Supportive Care and Monitoring in Ascites & Spontaneous Bacterial Peritonitis

1. Respiratory Support

Rationale: Cirrhotic patients with SBP are at high risk for respiratory failure due to sepsis-induced ARDS, volume overload, or large-volume ascites causing hepatic hydrothorax. Careful ventilator management and correction of coagulopathy are crucial to minimize secondary lung injury.

A. Indications for Intubation

• Severe hypoxemia: PaO₂/FiO₂ ratio less than 150 mmHg despite high-flow supplemental oxygen.
• Acute hypercapnic respiratory failure: PaCO₂ greater than 60 mmHg with a resulting pH less than 7.20.
• Inability to protect the airway due to altered mental status (e.g., severe hepatic encephalopathy).

B. ARDS (Berlin) Criteria

1. Timing: Onset within one week of a known clinical insult (e.g., SBP).
2. Imaging: Bilateral opacities on chest X-ray or CT scan.
3. Origin of Edema: Respiratory failure not fully explained by cardiac failure or fluid overload.
4. Oxygenation Impairment (on PEEP ≥5 cm H₂O):
   • Mild: PaO₂/FiO₂ is 201–300 mmHg.
   • Moderate: PaO₂/FiO₂ is 101–200 mmHg.
   • Severe: PaO₂/FiO₂ is ≤100 mmHg.

C. Lung-Protective Ventilator Strategy

• Tidal Volume (Vₜ): Target 6 mL/kg of predicted body weight.
• Plateau Pressure (Pₚₗₐₜ): Maintain below 30 cm H₂O to prevent barotrauma.
• PEEP: Use incremental titration to improve oxygenation while avoiding excessive PEEP that could increase portal pressure and reduce venous return.
• Recruitment Maneuvers: Employ judiciously, as they can cause transient hypotension.

D. Coagulopathy and Airway Management

• Aim for platelets ≥50,000/µL and an INR ≤2.0 before elective intubation.
• Administer platelet transfusions for counts below 50,000/µL.
• Consider fresh frozen plasma (FFP) for an INR greater than 2.0.
• Utilize video laryngoscopy or fiberoptic guidance to improve first-pass success and minimize airway trauma.

2. Hemodynamic Support

Rationale: The systemic inflammation from SBP causes splanchnic vasodilation, reducing effective arterial blood volume and precipitating hepatorenal syndrome-acute kidney injury (HRS-AKI). Albumin and vasopressors are used in tandem to restore volume, increase systemic vascular resistance, and optimize renal perfusion.

A. Albumin Infusions

Albumin is indicated for all patients with SBP (defined as an ascitic fluid polymorphonuclear [PMN] count ≥250/mm³) who are started on antibiotics. It works by expanding intravascular volume and blunting the activation of the renin-angiotensin-aldosterone system.

B. Vasopressor Selection

The goal of vasopressor therapy is to counteract splanchnic vasodilation and improve mean arterial pressure (MAP), thereby increasing renal perfusion pressure.

C. Invasive Monitoring

• Arterial Line: Essential for continuous, real-time MAP monitoring and frequent arterial blood gas sampling.
• Central Venous Catheter (CVC): Allows for secure administration of vasopressors. While CVP trends can be followed, absolute values are unreliable for guiding fluid resuscitation in cirrhosis due to ascites and altered intrathoracic pressures. Dynamic indices like pulse pressure variation (PPV) may be more useful in mechanically ventilated patients.

3. ICU-Related Complication Prevention

Rationale: Critically ill cirrhotic patients are highly susceptible to secondary complications. Standardized prophylaxis protocols are vital to reduce the risk of venous thromboembolism (VTE), stress-related mucosal bleeding, and device-associated infections.

A. VTE Prophylaxis

• Pharmacologic: Low-molecular-weight heparin (e.g., enoxaparin 40 mg SC once daily) is preferred. Hold if platelets are <50,000/µL or INR is >2.5.
• Mechanical: Use intermittent pneumatic compression (IPC) devices when the bleeding risk is high or pharmacologic prophylaxis is contraindicated.

B. Stress Ulcer Prophylaxis

• Indications: Mechanical ventilation for >48 hours, significant coagulopathy (platelets <50,000/µL or INR >1.5), or treatment with high-dose corticosteroids.
• Preferred Agent: Proton pump inhibitors (PPIs), such as pantoprazole 40 mg IV daily.
• Alternative: Histamine-2 receptor antagonists (H₂-blockers) can be used if PPIs are contraindicated.

C. Infection Control

• Central Line Bundle: Adhere strictly to all components, including chlorhexidine skin preparation, maximal sterile barrier precautions during insertion, and routine dressing care.
• Device Management: Perform daily reviews of all invasive lines and catheters, removing any that are no longer medically necessary.
• Standard Precautions: Emphasize strict hand hygiene and use of contact precautions as appropriate.

4. Management of Iatrogenic Organ Dysfunction

Rationale: The cirrhotic liver and kidneys are exquisitely sensitive to drug-induced injury. Proactive avoidance of nephrotoxic agents and prompt management of drug-related side effects are essential to preserve organ function.

A. Drug-Induced Nephrotoxicity

• Avoidance: Nonsteroidal anti-inflammatory drugs (NSAIDs) and aminoglycoside antibiotics should be avoided in patients with cirrhosis whenever possible.
• Cautious Use: If an aminoglycoside is required for a multidrug-resistant organism, use once-daily dosing, monitor trough levels closely, and discontinue at the first sign of a rise in serum creatinine.

B. Beta-Blocker-Related Hypotension

• During an acute SBP episode with hemodynamic instability, nonselective beta-blockers (e.g., propranolol, nadolol, carvedilol) used for portal hypertension should be temporarily held or dose-reduced to prevent worsening hypotension and blunting of the compensatory heart rate response.

C. Early Detection and Reversal

• Monitor hourly urine output.
• Check serum creatinine and BUN daily.
• If a drug-induced injury is suspected, discontinue the offending agent immediately and provide supportive care, which may include volume expansion with albumin.

5. Monitoring & Goals of Care

Rationale: Successful management requires frequent reassessment to titrate therapy appropriately. Concurrently, multidisciplinary discussions are crucial to ensure that the intensity of care aligns with the patient’s values, prognosis, and long-term goals.

A. Laboratory Monitoring

• Daily: Serum creatinine, BUN, electrolytes, AST, ALT, total bilirubin, and albumin.
• As Needed: INR and platelet count, especially prior to any invasive procedures.

B. Hemodynamic Monitoring

• Continuous: Mean arterial pressure (MAP) via an arterial line.
• Serial: Serum lactate levels to assess lactate clearance as a surrogate for improved tissue perfusion.

C. Multidisciplinary Rounds & Family Meetings

• Regularly engage the core team of critical care, hepatology, clinical pharmacy, and nursing to optimize the care plan.
• Conduct frequent family meetings to discuss the patient’s progress, prognosis, and goals of care. Clearly document advance directives and transplant candidacy status.

D. Ethical Considerations

• Carefully weigh the potential benefits and burdens of life-sustaining treatments like renal replacement therapy (RRT), prolonged mechanical ventilation, or transjugular intrahepatic portosystemic shunt (TIPS).
• In cases of refractory shock or multiorgan failure with poor prognosis, early involvement of the palliative care team is essential to support the patient and family.