Recognizing, quantifying and managing patient-ventilator asynchrony in invasive and noninvasive ventilation.

INTRODUCTION: Patient-ventilator asynchrony may occur with modes of partial ventilatory support. Because this problem is associated with worsened outcomes, identifying and managing asynchronies has been recognized as a relevant clinical problem during both invasive and noninvasive (NIV) mechanical ventilation. Areas covered: In this review article, we first describe the different forms of patient-ventilator asynchrony and how they are classified and quantified. Then, we show how these asynchronies can be recognized, considering the techniques used to properly detect asynchronies, by either ventilator waveform observation, or through systems based on more complexes mathematical algorithms, by means of adjunctive signals, such as the electrical activity of the diaphragm or esophageal pressure. Finally, we describe the actions that can be undertaken in order to limit the rate of asynchronies during both invasive ventilation and NIV mechanical ventilation, such as modifications of the ventilator mode and/or settings, variation of the sedation regimen (type and doses), and other technical pitfalls. Expert commentary: Detection of asynchronies is crucial in order to reduce their incidence, adopting adjustments of the ventilator settings, sedation regimen, and other technical pitfalls. It remains to be clarified whether the relationship between high incidence of asynchrony and worsened outcome is causative or just associative.