Question 14

College Answer

Mental state could be severely depressed or patient may be agitated or confused.  

In general the potential aetiologies are the same, though some more likely in each type of state.   Consider: decreased oxygen delivery to braiin (hypoxaemia, low cardiac output, low blood pressure), effects of drugs (those administered or those withdrawing from), intracerebral pathology (thromboembolism, rarely bleed eg. into undetected secondaries), electrolyte disorders (especially glucose, Na and Calcium), infections (unlikely; eg. systemic/meningitis/encephalitis), postoperative confusional state (uncertain but probably multifactorial aetiology), post-ictal or psychiatric disorder.

Management involves exclusion of  reversible and  specific treatable causes considered likely/possible (eg. SpO2, vital signs, glucose, electrolytes, review drugs and history).  Appropriate treatment of any specific abnormalities detected. Protection of patient and staff with cautious use of restraint (chemical or physical) if absolutely necessary or specifically indicated.

Discussion

Potential aetiology for a severely altered mental status post hepatic resection:

• Hypoxia due to intrapulmonary portosystemic shunting, atelectasis or aspiration
• Hypercapnea due to right pleural effusion
• Hepatic encephalopathy due to high ammonia
• Cerebral oedema
• Diminished capacity to metabolise anaesthetic drugs and sedatives
• Intracranial haemorrhage in the context of coagulopathy
• Septic encephalopathy post-operatively

Management:

Specific management of hepatic encephalopathy

• Lactulose
• Rifaximin
• Avoidance of hyponatremia
• Nutritional management:
  • Branched-chain amino acids (BCAAs) and a reduced amount of aromatic amino acids
  • High fiber diet
  • Pro-biotics (though their benefit is unclear)

Management of the precipitating cause

• Stop GI bleeding (endoscopy, banding, etc)
• Antibiotics for SBP
• Correct dehydration
• Withdraw hepatotoxins

Supportive management of the encephalopathic patient

1. Support the airway.  If the patient is comatose or uncooperative, they may require intubation in order to correct disorders of gas exchange (as they may not be compliant with NIV and chest physiotherapy)
2. Wean ventilation to spontaneous mode as tolerated.​ Hypoxia and hpercapnea can be readily corrected if the patient is mechanically ventilated; otherwise, posture with chest physiotherapy and deep breathing exercises are crucial
   Avoid NIV; abdominal distension and a fluctuating level of consciousness will likely result in aspiration. HFNP is ok. 
3. Support haemodynamically;
   noradrenaline +/- terlipressin may be appropriate if hepatorenal syndrome is suspected
   Albumin (20%) is a reasonable resuscitation fluid
   Hepatic flow should be optimised by monitoring for abdominal compartment syndrome
4. Avoid sedation. As needed, use drugs which do not depend on hepatic metabolism (eg. remifentanyl).
   Cerebral oedema and the potential for intracranial catastrophe should be investigated with a CT brain
5. Correct electrolyte derangement
6. Monitor renal function (hepatorenal syndrome)
7. Ensure BSL is monitored and supplemental glucose is made available
   Ensure thiamine is co-administerd with glucose!
8. Correct clinically significant anaemia. 
   Address haematinic factor deficiencies.
9. Antibiotics as appropriate: ceftriaxone may be required if SBP is a real possibility.
   Blood cultures and inflammatory markers should be collected.

Wendon, Julia, et al. "Critical care and cirrhosis: outcome and benefit." Current opinion in critical care 17.5 (2011): 533-537.

Riggio, Oliviero, et al. "Management of hepatic encephalopathy as an inpatient." Clinical Liver Disease 5.3 (2015): 79-82.

Bajaj, J. S. "Review article: the modern management of hepatic encephalopathy." Alimentary pharmacology & therapeutics 31.5 (2010): 537-547.

Amodio, Piero, et al. "The nutritional management of hepatic encephalopathy in patients with cirrhosis: International Society for Hepatic Encephalopathy and Nitrogen Metabolism Consensus." Hepatology 58.1 (2013): 325-336.

Als-Nielsen, Bodil, Lise Lotte Gluud, and Christian Gluud. "Nonabsorbable disaccharides for hepatic encephalopathy." Cochrane Database Syst Rev 2 (2004).

Bass, Nathan M., et al. "Rifaximin treatment in hepatic encephalopathy." New England Journal of Medicine 362.12 (2010): 1071-1081.