Describe the physiological consequences of Positive End-Expiratory Pressure 
(PEEP). 

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College Answer

Most answers were quite brief and superficial. They simply did not cover enough of the required 
knowledge base to gain a pass mark. A definition of PEEP is a useful way to start this answer and 
this was missing in more than half the answers. Deficiencies in knowledge included even the 
primary respiratory and cardiovascular effects of PEEP. Many candidates incorrectly concluded 
that PEEP would increase afterload and decrease pulmonary vascular resistance. Some 
candidates provided description of the cardiovascular effects of Valsalva, which was not part of 
the question. It was expected candidates would also mention physiological effects on other 
organ systems such as potential cerebral and renal effects.
This topic (Level 1) requires a detailed knowledge and candidates should read widely to gain the 
depth of understanding required. The core material is covered in texts such as Nunn’s’ Applied 
Respiratory Physiology and additional applied information can be found in a variety of texts such 
as Textbook of Critical Care by Fink et al, Irwin and Rippe’s Intensive Care Medicine or Miller’s 
Anaesthesia.