Test your IntelliVence (Vol 17 Issue 5)

Author: Jean-Michel Arnal, Reviewer: David Grooms

This patient is intubated and ventilated using pressure support (PS) mode. Why is the shape of the flow and pressure waveforms abnormal?

Answer: The pressure waveform shows a very steep decrease before the mechanical breath (1). During inspiration, the pressure rises instead of having a square shape (2). Flow during inspiration is rounded instead of having a triangular shape (3), and there is early cycling because of the small distortion of flow at the beginning of expiration (4).

All these abnormalities mean that the patient has a strong inspiratory effort and the ventilator is not providing enough flow. This flow starvation in PS can be corrected by increasing pressure support and shortening the pressure ramp.

flow starvation, pressure support, flow waveform, pressure waveform, early cycling, inspiration, expiration, pressure ramp

Date of Printing: 03.03.2021
The content of this newsletter is for informational purposes only and is not intended to be a substitute for professional training or for standard treatment guidelines in your facility. Any recommendations made in this newsletter with respect to clinical practice or the use of specific products, technology or therapies represent the personal opinion of the author only, and may not be considered as official recommendations made by Hamilton Medical AG. Hamilton Medical AG provides no warranty with respect to the information contained in this newsletter and reliance on any part of this information is solely at your own risk.