Aortocaval compression

Question 1

What is aortocaval compression

Answer 1

When the gravid uterus compresses the maternal abdominal aorta and inferior vena cava

Question 2

What occurs in aortocaval compression

Answer 2

• From 20 weeks gestation, in the supine position, the gravid uterus can compress IVC and aorta, reducing venous return
• This decreases cardiac output by up to 40%, causing supine hypotension
• Supine hypotension can precipitate maternal collapse, which is usually reversed by turning the woman into the left lateral position

Question 3

Presentation of aortocaval compression

Answer 3

Aortocaval compression is thought to be the cause ofsupine hypotensive syndrome -

characterized by pallor, tachycardia, sweating, nausea, hypotension and dizziness whichoccurs when a pregnant woman lies on her back and resolves when she is turned on her side

Question 4

Management of aortocaval compression

Answer 4

Keep mother supine and apply left manual uterine displacement or 30-degree tilt if on theatre table