Gastrointestinal

Question 1

Precipitants of Hepatic Encephalopathy

Answer 1

Precipitants

•upper GIT bleeding (protein load)
•alkalosis
•hypokalaemia
•infection
•high protein diet
•hepatoma
•hypoglycaemia
•drugs
-paracetamol
-sedatives
-diuretics
•portal vein thrombosis

Question 2

Management of Hepatic Encephalopathy

Answer 2

Management

•lactulose

• 30mL 1-2 hourly to produce laxative effect
• 1mL/kg in children up to 30 mL
• some doubt regarding efficacy
• PEG may be as effective1

•cefotaxime 1g IV 8 hourly (25mg/kg) or ceftriaxone 1g IV daily

•normal protein diet
-protein restriction does not appear to have benefit

• embolisation of porto-systemic shunts if resistant to initial therapy
• referral for consideration of liver transplantation if
• 2 admissions for hepatic encephalopathy in the previous 6 months
• absence of comorbidities that would preclude surgery
• abstinence from alcohol

•consider end of life care

Question 3

Myxoedema Coma Features

Answer 3

Features of hypothyroidism plus:

•altered mental state
•seizures
•hypothermia
•hypoventilation
•cardiovascular compromise
-hypotension
-bradycardia
-pericardial effusion
•hypoglycaemia
•hyponatraemia
•paralytic ileus
•urinary retention

•Precipitating events are usually present

• infection
• stroke
• myocardial infarction
• medication changes

Question 4

Treatment of Myxoedema Coma

Answer 4

Thyroxine

• oral T4
• 75 - 150 µg/day
• only 50% bioavailability in well patients
• in older patients or those with ischaemic heart disease start with a lower dose of 25 µg/day
• duration of effect 1-3 weeks

In myxoedema coma

•no universally accepted replacement regimen

T3
•dose
-initial 25-50 µg IV bolus
-10- 20 µg 8 hourly IV up to 60 µg maximum per day

• has more rapid onset and does not rely on peripheral conversion of T4 to T3 which may be very variable
• has potential for cardiac adverse effects, particularly arrhythmias
• clinical response is faster with T3
• some advocate continuous infusions using 20 µg per day questioning the need for an initial bolus
• may also be given via NGT (has good oral bioavailability although IV preferred initially until return of gastrointestinal function)

T4

•dose

• IV 300-500 µg/bolus
• then 50 µg IV/day
• improvement is felt to be more smooth with T4 than T3
• may have less cardiovascular adverse effects
• barely perceptible improvement at 24 hours
• change to oral T4 when gastrointestinal function returns
• combined approaches with administration of both T3 and T4 are also described

Steroids

• impaired glucocorticoid response to stress
• hydrocortisone 100 mg 6 hourly

Fluids
•water restriction for hyponatraemia

Other
•rewarming
•intensive supportive treatment
•avoid drugs with sedative or respiratory depression effects
•treat precipitating events