BackgroundTo study the effects of different positive end expiratory pressure (PEEP) on blood pressure and heart function in elderly patients with hypertension.MethodsForty elderly patients above 65 years of age treated with mechanical ventilation were divided into two groups: a control group of non-hypertensive subjects (n = 18) and a hypertension group (n = 22) patients with essential hypertension. Changes in blood pressure, central venous pressure (CVP), central venous oxygen saturation (ScvO2), heart rate, and airway pressure were determined in response to different selected PEEP levels of 0, 2, 4, 6, 8, 10 and 12 cm H2O under SIMV(PC) + PSV mode throughout the study.ResultsIn both groups, the increase in PEEP led to an increase in CVP and airway pressure. When PEEP was above 4 cm H2O in the hypertension group, a decrease in blood pressure and ScvO2, and an increase of heart rate were observed. These results indicated that cardiac output significantly decreased.ConclusionHigh levels of PEEP can significantly influence changes in blood pressure and heart function in elderly patients with hypertension.Trial registrationThis trial was retrospectively registered, The Chinese trial registration number is ChiCTR-ROC-17012873. The date of registration is 10-2-2017.