General anaesthetics allergy

About general anaesthetics allergy

General anaesthesia uses several drugs to keep a person unconscious, pain-free and still during surgery, including anaesthetic agents, muscle relaxants, opioids and antibiotics. Serious allergic reactions are rare but important, and identifying the culprit is difficult because the drugs are given together within minutes. The most common triggers of true IgE-mediated anaphylaxis under anaesthesia are muscle relaxants and certain antibiotics, while chlorhexidine antiseptic and latex are also recognised. Careful investigation after any reaction is essential.

Reactions appear rapidly once drugs are given, with flushing, hives, swelling, a fall in blood pressure, difficulty ventilating the lungs and, at worst, anaphylaxis with collapse, matching the rapid onset. Anaesthetists recognise and treat these events immediately because the patient cannot report early symptoms. Some muscle relaxants can cross-react, so pinning down the drug matters.

Management after any suspected reaction involves referral to a specialist anaesthetic allergy clinic, where testing can identify the responsible agent and confirm which drugs are safe for future operations. The findings are recorded and shared so future anaesthesia can be planned. Anyone with a known reaction should tell their surgical and anaesthetic team beforehand and carry a medical alert. During surgery a severe reaction is managed at once by the clinical team; outside hospital, anaphylaxis is a medical emergency call 999. Never assume which drug was responsible without specialist assessment.