Bedside waveforms interpretation as a tool to identify patient-ventilator asynchronies

Objective During assisted modes of ventilatory support the ventilatory output is the final expression of the interaction between the ventilator and the patients controller of breathing. This interaction may lead to patient-ventilator asynchrony, preventing the ventilator from achieving its goals, and may cause patient harm. Flow, volume, and airway pressure signals are significantly affected by patient-ventilator interaction and may serve as a tool to guide the physician to take the appropriate action to improve the synchrony between patient and ventilator. This review discusses the basic waveforms during assisted mechanical ventilation and how their interpretation may influence the management of ventilated patients. The discussion is limited on waveform eye interpretation of the signals without using any intervention which may interrupt the process of mechanical ventilation.Discussion Flow, volume, and airway pressure may be used to (a) identify the mode of ventilator assistance, triggering delay, ineffective efforts, and autotriggering, (b) estimate qualitatively patients respiratory efforts, and (c) recognize delayed and premature opening of exhalation valve. These signals may also serve as a tool for gross estimation of respiratory system mechanics and monitor the effects of disease progression and various therapeutic interventions.Conclusions Flow, volume, and airway pressure waveforms are valuable real-time tools in identifying various aspects of patient-ventilator interactionElectronic Supplementary Material Electronic supplementary material to this paper can be obtained by using the Springer Link server located at