1. Valve function and ventricular status: residual mitral stenosis/regurgitation, pulmonary hypertension, LV/RV dysfunction, atrial fibrillation, heart failure.
2. Anticoagulation: many mechanical-valve patients are on therapeutic LMWH or UFH. This may rule out neuraxial anesthesia.
3. Avoid abrupt haemodynamic changes: tachycardia, hypotension, hypoxia, hypercarbia, acidosis, major fluid loading, and postpartum autotransfusion can precipitate failure.

Preoperative essentials

• Multidisciplinary plan: obstetrician, cardiology, cardiac anesthetist, neonatology.
• Recent echo: prosthetic valve gradients/function, pulmonary pressures, ventricular function.
• ECG, Hb, platelets, coagulation tests, renal function, blood cross-match.
• Establish whether valve is mechanical or bioprosthetic and exact timing/dose of last LMWH/UFH/warfarin.
• Consider arterial line before induction for significant pulmonary hypertension, LV/RV dysfunction, severe symptoms, or anticipated haemodynamic instability.
• Avoid routine large fluid preload. Use small, guided aliquots only.
• Have phenylephrine/noradrenaline ready, and oxytocin administered slowly after delivery.

Choice of anesthetic technique

If anticoagulation has been held safely and cardiac status is stable

• Do not give a routine single-shot full-dose spinal in a fragile cardiac patient, particularly if pulmonary hypertension or ventricular dysfunction exists.
• Maintain SVR and coronary perfusion with a prophylactic vasopressor infusion, usually phenylephrine if heart rate is adequate.
• Keep left uterine displacement and give oxygen.
• The American Society of Anesthesiologists requires full monitoring and immediate obstetric and neonatal support for neuraxial cesarean anesthesia, as outlined in its obstetric neuraxial statement.

If therapeutic anticoagulation is ongoing, timing is inadequate, there is fetal urgency, or neuraxial is contraindicated

General anesthesia: practical induction plan

1. Position and preparation
   • Head-up / ramped position, left uterine displacement.
   • Preoxygenate thoroughly with tight mask seal.
   • Two good IVs, arterial line if time permits, defibrillator and vasoactive infusions prepared.
   • Phenylephrine or norepinephrine infusion connected before induction.
   • Aspiration prophylaxis as per local protocol.
2. Haemodynamic targets
   • Sinus rhythm if possible.
   • Avoid tachycardia, especially with residual mitral stenosis or pulmonary hypertension.
   • Avoid hypotension and abrupt reduction in SVR.
   • Maintain oxygenation, normocapnia, normothermia, and normal acid-base status.
   • Avoid fluid overload.
3. Induction
   • Modified RSI with gentle mask ventilation only if needed to prevent desaturation.
   • Use a titrated induction agent appropriate to BP and ventricular function:
     • Etomidate is reasonable if poor ventricular reserve or hypotension.
     • Propofol in reduced, titrated dose only if haemodynamically robust and vasopressor support is ready.
   • Add a small, titrated opioid dose to blunt intubation response if fetal condition permits.
   • Use rocuronium or succinylcholine for RSI according to contraindications and local practice.
   • Treat BP fall immediately with phenylephrine or norepinephrine rather than fluid boluses.
4. Intubation and maintenance
   • Gentle laryngoscopy. Aim to prevent hypertension and tachycardia.
   • Volatile anesthetic at the minimum effective concentration until delivery, plus oxygen/air.
   • Avoid nitrous oxide if there is significant pulmonary hypertension or RV dysfunction.
   • Ventilate to normocapnia. Avoid high airway pressures and excessive PEEP, particularly with pulmonary hypertension/RV impairment.
   • After delivery, deepen anesthesia and provide opioid analgesia.
5. Uterotonics
   • Give oxytocin slowly as an infusion, not a rapid IV bolus, because sudden vasodilation/tachycardia can be poorly tolerated.
   • Avoid or use extreme caution with ergometrine in pulmonary hypertension, hypertension, ischemic disease, or significant cardiac dysfunction.
   • Use carboprost cautiously in asthma and pulmonary hypertension.
6. Postpartum
   • Extubate fully awake only if stable, normothermic, well oxygenated, and not fluid overloaded.
   • HDU/ICU monitoring is appropriate in significant pulmonary hypertension, ventricular dysfunction, symptomatic disease, major hemorrhage, or difficult anticoagulation management.
   • The immediate postpartum period is high-risk because uterine involution and relief of caval compression increase venous return.

One-line viva answer

Main anesthesia concerns in MVR patient with mitral stenosis

Hemodynamic goals: remember “slow, sinus, stable, not overloaded”

• Slow-normal heart rate: avoid tachycardia because diastolic filling time shortens, raising LA and pulmonary pressures.
• Maintain sinus rhythm: atrial contraction is important for LV filling. Treat new AF with rapid ventricular response urgently.
• Maintain preload, but avoid fluid overload: the patient needs adequate filling, yet excess fluid can precipitate pulmonary edema.
• Maintain SVR and blood pressure: avoid sudden sympathectomy or hypotension.
• Avoid raised PVR: prevent hypoxia, hypercarbia, acidosis, pain, hypothermia, and high airway pressures.
• Avoid aortocaval compression: left uterine displacement.

