Effect of applied positive end expiratory pressure (PEEP) on the auto PEEP in chronic obstructive pulmonary disease patients

Abstract

The presence of intrinsic positive end expiratory pressure has profound implications in the management of critically ill patients. PEEPi may impair cardiac output and impose a significant inspiratory threshold load. The current study was conducted on 12 COPD patients admitted to the critical care unit of Alexandria Main University Hospital to assess the presence and the magnitude of intrinsic PEEP. The aim of the present work was to study the effect of applied PEEP on patients with chronic dbstructive pulmonary disease having auto PEEP on mechanical ventilation. • All COPD patients were ventilated using the assisted control mode of mechanical ventilation. Patients were subjected to the following:

History taking,clinical examination, measurement of auto PEEP, static auto PEEP: using mechanical ventilator valve occlusion method, dynamic auto PEEP: mathematically (i.e. the difference between end inspiratory static pressure and the sum of tidal volume/static compliance (VT/C)

and PEEP), measurement of lung mechanics:

Static compliance, dynamic compliance and airway pressures, measurement of right ventricular haemodynamics: using Swan Ganz catheter for measuring: Cardiac output, right ventricular end diastolic pressure (i.e. CVP), mean pulmonary artery pressure and measurement of total oxygen consumption. All measurements were done before and after applying external PEEP equivalent to 50% and 100% of the • measured auto PEEP.