What preoperative and postoperative care is recommended for a patient with a history of liver disease undergoing a hepatectomy, including the use of Cardiopulmonary Exercise Testing (CPET)?

CPET in Hepatectomy: Preoperative Risk Stratification

Cardiopulmonary exercise testing (CPET) should be performed preoperatively in high-risk patients undergoing hepatectomy—specifically those over 65 years or younger patients with significant comorbidities—to stratify perioperative risk and guide postoperative care intensity. 1

Indications for Preoperative CPET

CPET is indicated when surgical mortality risk exceeds 5% or when patient factors suggest increased morbidity risk, including advanced age, cardiovascular risk factors, multisystem disease, or poor functional status 2. For hepatectomy specifically, CPET provides superior risk assessment compared to standard pulmonary function tests or resting cardiac evaluation, as these cannot reliably predict exercise performance or functional capacity 3.

Critical CPET Thresholds for Hepatectomy

An anaerobic threshold (AT) below 9.9 ml O₂/kg/min is 100% sensitive and 76% specific for in-hospital mortality after hepatic resection, with no deaths occurring above this threshold. 1 This represents the single most important prognostic marker from CPET testing.

Additional prognostic markers include:

• VE/VCO₂ at AT above 34.5 predicts postoperative complications with 84% specificity and 76% positive predictive value 1
• Peak VO₂ less than 50-60% predicted correlates with higher morbidity and mortality, though this threshold was established primarily for lung resection 3
• Absolute oxygen uptake at AT (L/min) predicts early hospital discharge when higher 4

Integration with Enhanced Recovery Protocols

A critical nuance emerges when CPET is used within enhanced recovery after surgery (ERAS) programs. When CPET guides perioperative care stratification rather than serving as a surgical exclusion criterion, low relative VO₂ at AT does not independently predict complications 4. This suggests CPET should inform the level of postoperative monitoring and support required, not deny surgery to otherwise appropriate candidates 2, 4.

In octogenarians undergoing hepatectomy within ERAS programs utilizing CPET-guided care, outcomes match those of patients aged 70-79, with chronological age failing to predict complications or survival on multivariate analysis 5.

Comprehensive Preoperative Assessment Beyond CPET

Nutritional Optimization

• Perform nutritional screening on all hepatectomy candidates using validated tools assessing weight loss, BMI, and fat-free mass index 3
• Malnourished patients (weight loss >10% or >5% over 3 months with reduced BMI or low fat-free mass index) require enteral supplementation for 7-14 days before surgery 3
• Delay surgery at least 2 weeks in severely malnourished patients to optimize nutritional status 6

Liver-Specific Assessment

• Volumetric assessment of future liver remnant (FLR) using CT or MRI is mandatory 7
• Indocyanine green (ICG) retention testing evaluates functional hepatic reserve 7
• Biliary drainage is required when bilirubin exceeds 50 mmol/L, with surgery ideally postponed until levels normalize 3, 6
• Clinically significant portal hypertension and Child-Pugh class B cirrhosis are absolute contraindications to major hepatectomy 7

Substance Cessation

• Smoking cessation at least 4 weeks preoperatively reduces respiratory and wound complications (risk ratio 0.42 with intensive intervention) 3, 6
• Alcohol cessation 4-8 weeks before surgery for heavy drinkers (>24 g/day women, >36 g/day men) 3, 6

Preoperative Fasting and Carbohydrate Loading

• Limit fasting to 6 hours for solids and 2 hours for liquids 3, 6
• Carbohydrate loading the evening before surgery and 2-4 hours before anesthesia improves insulin resistance 3, 6

Perioperative Management Strategies

Medication Management

• Avoid long-acting anxiolytics, particularly in elderly patients 3, 6
• Avoid preoperative gabapentinoids and NSAIDs 3, 6
• Adjust acetaminophen dosing according to extent of resection 3, 6
• Administer methylprednisolone 500 mg preoperatively (except in diabetics) 3, 6

Thromboprophylaxis

• Start low molecular weight heparin or unfragmented heparin postoperatively (not preoperatively) unless exceptional circumstances exist 3, 7, 6
• Apply intermittent pneumatic compression devices before anesthesia induction 3, 6

Antimicrobial Prophylaxis

• Administer antibiotic prophylaxis (e.g., cefazolin) within 60 minutes before incision, with no benefit to extending into the postoperative period 3, 6
• Use chlorhexidine-alcoholic solution for skin preparation over povidone-iodine 6

Intraoperative Hemodynamic Management

Maintain low central venous pressure (CVP <5 cm H₂O) during hepatic transection using balanced crystalloids as maintenance fluid 8, 7. This significantly reduces blood loss without compromising outcomes 8.

• Use balanced crystalloids (lactated Ringer's) over 0.9% saline to avoid hyperchloremic acidosis 8
• Avoid excessive crystalloid administration, as this can be as harmful as blood loss 8
• Consider goal-directed fluid therapy (GDFT) after hepatic resection to restore tissue perfusion, particularly in patients with comorbidities and reduced cardiac function 8

Transfusion Strategy

• Implement restrictive transfusion strategy (transfuse when hemoglobin <7 g/dL with target 7-9 g/dL) to avoid increasing portal pressure 8
• Avoid prophylactic blood product transfusion based solely on laboratory values, as this increases complications without reducing bleeding 8

Postoperative Care

• Start thromboprophylaxis postoperatively with LMWH or unfragmented heparin 7
• Implement early oral intake with normal diet immediately after hepatectomy 7
• Monitor weight gain, as increase >3.5 kg on postoperative day 2 predicts major complications 8
• Establish early mobilization (out of bed) from operative day through discharge 8

Common Pitfalls to Avoid

• Do not use CPET results to exclude patients from surgery; instead, use them to stratify postoperative care intensity 2, 4
• Do not rely on traditional coagulation tests (INR, PT) to predict bleeding risk, as these overestimate coagulopathy after hepatectomy 8
• Do not perform smoking cessation less than 4 weeks before surgery, as this does not improve outcomes 3
• Do not neglect treatment of underlying infections or acute kidney injury, as these contribute more to bleeding risk than coagulation abnormalities 8