Need your expertise
- Alberto
- Feb 28, 2019
- 1 min read
Thoracic cage sarcoma. 3rd to 6th anterior ribs resection - significant chest in-drawing and paradoxical chest wall movements with spontaneous breaths.
Patient on SIMV-PS. PEEP 8. Can anyone explain to me the increase in airway pressure during the early expiration (red arrow) and the two-slope appearance of the assisted breaths (blue arrow) ?
Hi everyone!
We are conducting an international survey to know the characteristics of professionals and medical units using esophageal pressure monitoring. We invite you to participate in this survey and share your valuable knowledge with us.
To participate in the survey, click on the link below:
https://es.surveymonkey.com/r/WJ3F5S7?lang=en
We appreciate your dissemination to other colleagues
Inspiratory flow decrease in a linerar way, that reflect a pasive patient and after a time increase in the middle of inspiratory time, that is the begining of patient inspiratory effort longer than the end of inspiratory mechanical time. As we can see in the oscilation in the expiratory flow and when the inspiratory effort suddenly finish, that produce the oscillation in airways pressure. I thinks that trigger reverse, with ratio 1:1, (inspiratory mechanical: neural inspiratory ratio)
The blue arrow: because of the constant inspiratory pressure profile, we should expect a decelerating inspiratory flow pattern. This deceleration is probably distorted (blue arrow) by an reversed triggered inspiration by the patient. The small pressure drop at this point is also suggestive for this.
Red arrow: this could also be explained by the initial high expiratory flow which resulted in a small pressure built up in the ventilatory circuit (flow -40l/min --> 0,67l/s causing a pressure rise of about 2cm H20 (resistance circuit and expiratory valve is not zero). Because the circuits does not only have a R but also a C value, flow and pressure could have a small phase setoff)
Thank you Jean-Michel! Do you think the delayed cycling could be related to the paradoxical chest wall movements with in-drawing of the area affected by the rib resection? Regarding active expiratory efforts, I know they are very difficult to assess clinically, but I did not notice any. Could it have been a delayed emptying of the lung underlying the area affected by the paradoxical movement?
Interesting case: Regarding the blue arrow, this change in the slope of inspiratory flow means usually the end of the patient inspiratory effort. This would mean a delayed cycling for this particular breath. The red arrow could then be an active expiratory effort. Best regards