01OverviewDefinition, clinical context and the essential points that orientate the chapter.
Tamponade lies on a continuum from compensated impaired filling to pulseless obstructive shock. Clinical trajectory, rate of fluid accumulation and echo physiology matter more than a centimetre measurement.
Point-of-care echo accelerates recognition, but diagnosis remains clinical-haemodynamic and treatment should not be delayed for CT in a crashing patient. The safest drainage route is chosen with imaging and cause in mind.
After decompression, identify the source—iatrogenic or traumatic bleeding, malignancy, infection, renal failure, inflammation or aortic catastrophe—and prevent recurrence.
Key points
- Tamponade is a haemodynamic diagnosis: intrapericardial pressure impairs filling and output; effusion size alone does not define it.
- Rapid haemopericardium can cause arrest with a small volume, while slowly accumulating malignant fluid may be very large before collapse.
- Tachycardia and raised JVP are common; Beck's triad is insensitive and may be altered by hypovolaemia or ventilation.
- Pulsus paradoxus above 10 mmHg supports tamponade but can be absent with severe LV dysfunction, ASD, pulmonary hypertension or positive-pressure ventilation.
- Echo clues include right-atrial systolic collapse, right-ventricular early-diastolic collapse, marked respiratory inflow variation and a plethoric IVC.
- Drainage is definitive; small fluid boluses may bridge selected preload-depleted patients but must not delay the procedure.
- Avoid unnecessary diuresis, vasodilation and positive-pressure ventilation before decompression because they can precipitate collapse.
- Trauma, type A aortic dissection, clotted haemopericardium and purulent/loculated effusion often require surgery rather than routine needle drainage.
02AetiologyUnderlying causes, associations and risk factors, with why each one matters.
Acute haemopericardium
Trauma, cardiac procedures, postoperative bleeding or type A aortic dissection can introduce blood rapidly. Pericardial pressure rises before the sac stretches, so even a modest haemopericardium may cause collapse.
Malignant effusion
Metastatic lung or breast cancer, lymphoma and other malignancies may involve the pericardium or impair lymphatic drainage, producing recurrent, often slowly accumulating effusions that eventually exceed pericardial reserve.
Inflammatory and infective disease
Viral or idiopathic pericarditis, bacterial infection including tuberculosis, and autoimmune inflammation can increase pericardial fluid. Purulent or loculated collections are particularly hazardous because complete drainage may be difficult.
Systemic disease
Advanced renal failure can cause uraemic pericarditis and effusion; hypothyroidism and other systemic disorders may also permit gradual fluid accumulation, sometimes becoming haemodynamically important before dramatic symptoms appear.
03PathophysiologyThe causal sequence from the underlying abnormality to symptoms and harm.
- 1Fluid enters a constrained space
Fluid accumulates between the visceral and parietal pericardium. The haemodynamic effect depends on accumulation rate, pericardial compliance and baseline filling pressures rather than measured effusion depth alone.
- 2Right-sided filling becomes restricted
As intrapericardial pressure approaches chamber pressure, right-atrial collapse, usually during systole, and right-ventricular collapse in early diastole may occur. Impaired filling raises systemic venous pressure and reduces effective venous return.
- 3Ventricular interdependence intensifies
During inspiration, increased right-sided filling shifts the interventricular septum towards the left ventricle because total cardiac volume is constrained. The resulting fall in left-sided filling and systolic pressure can produce an exaggerated inspiratory pressure drop, or pulsus paradoxus.
- 4Compensation gives way to shock
Stroke volume falls while tachycardia and vasoconstriction may initially preserve arterial pressure. If compression progresses, coronary and tissue perfusion deteriorate, causing hypotension and organ dysfunction and potentially culminating in pulseless electrical activity from severe obstructive shock.
04Clinical features and red flagsSymptoms, examination findings, patterns of presentation and time-critical warnings.
Tachycardia, dyspnoea, raised JVP, narrow pulse pressure, pulsus paradoxus and cool peripheries may precede hypotension.
Hypotension, confusion, oliguria, mottling, rising lactate and syncope indicate failing output and demand immediate drainage.
PEA after cardiac intervention, penetrating trauma or known effusion should trigger immediate ultrasound and resuscitative source control.
Low voltage or electrical alternans may occur with a large swinging-heart effusion but is neither sensitive nor required.
