The objective of the present study was to compare the effects of continuous ultrasound (
CUS) with pulsed ultrasound (
PUS) in patients with chronic
rhinosinusitis (CRS). In this prospective, randomized, double-blind, parallel group study, 40 patients (10 losses) with CRS participated. Patients received either continuous or pulsed (1:9) 1 MHz ultrasound (US) using a US head of 1 cm2 at 1 W/cm2 and 0.5 W/cm2 for the maxillary and frontal sinuses, respectively. Treatment was performed in 10 sessions, 3 days per week, with US given every other day. The primary outcome measure was percent improvement in the
Sinusitis Symptom Score. Measurements were taken before and after 10 treatment sessions. The patients were followed up monthly for 2 months.
After treatment, both groups improved significantly on the
Sinusitis Symptoms Score. Patients who received
PUS had significantly decreased total symptom scores compared with patients receiving
CUS (mean change 9.8 vs. 5.6, p = 0.049). The percent improvement in the
Sinusitis Symptom Score between the
PUS group (65.2 SD 23.1) and the
CUS group (43.9 SD 40.7) was not statistically significant (p = 0.09). The effect size for each treatment was large;
PUS: d = 3.92 and
CUS: d = 1.93. Symptom improvement in both groups was similar at the 2-month follow-up. These results support the use of therapeutic US for CRS. This pilot study gives only marginal evidence to favor
PUS over
CUS.