Pressure-controlled Continuous Mandatory Ventilation (PCV)

Created on Tue, 06/16/2015 - 17:46
Last updated on Tue, 06/16/2015 - 17:51

PCV Pressure Control Ventilation

  • Pressure Controlled
  • Time-Triggered (but doesn’t have to be)
  • Pressure-limited, Flow-limited (but doesn’t have to be flow-limited)
  • Time-Cycled

 

The key feature is, A PRESSURE VALUE IS TARGETED. You tend to take what tidal volume you can get.

This mode is typically used in patients with reduced lung compliance.

 

Typically, this mode is flow-triggered- the patient will become tachypneic if the tidal volume is inadequate, and this will compensate somewhat for the low tidal volumes you would expect in someone with very stiff lungs.

You get little control over the minute volume. The patient may take as many pressure-supported breaths as he feels like, all you can do is guarantee a certain minute volume with volume-controlled IMV.

CMV, IMV, SIMV, ACV- all these modes can be pressure-controlled. In this instance, the concept is demonstrated in the context of a CMV mode. But yes, you can set pressure as the control variable on any mode.

 

References

Most of this information comes from only two textbooks. With "Basic Assessment and Support in Intensive Care" by Gomersall et al (as well as whatever I picked up during the BASIC course) as a foundation, I built using the humongous and canonical "Principles and Practice of Mechanical Ventilation" by Tobins et al – the 1442 page 2nd edition.

Jonson B, Beydon L, Brauer K et al. Mechanics of respiratory system in healthy anesthetized humans with emphasis on viscoelastic properties. J Appl Physiol 1993; 75 : 132–40.

Zavala, Elizabeth et al.Effect of Inverse I: E Ratio Ventilation on Pulmonary Gas Exchange in Acute Respiratory Distress Syndrome Anesthesiology: January 1998 - Volume 88 - Issue 1 - p 35–42