Postpartum Collapse

Definition

• Loss of consciousness or altered mental status
• Cardiovascular collapse (shock, cardiac arrest)
• Severe hypoxia / respiratory arrest
• Seizures

Causes (Differential Diagnosis)

1. Haemorrhage (Most Common)

• Primary PPH: blood loss >500 mL (vaginal) or >1000 mL (C-section) within 24 h
• Causes - "4 Ts": Tone (uterine atony ~70%), Tissue (retained placenta), Trauma (lacerations, uterine rupture), Thrombin (coagulopathy/DIC)
• Concealed haemorrhage (broad ligament, intraperitoneal) can cause collapse without visible bleeding
• Hepatic rupture (e.g., HELLP syndrome) - presents with abdominal pain + cardiovascular collapse

SCHWARTZ'S Principles of Surgery, 11e - "Atony is the most common cause of postpartum haemorrhage. It is typically treated with fundal massage and uterotonics such as oxytocin, methylergonovine, carboprost tromethamine, and misoprostol."

2. Amniotic Fluid Embolism (AFE)

• Rare (2-6 per 100,000), highly lethal (mortality 11-43%, some series up to 86%)
• Sudden cardiovascular collapse during/immediately after labour or within 48 h of delivery
• Biphasic haemodynamic pattern: initial pulmonary hypertension → left ventricular failure
• Associated with DIC in ~50%, seizures, hypoxia
• Risk factors: older maternal age, induction of labour, high parity, caesarean section, placental abruption, meconium-stained liquor, ruptured membranes with intrauterine procedures
• Mechanism: likely anaphylactoid/complement-mediated (renamed "anaphylactoid syndrome of pregnancy")

Creasy & Resnik's Maternal-Fetal Medicine - "Most patients with AFE present with sudden cardiovascular collapse during labour or delivery, followed by profuse bleeding and DIC."

Murray & Nadel's Respiratory Medicine - "AFE should be considered in any pregnant or immediately postpartum woman with sudden cardiac arrest or cardiovascular collapse, seizures, respiratory distress or hypoxia, particularly in the context of associated coagulopathy."

3. Pulmonary Embolism (VTE)

• Pregnancy increases VTE risk 5-10 fold; risk is highest at 3-6 weeks postpartum
• Presents with sudden dyspnoea, chest pain, tachycardia, hypoxia, and potentially cardiopulmonary collapse
• Risk factors: C-section (especially emergency), obesity, thrombophilia, immobility, age >35, preeclampsia, multiparity

4. Eclampsia

• Seizures (with or without hypertension) up to 6 weeks postpartum
• May present as collapse/loss of consciousness

5. Sepsis / Septic Shock

• Postpartum endometritis (commonest puerperal infection), wound infection, retained products
• Sepsis accounts for ~15% of maternal deaths worldwide
• Causative organisms: gram-positive cocci, gram-negative coliforms, anaerobes, Chlamydia, Mycoplasma

6. Peripartum Cardiomyopathy (PPCM)

• Incidence ~1 in 2,229 pregnancies; onset days to weeks after delivery
• Presents from mild fatigue to florid pulmonary oedema and cardiogenic collapse
• Mortality ~15% worldwide; risk factors: advanced age, preeclampsia, multiparity, African descent

7. Air Embolism

• Via subplacental venous sinuses during delivery, C-section, intrauterine procedures, or orogenital sex in the puerperium
• Dyspnoea, chest pain, presyncope → haemodynamic collapse

8. Other / Less Common

• Aortic dissection / ruptured aortic aneurysm
• Intracranial haemorrhage (associated with severe hypertension/preeclampsia)
• Pheochromocytoma crisis (cardiovascular collapse peripartum/postpartum - can be dramatic)
• Thyroid storm (postpartum thyrotoxicosis rebound)
• Spinal/epidural haematoma or high spinal block
• Anaphylaxis (drugs, blood products, latex)
• Aspiration pneumonitis (Mendelson's syndrome)
• Hypoglycaemia

Investigations

Immediate Bedside

Bloods (send urgently)

Imaging

Creasy & Resnik's - "Early performance of echocardiography can help identify right ventricular failure, and targeted treatment can improve cardiac function."

