In cases where a patient exerts minimal inspiratory effort, the flow-time scalar usually displays an exponential decay, while the pressure remains constant throughout the inspiratory phase in pressure support mode. A similar appearance can also be observed during false triggering when the patient is in a passive state.  In the second breath, the waveform exhibits typical characteristics of pressure support waveforms, indicating the possibility of either a patient-triggered br

The following waveform illustrates three consecutive breaths, each with distinct morphologies. On this ventilator (Maquet, Getinge), patient-triggered breaths are marked in pink at the initial rise in pressure and flow, corresponding to pressure or flow triggering. In this case, flow triggering was used. The breaths appear to be patient-triggered, as suggested by a small negative deflection in airway pressure preceding inspiration and the pink marking on the flow–time scalar.

This patient with Guillain–Barré syndrome had been on mechanical ventilation for more than five days. When transitioned to pressure support mode, the ventilator waveforms showed patient-triggered breaths, and clinically the patient appeared comfortable, without accessory muscle use or tachypnea. However, the patient’s muscle strength remained at grade 1, and in neuromuscular weakness, such low muscle power would typically result in marked work of breathing on pressure support

PIC 1:The pressure-time scalar exhibits pressure drops varying in amplitude beneath the baseline. Smaller pressure drops (0.5 cm H2O) and larger pressure drops (2 cm H2O) arise from cardiac pulsations and patient's inspiratory efforts, respectively. PIC 2: False trigger (also known as auto trigger) Opting for a pressure trigger sensitivity threshold of 0.5 cm H2O can lead to both cardiac oscillations and inspiratory efforts meeting this threshold, leading to a situation wher

The following image illustrates four types of patient-ventilator interactions that can occur while triggering a breath 1) Early trigger: A mechanical breath is initiated before the onset of neural inspiration. Revere trigger is an example of early trigger where passive mechanical inflation triggers diaphragm contraction. 2) Late trigger: Mechanical inflation begins more than 100 milliseconds after the start of the patient's inspiration. 3) Failed Trigger:  Also known as an in

All these breaths appear to be patient-triggered, as indicated by the pressure drop before each inspiration. However, this pressure drop is actually caused by a large leak from the mask, leading to a breath being delivered—this is known as a false trigger or auto-trigger. The expiratory limb of the volume- time scalar fails to reach the baseline before the next breath because of a significant leak. Additionally, the area under the expiratory flow-time scalar is much smaller c

These breaths appear to be patient-triggered, as indicated by the purple color on the ascending limb of the inspiratory flow-time scalar (with flow trigger setting). During mid-inspiration, a notch is visible in the pressure-time scalar, suggesting inspiratory muscle contraction leading to a pressure drop. Correspondingly, an increase in inspiratory flow can be observed, indicating the patient's inspiratory effort. This pattern suggests that each breath is patient-triggered,