negative end-expiratory pressure 

CRITICAL CARE, PULMONOLOGY

A format for mechanical ventilation in which negative (subatmostpheric) pressure–i.e., suction is applied during ventilation. Recent data suggest that it may be useful during CPR and circulation may be significantly augmented by generation of a negative end expiratory pressure between each breath. 

Pros NEEP raises the pressure gradient between the patient’s airway and the atmosphere, thereby increasing the expiratory flow rate, lowers the mean intrathoracic pressure over the regulatory cycle, and enhances the venous return and cardiac output 

Cons NEEP predisposes to airway collapse, air trapping, and alveolar rupture, which is not good for patients with decreased elastic recoil.

Reference Segal N, et al, Resuscit. 2012 Aug 17

http://www.ncbi.nlm.nih.gov/pubmed/22902465