What is an Amniotic Fluid Embolism?
Amniotic Fluid Embolism is a rare and life threatening complication during pregnancy or childbirth, often resulting in death. It occurs when amniotic fluid, foetal cells, hair, or other materials enter the blood system of a pregnant woman. Amniotic fluid is the fluid that surrounds the unborn baby (foetus) during pregnancy. It provides nourishment and protection to the foetus. Amniotic fluid can enter the blood circulation via tears in the uterus or cervix during labour and delivery, or through partial separation of the placenta.
The process of Amniotic Fluid Embolism is not fully understood, but it is considered to occur in 2 phases. When the mentioned substances enter the blood circulation of the pregnant woman, a reaction occurs that leads to spasm of the pulmonary (lung) blood vessels, interrupting normal blood supply through the heart and lungs. This lack of blood supply is called hypoxia. Hypoxia causes myocardial (heart) and pulmonary capillary (lung blood vessel) damage, which results in heart failure, and severe inflammation of the lungs (Acute Respiratory Distress Syndrome). This is phase 1. In phase 2 there is massive blood loss from the uterus, and abnormal clotting of the blood (coagulopathy). This is called the haemorrhagic phase. Both phases may lead to cardiac arrest, and often death.
The signs of amniotic fluid embolism are shortness of breath and low blood pressure, which is quickly followed by cardiac arrest. The patient may also have a seizure. Massive bleeding associated with abnormal blood clotting (coagulopathy) follows and then often death. Up to 50% of patients die within the first hour after the onset of their symptoms. The maternal death rate is as high as 85%.
What are the risk factors of Amniotic Fluid Embolism?
Amniotic Fluid Embolism may occur in healthy women during labour, during caesarean section, after abnormal vaginal delivery, or during the second trimester of pregnancy. It may also occur up to 48 hours post delivery. Identified risk factors include:
- Older maternal age
- Multiparity (more than one child)
- Intense contractions during labour
- Abdominal trauma
- Caesarean section
- Tears in the uterus or cervix
- Early separation of the placenta from the uterus wall
- Intestinal material from the foetus entering the woman’s blood stream
- Foetal distress
- Foetal death
- Male baby
What is the treatment of Amniotic Fluid Embolism?
The treatment is supportive. If the patient has a cardiac arrest, cardiopulmonary resuscitation (CPR) will be required. If the woman does not respond to resuscitation, an emergency caesarean section will be performed after the mother has died. The foetus will be monitored closely for signs of distress. There is nothing a pregnant woman can do to prevent having an amniotic fluid embolism.
What happens in ICU?
- Monitoring of the heart rate, blood pressure, respiratory rate, oxygen saturation and temperature. This will be seen on a bedside monitor.
- An arterial line may be inserted to monitor blood pressure and to take blood samples
- Medication including drugs to support the blood pressure and cardiovascular system, as well as intravenous fluids may be given via a central venous catheter. These will be given via infusion pumps. Blood products including fresh frozen plasma, cryoprecipitate, and platelets may be given for abnormal blood clotting (coagulopathy).
- Mechanical ventilation via an endotracheal tube will be required to assist with breathing. The ventilated patient will require suctioning to remove secretions from the lungs and airways.
- Nutrition may be given via a nasogastric tube. This is a tube that is placed in the nose and goes down the throat into the stomach. Fluid can also be removed from the stomach via the nasogastric tube.
- Insertion of an indwelling bladder catheter to drain and measure urine output.
- Chest x rays and other tests such as blood tests, CT scan, MRI, echocardiogram, electrocardiogram (ECG), and urine tests.
- Sequential compression devices may be put on the legs to prevent deep vein thrombosis.
- An air mattress may be used to prevent pressure areas developing on the skin.
How long will the patient remain in ICU?
The prognosis after Amniotic Fluid Embolism is very poor, and most women do not survive. If a patient survives the embolism, there is a risk of them having a hypoxic brain injury (brain damage) as a result of the lack of oxygen to the brain. Please ask the ICU nurse or doctor if you have any questions about your relative.
The information contained on this page is general in nature and therefore cannot reflect individual patient variation. In addition it reflects Australian intensive care practice which may differ from other countries. It is meant as a back up to specific information which will be discussed with you by the Doctors and Nurses caring for your loved one. ICCMU attests to the accuracy of the information contained here BUT takes no responsibility for how it may apply to an individual patient. Please refer to the full disclaimer.
Amniotic Fluid Embolism Version 1
Author Kathleen Ryan CNC ICCMU
First published August 2008