Understanding Neurogenic Patient-Ventilator Discordance and its Management

Patients with an acutely injured brain may resist the mechanical physics of the ventilator. Neurogenic respiratory breathing patterns generated by the patient may result in the ventilator failing to synchronize with this abnormal drive. This asynchrony may be perceived as distress and with a high respiratory drive could also lead to global lung stress and diaphragmatic myoinjury, and affect liberation from the mechanical ventilator at a later point. Patient-ventilator synchrony concerns have rarely been prioritized in neurocritical care guidelines and are often inappropriately treated with escalating sedation. Starting with the essentials of waveform interpretation and moving towards more complex interpretations of these asynchronies, this review provides insight into the common themes of neurogenic synchrony concerns in mechanically ventilated patients. High respiratory drive, double-triggering/ breath-stacking, and reverse triggering are the most prevalent observations. Adjusting the ventilator can improve patient-ventilator interaction and a number of options to remediate these synchrony concerns are provided.