CPB hypotension: causes
Pretest
Question 1
True or False
The potential causes of hypotension after CPB include
1. hypovolemia,
2. ventricular failure/dysfunction,
3. air emboli in the venous graft,
4. kinked or clotted grafts.
Keyword
Separation from CPB can be marked by hemodynamic instability, as sudden changes can occur in preload, contractility, and afterload.
The potential causes of hypotension after CPB are varied and include hypovolemia, ventricular failure/dysfunction, air emboli in the venous graft, kinked or clotted grafts, excessive cardioplegia, focal/global areas of myocardial ischemia or infarction, bradycardia/arrhythmias, hypothermia, hypocalcemia, inadequate ventilation, and changes in SVRI.
After excluding possible causes, low SVRI may be responsible for the encountered hypotensive episode after the discontinuation of CPB.
Hemodynamic instability activates a complex array of interacting neural and hormonal reflexes, typified by two distinct phases.
MAP is maintained in the first phase by a progressive increase in systemic vascular resistance and heart rate, primarily resulting from activation of the sympathetic nervous system and the renin-angiotensin system.
Post test
Question 1
True or False
The potential causes of hypotension after CPB include
1. hypovolemia,
2. ventricular failure/dysfunction,
3. air emboli in the venous graft,
4. kinked or clotted grafts.
Answer:
TTTT