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Supine hypotensive syndrome: everything you need to know

We know we are probably preaching to the choir, but during pregnancy, your body undergoes many changes, and while some of them can be amazing, like your cute baby bump, others can be a bit more troublesome. One of those sneaky surprises is Supine Hypotensive Syndrome, a fancy term for when lying on your back suddenly feels like a bad idea. While it's a temporary glitch in the grand pregnancy process, understanding and preventing it is key to keeping you and your growing baby safe and healthy.

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 Supine hypotensive syndrome of pregnancy - A review of current knowledge

We suggest that the routine 15 degree lateral tilting of all women in obstetric anaesthesia be abandoned, given that it has been shown to be ineffective. Furthermore, we recommend that the term ‘supine hypotensive syndrome’ be used instead of ‘aortocaval compression syndrome’ to ensure nomenclature that does not perpetuate a wrongly understood pathophysiological condition. Lastly, we encourage research to identify and define those few women that are truly affected by supine hypotensive syndrome.

Articles of Interest

Aortocaval Compression Syndrome

Aortocaval compression syndrome is also known as a supine hypotensive syndrome. It typically occurs in pregnant females, usually after 20 weeks of gestation, when the patient is in the supine position. Blood flow from the lower extremities back to the maternal heart and central circulation is impeded due to the uterus compressing the inferior vena cava and aorta.

Does Left Lateral Tilt Effectively Treat Supine Hypotensive Syndrome?

Maternal cardiovascular compromise and fetal hypoxia are well recognized side effects of supine positioning in advanced pregnancy. Supine hypotensive syndrome (SHS) is a clinical diagnosis loosely defined as a clinically significant decrease in maternal cardiac output due to presumed compression of the inferior vena cava and aorta by the gravid uterus within a few minutes (3-10 minutes) of assuming the supine position. SHS can be rapidly reversed with decompression of the great vessels.

Simple tips for managing the critically-Ill pregnant patient

The supine-hypotension syndrome occurs after the 20th week of pregnancy as the gravid uterus compresses the IVC and aorta, reducing cardiac output by up to 30%. Placing a 30-degree right hip-wedge under the patient will relieve this obstruction.

Supine hypotensive syndrome

Supine hypotensive syndrome is characterized by severe supine symptoms and hypotension in late pregnancy, which compel the unconstrained subject to change position. Rarely, it may manifest even from the fifth month of pregnancy or postpartum, as well as in the pelvic tilt or sitting positions. Although inferior vena cava compression, influenced primarily by the size of the uterus and exact maternal and fetal position, is the major determinant in its development, other factors may also be important in modulating the circulatory effects of such compression.

Supine Hypotensive Syndrome: A Comprehensive Review of Literature

While "supine hypotensive syndrome" is well known to medical professionals in the United States, this may not be recognized well in other countries. In the "No Pain Labor & Delivery-Global Health Initiative" trips, it was observed that the parturient lying on their backs during laboring, resulting in hypotensive episodes and non-reassuring fetal heart rates resulted in subsequent misjudgment of the need for cesarean delivery by clinicians. As part of the educational effort, literature were searched between 1950 and 2014 with key word "supine hypotensive syndrome", "supine hypotension syndrome", "late pregnancy" in PubMed to review the history, clinical presentations and management of supine hypotensive syndrome. The emphasis is that supine hypotensive syndrome occurs more than expected, and that left uterine displacement is not optional after 20 or more weeks of pregnancy.

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FOAMfrat

While not EVERY pregnant patient needs to be laying in the “left lateral recumbent position”, gravid patients with hypotension or signs of fetal distress should be placed on their left side to shift the weight off the IVC and allow adequate venous return. The IVC is a low pressure vessel and can easily become obstructed depending on weight of the fetus as it relates to central venous pressure.