Case Presentation: Anaesthetic Management of a 20-Year-Old Female with Moderate Pericardial Effusion Scheduled for Pericardiectomy

1. CASE OVERVIEW

2. PATHOPHYSIOLOGY OF PERICARDIAL EFFUSION AND TAMPONADE

2.1 Pericardial Physiology

• Initially, the pericardium has "reserve volume" - small amounts of fluid cause little pressure rise.
• Once the limit of pericardial stretch is exceeded, small additional volumes cause steep, disproportionate pressure rises.
• Chronic slow accumulation allows pericardial stretch and adaptive compensation; effusions of up to 1-2 litres may be well tolerated. Acute rapid accumulation of even 150-200 mL can precipitate tamponade.

2.2 Mechanism of Cardiac Tamponade

1. Equalisation of pressures across all four chambers - RA, RV, and LA diastolic pressures rise to equal intrapericardial pressure. Atrial and ventricular diastolic transmural pressures approach zero.
2. Impaired chamber filling - stroke volume falls.
3. Ventricular interdependence - as the heart cannot expand within the rigid pericardial sac, inspiration-driven increase in right heart filling compresses the left ventricle (septum shifts left). During expiration, the reverse occurs. This manifests clinically as pulsus paradoxus (systolic BP drop >10 mmHg on inspiration).
4. Compensatory adrenergic surge - tachycardia, peripheral vasoconstriction, and increased contractility partially preserve cardiac output (CO). When these mechanisms are overwhelmed, CO falls precipitously.

2.3 Haemodynamic Fingerprint of Tamponade

2.4 Quantifying the Effusion

• Trivial: <5 mm
• Small: 5-10 mm
• Moderate: 10-20 mm
• Large: >20 mm

3. PREOPERATIVE ASSESSMENT

3.1 History and Symptoms

• Symptoms of tamponade physiology: dyspnoea (most common), orthopnoea, chest pain/fullness, fatigue, palpitations, weakness, and anorexia.
• Beck's Triad (in severe tamponade): hypotension + raised JVP + muffled/distant heart sounds.
• Note: patients with chronic/slowly accumulating effusions may not exhibit Beck's triad. Young patients with high sympathetic tone may maintain BP until sudden decompensation.
• Positional symptoms - ability to lie flat (relevant for airway positioning and TEE placement).
• Aetiology-specific inquiry: history of tuberculosis exposure or contact, autoimmune symptoms (joint pains, rash, systemic illness), recent viral illness, previous chest radiation, prior cardiac surgery, renal disease, malignancy.

3.2 Physical Examination

• Vital signs including bilateral BP and pulsus paradoxus measurement (manual BP or arterial waveform).
• Jugular venous pressure and waveform character.
• Kussmaul sign (JVP rising on inspiration - more typical of constriction but may be present).
• Heart sounds - muffling, friction rub.
• Hepatomegaly, ascites, peripheral oedema (features of constrictive physiology if present).
• Respiratory assessment - coexisting pleural effusions are common.

3.3 Investigations

• RA systolic collapse (sensitivity 50-100%, specificity 33-100%) - earliest sign.
• RV diastolic collapse - more specific (75-90%) but lower sensitivity (48-60%); indicates haemodynamic significance.
• LA collapse - rare, highly specific for severe tamponade.
• IVC plethora (>2.1 cm, <50% collapse on inspiration).
• Inspiratory Doppler variation: >25% reduction in mitral inflow velocity; >40% variation in tricuspid inflow.

3.4 Risk Stratification

1. Does this patient have tamponade physiology currently or is she at risk of developing it under anaesthesia?
2. Is CPB likely to be needed?
3. Does coexisting disease (autoimmune, renal, pulmonary) affect anaesthetic planning?

• Vasodilation from induction agents reduces SVR.
• Positive pressure ventilation (PPV) reduces venous return.
• Tachycardia is blunted by anaesthetic agents.
• Myocardial depression reduces contractility.

