title: [Clinical study of the setting of positive end expiratory pressure in patients with acute cardiogenic pulmonary edema during mechanical ventilation].
abstract: OBJECTIVE
  To compare the effects on hemodynamics and lung mechanics when different positive end expiratory pressure (PEEP) levels were used in acute cardiac pulmonary edema.
  
  
  METHODS
  Thirty-nine patients with respiratory failure and treated with mechanical ventilation were divided into two groups according to cardiac index (CI). The changes of hemodynamics [including cardiac output (CO), CI, pulmonary capillary blood flow (PCBF), central venous pressure (CVP), surround vascular resistance (SVR)], lung mechanical variables [intrinsic positive end expiratory pressure (PEEPi), peak inspiratory pressure (Ppeak), mean of airway pressure (Pmean), minute volume (MV), alveolar tidal volume (Vtalv)], percutaneous saturation of oxygen (SpO(2)) and blood pressure (BP) were determined with when selected different PEEP levels under the bi-level positive airway pressure (BIPAP) mode in normal cardiac function group (n=18, CI> or =2.0 L.min(-1).m(-2)) and poor cardiac function group (n=20, CI<2.0 L.min(-1)xm(-2)).
  
  
  RESULTS
  In normal cardiac function group, PEEP has no effect on hemodynamics when varied from 0-13 cm H(2)O (1 cm H(2)O=0.098 kPa), and Ppeak and PEEPi increased with the elevation of PEEP. Resistance of airway (R) fell when PEEP was increased. However, in poor cardiac function group SVR, CO, CI showed curvilinear changes with an increase in PEEP, and CO, CI were high when PEEP changed from 0 to 7 cm H(2)O, but dropped markedly when PEEP was increased in 13 cm H(2)O, while the changes of SVR was the reverse of CO and CI. The effects on lung mechanics varied relatively smaller range when PEEP was set between 5-7 cm H(2)O, and the burden of breathing was slight.
  
  
  CONCLUSIONS
  The mode of artificial ventilation should be adjusted according to the changes in hemodynamics and lung mechanics. PEEP should be individualized, and 5-7 cm H(2)O (normally below 10 cm H(2)O) is suitable.
authors.affiliation: Department of Intensive Care Unit, Tianjin Third Central Hospital, Tianjin 300170, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Ling
authors.initials: L
authors.lastname: Huang
authors.forename: Yin-zhi
authors.initials: YZ
authors.lastname: Qin
authors.forename: Na-xin
authors.initials: NX
authors.lastname: Zhang
authors.forename: Shu-peng
authors.initials: SP
authors.lastname: Wang
mesh_terms: D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D004489:Edema, Cardiac / Q000503:physiopathology / Q000628:therapy*; D005260:Female; D006321:Heart / Q000503:physiopathology; D006801:Humans; D008168:Lung / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011175:Positive-Pressure Respiration / Q000379:methods*; D011654:Pulmonary Edema / Q000503:physiopathology / Q000628:therapy*; D016896:Treatment Outcome