Utility of peak inspiratory flow in managing subglottic stenosis

To identify the utility of peak inspiratory flow (PIF) in the assessment and management of subglottic stenosis through correlation of clinical presentation with PIF.

Case report.

Review of the clinical course of a 31-year-old woman with the diagnosis of granulomatosis with polyangiitis. Repeated PIF measurements at clinic visits were obtained over a 30-month follow-up.

Twenty-seven PIF measurements were obtained at 31 otolaryngology clinic visits. Correlations were identified between low PIF measurements with the clinical symptom shortness of breath (2.04±0.38 L/s, n=10), clinically recorded stridor at rest (1.64±0.41 L/s, n=3), and urgent operative intervention (1.60±0.23 L/s, n=5). Correlations were identified between high PIF measurement with patient report of normal breathing (3.07±0.35 L/s, n=16) and clinical observation of absence of stridor at rest (2.81±0.32 L/s, n=23). There was a statistically significant difference in the patient's PIF values with patient-documented shortness of breath vs no shortness of breath (P=.001) and clinician-noted stridor vs no stridor (P=.017).

Peak inspiratory flow measurements correlate with degree of airway compromise and are helpful to monitor the degree of airway obstruction and document response to treatment.