4. PREOPERATIVE OPTIMISATION

1. Avoid dehydration - ensure euvolaemia or mild hypervolaemia before induction. IV crystalloid preloading is standard practice. Hypovolaemia significantly worsens tamponade physiology.
2. Maintain sympathetic tone - avoid preoperative anxiolytics that blunt heart rate (benzodiazepines and opioids reduce sympathetic drive; use cautiously or avoid).
3. Avoid beta-blockers - tachycardia is the primary compensatory mechanism preserving CO; beta-blockade is contraindicated.
4. Treat underlying cause where possible (anti-tuberculous therapy if TB confirmed, NSAIDs/colchicine for idiopathic/viral pericarditis).
5. Correct coagulopathy pre-emptively.
6. Review medications: ACE inhibitors, ARBs, or any vasodilators should be withheld.
7. In haemodynamically compromised patients: consider pericardiocentesis under local anaesthesia first to partially relieve tamponade, followed by general anaesthesia for definitive surgery.

5. ANAESTHETIC GOALS AND HAEMODYNAMIC TARGETS

6. ANAESTHETIC TECHNIQUE

6.1 Monitoring

• Invasive arterial line (radial artery preferred) - real-time beat-to-beat BP monitoring; allows detection of pulsus paradoxus and immediate detection of haemodynamic collapse. This is mandatory - placed under local anaesthesia before induction.
• Central venous catheter (CVC) - internal jugular or subclavian; for CVP monitoring, drug infusions, and emergency drug delivery. Internal jugular preferred.
• Pulmonary artery catheter (Swan-Ganz) - consider in severe cases; demonstrates pressure equalisation (RVEDP = LVEDP = PCWP = intrapericardial pressure). Post-pericardiectomy, demonstrates return of normal pressure gradients. However, its insertion may be technically difficult with tamponade.
• Transoesophageal echocardiography (TEE) - gold standard for intraoperative monitoring of effusion, chamber collapse, ventricular filling, wall motion, and adequacy of drainage. Placed after intubation.
• Standard AAGBI monitoring: SpO2, ETCO2, ECG (lead II and V5), temperature.
• Defibrillator pads: applied before induction (arrhythmias including VF may occur during pericardium manipulation).
• Urinary catheter: for output monitoring, particularly if CPB is anticipated.
• Blood warmer and rapid infusion device - large-bore IV access (minimum 2 large-bore peripheral IVs).

6.2 Operating Room Preparation

• Surgeon should be scrubbed, sterile draped, and ready to incise before induction is commenced. This means if haemodynamic collapse occurs at induction, surgical drainage can be performed immediately.
• Vasopressors and inotropes drawn up and immediately available:
  • Metaraminol or phenylephrine - bolus vasopressors to maintain SVR.
  • Noradrenaline infusion - for sustained vasopressor support.
  • Adrenaline (epinephrine) - as inotrope/vasopressor in extremis.
  • Atropine - for bradycardia.
  • Dopamine infusion - inotrope option.
• IV fluids running freely.
• Defibrillator charged.
• Emergency pericardiocentesis kit available.

6.3 Induction of Anaesthesia

Agent of Choice: Ketamine

• Ketamine 1-2 mg/kg IV (or 0.5-1 mg/kg in compromised patients) is the induction agent of choice for patients with pericardial effusion and tamponade physiology.
• Mechanism: Sympathomimetic - stimulates endogenous catecholamine release, maintaining HR, SVR, and contractility.
• Haemodynamically, ketamine raises or maintains BP, HR, and CO - the ideal profile for this physiology.
• Caveat: in patients with maximal endogenous sympathetic activation (catecholamine-exhausted state), ketamine's intrinsic myocardial depressant effects may be unmasked; use with caution.
• Etomidate (0.2-0.3 mg/kg IV) is the second-line alternative - minimal cardiovascular depression, no histamine release, preserves myocardial contractility and vascular tone.
• Propofol: Avoid as primary induction agent - profound vasodilation and myocardial depression.
• Thiopentone: Avoid - vasodilation, myocardial depression, histamine release.

Muscle Relaxation

• Succinylcholine 1.5 mg/kg for rapid sequence induction (RSI) if aspiration risk present (full stomach).
• Rocuronium 1.2 mg/kg for modified RSI, particularly if succinylcholine contraindicated.
• Alternatively, vecuronium or rocuronium at standard intubating doses for elective pericardiectomy without aspiration risk.
• Avoid pancuronium if heart rate is already high (vagolysis).

