Alcoholic withdrawal Flashcards
What is alcohol withdrawal?
Occurs in patients who are alcohol dependent and have stopped or reduce their intake within hours or days of presentation.
What is the epidemiology of alcohol withdrawal: Prevalence?
Harmful use of alcohol or alcohol dependence occurs in 5% of drinkers aged over 15 years.
What is the aetiology of alcohol withdrawal?
Ethanol interacts with GABA and NMDA receptors. Alcohol withdrawal is characterised by signs of overactivity of the SNS because chronic alcohol consumption results in upregulation of post-synaptic NMDA receptors and downregulation of post-synaptic GABA receptors. A decrease in blood ethanol therefore results in an imbalance between stimulatory NMDA and inhibitory GABA systems in the CNS. Excess stimulation leads to the signs and symptoms of alcoholic withdrawal syndrome.
What are the signs/symptoms of alcohol withdrawal? (x9)
- Features of chronic or decompensated liver disease: hepatomegaly, jaundice, ascites, caput medusa, palmar erythema
- Features of poor nutrition: look for signs of Wernicke’s encephalopathy in thiamine deficiency, and Vitamin D deficiency (may be anorexic)
- Acute intercurrent illness such as pneumonia, pancreatitis, hepatitis and gastritis are common
- Anxiety
- N&V
- Autonomic dysfunction: tremor, tachycardia, sweating, palpitations
- Insomnia
- Seizures (generalised tonic-clonic) in severe alcohol withdrawal
- Delirium tremens characterised by profound confusion, hallucinations (characteristically frightening delusions) and may describe pins and needles or burning.
What blood investigations are there for alcohol withdrawal? (x6)
- VBG: respiratory alkalosis in patients with delirium tremens due to elevated cardiac indices, hyperventilation, increased oxygen delivery and oxygen consumption. May also show hypochloraemia metabolic acidosis with vomiting, or metabolic acidosis if alcohol ketoacidosis is present.
- Blood glucose: hypoglycaemia secondary to poor nutrition
- FBC: increased MCV (from vitamin B12 or folate deficiency) and thrombocytopenia (from splenomegaly, folate deficiency or a direct toxic effect of alcohol on production and function of platelets)
- U&Es: hypomagnesaemia, hypokalaemia, hypophosphataemia
- LFTs: ALT, AST and GGT elevated, with AST:ALT >2.
- Coagulation studies: prolonged INR and PT
What other investigations are there for alcohol withdrawal?
- CT head: in patients with related seizure, suspected head injury or altered cognition.
- CXR: if there are signs of respiratory distress to screen for pneumonia
- ECG in patients with secondary tachycardia to look for arrhythmias
- Amylase/lipase to screen for acute pancreatitis
- EEG in alcohol-related seizures
What is alcohol ketoacidosis?
Occurs from chronic alcohol intake in the setting of poor nutrition, leading to depleted hepatic glycogen stores which reduces glucose availability which leads to hypoglycaemia and ketone metabolism. This leads to abdominal pain, N&V and hyperventilation. May be a cause of alcohol withdrawal.
How is alcohol withdrawal medically managed? (x3)
- Benzodiazepine and plan weaning regimen
- Antipsychotic if delirium tremens fail to improve despite Benzos.
- Seizures: ensure patent airway immediately
What supportive management is there for alcohol withdrawal? (x5)
- Rehydration
- Correct electrolyte imbalances
- Correct hypoglycaemia
- Nutritional support: thiamine (vitamin B1) which is given as Pabrinex
- Counselling and community groups
What is the purpose of giving Pabrinex?
Prevents Wernicke’s encephalopathy which is a result of thiamine deficiency. It can manifest as Korsakoff’s syndrome.
What are the different ways benzodiazepines are used to treat alcohol withdrawal?
- Delirium tremens: begin with oral lorazepam or diazepam in patients, moving to IV lorazepam if ineffective.
- Withdrawal seizures: treat with IV lorazepam.
- No seizures or delirium tremens: long-acting oral benzodiazepine such as chlordiazepoxide
What are the complications of alcohol withdrawal? (x2)
Over-sedation if delirium tremens is treated with sedatives (where anti-psychotics and benzodiazepines fail), and status epilepticus (seizure lasting more than 5 minutes)
What is the prognosis of alcohol withdrawal patients? (x3 points)
Delirium tremens is fatal in 15-20& of patients if left untreated. Patients may describe insomnia and persistent autonomic symptoms for a few months after the acute withdrawal phase. Around 50% of patients remain abstinent from alcohol for a year.
How can alcohol misuse be assessed?
Assessment tools for alcohol misuse include AUDIT (most useful) and CAGE (easiest)
What is the recommended limit of alcohol units a drink?
14 units a week (6 pints of beer or 7 glasses of wine)
