How does the NASG actually work to stop hemorrhage and reverse shock?

The NASG is an ingenious device used to stop hemorrhage and reverse shock, stabilizing a woman postpartum.   It has been proven in multiple clinical studies, starting in Egypt, Nigera, Zambia and Zimbabwe.  Maternova manufactures the NASG under our brand and has been doing so since 2017 in an effort to scale the awareness and use of this device. The WHO started includes the NASG in their management guide for the management of the PPH in 2012.

The mechanism of action depends on the materials used to fabricate the device.  We start with strong 6 mm thick CR neoprene with a purple laminate attached to neoprene. The quality and thickness of the neoprene, the strength of the nylon thread and the strength of the double velcro work to create the circumferential compression. 

As first documented by Suellen Miller and team, the NASG "reduces vascular volume under the compressed areas, while expanding the central circulation by increasing preload, peripheral resistance, and cardiac output."  With more blood being supplied to the brain, heart and lungs (squeezed up from the legs by the NASg), blood pressure increases and shock is reversed. Multiple studies confirm that the NASG should be used as first line treatment for hemorrhage and hypovolemic shock.  

The TANN (in Spanish) or NASG acts also as an obstetric first aid device applying pressure to the uterus, akin to the midwife's use of a fist pressing down on the abdominal aorta and applying uterine massage.

There is a large dense foam ball sewn securely into a foam rectangle, all designed to pulled snug around the uterus and tightened with sewn-on velcro.  The strength of the sewn-on velcro is also important for securing the ball 'in action' as it presses down onto the uterus.  When the foam ball, of a specific density and size, exerts the force downward and into the uterine cavity.  Specific studies have measured the force exerted and determined that the NASG (if CE-marked and made in a PATH-approved factory according the original specifications) if applied and removed carefully is capable of reducing mortality by 50%.  

The pressure from the dense foam ball sewn into the middle section of the NASG acts to compress blood vessels in the uterus, thus reducing the amount of blood loss.