Skull and Sinus

Abstract

Traditional outpatient diagnosis of acute rhinosinusitis frequently results in overuse of antibiotics. Point-of-care ultrasound (POCUS) of the maxillary sinus is specific for clinically important fluid, but may miss subtle abnormalities that are rarely clinically important. The ethmoid and frontal sinuses are more challenging to image and are infrequently abnormal in isolation from the maxillary sinus. The absence of maxillary sinus fluid is a strong reason to avoid antibiotics in most patients, and helps reassure them. However, a patient with fever, severe symptoms suggestive of sinusitis, but no fluid with maxillary ultrasound, may need a computerized tomography (CT) scan to look for isolated ethmoid, frontal, or sphenoid sinusitis. A few clinical studies, and our clinic’s experience, suggest that ultrasound can substantially reduce antibiotic use for sinusitis [1–3], although there are no large randomized trials to confirm this. Only 23% of patients suspected of sinusitis in our clinic had positive ultrasound [3]. The presence of fluid does not differentiate between viral and bacterial disease, so the final antibiotic decision requires integration of ultrasound with the rest of the patient findings.