Images in Sleep MedicineAltering ventilator inspiratory time can reduce autocycling during sleep
Section snippets
Introduction to the case
We report on a 51-year-old man with chronic respiratory failure due to motor neurone disease (amyotrophic lateral sclerosis) referred for overnight polysomnography (PSG) to optimise nocturnal non-invasive positive pressure ventilation (NIPPV).
NIPPV was delivered with a full-face mask and ResMed (San Diego, CA) VPAP™ IV ST in spontaneous/timed mode with the following initial settings: inspiratory pressure = 11 cm H2O, expiratory pressure = 5 cm H2O and respiratory rate = 12 breaths/min. The
Image analysis
Figure 1a demonstrates multiple episodes of rapid cycling between inspiratory pressure and expiratory pressure in the absence of coordinated respiratory movements (see inset for a magnified view). Device-derived flow tracings are erratic. The delivered rate (38 bpm) greatly exceeds the set backup respiratory rate (12 bpm). There is no evidence of excessive leak. This is consistent with autocycling.
Following the increase in Timin, Fig. 1b demonstrates improved patient–ventilator synchrony with
Discussion
Autocycling (or rapid cycling) is a form of patient–ventilator asynchrony (PVA) that can be recognised by the rapid delivery of multiple cycles of ventilator breaths above the preset backup respiratory rate and without evidence of patient effort [1]. The phenomenon appears similar to auto-triggering, but it is differentiated by the presence of multiple consecutive breaths.
In flow-triggered ventilators, autocycling and auto-triggering are believed to arise due to the presence of disturbances in
Conflict of interest
The ICMJE Uniform Disclosure Form for Potential Conflicts of Interest associated with this article can be viewed by clicking on the following link: http://dx.doi.org/10.1016/j.sleep.2015.05.009.
. ICMJE Form for Disclosure of Potential Conflicts of Interest form.
References (6)
Patient-ventilator interaction
Br J Anaesth
(2003)- et al.
Effect of sleep on patient/ventilator asynchrony in patients undergoing chronic non-invasive mechanical ventilation
Respir Med
(2007) - et al.
Autocycling and increase in intrinsic positive end-expiratory pressure during mechanical ventilation
Acta Anaesthesiol Scand
(2001)
Cited by (4)
The optimisation of noninvasive ventilation in amyotrophic lateral sclerosis: A systematic review
2021, European Respiratory JournalOptimizing the noninvasive ventilation pathway for patients with amyotrophic lateral sclerosis/motor neuron disease: a systematic review
2019, Amyotrophic Lateral Sclerosis and Frontotemporal DegenerationAutocycling during noninvasive positive pressure ventilation producing a prolonged severe apnea and syncope
2019, Journal of Clinical Sleep Medicine