Development of Anti-Shock Garment for PPH
The anti-shock garment was originally developed by George Crile as an inflatable pressure suit to maintain blood pressure during surgery. During the 1970s this morphed into military anti-shock trousers, a compression garment used to treat soldiers on the battlefield in shock. The first use in obstetric settings began in 2002 when Dr. Paul Hensleigh & Carol Brees began using the garment in a hospital in Pakistan. Following that introduction, Dr. Suellen Miller, along with her colleagues from the University of California San Francisco’s Bixby Center for Global Reproductive Health, initiated multiple studies of the Non-pneumatic Anti-Shock Garment (NASG) for the management of obstetric haemorrhage around the world.
Postpartum Haemorrhage Background
Postpartum haemorrhage (PPH) is excessive bleeding following delivery of a baby and is the most common cause of maternal death worldwide. In sub-Saharan Africa it is the leading cause of maternal mortality. About 20% of women experience some form of postpartum haemorrhage following birth. According to Stanford Children’s Hospital, PPH is commonly defined as blood loss of 500 ml or more within 24 hours after birth, while severe PPH is defined as blood loss of 1000 ml or more within the same timeframe according to World Health Organisation (WHO). For women who are anemic, and a large number of women across Africa are anemic, PPH is a life-threatening condition.
Several leaders in the global health community including USAID, the Gates Foundation, the Safe Motherhood Program at UCSF and VIA Global Health have dedicated significant resources to expanded awareness and adoption of the NASG worldwide.
Causes of Postpartum Haemorrhage
According to a 2007 study the most common causes of postpartum haemorrhage are uterine atony, trauma, retained placenta or placental abnormalities and coagulopathy.
- Tone: uterine atony is the inability of the uterus to contract and may lead to continuous bleeding. Retained placental tissue and infection may contribute to uterine atony. Uterine atony is the most common cause of postpartum hemorrhage.
- Trauma: injury to the birth canal, which includes the uterus, cervix, vagina and the perineum, can happen even if the delivery is monitored properly. The bleeding is substantial as all these organs become more vascular during pregnancy.
- Tissue: retention of tissue from the placenta or fetus as well as placental abnormalities such as placenta accreta and percreta may lead to bleeding.
- Thrombin: a bleeding disorder occurs when there is a failure of clotting, commonly seen with diseases known as coagulopathies.
Additionally, according to the Children’s Hospital of Philadelphia the causes of postpartum haemorrhage can vary widely. Some of the most common include:
- Placental abruption. The early detachment of the placenta from the uterus.
- Placenta previa. The placenta covers or is near the cervical opening.
- Overdistended uterus. Excessive enlargement of the uterus due to too much amniotic fluid or a large baby, especially with birth weight over 4,000 grams (8.8 pounds).
- Multiple pregnancy. More than one placenta and overdistention of the uterus.
- Gestational hypertension or preeclampsia. High blood pressure of pregnancy.
- Having many previous births
- Prolonged labor
- Medications to induce labor
- Medications to stop contractions (for preterm labor)
- Use of forceps or vacuum-assisted delivery
- General anesthesia
Prevention and Treatment of PPH in Africa
In many cases PPH can be prevented by managing risk factors and the use of uterotonics such as oxytocin or misoprostol to stimulate uterine contractions after the baby is born. Managing other risk factors such as anemia, obesity and certain medications can also assist in the prevention of obstetric haemorrhage.
In many cases oxytocin and ergotamine may provide sufficient treatment, particularly for mild cases of PPH when the uterus is not contracting. Unfortunately both of these treatments are not always available as they require careful handling and oxytocin must be kept at specific temperatures. However, in low resource settings, particularly in home births, rural clinics, and non-obstetric hospitals, additional measures may be necessary to reduce the potential for life-threatening complications.
Since 2002, non-pneumatic anti-shock garment has been used in dozens of countries to save the lives of thousands of women, from the United States to South Africa. Across numerous clinical trials and pilots projects, the NASG has demonstrated a 40 to 80% reduction in maternal mortality in low to middle income countries.