Electrochemical nasal nitric oxide measurement during laryngeal mask ventilation as primary ciliary dyskinesia screening.

Introduction: Diagnosis of primary ciliary dyskinesia (PCD) can be challenging, especially in children of preschool age. Measurement of nasal nitric oxide (nNO) production helps in making the diagnosis. While chemiluminescence-based nNO measurement is sufficiently established, measuring nNO using electrochemical devices is common in older patients, although data on their repeatability and accuracy are scarce. Methods: This is a retrospective analysis of nNO measurements using an electrochemical technique (ECnNO) in 52 children undergoing bronchoscopy including 10 PCD cases. Using a novel approach to obtain electrochemical measurements in even very young children (n=31) (59.6%) were <5 years of age), ECnNO was measured while patients were in breath-hold during ventilation with laryngeal mask (ECnNO LAMA). For agreement, the intraclass correlation coefficient (ICC) was calculated. Precision is described by the measurements' coefficient of variation. Results: ECnNO LAMA measurements yielded an overall substantial ICC of 0.974 (95% CI 0.972-0.990) with no statistical difference for patients over or under 5 years. The overall coefficient of variation was 0.116 and thus comparable to chemiluminescence-based measurements in this age group. Conclusion: The novel ECnNO LAMA technique is feasible and showed promising repeatability and precision in screening for PCD in children <5 years of age. While further studies are needed, this method may help diagnose PCD in young patients and simplify a troublesome differential diagnostic process.