What is the differential diagnosis and management approach for a patient with sudden onset breathlessness 2 days post Lower Segment Caesarean Section (LSCS)?

Differential Diagnosis for Post-LSCS Breathlessness

A patient presenting with sudden onset breathlessness 2 days post-LSCS requires immediate consideration of pulmonary embolism as the most life-threatening diagnosis, followed by systematic evaluation for peripartum cardiomyopathy, amniotic fluid embolism, aspiration pneumonitis, and pulmonary edema.

Critical Life-Threatening Differentials (Prioritized by Mortality Risk)

1. Pulmonary Embolism (PE)

• Highest priority diagnosis - venous thromboembolism occurs in 2.6 per 1,000 cesarean births, making it a leading cause of maternal mortality 1
• Cesarean section significantly increases thrombotic risk compared to vaginal delivery 1
• Classic presentation: sudden dyspnea, chest pain, tachycardia, hypoxemia 2

2. Peripartum Cardiomyopathy

• Can present within days postpartum with acute heart failure symptoms 2
• Manifests as dyspnea, orthopnea, peripheral edema, and hypotension 2
• More common in women with pre-existing cardiac risk factors 1

3. Amniotic Fluid Embolism (AFE)

• Rare but catastrophic complication occurring peripartum or immediately postpartum 2
• Presents with sudden cardiovascular collapse, respiratory distress, and coagulopathy 2
• Mortality rate approaches 20-40% despite aggressive management 2

4. Aspiration Pneumonitis

• Risk increased if general anesthesia was used for LSCS 2
• Failed intubation or airway management issues during surgery increase risk 2
• Presents with acute respiratory distress, hypoxemia, and infiltrates on imaging 2

5. Pulmonary Edema

• Can result from fluid overload, cardiac dysfunction, or pre-eclampsia/HELLP syndrome 2
• HELLP syndrome complications include pulmonary edema and can persist postpartum 2, 3
• Presents with dyspnea, crackles on auscultation, and hypoxemia 2

6. Pneumothorax

• May occur from positive pressure ventilation during general anesthesia 2
• Presents with sudden dyspnea, chest pain, and decreased breath sounds unilaterally 4

7. Hemorrhagic Complications

• Postpartum hemorrhage can cause hypovolemic shock presenting as dyspnea and hypotension 2
• Intra-abdominal bleeding from surgical complications 1

8. Sepsis/Pneumonia

• Postpartum infections are 5-7 times more common after cesarean section 1
• Can present with respiratory symptoms, fever, and hemodynamic instability 3

Diagnostic Algorithm

Step 1: Immediate Assessment (First 5 Minutes)

• Perform ABC assessment focusing on airway patency, breathing adequacy, and circulatory status 4
• Measure vital signs: pulse rate, respiratory rate, blood pressure, continuous pulse oximetry 4
• Monitor for warning signs: stridor, obstructed breathing pattern, agitation - these should never be ignored 4
• Establish continuous cardiac monitoring 4
• Administer 100% oxygen immediately 2

Step 2: Critical Stabilization Measures

• Establish IV access above the diaphragm 2
• Position patient appropriately - avoid supine hypotension if still pregnant/early postpartum 2
• Assess for hypotension (systolic BP <100 mmHg or <80% baseline) 2
• Have difficult airway equipment immediately available 4

Step 3: Essential Immediate Investigations

Laboratory Studies (STAT):

• Complete blood count with platelet count 2, 3
• Coagulation profile: PT, PTT, fibrinogen, D-dimer 2, 3
• Arterial blood gas to assess oxygenation and acid-base status 2
• Troponin and BNP/NT-proBNP for cardiac evaluation 5
• Liver function tests (AST, ALT, bilirubin) to evaluate for HELLP syndrome 2, 3
• Renal function (creatinine, urea) 2, 3
• Peripheral blood smear for microangiopathic hemolytic anemia 2

Imaging Studies (Priority Order):

• ECG immediately - assess for cardiac ischemia, arrhythmias, right heart strain pattern (S1Q3T3 in PE) 4, 3
• Chest X-ray - evaluate for pulmonary edema, pneumonia, pneumothorax, aspiration 2, 3
• Echocardiogram - assess ejection fraction, wall motion abnormalities, right ventricular function, pulmonary artery pressures 4, 5
• CT pulmonary angiography (CTPA) - gold standard for PE diagnosis if clinically suspected and patient stable enough for transport 2
• Venous duplex ultrasound of lower extremities - if PE suspected but CTPA contraindicated 2

Step 4: Specific Diagnostic Considerations

If HELLP Syndrome Suspected:

• Thrombocytopenia correlates with liver dysfunction severity 2, 3
• Look for epigastric pain, right upper quadrant tenderness, visual changes 2, 3
• Severe pre-eclampsia criteria: BP >160/90 mmHg, proteinuria >5g/24h, oliguria <400ml/24h 2, 3

If Cardiac Etiology Suspected:

• Obtain echocardiogram to assess for peripartum cardiomyopathy 4, 5
• Measure pulmonary artery pressures - mPAP >25 mmHg suggests pulmonary hypertension 5
• Check for elevated filling pressures and reduced ejection fraction 5

If PE Suspected:

• Calculate Wells score or use clinical gestalt 2
• D-dimer has limited utility postpartum (physiologically elevated) but negative result helpful 2
• CTPA is diagnostic test of choice despite radiation concerns - maternal survival takes priority 2

Common Pitfalls to Avoid

• Do not delay oxygen therapy while awaiting investigations - hypoxemia develops rapidly in postpartum patients due to decreased functional residual capacity 2
• Do not rely solely on pulse oximetry for monitoring ventilation - it does not detect hypercarbia 4
• Do not dismiss tachypnea - respiratory rate is a critical indicator of respiratory status and often the first sign of deterioration 4
• Do not assume normal D-dimer excludes PE - pregnancy and postpartum state cause physiologic elevation 2
• Do not overlook HELLP syndrome - it can present or worsen postpartum and is often misdiagnosed as other conditions 2, 3
• Do not delay definitive imaging if PE is suspected - maternal mortality from untreated PE far exceeds radiation risks 2

Monitoring Requirements

• Continue pulse oximetry and vital signs monitoring until stable 4
• Serial respiratory rate measurements every 15-30 minutes initially 4
• Continuous cardiac monitoring for arrhythmias 4
• Hourly urine output monitoring via urinary catheter 2, 3
• Consider central venous catheter for critically ill patients to guide fluid management 2, 3