A-E Examination: Amniotic Fluid Embolism
Author – Dr Kalyani Shinkar Editor – Dr James Mackintosh
Last updated 05/03/25
Table of Contents
How to Use
Candidate:
- Read the brief below (1 minute).
- Take a brief history and a perform a A-E examination (10 minute).
- Handover the patient (1 minute)
- Answer viva questions (2 minutes).
Patient/Examiner:
- Familiarise yourself with the history & examination findings
- After completing the history, viva the candidate
Candidate Brief
You are an F1 on the labour ward. Mrs Amy Sampson is a 38-year-old woman who is 38 weeks pregnant with her fourth child. The midwife reports that the patient started having regular uterine contractions 2 hours ago and has suddenly become short of breath and hypotensive. Please perform an A-E examination of this patient.
Handover From the Midwife:
- Mrs Sampson’s gestational age is 38 weeks
- She is gravida 1, para 0 (G1,P0)
- She has planned to have a vaginal delivery
- She became visibly short of breath and hypotensive 5 minutes ago.
- She has attended all her pregnancy scans, which have been normal.
- Obstetric history is unremarkable
- PMHx - Nil comorbidities
- DHx - Not taking any medications, NKDA
Introduce yourself, confirm the patient’s identify, and gain consent to examine the patient
- Patient confirms full name and DOB
- She gives consent for you to examine her
End of bed inspection
- She appears visibly short of breath and has signs of respiratory distress (cyanosis, nasal flaring and gasping for breath)
- She appears slightly drowsy and confused
Airways
- Assess the patency of the patient’s airway, ensure that the patient is able to breathe effectively, and there are no airway obstructions.
- Her airway is patent, as she is able to talk in full sentences
- There are no airway obstructions
Breathing
- Inspect for signs of respiratory compromise (e.g. cyanosis, see-saw breathing, use of accessory muscles, nasal flaring, pursed lip breathing, or increased work of breathing)
- There is evidence of cyanosis, nasal flaring, and increased work of breathing
- Respiratory rate
- RR = 32
- O2 sats
- O2 sats = 93% on RA
- Give 15L of O2 via a non-breather mask (O2 sats target 94-98%)
- Palpate for tracheal deviation and symmetrical chest expansion
- Trachea is central and there is symmetrical chest expansion
- Percuss
- Percussion note is resonant throughout
- Auscultate for reduced breath sounds or added sounds
- Vesicular breathing bilaterally
- No added sounds
- Perform an ABG
- ABG shows hypoxia only i.e. type 1 respiratory failure
- Order a CXR
- CXR is normal
- Reassess after each intervention
- O2 sats have increased to 95%
Circulation
- Inspection (e.g. pale, sweating, clammy)
- Temperature of hands
- Cold
- CRT
- CRT = 3 seconds
- Heart rate
- 121 bpm
- Blood pressure
- 97/62mmHg
- Insert 2 large bore IV cannulae into each antecubital fossae
- Take bloods (FBC for anaemia, U&Es to check for electrolyte imbalances, LFTs for baseline, CRP for infection/inflammation, D-dimer to rule out PE, coagulation studies to check for DIC, group and save to determine blood group, and do a VBG to check her lactate levels)
- Fluid resuscitation (500ml of 0.9% NaCl over <15 mins)
- JVP
- Not raised
- Apex beat
- Palpable in the left 5th ICS midclavicular line
- Heart sounds
- Normal
- Fluid status
- Dry mucous membranes and has not passed urine since she came to hospital 2 hours ago
- Perform an ECG
- Sinus tachycardia
- Catheterise the patient
- Monitor fluid input/output
- Reassess after each intervention
- Heart rate is 111 and blood pressure is 102/75mmHg following IV fluid bolus
Disability
- Level of consciousness (AVPU or GCS if a neurological cause for the patient’s presentation is suspected)
- Responsive to voice
- Pupils
- Equal and reactive to light
- Blood glucose levels
- 6.3
- Temperature
- 37.3°C
Exposure
- Fully expose the patient by removing their clothing whilst preserving their dignity
- Look for any signs of trauma, swelling, bruises, scars, rashes, or signs of a DVT
- Petechiae and ecchymoses are present
- Obstetric examination:
- No abdominal or uterine tenderness. Foetal lie is longitudinal, presentation is cephalic, and head is not engaged.
- Vaginal examination:
- Cervical os is open.
- Cervix is 4cm dilated and fully effaced.
After completing the initial A-E assessment, reassess! Re-assess the patient to identify any additional clinical changes and effectiveness of any interventions you have performed.
What are your differential diagnoses?
- Amniotic fluid embolism (due to sudden onset dyspnoea and signs of acute respiratory distress during childbirth with signs of haemodynamic instability, altered neurological status, and DIC)
- PE (due to sudden onset dyspnoea and signs of acute respiratory distress)
- Postpartum Haemorrhage (due to signs of haemodynamic instability – hypotension and tachycardia)
Given a likely diagnosis of amniotic fluid embolism, how would you manage this patient?
