The anti-inflammatory role of therapeutic ultrasound and low-level laser in chronic rhinosinusitis: A fractional exhaled nitric oxide outcome hypothesis

Chronic rhinosinusitis is defined as a complex of disorders whose main feature is nasal and paranasal sinus mucosal inflammation for at least three months. Inflammation plays a key role in chronic rhinosinusitis. Fractional exhaled nitric oxide is used to monitor eosinophilic airway inflammation in the human lower airways. Fractional exhaled nitric oxide levels are paradoxically low in some chronic rhinosinusitis patients. This has been attributed to sinus ostia obstruction. However, a recent study has demonstrated that fractional exhaled nitric oxide levels could serve as a chronic rhinosinusitis inflammation biomarker independent of lower airway inflammatory disease and could be used as a treatment response biomarker. Therapeutic ultrasound and low-level laser therapy have been used in chronic rhinosinusitis management. Through a variety of mechanisms, ultrasound enhances bacterial killing. Low level laser therapy increases nitric oxide release and ATP levels. It also reduces inflammation and accelerates tissue repair. Fractional exhaled nitric oxide levels could be used to evaluate the anti-inflammatory actions of therapeutic ultrasound and low-level laser therapy in chronic rhinosinusitis patients. A hypothesis that fractional expired nitric oxide measurements could be a useful biomarker to evaluate their potential anti-inflammatory mechanisms and monitor their treatment efficacy is proposed. This could contribute to a better understanding of these therapies in chronic rhinosinusitis management. An improved understanding of treatment efficacy could lead to improved management strategies.