Influence of different positive end-expiratory pressure and postures on central venous pressure of patients with mechanical ventilation

Objective To explore the influence of different positive end-expiratory pressure (PEEP) and postures on central venous pressure (CVP) of patients with mechanical ventilation.Methods A total of 48 patients with mechanical ventilation due to respiratory failure were selected.CVP values when PEEP was at 0,3,6,9,12,15 and 18 cm H2O and the values when patients were placed in supine position or when bedside was lifted by 15°,30°,45°and 60°in supine position were detected.Results CVP value increased with the increase of PEEP level,and it was markedly higher when PEEP≥15 cmH2O than that when PEEP was 0 ～ 12 cmH2O (P ＜0.05 or P ＜0.01).Different PEEP had insignificant influence on heart rate (HR) and mean arterial pressure (MAP) (P ＞ 0.05).However,saturation of blood oxygen (SpO2) increased with the increase of PEEP level,which increased more significantly when PEEP ≥ 12 cmH2O than that when PEEP ≤6 cmH2O (P ＜ 0.01).CVP value was markedly higher in supine position than that when bedside was lifted by 15°,30°,45°and 60°(P ＜0.05 or P ＜0.01).The larger the angle of supine position was,and lower the CVP value became.And different postures had no influence on levels of HR,MAP and SpO2 (P ＞ 0.05).Conclusion Different PEEP and postures have great influence on CVP values,and severe patients should be placed in original position when detecting CVP.