Published on October 17th, 2012 | by Daniel Jolley
Aortocaval compression – One Minute Anesthesia
A brief video summary of ‘aortocaval compression’, an important topic in obstetric anesthesia.
Aortocaval compression is a common problem for many pregnant women. It is first detectable at 13 weeks although not clinically significant until 20 weeks. All women experience some degree of inferior vena cava compression by the gravid uterus at term, although physiological consequences and symptoms vary due to alternative routes of venous return, such as the epidural venous plexus.
In the spectrum of aortocaval compression the most severe involves compression of both IVC and the aorta producing marked hypotension, unconsciousness and potentially even cardiac arrest.
The sympathectomy associated with spinal or epidural anesthesia can also have a profound affect on the maternal cardiovascular system in the presence of aortocaval compression.
At term 60% of all women are symptomatic when supine. 10% will see a fall of 30 mmHg or more in their systolic blood pressure (‘Supine hypotension syndrome’) and 8% experience bradycardia and hypotension.
- Vanden Hoek TL, et al. 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science. Part 12: Cardiac Arrest in Special Situations. 2010.
- Burton, J. Supine Hypotensive Syndrome. April 14 2007.