- Call for help immediately
- Call 2222 ‘obstetric emergency’
- Prepare for advanced airway management, including intubation and mechanical ventilation, if respiratory distress worsens
- Provide supportive care (supplemental oxygen, IV fluids, and vasopressors to maintain blood pressure)
- Arrange CTG monitoring to assess foetal well-being.
- Prepare for urgent delivery of the baby
- Arrange for urgent transfer to ICU for ongoing management and monitoring
3. Please Handover this patient to the obstetrics and gynaecology registrar using the SBAR or equivalent format.
- Hi, my name is Dr. Joe Bloggs and I’m calling from the labour ward. Can I please confirm who I am speaking to?
- I’m really worried about a patient I’ve just examined, I think she’s having an amniotic fluid embolism.
- She is a 38-year-old woman called Amy Sampson who presented with sudden-onset dyspnoea and hypotension 5 minutes ago during delivery, which started 2 hours ago
- She is G1P0
- Her obstetric history is unremarkable. She has no comorbidities or allergies.
- On inspection, she appeared visibly short of breath, cyanotic, and had signs of respiratory distress, including nasal flaring and an increased respiratory rate of 32
- Her airway was patent
- She was tachypnoeic and hypoxic. Examination of her chest was unremarkable. I have given her 15L of O2 via a non-rebreather mask and have ordered an ABG and CXR.
- She was tachycardic and hypotensive. I inserted 2 large bore IV cannulae and have taken bloods, including FBC, U&Es, LFTs, CRP, D-dimer, coagulation studies, and VBG. I have given her a fluid bolus and inserted a catheter.
- She appeared drowsy and confused, and was only responsive to voice. She was apyrexial and her BM was normal.
- On exposure, she had petechiae and ecchymoses. Her calves were soft and non-tender.
- Can you please come and see her? In the meantime, is there anything you would like me to do?
What is an Amniotic Fluid Embolism?
An amniotic fluid embolism is a rare but potentially life-threatening obstetric emergency that carries a very high mortality rate. It is when amniotic fluid enters the mother’s bloodstream suddenly. This typically occurs during pregnancy, childbirth, or immediately after childbirth, but can also occur following other obstetric procedures such as caesarean section or amniocentesis. The amniotic fluid contains foetal tissue, which results in a severe immune reaction from the mother, similar to an anaphylactic reaction.
Causes and Risk Factors
The cause of amniotic fluid embolism is not fully understood, but several maternal and foetal risk factors have been identified. Maternal risk factors include older maternal age, multiparity, multiple pregnancy, induction of labour, instrumental delivery, C-section, placenta previa, eclampsia, and abdominal trauma. Foetal risk factors include foetal distress and foetal death.
Clinical Presentation
The symptoms often develop suddenly and progress quickly.
- Acute Respiratory Distress: The earliest and most significant symptom is often sudden dyspnoea and signs of acute respiratory distress. Patients may also present with cyanosis and hypoxia owing to compromised gas exchange in the lungs.
- Cardiovascular Collapse: Haemodynamic compromise often quickly follows and may manifest as hypotension and tachycardia.
- Encephalopathy: Signs of neurological dysfunction including altered mental status, seizures, and coma, are thought to occur secondary to hypoxia.
- DIC: Amniotic fluid embolism can cause coagulation disorders leading to DIC, resulting in bleeding manifestations.
Diagnosis
- Clinical Presentation: Diagnosis is mainly based on clinical signs and symptoms.
- Laboratory Tests: Coagulation studies may reveal evidence of DIC:
- Platelets: thrombocytopaenia (↓platelet count) & ↑bleeding time
- Prolonged clotting times (↑aPTT & ↑PT)
- ↑D-dimer
- ↓Fibrinogen
- Imaging: CXR or chest CT scan may show findings of acute respiratory distress syndrome (ARDS).
- Special Tests: CTG monitoring of the baby (foetal bradycardia can occur secondary to maternal hypoxia)
Management
Management is mainly supportive and often requires a multidisciplinary approach involving obstetricians, anaesthetists, critical care physicians, and haematologists.
- Supportive Care: Management focuses on stabilising the patient’s airway, breathing, and circulation. This may include supplemental oxygen, intubation and mechanical ventilation, fluid resuscitation, and vasopressor support to maintain blood pressure.
- Correction of Coagulopathy: Patients with DIC may require blood components to correct coagulopathy, including fresh frozen plasma, platelets, and cryoprecipitate.
- Advanced Cardiac Life Support (ACLS) may be necessary in cases of severe cardiovascular collapse.
- Urgent Delivery of the baby if amniotic fluid embolism occurs during labour.
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2. https://www.mkuh.nhs.uk/wp-content/uploads/2022/10/Amniotic-Fluid-Embolus-.pdf
3. Metodiev, M et al. (2018). Amniotic fluid embolism. BJA
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