Factors affecting arterial pulse pressure variation in mechanically ventilated patients after cardiac surgery

Abstract

The aim of present study was to identify the factors those may affect the arterial pulse pressure variations (∆PP) induced by mechanical ventilation in patients who underwent cardiac surgery. Materials & Methods: This study was conducted in Madani Heart Hospital in Tabriz, during 9-month period from August 2017 to April 2018. A total of 292 adult patients who underwent elective cardiac surgery and admitted to the intensive care unit, enrolled in this study. The main including criterion was the need for full mechanical ventilation at first three hours of admission. In this period ∆PP between exhalation and inhalation phases was measured and its relationship with demographic characteristics, characteristics of cardiac disease and surgery and cardiopulmonary bypass (CPB), pre and postoperative echocardiography, cardiovascular drugs, pre and postoperative hemodynamic variables, mechanical ventilation characteristics and postoperative complication rate was evaluated. Results: In hospital mortality and postoperative complication happened in two (0.7%) and 50 patients (17.12%), respectively. Left and right ventricular dysfunction increased the ∆PP (p=0.001). There was not any significant relation between ∆PP intensity and need to inotropic support, vasodilators and vasopressor agents (P>0.05). Overall, the ΔPP was higher in patients requiring redo surgery within the first 24 hours (P=0.004). In patients with cardiac tamponade, the ΔPP was significantly more than non tamponade patients (P=0.001). In patients with open sternum, ΔPP was same as in closed sternum patients. There was not any correlation between ΔPP severity and fluid balance and bleeding rate at the first 24 hours.