[Cohort of patients initiated to home ventilation. Observational and prospective study]

Monitoring of noninvasive ventilation: comparative analysis of different strategies

Background

Noninvasive ventilation (NIV) represents an effective treatment for chronic respiratory failure. However, empirically determined NIV settings may not achieve optimal ventilatory support. Therefore, the efficacy of NIV should be systematically monitored. The minimal recommended monitoring strategy includes clinical assessment, arterial blood gases (ABG) and nocturnal transcutaneous pulsed oxygen saturation (SpO₂). Polysomnography is a theoretical gold standard but is not routinely available in many centers. Simple tools such as transcutaneous capnography (TcPCO₂) or ventilator built-in software provide reliable informations but their role in NIV monitoring has yet to be defined. The aim of our work was to compare the accuracy of different combinations of tests to assess NIV efficacy.

Methods

This retrospective comparative study evaluated the efficacy of NIV in consecutive patients through four strategies (A, B, C and D) using four different tools in various combinations. These tools included morning ABG, nocturnal SpO₂, TcPCO₂ and data provided by built-in software via a dedicated module. Strategy A (ABG + nocturnal SpO₂), B (nocturnal SpO₂ + TcPCO₂) and C (TcPCO₂ + builtin software) were compared to strategy D, which combined all four tools (NIV was appropriate if all four tools were normal).

Results

NIV was appropriate in only 29 of the 100 included patients. Strategy A considered 53 patients as appropriately ventilated. Strategy B considered 48 patients as appropriately ventilated. Strategy C misclassified only 6 patients with daytime hypercapnia.

Conclusion

Monitoring ABG and nocturnal SpO₂ is not enough to assess NIV efficacy. Combining data from ventilator built-in software and TcPCO₂ seems to represent the best strategy to detect poor NIV efficacy.

Trialregistration Institutional Review Board of the Société de Pneumologie de Langue Française (CEPRO 2016 Georges)

[Obesity hypoventilation syndrome and initial compliance with non-invasive ventilation]

INTRODUCTION

The obesity hypoventilation syndrome (OHS) has an increasing prevalence. Compliance with first-line non-invasive ventilation has not been evaluated, taking into account patients' initial comorbidities. This study consisted of identification of the factors associated with compliance with non-invasive ventilation during the first six months of use.

METHODS

A monocentric retrospective study, gathering patients from the pneumology department of Gabriel-Montpied hospital in Clermont-Ferrand, from April 2010 to October 2019. The analysis was carried-out through the collection of computerised medical records (age, mode of entry, patient comorbidities) and compliance reports (average daily hours of use) provided by the regional service provider for the Auvergne area (AIRRA).

RESULTS

Being hospitalized for an acute exacerbation and being older than seventy-five years were factors associated with an improved compliance to non-invasive ventilation, with an increase of 1.47h/d and 2.73h/d (P value: 0.018 and 0.02, respectively). Moreover, patients with obstructive sleep apnea hypopnea syndrome and recipients of therapeutic education may prove more compliant over time.

CONCLUSION

Age greater than seventy-five years and being hospitalized for an acute exacerbation are predictors of better use of non-invasive ventilation in OHS.