To evaluate the sensitivity and specificity of a screening test panel for nocturnal hypoventilation (NH) and other sleep related respiratory events during monitoring of patients with chronic hypercapnic respiratory failure (CRF) treated with NIV.

We performed a prospective study at Oslo University Hospital. Eligible for inclusion were consecutive adults with CRF due to neuromuscular diseases or chest wall disorders treated with NIV scheduled for a follow-up visit. All patients underwent the screening test panel (clinical evaluation, daytime arterial blood gas (ABG), nocturnal pulse oximetry (SpO₂) and data from ventilator software) and the reference tests; sleep polygraphy and nocturnal transcutaneous CO₂.

Of 67 patients included, NH was confirmed in 23–50 according to the 3 definitions used for NH, apnea-hypopnea index (AHI_polygraphy) ≥ 10 was confirmed in 16 and patient-ventilator asynchrony (PVA) ≥ 10% of total recording time in 14. Sensitivity of the combined screening test panel for NH was 87% (95% confidence interval 66–97), 84% (66–95) and 80% (66–90), for abnormal AHI_polygraphy 91% (59–100) and for PVA 71% (42–92). Sensitivity for NH of SpO₂ was 48% (27–69), 39% (22–58) and 38% (24–53) and of daytime ABG 74% (52–90), 74% (55–88) and 68% (53–80). Sensitivity and specificity of AHI_software for AHI_polygraphy ≥ 10 was 93% (68–100) and 92% (81–98) respectively.

In patients treated with long term NIV, screening test panel, nocturnal SpO₂ and daytime ABG all failed to accurately detect NH, underlining the importance of nocturnal monitoring of CO₂. AHI_software accurately identified obstructive events and can be used to modify NIV settings.

N° NCT01845233.