The Clinical Value of Pulse Pressure Variation to Monitor the Fluid Responsiveness and Effects of PEEP in Ventilated Patients with Acute Lung Injury / 中国呼吸与危重监护杂志

ABSTRACT

Objective To investigate whether pulse pressure variation (△PP) reflect the effects of PEEP and fluid resuscitation (FR) on hemodynamic effects.Methods Twenty critical patients with acute lung injury was ventilated with volume control (VT =8 mL/kg,Ti/Te = 1 2) ,and PaCO2 was kept at 35 to 45 mm Hg.PEEP was setted as 5 cm H2O and 15 cm H2O in randomized order.Hemodynamic parameters including cardiac index, pulse pressure, central venous pressure, etc.were monitered by PiCCO system.Measurements were performed after the application of 5 cm H2O PEEP (PEEPs group)and 15 cm H2O PEEP (PEEP15 group) respectively.When the PEEP-induced decrease in cardiac index (CI) was > 10%, measurements were also performed after fluid resuscitation.Results Compared with PEEPs group, CI was decreased significantly in PEEP15 group(P < 0.05), and APP was increased significantly (P < 0.05).In 14 patients whose PEEP-induced decrease in CI was > 10%, fluid resuscitation increased CI from (3.01±0.57)L · min-1· m-1to (3.62±0.68)L · min-1 · m-2(P<0.01),and decreased △PP from (17±3)% to (10±2) % (P < 0.01).PEEP15-induced decrease in CI was correlated negatively with APP on PEEP5 (r =-0.91,P < 0.01) and with the PEEP15-induced increase in △PP (r =-0.79, P < 0.01).FR-induced changes in CI correlated with APP before FR (r = 0.96, P < 0.01) and with the FR-induced decrease in APP (r =-0.95, P < 0.01).Conclusions In ventilated patients with ALI, △PP may be a simple and useful parameter in predicting and assessing the hemodynamic effects of PEEP and FR.