As well as noting the nature of an allergy, you must also:

• Obtain a history of allergy
• Document clearly any allergies and share this information with the theatre team
• Avoid all substances that the patient has a true allergy to

It is important to remember that patients may be reluctant to reveal addictions to alcohol or illicit drugs, but alcohol history and illicit drug misuse is an important part of the history.

When dealing with patients who have an alcohol addiction:

• Patients may present with acute intoxication or the effects of chronic alcohol consumption, such as cardiomyopathy, pancreatitis and gastritis
• Chronic alcohol abuse can induce liver enzymes and may shorten the action of anaesthetic drugs

Possible additional problems with intravenous drug users include difficult venous access and the risk of septicaemia.

For both these groups of patients, withdrawal syndrome may develop perioperatively if alcohol or drugs are stopped abruptly.