Advances in intensive care management and monitoring have been associated with reduced mortality in patients with acute liver failure, with rates declining to approximately 55%, alongside evolving strategies emphasizing noninvasive neuromonitoring, early renal replacement therapy, and targeted hemodynamic support.
Acute liver failure (ALF) is defined as having an international normalized ratio or prothrombin time greater than 1.5, combined with the onset of hepatic encephalopathy within 4 weeks of the symptom onset in a patient without preexisting liver disease.
In this review published in Current Opinion in Anesthesiology, the authors summarized perioperative and critical care management approaches, focusing on neurologic, hemodynamic, renal, and coagulation considerations.
Epidemiology and Clinical Course
ALF remains rare, with an estimated incidence of one case per million annually and about 2,000 to 3,000 cases per year in the US. Hepatitis A and E infections are major causes of ALF in younger patients, particularly in low- and middle-income countries, with mortality rates over 50%. Survival rates among patients diagnosed with ALF have significantly improved in recent years, with mortality rates declining from 85% to about 55%. One-year survival following liver transplantation is approximately 65% to 70%.
Neurologic Complications and Monitoring
Hepatic encephalopathy with brain edema is a primary driver of mortality, accounting for 30% of deaths. Ammonia levels above 100 μmol/L predict severe encephalopathy with 70% accuracy, while levels above 200 μmol/L are strongly associated with intracranial hypertension and brain herniation.
Recent guidelines do not recommend obtaining invasive intracranial pressure monitoring because of associated risks and lack of demonstrated outcome benefit. One cohort reported intracranial bleeding in 10% of patients undergoing invasive monitoring. Noninvasive neuromonitoring approaches, including transcranial Doppler and other bedside tools, are increasingly used to assess intracranial dynamics.
Osmotic therapies, including mannitol and hypertonic saline, are described as equally effective for reducing intracranial pressure, with sodium targets of 145 to 155 mEq/L.
Hemodynamic Management
Patients with ALF frequently exhibit a hyperdynamic circulatory state characterized by elevated cardiac output and low systemic vascular resistance. Initial management includes crystalloid resuscitation, with normal saline preferred due to frequent hyponatremia. In addition, many patients with ALF may have a reduced metabolic capacity to process acetate and lactate.
If hypotension persists with mean arterial pressure below 60 mmHg despite fluids, vasopressor therapy is recommended, with norepinephrine as the first-line agent. Vasopressin may be added at low doses in refractory cases. Advanced invasive monitoring is advised to guide fluid and vasopressor management.
Acute Kidney Injury and Renal Replacement Therapy
Acute kidney injury occurs in 70% of patients with ALF, with 30% requiring renal replacement therapy. Early initiation of continuous renal replacement therapy should be considered, and ICU guidelines conditionally recommend early initiation in patients with ALF, particularly with rapidly rising ammonia or ammonia above 150 μmol/L and established cerebral edema.
Continuous renal replacement therapy is preferable to intermittent hemodialysis because it provides less hemodynamic impact due to greater stability of mean arterial pressure and renal perfusion.
Coagulation Management
Standard coagulation tests, including prothrombin time and activated partial thromboplastin time do not accurately reflect global hemostasis in ALF or bleeding risk. Coagulation is increasingly understood as “rebalanced,” with simultaneous reductions in procoagulant and anticoagulant factors.
Viscoelastic testing, including thromboelastography and rotational thromboelastometry, provides a better assessment of the entire coagulation process, including clot formation and degradation. However, standardized protocols for transfusion guidance are lacking.
Multiorgan Failure and Outcomes
ALF affects multiple organ systems simultaneously, including the brain, cardiovascular system, kidneys, and coagulation cascade, necessitating coordinated multidisciplinary management.
When patients with ALF are immediately transferred to referral centers with the expertise for treating them, outcomes are significantly improved, and death rates are reduced by nearly 50%.
The authors conclude that “multiorgan failure associated with ALF requires rapid and aggressive treatment to mitigate the risk of fatal outcomes.” They also note that ALF is infrequent and that much of the available evidence remains limited, underscoring the need for standardized management protocols.
Source: Current Opinion in Anesthesiology
Disclosures: The authors reported no conflicts of interest.
