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Effects of Sound Frequencies on Pain and Comfort During Intramuscular Injection: A Randomized Controlled Study
Saeed Mohammadi1, Ebrahim Ezzati2, Rooghaye Mahooti3
1Department of Anesthesiology, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran.
Objective:
The present study aimed to evaluate the effects of sound frequencies on pain induced by intramuscular injection (IMI).
Methods:
This was a double-blind study involving IMI candidates who were randomly divided into 10 equal groups, including intervention, inactive, and control groups (30 patients per group). In the intervention groups, patients received sound stimulation at frequencies ranging from 10 to 200 Hz at 50 dB during IMI. No sound stimulation was provided in the control and inactive groups. Pain and comfort levels were assessed using a visual analog scale, along with monitoring changes in blood pressure and heart rate.
Results:
The study results indicated that as sound frequency increased, pain levels decreased compared to the control and inactive groups. The reduction in pain and increase in comfort scores were most significant at frequencies of 150 and 200 Hz. Tachycardia intensity at 150 and 200 Hz was significantly lower than in the inactive and 10 Hz groups. The increase in systolic blood pressure at frequencies of 40 to 200 Hz was significantly lower than in the inactive group, and also at 200 Hz compared to the control and 10 to 50 Hz groups. Additionally, diastolic blood pressure at 200 Hz was significantly lower than in the control, inactive, and 10 to 50 Hz groups.
Conclusion:
The study concluded that sound can reduced IMI pain, as well as postinjection changes in blood pressure and heart rate. This nonpharmacological and noninvasive intervention demonstrated greater changes at higher frequencies.
