I'm sharing this image to illustrate that an upward deflection in the first half of the expiratory flow-time curve can sometimes be misinterpreted as an early cycling dyssynchrony. In this instance, the upward deflection in the expiratory flow-time curve was caused by a failed trigger. The patient completed one breath within the predetermined inspiratory time and began inhaling during the early expiratory phase, leading to the observed upward deflection. This particular scena

Ventilator ends the inspiratory phase before the conclusion of neural inspiration leading to an upward deflection in the expiratory flow time scalar (expiratory flow reduced because of continuation of neural inspiration after the end of mechanical inflation).

In volume control mode, the morphology of the flow-time scalar is fixed and unaffected by respiratory system mechanics or Pmus. However, in pressure control mode, a strong Pmus can alter the morphology of the pressure-time scalar. Instead of the normal exponential decay, a sinusoidal waveform may appear in the presence of strong Pmus, and there may be an increase in the peak inspiratory flow.  The inspiratory limb of the flow-time scalar may reach the baseline early when ther

You can observe three pairs of breaths (double trigger) in this image. The first breath in double trigger is triggered by the machine, characterized by a rapid increase in pressure that reaches the pressure alarm limit, causing pressure cycling. The subsequent breath is a patient triggered mandatory breath. The pressure-time scalar deviates below the baseline due to strong inspiratory effort, known as work shifting. As the inspiratory muscles relax, the pressure-time scalar r

In pressure control mode, the pressure remains constant regardless of the respiratory mechanics. Conversely, in volume control mode, the morphology of the pressure-time scalar is influenced by Pmus (muscle pressure generated by inspiratory muscles), resistance, and compliance of the respiratory system.  In volume control mode a stronger Pmus can cause a downward deviation in the pressure-time scalar. Increased resistance results in a higher peak inspiratory pressure and a gre

These breaths are patient triggered breaths. Due to significant air leak from the mask, the % flow cycling threshold is not reached, and the ventilator fails to terminate inspiration. Meanwhile, the patient completes one full breath cycle (inspiration and expiration) and initiates another, leading to a second peak in the inspiratory flow-time scalar. In pressure control or pressure support modes, an air leak causes the ventilator to increase flow in an attempt to maintain the