Anaphylaxis Alex Pearce-Smith

Scenario A patient who is well but has been called in for a medication review has just sat down. Suddenly the practice nurse bursts in and announces that a patient to whom she has just vaccinated seems to be having a severe reaction. A patient who is well but has been called in for a medication review has just sat down. Suddenly the practice nurse bursts in and announces that a patient to whom she has just vaccinated seems to be having a severe reaction.

In Groups/Pairs Think About…. What do you do initially? What do you do initially? What is your assessment? What is your assessment? What are the signs of anaphylaxis? What are the signs of anaphylaxis?

Assessment Excuse yourself from patient – go straight to sick patient and assess - ?help ABCDE. Excuse yourself from patient – go straight to sick patient and assess - ?help ABCDE. Severe/Life threatening features in anaphylaxis. Severe/Life threatening features in anaphylaxis. –A Swelling, Hoarseness, Stridor. –B RR, Wheeze, Sats <92%. –C Pale, clammy, Low BP. –D Confused/Drowsy/Coma.

Recognising Anaphylaxis Anaphylaxis likely when ALL 3 criteria met Anaphylaxis likely when ALL 3 criteria met 1.Sudden onset and rapidly progressing symptoms. 2.Life threatening Airway/Breathing/Circulatory problems. 3.Skin/Mucosal changes (angio-oedema, flushing or urticaria) PMH and circumstances may help (ie given vaccine). PMH and circumstances may help (ie given vaccine).

Skin Changes Usually first feature but may be absent in upto 20% of cases. Usually first feature but may be absent in upto 20% of cases. May be subtle or dramatic. May be subtle or dramatic. May be just skin, just mucosal or both. May be just skin, just mucosal or both. Maybe patchy or generalised erythematous rash. Maybe patchy or generalised erythematous rash. May be urticaria – usually itchy. May be urticaria – usually itchy. Angioedema is similar to urticaria but affects the deeper tissues – usually eyelids and lips but sometimes mouth and throat. Angioedema is similar to urticaria but affects the deeper tissues – usually eyelids and lips but sometimes mouth and throat. Not an indicator of severity – most systemic skin reactions do not end up as anaphylaxis. Not an indicator of severity – most systemic skin reactions do not end up as anaphylaxis.

Skin Presentations

Differential Diagnoses Vasovagal attack. Vasovagal attack. Panic attack. Panic attack. Idiopathic urticaria. Idiopathic urticaria. Breath-holding episode in a child. Breath-holding episode in a child.

Management ABC assessment indicates severe/life- threatening. ABC assessment indicates severe/life- threatening. –Lie flat, feet up*. –Remove trigger (e.g. bee sting). –IM adrenaline 0.5mg adult (over 12) less for children/babies. –Oxygen. –Fluid Challenge (crystalloid). –Chloramphenamine and hydrocortisone. –Some should be calling 999.

Management Should go to hospital for further management/observation – 6hrs minimum but most discharged by 24 hrs if good response. Should go to hospital for further management/observation – 6hrs minimum but most discharged by 24 hrs if good response. Various indicators for longer observation. Various indicators for longer observation. Review by senior clinician before discharge. Review by senior clinician before discharge. Specialist follow up in allergy clinic. Specialist follow up in allergy clinic.

Common Triggers Food (especially nuts) Food (especially nuts) Drugs Drugs –Antibiotics esp penicillin and cephalosporin –Anaesthetic drugs –Other drugs esp NSAIDs. Venom – esp wasp stings. Venom – esp wasp stings.

Mortality Less than 1% mortality. Less than 1% mortality. About 20 deaths per year in UK recorded due to anaphylaxis but may be underestimate. About 20 deaths per year in UK recorded due to anaphylaxis but may be underestimate. Asthmatics more at risk. Asthmatics more at risk. Deaths happen quickly after contact with allergen. Deaths happen quickly after contact with allergen. –Food 30 mins. –Venom 15 mins. –IV medications 5 mins.

In conclusion If severe or life-threatening symptoms and clinical suspicion of anaphylaxis – give adrenaline. If severe or life-threatening symptoms and clinical suspicion of anaphylaxis – give adrenaline. Remember ABC – you may not get beyond A. Remember ABC – you may not get beyond A.

For More Information For details about the recommended recognition and management of anaphylaxis including correct paediatric dosages etc go to Resuscitation Council Website. For details about the recommended recognition and management of anaphylaxis including correct paediatric dosages etc go to Resuscitation Council Website.