Patient effort at a glance

Abstract

A: Patient with little effort. Top: Volume Controlled Ventilation: airway pressure in cmH2O in yellow, constant flow in L/min in pink. Middle: Pressure controlled ventilation: airway pressure in cmH2O in yellow, decelerating flow in L/min in pink. Bottom: Esophageal pressure in cmH2O. B: Patient with high effort. Top: Volume Controlled Ventilation: airway pressure with convex negative deflection during trigger and first half of inspiration (blue arrow). Middle: Pressure controlled ventilation: airway pressure with negative deflection during the trigger (yellow arrow) and slight convex deflection (green arrow), concave deflection in the flow (orange arrow). Bottom: Convex deflection in esophageal pressure (grey arrow).

Identifying asynchronies: work shifting and double triggering

“…The effect on the flow is usually apparent on the decelerating or the descending flow but not the constant flow, with a concavity of the curve correlates to the patients' muscle pressure. 18 Additionally, flow starvation results in an increasing load to the patients' respiratory muscles. 19 The maximum expression of flow asynchrony is when airway pressure is less than or equal to the programmed PEEP, indicating that there is no ventilator inspiratory support.…”