1 min. Propofol 2 mg/kg was infused, with the first 25% delivered at 600 mL/hour, and pain assessed using the McCrirrick and Hunter verbal rating score. The primary outcome was pain on propofol injection. Continuous variables were analyzed using one-way analysis of variance or Kruskal-Wallis tests, categorical variables with χ² tests, with Bonferroni correction applied for multiple primary outcome comparisons. Among 275 analyzed patients, the incidence of no pain was highest in the pressure vibration device group 51.1%; 95% CI 42.4% to 59.8% compared with placebo 30.4%; 95% CI 21.0% to 39.8% and ketamine 33.0%; 95% CI 23.3% to 42.6%; (p=0.001). Severe pain was more frequent in the placebo group (18.5%; 95% CI 10.5% to 26.4%) than in the ketamine (5.5%; 95% CI 0.8% to 10.2%) and vibration groups (4.3%; 95% CI 0.2% to 8.5%; (p=0.001). Recall of injection pain at 1 week was significantly higher with placebo compared with ketamine and vibration device (55.4%, 37.4%, and 26.1%, respectively; p<0.001). Hemodynamic variables and adverse events were comparable across groups. The pressure vibration mechanical device significantly reduced the incidence and severity of propofol injection pain compared with placebo and was at least as effective as low-dose ketamine. Pain recall at 1 week was higher with placebo. This device provides an effective, reusable, non-pharmacological alternative without drug-related adverse effects. CTRI/2022/12/048300.