Approach Options

6.4 Airway Management

• Oral endotracheal intubation with a cuffed ETT.
• RSI technique if aspiration risk (dyspnoea may limit preoperative fasting).
• Pre-oxygenation is essential.
• Avoid early institution of IPPV until the pericardium is opened (if at all possible).
• Maintain spontaneous ventilation if feasible during the critical period of pre-drainage haemodynamic instability.

6.5 Ventilatory Management

• Increases intrathoracic pressure → reduces venous return → worsens cardiac filling.
• Goldman-Cecil states: "The initiation of mechanical ventilation in a patient with tamponade may produce a sudden drop in blood pressure because the positive intrathoracic pressure further impairs cardiac filling." (Goldman-Cecil Medicine, p. 718)
• Avoid high PEEP.
• If PPV required:
  • Use low tidal volumes (6-7 mL/kg ideal body weight).
  • High respiratory rate to compensate for low tidal volumes.
  • Low PEEP (0-5 cmH2O).
  • Minimise mean airway pressure.
  • Target: SpO2 ≥95%, ETCO2 35-45 mmHg.

6.6 Maintenance of Anaesthesia

• Balanced anaesthesia - judicious low-dose volatile agent (sevoflurane or isoflurane) combined with opioid infusion and neuromuscular blockade.
• Avoid high concentrations of volatiles - dose-dependent myocardial depression and vasodilation.
• Total intravenous anaesthesia (TIVA) with propofol + remifentanil infusion is a reasonable alternative but requires careful titration to avoid hypotension; ketamine infusion as adjunct is beneficial.
• Opioid analgesia: fentanyl (boluses), morphine, or remifentanil infusion.
• Neuromuscular blockade maintained throughout thoracic surgery.
• BIS monitoring (bispectral index) - helpful to avoid awareness given haemodynamic constraints that may limit anaesthetic depth.

6.7 Surgical Approach and CPB Considerations

• Sternotomy (most common): Full access, allows conversion to CPB. Preferred for complete pericardiectomy.
• Left anterolateral thoracotomy: Alternative; limited access; less likely to require CPB.

• Pericardiectomy may require CPB if the pericardium is densely adherent to the myocardium (requiring stripping) or if cardiac injury occurs during dissection.
• Pre-CPB: Heparinisation (300-400 units/kg), ACT target >480 seconds.
• On CPB: Mild hypothermia (32-34°C) or normothermic CPB; myocardial protection via cardioplegia if required.
• Blood conservation strategies (cell salvage, antifibrinolytics - tranexamic acid) are important given risk of coagulopathy.

7. INTRAOPERATIVE CONSIDERATIONS AND HAZARDS

7.1 Haemodynamic Instability at Induction

• The most dangerous moment. Maintain SVR and HR aggressively with vasopressors.
• Have a low threshold to immediately administer vasopressors (metaraminol 0.5-1 mg IV bolus or phenylephrine 50-100 mcg IV bolus) and inotropes (adrenaline 10-50 mcg IV bolus) if BP falls.

7.2 Coagulopathy

• Consumptive coagulopathy is a recognised complication specific to pericardiectomy.
• Stripping the pericardium from the myocardial surface releases fibrinolytic activators, activating complement and coagulation cascades. This leads to diffuse bleeding beyond pure surgical bleeding.
• Management:
  • Fresh frozen plasma (FFP) pre-emptively.
  • Cryoprecipitate for fibrinogen replacement.
  • Platelet transfusion if counts <50,000 in bleeding field.
  • Tranexamic acid (antifibrinolytic): 1 g IV at induction, repeat 1 g in CPB prime.
  • Protamine after CPB to reverse heparin.
  • Cell salvage.
  • Point-of-care coagulation testing (ROTEM/TEG) to guide haemostatic therapy.