Management

Immediate (First Minutes - ABCDE Approach)

1. Call for help: senior obstetrician, anaesthetist, midwife, haematologist, intensivist
2. Airway: protect airway; intubate if GCS <8 or respiratory failure (caution - difficult airway in obstetric patients, failed intubation rate 8× general population)
3. Breathing: high-flow oxygen (15 L/min via non-rebreather mask); consider ventilatory support
4. Circulation: two large-bore IVs; fluid resuscitation (crystalloid initially); send urgent bloods; activate massive transfusion protocol (MTP) if haemorrhage suspected
5. Position: left lateral tilt if gravid uterus still present (to relieve aortocaval compression); Trendelenburg/left lateral decubitus for suspected air embolism
6. Monitor: continuous SpO2, ECG, BP, urine output

Cause-Specific Management

Postpartum Haemorrhage

• Uterine massage + bimanual compression
• Uterotonics: oxytocin 10 IU IM/IV infusion (do NOT give rapid IV bolus - causes severe hypotension), ergometrine 500 mcg IM, carboprost 250 mcg IM, misoprostol 800-1000 mcg rectal/sublingual
• Massive transfusion (pRBC:FFP:platelets in 1:1:1 ratio); target fibrinogen >2 g/L (tranexamic acid 1 g IV within 3 h)
• Surgical: uterine tamponade balloon, B-Lynch suture, uterine artery ligation, radiological embolisation, hysterectomy if uncontrolled

Amniotic Fluid Embolism

• Aggressive cardiopulmonary support: intubation + vasopressors (noradrenaline, vasopressin)
• Massive transfusion with emphasis on coagulation factors; FFP, cryoprecipitate, platelets
• Treat right ventricular failure (echo-guided)
• Consider venoarterial ECMO for refractory ventricular dysfunction
• If viable fetus still in utero: expedited delivery (perimortem C-section within 4 minutes of maternal cardiac arrest if no ROSC)
• No specific pharmacological antidote; supportive care is the mainstay

Pulmonary Embolism

• Haemodynamically unstable: systemic thrombolysis (alteplase 100 mg IV over 2 h) or surgical embolectomy
• Anticoagulation: unfractionated heparin IV (in massive PE); LMWH for stable patients
• CT-PA is gold standard; V/Q scan if CT unavailable or contrast contraindicated

Eclampsia

• Magnesium sulphate: loading dose 4-6 g IV over 15-20 min, then 1-2 g/h infusion
• Antihypertensives: labetalol IV, hydralazine IV, nifedipine oral (target SBP <160, DBP <110)
• Airway protection; benzodiazepines for refractory seizures

Sepsis

• Sepsis-6 bundle within 1 hour: blood cultures, high-flow O2, IV fluids, broad-spectrum antibiotics (piperacillin-tazobactam ± gentamicin), lactate, urine output
• Source control: surgical drainage, evacuation of retained products if indicated

Peripartum Cardiomyopathy

• Diuretics (furosemide), vasodilators (hydralazine during pregnancy, ACE-inhibitors postpartum), beta-blockers (carvedilol/bisoprolol)
• Bromocriptine (prolactin inhibition) may improve outcomes
• Mechanical support (IABP, ECMO) for refractory cardiogenic shock

Air Embolism

• Left lateral decubitus + Trendelenburg position (traps air in right ventricular apex away from outflow)
• High-concentration oxygen (facilitates N2 resorption)
• Central venous catheter to aspirate air from right ventricle if haemodynamically compromised

Summary Table

• Creasy & Resnik's Maternal-Fetal Medicine, 8e (Amniotic Fluid Embolism, VTE, Obstetric Haemorrhage)
• Rosen's Emergency Medicine (Postpartum Problems, Peripartum Cardiomyopathy, AFE)
• Murray & Nadel's Textbook of Respiratory Medicine (AFE, Air Embolism, Aspiration)
• Schwartz's Principles of Surgery, 11e (PPH management)
• Miller's Anesthesia, 10e (Uterine Atony, AFE)