A patient reports a burning sensation during ultrasound treatment. What should the therapist do first?

When a patient reports a burning sensation during ultrasound treatment, the first priority is to ensure the patient's safety and comfort. Temporarily discontinuing the treatment and checking the coupling agent is the most appropriate action because a burning sensation may indicate that the ultrasound head is not properly coupled to the skin, which can lead to overheating and potential injury to the tissue.

By stopping the treatment, the therapist can investigate the cause of the discomfort, such as inadequate gel application or an inappropriate choice of ultrasound parameters. Checking the coupling agent is crucial because effective transmission of ultrasound waves through the skin requires proper coupling, which is achieved with a sufficient layer of gel. If the gel is too thick or insufficient, it can result in excessive heat buildup and discomfort for the patient.

Continuing treatment without addressing the patient's experience can lead to further discomfort or even tissue damage, so it's essential to take a methodical approach to ensure a safe and effective treatment modality.