7.3 Arrhythmias

• Direct myocardial manipulation and exposure of raw myocardial surface during pericardial stripping causes arrhythmias including:
  • Atrial fibrillation (most common).
  • Ventricular ectopics.
  • Ventricular fibrillation (rare but requires immediate defibrillation).
• Preventive/management measures:
  • Defibrillator pads applied before induction.
  • Maintain normal electrolytes (K+: 4.0-5.0 mmol/L, Mg2+ ≥1.0 mmol/L).
  • Amiodarone infusion (150 mg IV over 10 min, then 1 mg/min) for AF/sustained atrial arrhythmias.
  • Lidocaine bolus (1-1.5 mg/kg) for ventricular arrhythmias.
  • Immediate DC cardioversion/defibrillation for haemodynamically compromising arrhythmias.

7.4 Post-Decompression Haemodynamics

• On surgical relief of tamponade/pericardial constriction, a sudden, dramatic haemodynamic change occurs:
  • Sudden hypertension and tachycardia - due to release of endogenous catecholamines plus removal of outflow restriction. Anticipate and treat with short-acting agents (esmolol, labetalol, nitrates).
  • RV failure may paradoxically occur after pericardiectomy for constriction - the previously "protected" RV is now acutely exposed to full pulmonary pressures. Manage with: inhaled nitric oxide or prostacyclin, RV inotropes (milrinone, dobutamine), avoid factors increasing PVR.
  • LV failure - the chronically underloaded LV may not acutely accommodate the sudden increase in ventricular filling. Manage with vasodilators, diuretics (furosemide), inotropes if needed.
  • Myocardial oedema after release of constriction may temporarily worsen ventricular function.
  • Miller's notes: "Once cardiac tamponade is relieved, endogenously generated and exogenously administered catecholamines may cause sudden, severe increases in blood pressure and heart rate. This phenomenon should be anticipated and treated." (p. 7772)

7.5 Injury During Pericardial Stripping

• Risk of coronary artery laceration, myocardial perforation, or chamber rupture, particularly where pericardium is densely calcified and adherent.
• Emergency CPB must always be available and set up.
• Surgeons and perfusionists must be immediately ready for cannulation.
• Massive haemorrhage protocol should be pre-activated where appropriate.

8. FLUID AND BLOOD MANAGEMENT

• Aggressive preload before induction (10-15 mL/kg crystalloid or colloid).
• Balanced crystalloid (Hartmann's/Plasma-Lyte) as primary fluid.
• Blood transfusion: target Hb ≥8 g/dL on CPB, ≥8-10 g/dL off CPB.
• Autologous cell salvage - mandatory for pericardiectomy.
• Group and crossmatch at least 4 units packed red cells; FFP and platelets on standby.
• Avoid hypervolaemia post-decompression - the freshly decompressed heart may not tolerate excessive preload.

9. REGIONAL ANAESTHESIA AND ANALGESIA

• General anaesthesia is mandatory; regional techniques are adjuncts.
• Thoracic epidural anaesthesia (TEA): T3-T6 level for sternotomy; provides excellent postoperative analgesia, reduces opioid requirements. Caution: avoid intraoperatively if haemodynamics are precarious (sympathetic block worsens vasodilation); best placed preoperatively and activated postoperatively.
• Bilateral intercostal nerve blocks (for thoracotomy approach): long-acting local anaesthetic (bupivacaine 0.25%, ropivacaine).
• Parasternal intercostal plane block or serratus anterior plane block for sternotomy.
• Systemic analgesia: IV paracetamol, NSAIDs (with caution if bleeding risk), IV morphine/fentanyl PCA.

10. POSTOPERATIVE MANAGEMENT

10.1 Disposition

• ICU admission mandatory post-pericardiectomy.
• Invasive haemodynamic monitoring continued (arterial line, CVP, PAC if placed).
• TEE available if haemodynamic instability occurs.

10.2 Respiratory Management

• Most patients will remain intubated and ventilated postoperatively.
• Lung-protective ventilation continued: low tidal volumes (6 mL/kg IBW), PEEP 5-8 cmH2O.
• Wean ventilatory support as haemodynamics stabilise and coagulopathy resolves.
• Extubation criteria: haemodynamic stability, adequate reversal of neuromuscular blockade, spontaneous breathing, adequate analgesia, normothermia, minimal chest drain output.