Specific concerns in a patient with previous MVR

1. Anticoagulation
   • Mechanical valve patients may be on warfarin, therapeutic LMWH, or UFH.
   • Neuraxial block is unsafe until anticoagulant timing, platelet count, and coagulation status meet local neuraxial-safety criteria.
   • If still therapeutically anticoagulated or urgent delivery is needed, use GA rather than risk spinal/epidural hematoma.
2. Prosthetic valve status
   • Check for prosthetic dysfunction or thrombosis, high transvalvular gradient, residual MS/MR, and infective endocarditis.
   • Obtain recent echocardiography: valve gradient, valve area/effective orifice, LA size, LV/RV function, and pulmonary artery pressure.
3. Pulmonary hypertension and RV dysfunction
   • A very high-risk combination. Avoid even brief hypoxia, hypercarbia, hypotension, or excessive positive-pressure ventilation.
   • Consider arterial line before induction and postoperative HDU/ICU care.
4. Atrial fibrillation and thromboembolism
   • Enlarged LA and mechanical valve increase risk.
   • Continue indicated rate control. Have a clear peri-delivery anticoagulation restart plan with cardiology.
5. Post-delivery autotransfusion
   • After delivery, uterine contraction/involution transfers blood centrally.
   • This can abruptly increase preload and LA pressure, producing pulmonary edema. Close monitoring is needed for at least the immediate postpartum period.

For LSCS: anesthesia implication

• If anticoagulation status permits and patient is stable: graded epidural or low-dose CSE is generally preferable to avoid sudden tachycardia and the stress response of laryngoscopy.
• Avoid an uncontrolled, conventional full-dose single-shot spinal in severe MS because abrupt fall in SVR may be poorly tolerated.
• If GA is required: use a modified, haemodynamically controlled RSI, with vasopressor prepared/running, adequate depth to blunt intubation response, and strict avoidance of tachycardia, hypoxia, hypercarbia, and fluid loading.
• Give oxytocin slowly by infusion, not as a rapid IV bolus. Avoid ergometrine in pulmonary hypertension or major cardiac disease.

1. MVR patient: anesthetic concerns

Main concerns

• Anticoagulation versus thrombosis
  • Mechanical MVR usually requires lifelong anticoagulation.
  • Main perioperative issue is balancing:
    • neuraxial hematoma / surgical bleeding if anticoagulation is active
    • prosthetic-valve thrombosis and systemic embolism if it is stopped too long.
  • Confirm: type of prosthesis, warfarin/LMWH/UFH regimen, last dose, INR, aPTT, platelet count, and bridging plan.
• Prosthetic valve dysfunction
  • Exclude valve thrombosis, obstruction, pannus, dehiscence/paravalvular leak, endocarditis, residual mitral stenosis or regurgitation.
  • Review a recent echocardiogram: prosthetic gradients, LV/RV function, pulmonary artery pressure, LA size.
• Arrhythmia and thromboembolism
  • AF is common, especially with enlarged LA.
  • Maintain rate control and avoid triggers for AF. Acute AF with rapid ventricular response can cause pulmonary edema and instability.
• Heart failure / pulmonary hypertension
  • Determine functional class, orthopnea, pulmonary edema, RV dysfunction, and pulmonary hypertension.
  • Avoid hypoxia, hypercarbia, acidosis, pain, hypothermia, and fluid overload.
• Infective endocarditis
  • Assess for fever, positive cultures, embolic features, or abnormal prosthetic function if clinically suspected. Routine antibiotic prophylaxis solely for a prosthetic valve is not generally indicated for uncomplicated LSCS, but give standard cesarean surgical prophylaxis.

Anesthetic goals in MVR

• Maintain stable HR and rhythm.
• Maintain adequate preload but avoid overload.
• Avoid major fall in SVR and hypotension.
• Avoid raised PVR.
• Plan anticoagulation interruption/restart with cardiology.
• Choice of neuraxial versus GA depends mainly on anticoagulation timing and cardiac condition, not the prosthetic valve alone.

2. MS patient: anesthetic concerns

Main concerns

Hemodynamic goals: slow, sinus, stable, euvolemic

• Slow-normal HR
  • Avoid tachycardia: it shortens diastole, worsens LV filling and increases LA/pulmonary venous pressure.
  • Avoid extreme bradycardia too.
• Maintain sinus rhythm
  • The atrial kick is important for ventricular filling.
  • New AF, especially rapid AF, needs urgent rate control and often rhythm management.
• Preload: adequate, not excessive
  • Hypovolemia reduces cardiac output.
  • Excess fluid rapidly causes pulmonary edema.
  • Do not give routine large IV preload before neuraxial block.
• Maintain SVR
  • Sudden fall in SVR can compromise perfusion and provoke compensatory tachycardia.
  • Treat hypotension promptly with a vasopressor, commonly phenylephrine when HR is acceptable.
• Keep PVR low
  • Avoid hypoxia, hypercarbia, acidosis, pain, hypothermia, high airway pressures and excessive PEEP.
  • This is especially important in pulmonary hypertension/RV dysfunction.
• Avoid aortocaval compression
  • Use left uterine displacement.
• High-risk postpartum period
  • Uterine contraction and postpartum autotransfusion increase central blood volume.
  • Risk: acute pulmonary edema, pulmonary hypertensive crisis, RV failure.
  • Monitor in HDU/ICU if severe MS, pulmonary hypertension, symptoms, or significant cardiac dysfunction.

Anesthetic implication for LSCS in MS

• Preferred if feasible: carefully titrated epidural or low-dose CSE, with vasopressor ready and close monitoring.
• Avoid: abrupt sympathectomy from an uncontrolled full-dose single-shot spinal in severe MS.
• If GA required: blunt laryngoscopy and surgical stress response, prevent tachycardia, maintain SVR, and ventilate to normocapnia with low airway pressures.
• Oxytocin: slow infusion, not rapid IV bolus.
• Avoid ergometrine in pulmonary hypertension or significant cardiac disease.