List the potential aetiology of a severely altered mental status in a 65-year-old man, 48 hours after major hepatic resection for hepatocellular carcinoma. Outline your management of this patient.
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.
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
Specific management of hepatic encephalopathy
- 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
- 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)
- 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.
- 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
- 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
- Correct electrolyte derangement
- Monitor renal function (hepatorenal syndrome)
- Ensure BSL is monitored and supplemental glucose is made available
Ensure thiamine is co-administerd with glucose!
- Correct clinically significant anaemia.
Address haematinic factor deficiencies.
- Antibiotics as appropriate: ceftriaxone may be required if SBP is a real possibility.
Blood cultures and inflammatory markers should be collected.
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