So how can you work out what are the phase variables in the ventilator cycle? Go back to this page to understand the cycle variables again if you are not sure.

 

 

 

Trigger Variable

Does the inspiration start because a preset pressure is detected? -YES- Inspiration is pressure triggered

NO

Does the inspiration start because a preset flow is detected?- YES- Inspiration is flow triggered

NO

Does the inspiration start because a preset volume is detected?- YES- Inspiration is flow triggered

NO

Inspiration starts because a preset time interval has elapsed?- YES- Inspiration is time triggered

Limit Variable

Does peak pressure reach preset value before inspiration ends?- YES- Inspiration is pressure limited

NO

Does peak volume reach preset value before inspiration ends?- YES- Inspiration is volume limited

NO

Does peak flow reach preset value before inspiration ends?- YES- Inspiration is flow limited

Cycle Variable

Does inspiratory flow end because a preset pressure is attained?- YES- Inspiration is pressure cycled.

NO

Does inspiratory flow end because a preset pressure is attained?- YES- Inspiration is volume cycled.

NO

Does inspiratory flow end because a preset flow is attained?- YES- Inspiration is flow cycled.

NO

Inspiration ends because a preset time interval has elapsed.- YES- Inspiration is time cycled.

Chatburn RL. Classification of Mechanical Ventilators. Respir Care 1992

Jevon

Jevon

Possibly the book I most highly recommend for nurses to use as their pocket guide. Phil Jevon is a practitioner in Walsall and has produced an easily read, pocket sized tool. You can click on the picture above  to purchase this excellent book.
Talley and O'Conner
Slightly less 'weighty' than Macleods but still with lots of useful detail and information. The latest copies also have a CD with good, well narrated examples of clinical examination.
Macleods
This title is 'Highly Commended' in the 2006 British Medical Association Awards! 'an incredibly thorough book which is very well illustrated - a must in a book explaining how to perform examinations' - ("Medical Student Review"). This book will show you how to: talk with a patient; take the history from the patient; examine a patient; formulate your findings into differential diagnoses and rank these in order of probability; and, use investigations to support or refute your differential diagnosis.