Effects of different positive end-expiratory pressures on efficacy of volume therapy guided by global end diastolic volume index and central venous pressure in patients with septic shock

Objective To compare the effect of different positive end-expiratory pressures (PEEPs) on the efficacy of volume therapy guided by global end-diastolic volume index (GEDVI) and central venous pressure (CVP) in patients with septic shock.Methods Twenty-five patients with septic shock complicated with respiratory failure,of both sexes,aged 18-64 yr,were enrolled in the study.Their APACHE [[scores were 13-31.The patients were endotracheally intubated and underwent volume-controlled ventilation,PEEP was 5-15 cmH2O,and pulse oxygen saturation was maintained ＞ 90 ％.The patients were divided into low PEEP (5-10 cmH2 O) group and high PEEP (11-15 cmH2 O) group depending on the different PEEP levels.6 ％ hydroxyethyl starch (200/0.5)6 ml/kg was infused over 30 min for volume therapy.Right internal jugular vein or subclavian vein was cannulated for CVP monitoring,and GEDVI was continuously monitored by pulse indicator continuous output monitoring (PiCCO) technology.CVP and GEDVI were recorded before and after volume therapy and the changing rate was calculated.Results Compared with CVP and GEDVI before volume therapy,CVP and GEDVI were significantly increased after volume therapy in low PEEP group (P ＜ 0.05),and GEDVI was increased after volume therapy (P ＜ 0.05) and no significant change was found in CVP after volume therapy in high PEEP group (P ＞ 0.05).Compared with low PEEP group,the changing rate of CVP was significantly decreased (P ＜ 0.05),and no significant change was found in the changing rate of GEDVI in high PEEP group (P ＞ 0.05).Conclusion High PEEP can decrease the efficacy of volume therapy guided by CVP,while exerts no effect on the efficacy of volume therapy guided by GEDVI in patients with septic shock. Key words: Positive-pressure respiration;  Cardiac output;  Central venous pressure;  Fluid therapy; Shock, septic