Pulmonary hypertension or RV failure can mask right-sided chamber collapse; worsening output with a known effusion still needs expert haemodynamic assessment.
Postoperative loculated clot may compress one chamber and produce atypical echo/JVP findings; TOE or CT may be required if stable enough.
05InvestigationsWhat to request, why it matters and how to interpret it.
Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.
- 01
Immediate focused TTEFirst step - Why
- Confirm fluid and haemodynamic effects and plan the safest access.
- Interpretation and limitations
- Integrate chamber collapse timing, Doppler respiratory variation, IVC and clinical state; absence of one sign does not exclude tamponade.
- 02
12-lead ECG and continuous monitoring - Why
- Detect alternans, low voltage, ischaemia and peri-arrest rhythm.
- Interpretation and limitations
- ECG supports but never rules out tamponade; PEA demands simultaneous resuscitation.
- 03
FBC, coagulation, group and crossmatch, U&E/eGFR, LFT, CRP and lactate - Why
- Assess bleeding, infection, organ perfusion and procedural preparation.
- Interpretation and limitations
- Correct coagulopathy when feasible but do not defer life-saving drainage in collapse; falling haemoglobin suggests haemopericardium.
- 04
Bedside pulsus paradoxus and haemodynamics - Why
- Support severity and trend response.
- Interpretation and limitations
- An inspiratory systolic BP fall above 10 mmHg supports tamponade; absence has important physiological exceptions.
- 05
CT/TOE in stable atypical cases - Why
- Define loculated/postoperative fluid, tumour, trauma or aortic disease.
- Interpretation and limitations
- Do not transfer an unstable patient away from immediate drainage/surgical capability solely for detailed imaging.
- 06
Pericardial fluid and tissue studies - Why
- Identify bacterial/TB, malignant and other causes after drainage.
- Interpretation and limitations
- Send cell count, culture, cytology and targeted tests based on context; do not let sampling delay decompression.
06Differential diagnosisRealistic alternatives and the features that help distinguish them.
High-risk pulmonary embolism
High-risk pulmonary embolism can also cause shock, raised JVP and right-ventricular dilatation. Thromboembolic risk, acute right-heart pressure overload without a haemodynamically significant pericardial effusion, and vascular imaging when the patient is stable enough support pulmonary embolism; the two conditions can occasionally coexist.
Tension pneumothorax
Tension pneumothorax produces obstructive shock with respiratory distress, but unilateral reduced breath sounds and absent lung sliding favour pleural pressure rather than pericardial fluid. An unstable patient needs immediate clinical treatment without waiting for confirmatory imaging.
Right-ventricular infarction
Right-ventricular infarction may give hypotension, raised JVP and clear lungs. Inferior ischaemic ECG changes, regional right-ventricular dysfunction and absence of tamponade physiology support infarction, although both conditions can coexist.
Hypovolaemic shock
Haemorrhage or severe volume loss causes tachycardia, hypotension and underfilled cardiac chambers. A clear source, usually low venous pressure and no pericardial collection favour hypovolaemia, noting that volume loss can mask tamponade signs and that mixed shock is possible.
07ManagementImmediate care, first-line treatment, alternatives and escalation.
01CrashUnstable tamponadeFirst stepShock, rapidly worsening perfusion or peri-arrest state with suspected effusion.+
- 1Call resuscitation, interventional cardiology and cardiothoracic/critical-care help; monitor, obtain IV/IO access and perform immediate focused echo during ongoing ABCDE care.
- 2Avoid induction/positive-pressure ventilation if possible until decompressed; if unavoidable, use expert haemodynamic planning with vasopressor and drainage readiness.
- 3Proceed to urgent image-guided pericardiocentesis when appropriate; choose emergency surgical drainage for trauma, suspected aortic rupture, clotted/postoperative or inaccessible effusion.
- 4A cautious crystalloid bolus can bridge clear preload depletion, but stop if congestion worsens and never substitute it for drainage.
02UrgentCompensated but threatenedEcho tamponade physiology or progressive symptoms without shock.+
- 1Keep monitored, fasting and in a drainage-capable area; review anticoagulants/coagulation, crossmatch and define the likely cause.
- 2Arrange urgent echo-guided drainage before deterioration, using the shortest safest fluid window and an indwelling catheter when appropriate.