10.3 Haemodynamic Management in ICU

• Continue vasopressor/inotrope infusions as needed; wean progressively.
• Monitor for:
  • Residual/recurrent effusion - repeat echocardiography at 24-48 hours.
  • Arrhythmias - particularly postoperative AF; manage per standard protocols.
  • Acute kidney injury - particularly if CPB used.
  • Low output state - post-pericardiectomy RV or LV dysfunction.

10.4 Chest Drain Management

• Chest drains (pericardial ± pleural) left in situ.
• Monitor hourly output: >200 mL/hr for 2 consecutive hours suggests significant bleeding requiring surgical re-exploration.
• Drain patency is essential - clot occluding drains may cause re-tamponade.

10.5 Pain Management

• Multimodal: IV paracetamol, opioid (morphine/oxycodone PCA), NSAIDs once haemostasis confirmed, thoracic epidural if placed.

10.6 Complications to Monitor

11. SPECIFIC CONSIDERATIONS FOR A 20-YEAR-OLD FEMALE

1. Aetiology in young females: Autoimmune disease (SLE, rheumatoid arthritis), tuberculosis, and viral pericarditis must be excluded. These may have systemic implications for anaesthesia (lupus nephritis, pulmonary hypertension, anaemia, thrombocytopenia, steroid-induced adrenal suppression requiring perioperative steroid cover).
2. Pregnancy/fertility: Confirm the patient is not pregnant (beta-hCG testing). Avoid teratogenic drugs. Consider menstrual history and thrombosis risk.
3. Drug considerations: Young females are more prone to histamine reactions; avoid histamine-releasing drugs. Latex allergy precautions if relevant.
4. Long-term outcomes: Prognosis depends on aetiology - idiopathic/viral effusions have excellent long-term outcomes (3-5% annual mortality rate for non-malignant causes per Goldman-Cecil). Autoimmune and TB-related effusions respond well to definitive treatment. Malignant effusion (rare at 20) carries very poor prognosis (~75% in-hospital or short-term mortality).
5. Body habitus: Younger patients may have better baseline cardiac reserve but may decompensate just as abruptly at induction.

12. QUICK REFERENCE SUMMARY CARD

REFERENCES AND SOURCES

1. Miller's Anesthesia, 10th Edition (Gropper et al.) - Chapter 50 (Cardiac Anaesthesia), pp. 7762-7773: Cardiac Tamponade, Anesthetic Management, Constrictive Pericarditis and Pericardiectomy; Chapter 33 (Intraoperative TEE), pp. 5025-5027.
2. Goldman-Cecil Medicine, International Edition - Chapter 62: Pericardial Disease, pp. 718-719.
3. Braunwald's Heart Disease, 11th Edition - Chapter 56/57/86: Pericardial Disease, Oncologic/Radiation-related pericarditis.
4. Fuster & Hurst's The Heart, 15th Edition - Chapter 16: Constrictive Pericarditis and Complete Pericardiectomy, p. 1612.
5. ROSEN's Emergency Medicine - Chapter: Pericardial Effusion and Cardiac Tamponade.
6. PMC7808091 - "Perioperative implications of pericardial effusions and cardiac tamponade" - BJA Education Review (2021). Full text available at PMC
7. WikiAnesthesia: Pericardiectomy - Lines/access/monitoring summary.

Clinical Teaching Points:

• The "moderate" label for this effusion does not guarantee haemodynamic stability under anaesthesia. Rate of accumulation, physiologic reserve, and the patient's sympathetic state determine true risk.
• The single most important principle: never induce general anaesthesia in a patient with tamponade physiology without the surgeon ready to immediately drain the pericardium.
• Ketamine's sympathomimetic profile makes it the pharmacological cornerstone of induction in this scenario.
• Pericardiectomy is uniquely dangerous because pericardial stripping triggers consumptive coagulopathy above and beyond surgical bleeding. Anticipate and treat proactively.
• Post-decompression haemodynamic swings (hypertension, tachycardia, acute RV or LV failure) can be as dangerous as pre-decompression instability.