ICU: Cardiopulmonary Interaction - Spontaneous breathing vs. Positive Pressure Ventilation

Optimum PEEP in adult patients with ARDS:

(Figure from ICU book - Paul Marino 2nd ed)

PEEP vs. Cardiac output

[Ref: Fessler, HE. Effects of CPAP on venous return. J Sleep Res 1995;4 (Suppl 1):44-49]

Beware of this first figure...this is a study in Sleep Apnea patients...it is an important question to ask whether this is entirely applicable to our cardiac ICU babies/infants!

Useful reference: The use, abuse and mystique of positive end-expiratory pressure. Am Rev Respir Dis 1988;138:475-8.

Anesthetized Dog:

(Following figures are from AC Chang's textbook - Pediatric Cardiac Intensive Care)

LV afterload

Vertical Dotted Lines enclose Inspiration