The effect of positive end-expiratory pressure on patients′state with chronic obstructive pulmonary disease

Objective To study the effects of different level of PEEP on chronic obstructive pulmonary complication of respiratory failure.Methods 40 patients with exacerbated COPD who required mechanical ventilation because of complication of respiratory failure were studied from November 2007 to February 2009.All of the patients were randomly divided into two groups:A group(20 cases,PEEP was set 5 cm H2O) and B group(20 cases,PEEP was set 10 cm H2O).The indexes of arterial blood gas analysis,pressure and hemodynamics were measured after mechanical ventilation.Results(1) Arterial blood gas analysis: the indexes of arterial blood gas analysis showed no significant group difference at 0.5 h after ventilation,and at 24 h after ventilation) in two groups patients,P0.05.(2) Airway pressure: after ventilation of 0.5 h,24 h,and peak inspiratory pressure,the plateau pressure in B group was significantly higher than that in A group,P0.05.(3) Hemodynamics: heart rate(HR),mean arterial blood pressure(MAP),systemic vascular resistance index(SVRI),cardiac output index(CI),left cardiac work index(LCWI),thoracic fluid conten(TFC) didn′t change markedly after the ventilation of 0.5 h in the two groups;HR,MAP,SVRI also didn′t change markedly after ventilation of 24 h in the two groups.However,at 24 h after ventilation CI,TFC,LCWI in B group were less than those in A group,P0.05.Conculsion Low levels of PEEP is helpful and safe to patients with COPD during mechanical ventilation.We should avoid negative effects with high level PEEP.