100 ms matter: Impact of back-up Ti on triggered breaths in pediatric NIV.

Abstract

Noninvasive ventilation (NIV) is widely used in children, including children with neuromuscular disorders (NMD). Pressure support (PSV) mode is the most used mode for home NIV, and combines controlled, assisted, and spontaneous breaths. The patient can trigger a breath based on the inspiratory trigger (TgI) sensitivity and cycle the breath based on the expiratory trigger (TgE) sensitivity. Some ventilators proposed to cycle the controlled breaths based on a back-up inspiratory time (Ti). There are no guidelines to adjust TgI parameter according to the age and/or disease of the patient. In patients with NMD, TgI may be set at a low sensitivity to impede the patient to trigger the breaths and force the respiratory muscles to rest, as done by some centers. It is not our practice, as we believe that a low TgI sensitivity will generate further respiratory efforts for the patients, particularly during some sleep periods or nighttime wakefulness. According to our experience, even with a high TgI sensitivity, our patients with NMD do not trigger the ventilator for almost the entire nighttime if they are efficiently ventilated. We report the cases of 4 children, including two children with NMD or suspicion of NMD, for whom an adaptation of the back-up Ti had a direct impact on the triggered/controlled breath ratio.