The Impact of Noradrenaline on Ventriculo-arterial Coupling and Central Cardiovascular Energy Delivery
Condition: Heart Diseases
MeSH terms: Heart Diseases
Study type: Interventional

Summary: 
      The study aims to examine how noradrenaline in combination with venous return influences the
      energy transmission from heart to central circulation and arteries - also called
      arterio-ventricular coupling.
    

Detailed description: 
      After being informed about the study 40 elective CABG patients with written informed consent
      will undergo assessment of their arterio-ventricular coupling postoperatively after coronary
      bypass graft surgery. Whilst still in deep general anesthesia on the CT ICU the study
      population will be assessed by echocardiographic examination (transthoracic and
      transesophageal), blood pressure tracing by arterial line, respiratory data and ECG in 4
      different situations.

      Initially the individual patient is either considered fluid responsive (SVV >13%) og non-
      responsive (SVV<13%) by using stroke volume variation assessed by echocardiography.

      In case of fluid responsiveness a fluid bolus of 4ml/kg of crystalloid fluid is given until
      SVV drops below 13% and the patient can be considered as fluid NON responder.

      Right afterwards the study patient is stabilized with a baseline dose of noradrenaline (NA)
      intravenously in a supine position (situation 1). Situation 2 will be a slight increase in NA
      dose stabilizing mean arterial pressure in a "baseline + 20mmHg" state. After reversing the
      NA dose back to base line level the patient is allowed a short period of rest to wean of drug
      effect (4-5 x t1/2, appr. 12min). Subsequently the patient is to be placed in a 20% semi
      upright position (Anti-Trendelenburg) causing an increase in fluid responsiveness (situation
      3). Following a phase of equilibration the dose of NA is again titrated up to obtain a 20mmHg
      increase in mean arterial pressure (situation 4).

      There will be logging of arterial pressure curve and VTI-tracing I LVOT simultaneously
      (ultrapower, uPWR) as well as calculation of energy delivery, cardiac power, oscillatory
      power and -fraction and both arterial and ventricular elastance in every of those 4
      situations.
    

Intervention name(s): Noradrenalin; Noradrenalin; Noradrenalin; Noradrenalin
Intervention type(s): Procedure; Procedure; Procedure; Procedure
Intervention description(s): Norepinephrine challenge (concentration 'A' ) in fluid responsive position; Norepinephrine challenge (concentration 'A') in non-fluid responsive position; Norepinephrine challenge (concentration 'B') in fluid responsive position; Norepinephrine challenge (concentration 'B') in non-fluid responsive position
Other intervention name(s): Anti-Trendelenburg position/Semiupright position (20degr); supine position; Anti-Trendelenburg position/Semiupright position (20degr); supine position
Intervention MeSH terms: Norepinephrine
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: Noradrenaline; Heart surgery; Intensive care; Cardiac physiology