Anesthesia for Hepatic Resection (Segmentectomy, Lobectomy)

🔶 Introduction

Hepatic resections are major surgeries performed for primary or secondary liver tumors, trauma, or benign liver lesions. They may involve:

• Segmentectomy – removal of one or more anatomical liver segments.
• Lobectomy (Hepatectomy) – removal of an entire liver lobe (right or left).

These procedures pose significant anesthetic challenges due to:

• Potential for massive blood loss.
• Coagulopathy due to underlying liver dysfunction.
• Need for low CVP anesthesia.
• Risk of post-resection liver failure.

🔷 Preoperative Evaluation

1. Liver Function Assessment

• Child-Pugh Score: Assesses synthetic function (bilirubin, albumin, INR, ascites, encephalopathy).
• MELD Score: Predicts mortality; higher score = higher perioperative risk.
• ICG clearance or LiMax test: Evaluates liver functional reserve.

2. Assessment of Comorbidities

• Portal hypertension (splenomegaly, thrombocytopenia, varices).
• Ascites, encephalopathy, nutritional status.
• Cardiopulmonary status: ECG, echocardiogram.

3. Imaging

• CT/MRI to evaluate vascular anatomy, segmental involvement.
• Volumetric studies to estimate future liver remnant (FLR).
• At least 30% FLR in normal liver, 40% if cirrhotic.

🔷 Intraoperative Anesthetic Management

1. Monitoring

• Standard ASA monitors.
• Invasive BP monitoring (arterial line).
• Central venous catheter (CVP guidance for low CVP technique).
• Large-bore IV access (2 wide bore peripheral lines or central line).
• Consider TEE for real-time volume and cardiac function assessment.
• Foley catheter with urine output monitoring.
• Temperature monitoring (risk of hypothermia).

2. Induction

• Rapid sequence induction (if ascites or full stomach).
• Avoid drugs with significant hepatic metabolism or prolonged half-life.
• Etomidate or propofol + short-acting opioids (fentanyl, remifentanil).
• Rocuronium preferred (non-hepatic metabolism).

3. Maintenance

• Balanced anesthesia: Low-dose volatile + opioids + NMB.
• TIVA is acceptable if desired.
• Avoid halothane (risk of halothane hepatitis).
• Use short-acting drugs (remifentanil, cisatracurium).
• Controlled ventilation; avoid high PEEP to maintain venous return.
• Normothermia (active warming measures).

🔷 Low CVP Anesthesia

Rationale:

Reduces hepatic venous pressure → ↓ blood loss during parenchymal transection.

Target:

• CVP <5 mmHg during resection phase.

Techniques:

• Fluid restriction pre-resection.
• Diuretics (furosemide/mannitol) ± controlled phlebotomy.
• Trendelenburg position avoided.
• Vasodilators (nitroglycerin) cautiously.
• TEE or stroke volume variation (SVV) may guide volume status.

Important: Volume resuscitation done after transection to avoid bleeding.

🔷 Fluid and Blood Management

Fluids:

• Restrictive fluid strategy until resection complete.
• Balanced crystalloids preferred.
• Albumin for colloid replacement if needed.
• Avoid starches (HES) – risk of AKI and coagulopathy.

Blood loss management:

• Cell saver (avoid in malignant tumors).
• Transfuse PRBCs to keep Hb >7–8 g/dL.
• FFP, platelets, cryoprecipitate guided by TEG/ROTEM.

🔷 Coagulation Monitoring

• Use TEG/ROTEM to guide transfusion.
• Check INR/PT/aPTT, fibrinogen.
• Correction of coagulopathy before surgery if significant.
• Vitamin K, FFP, cryoprecipitate based on findings.

🔷 Surgical Phases and Anesthesia Goals

1. Pre-resection (mobilization phase):

• Hemodynamic stability.
• Avoid volume overload.
• Maintain normothermia and normoglycemia.

2. Transection (parenchymal cutting):

• Low CVP crucial.
• Blood loss control.
• Close coordination with surgeon.

3. Post-resection (after transection):

• Restore volume and perfusion.
• Monitor for reperfusion injury (hypotension, hyperkalemia).
• Gradual fluid resuscitation.
• Avoid air embolism.

🔷 Postoperative Care

ICU Transfer if:

• Major resection.
• Blood loss >1–1.5 L.
• Coagulopathy.
• Comorbidities.

Complications:

• Bleeding.
• Liver failure (monitor INR, bilirubin, ammonia).
• AKI.
• Infection, sepsis.
• Electrolyte disturbances.

🔷 Key Drugs to Avoid or Use With Caution

• Avoid halothane (hepatotoxic).
• Use caution with:
• Morphine (active metabolites).
• Midazolam (prolonged sedation).
• Muscle relaxants with hepatic metabolism (pancuronium, vecuronium).

Use cisatracurium or atracurium (Hofmann elimination) for safer NMB.

🔷 Summary Table