- 3If loculated, recurrent, purulent, malignant or tissue diagnosis is needed, involve surgeons early for window/biopsy rather than serial blind aspirations.
- 4EscalationEscalate immediately if BP, mentation, urine output or lactate worsens.
03Aorta/traumaHaemopericardium source controlType A dissection, penetrating/blunt trauma or postoperative bleeding suspected.+
- 1DefinitiveActivate cardiothoracic/major-trauma pathway and obtain immediate expert echo; CT only if haemodynamically able to reach definitive surgery safely.
- 2DefinitiveFor type A dissection, urgent aortic repair is definitive; uncontrolled rapid pericardiocentesis can increase bleeding by restoring pressure.
- 3If a dissection patient will otherwise die before theatre, only a senior multidisciplinary team should consider controlled small-volume drainage as a bridge.
- 4For clotted or ongoing surgical bleeding, proceed to operative decompression and haemostasis.
04AftercarePost-drainage cause and recurrenceHaemodynamics improve after decompression.+
- 1Leave/withdraw the drain according to output and repeat echo; watch for reaccumulation, bleeding, pneumothorax and pericardial-decompression syndrome.
- 2Send targeted microbiology/cytology and treat the cause; purulent disease requires antibiotics plus complete drainage, malignancy needs oncology and recurrence planning.
- 3Re-image before/after drain removal and arrange follow-up based on cause; recurrent fluid may need a surgical window or pericardiectomy.
08ComplicationsImportant consequences, why they occur and why they matter clinically.
Multi-organ hypoperfusion
Progressive filling restriction reduces cardiac output and organ blood flow, causing confusion, oliguria, lactic acidosis, hepatic injury and myocardial ischaemia even before profound hypotension becomes evident.
Pulseless electrical activity
Extreme pericardial pressure can prevent meaningful ventricular filling despite continuing electrical activation. This may produce pulseless electrical activity and requires immediate decompression alongside resuscitation and source control.
Pericardial decompression syndrome
After drainage, pericardial decompression syndrome is a rare and incompletely understood deterioration characterised by ventricular dysfunction, hypotension and/or pulmonary oedema. New deterioration after apparently successful decompression requires urgent reassessment for this syndrome and for alternatives such as bleeding, pneumothorax or recurrent tamponade.
Recurrent or loculated tamponade
Persistent bleeding, malignancy, infection or an obstructed drain can allow fluid to reaccumulate; postoperative clot may instead compress a single chamber, producing atypical findings and renewed haemodynamic compromise.
09Monitoring and follow-upTreatment response, safety checks and longer-term review.
- Continuous ECG, BP, oxygen saturation, mental state, capillary refill and urine output until stable after drainage.
- Serial lactate, haemoglobin, renal function and coagulation according to shock/bleeding context.
- Repeat focused echo immediately for recurrent hypotension and around drain removal.
- Chart pericardial drain output and character; abrupt cessation with deterioration may mean blockage, not resolution.
- Watch after drainage for paradoxical pulmonary oedema or ventricular failure consistent with decompression syndrome.
- Track culture/cytology and ensure cause-specific referral rather than treating drainage as the final diagnosis.
10Special situationsVariants, exceptions and circumstances that change the usual approach.
Pressure, not volume
The pericardial pressure-volume curve is steep: accumulation rate and pericardial compliance explain why 100 mL can kill while 1 L may be tolerated.
Hypotension is late
Compensation can preserve BP until sudden collapse; raised JVP and tachycardia with echo physiology deserve action before shock.
Ventilation can unmask collapse
Positive intrathoracic pressure reduces venous return to an already underfilled heart; decompression first when feasible.
Postoperative tamponade can be regional
A loculated clot compressing the LA or RV may not show a circumferential effusion or classic chamber-collapse sequence.
Aortic tamponade is different
The pericardial pressure may temporarily limit haemorrhage; surgery is the target and any bridge drainage must be controlled.
11Common pitfallsFrequent interpretation and management errors.
- 01
Waiting for Beck's triad or hypotension before acting.
- 02
Equating a large effusion with tamponade or a small effusion with safety.
- 03
Intubating or aggressively diuresing before decompression without recognising preload dependence.
- 04
Sending an unstable patient to CT when bedside echo and drainage are available.
- 05
Performing unrestricted pericardiocentesis for suspected type A dissection instead of urgent surgical source control.