31st January 2024

Delirium tremens

Background

Delirium tremens is a form of severe and acute withdrawal from alcohol and can be considered a medical emergency. The condition develops approximately two to three days after sudden cessation of alcohol altogether or reduction in drinking quantity. Long-term, heavy alcohol intake causes a compensated GABA and NMDA (glutamate) neurotransmitter imbalance. However, when alcohol use is suddenly stopped, glutamate neural pathways become hyper-excitable with unregulated activity, leading to the symptoms of delirium tremens.

Presentation

The usual timeline of symptom development is as follows:

1. Tremor – can appear only a few hours after drinking is suddenly reduced/stopped.
2. Hallucinations – usually visual and commence about one day after tremors begin.
3. Seizures – these tend to be grand mal and can happen at any point from the second day onwards alongside tremor and hallucinations.

Diagnosis

A diagnosis of delirium tremens can be made in a patient presenting with both delirium and symptoms of alcohol withdrawal. Delirium tremens can last up to eight days (three to four on average) with approximately a one to four percent mortality rate.

Differential diagnoses

Alcohol hallucinosis (sometimes referred to as ‘alcohol-induced psychotic disorder’) can present very similarly to delirium tremens, but they are not identical conditions. ICD-10 describes alcohol hallucinosis as characterised by hallucinations, which develop within two weeks of heavy alcohol intake and last for at least 2 or more days. Unlike delirium tremens, impaired cognition should not be a major feature of the condition.

There is little information available about this condition; however, it does seem to be recognised as distinct from delirium tremens and schizophrenia, and dopamine and serotonin receptor involvement have been suggested as likely aetiological factors to consider. Proposed treatments currently also include benzodiazepines, atypical antipsychotics, and abstinence from alcohol (if safely achievable).

Although delirium tremens is a clinical condition, other organic conditions which have similar symptom profiles and should be considered where appropriate, e.g., space-occupying lesions.

Management

The mainstay of treatment for delirium tremens are benzodiazepines; NICE guidance currently lists oral lorazepam as the first line interventional medication to offer, followed by haloperidol or IM lorazepam. Benzodiazepines restore the neurotransmitter imbalance described above by promoting upregulation of GABA receptors, facilitating decreased neural intracellular excitation.

Early intervention can prevent later more severe features such as seizures, and NICE guidance also recommends offering those at high risk of developing the condition a “medically assisted” withdrawal as part of reducing the risk of the condition occurring. The Clinical Institute Withdrawal Assessment for Alcohol (CIWA) is a rating scale (10 items with a maximum score of 67 points) that can rate the severity of withdrawal from alcohol to support necessary treatment and intervention, e.g., administration of chlordiazepoxide if needed. A brief score explanation is as follows:

• Mild withdrawal = 10 or less points
• Moderate withdrawal = 11 to 15 points
• Severe withdrawal = 16 or more points

If Untreated, delirium tremens can lead to autonomic dysfunction, including hyperthermia, arrhythmias and, in severe cases, death. The delirium described may not always be solely due to alcohol cessation/reduction. Other coexisting causes can be present, e.g., electrolyte imbalances, and must also be explored as part of optimal management.

References

• Grover S, Ghosh A. Delirium tremens: Assessment and management [Internet]. Journal of clinical and experimental hepatology. U.S. National Library of Medicine; 2018 [cited 2022Dec3]. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6286444/
• NICE. Recommendations: Alcohol-use disorders: Diagnosis and management of physical complications: Guidance [Internet]. NICE. 2017 [cited 2022Dec3]. Available from: https://www.nice.org.uk/guidance/cg100/chapter/Recommendations
• Bhat PS, Ryali VSSR, Srivastava K, Kumar SR, Prakash J, Singal A. Alcoholic hallucinosis. Industrial Psychiatry Journal. 2012;21(2):155.
• Masood B, Lepping P, Romanov D, Poole R. Treatment of alcohol-induced psychotic disorder (alcoholic hallucinosis)—a systematic review. Alcohol and Alcoholism. 2017;53(3):259–67.
• Stankewicz HA, Richards JR, Salen P. Alcohol related psychosis – statpearls – NCBI bookshelf [Internet]. 2022 [cited 2022Dec3]. Available from: https://www.ncbi.nlm.nih.gov/books/NBK459134/
• The ICD-10 classification of mental and behavioural disorders: Clinical descriptions and diagnostic guidelines [Internet]. World Health Organization. World Health Organization; 1992 [cited 2022Dec3]. Available from: https://apps.who.int/iris/handle/10665/37958
• Department of Health and Social Care. Chapter 12: Alcohol [Internet]. GOV.UK. 2021 [cited 2022Dec3]. Available from: https://www.gov.uk/government/publications/delivering-better-oral-health-an-evidence-based-toolkit-for-prevention/chapter-12-alcohol