Effect of a Higher Blood-pressure on Right Ventricular Function

Right ventricular (RV) dysfunction in cardiac surgery is an independent risk factor for morbidity and mortality. Raising the systemic blood pressure with norepinephrine seems to have a positive influence on the right ventricular function in several animal studies. The current study is designed to evaluate the effect of a higher blood pressure on the RV function in post cardiac surgery patients.

Goal: To demonstrate differences in RV function by raising the systemic blood pressure with norepinephrine. Study design: randomized controlled trial Study population: 78 postoperative cardiac surgery patients admitted at the ICU. Intervention: Group 1: (N=22): RVEF<20% and MAP≤65mmHg. Intervention with norepinephrine to reach a MAP of 85mmHg for a maximum duration of two hours. Group 2: (N=22): RVEF <20% and MAP≤65mmHg. Control group: treatment according to current standards. Hypotensive patients are treated with fluids and/or vasopressors to gain a mean arterial pressure (MAP) of 65mmHg. Group 3: (N=17): RVEF between ≥20 and <30% and MAP ≤65mmHg. Intervention with norepinephrine to reach a MAP of 85mmHg for a maximum duration of two hours. Group 4: (N=17): RVEF between ≥20 and <30% and MAP ≤65mmHg. Control group: treatment according to current standards. Hypotensive patients are treated with fluids and/or vasopressors to gain a mean arterial pressure (MAP) of 65mmHg. Endpoints: Primary endpoint is the difference between the intervention and the control group in the change over time between baseline and the end of the study period (T4) in RVEF. Secondary endpoints are the echocardiographic parameters of RV and LV contractility, RV end-diastolic pressure, cardiac index, and fluid balance.

intervention with norepinephrine to reach a MAP of 85 mmHg for a maximum duration of 1 hour, observation of the effect on right ventricular function

control group; treatment according to current standards, observation of the effect on right ventricular function

Primary endpoint is the difference between the intervention and the control group in the change over time between baseline and the end of the study period (T4) in RVEF.

Inclusion Criteria: post operative cardiac surgery patients, full sternotomy admission at ICU informed consent right ventricular monitoring by pulmonary artery catheter. RVEF <30% + MAP ≤ 65mmHg Exclusion Criteria: no informed consent acute surgery Off pump cardiac surgery Severe tricuspid insufficiency Allergy to norepinephrine Severe left ventricular hypertrophy with systolic anterior movement Chronic use of alpha-blockers Irregulair heart rhythm Surgical reasons to maintain a low blood pressure.