Anaphylaxis

Severe Anaphylactic Reactions

ManifestationRespiratory difficultySigns of shock/hypotensionInvolvement of skin/mucosal tissueGI symptoms

Manifestations of severe anaphylaxisRespiratory DifficultyProgressive stridor, wheezing, dyspnoeaReduced PEFHypoxaemia

Manifestations of severe anaphylaxisSigns of shock/HypotensionLightheadedness, hypotonia, syncopeSystolic BP < 90mmHg, or > 30% decrease

from patient’s baselineIncontinence

Manifestations of severe anaphylaxisInvolvement of skin/mucosal tissueGeneralised hives, pruritisPale or flushedSwollen face, lips, tongue, uvulaRhinitis

Manifestations of severe anaphylaxisGI symptomsCrampy abdominal painsNausea, vomiting, diarrhoea

Manifestations of severe anaphylaxisReactions may be slow, progressive, or

rapidly fatal within minutes.Manifestations may be delayed, or persist

> 24hrsMay recur (biphasic) up to 36hrs after initial

onsetGenerally, the shorter the interval between

exposure and reaction, the more severe the reaction

Management of AnaphylaxisIt consist of the following measures:1. Remove or stop the precipitating agent2. Administer drugs

Oxygen Adrenalin Establish Rapid IV access (crystalloid fluids) Glucagon Antihistamin Corticosteroids Inhaled beta-agonists H2 Receptor blocker

3. Admission for observation4. Preventing recurrence

Management of AnaphylaxisAirway and OxygenMust be given as soon as possibleMaintain airway patencyGive high flow oxygenUse a rebreather maskPosition patient in a semi-Fowler’s position

(unless hypotensive) to assist breathingPulse oxymetry if available, and monitor vital

signs continuouslyIf impending airway obstruction

(angioedema), intubate or consider cricothyrotomy

Management of AnaphylaxisAdrenalin (1mg/ml 1:1000)Should be given IM, never SCAdults: 0.5mlChildren: 0.01mg/kg

6-12 yrs: 0.3ml2-5 yrs: 0.2ml< 2 yrs: 0.1ml

Repeat every 5-15 minutes if no improvement and consider IV continuous infusion at 2-10 mcg/min (0.1-1mcg/kg/min)

Management of AnaphylaxisCaution on adrenalin:IV adrenalin is potentially hazardous in

anaphylaxis, should only be considered if life-threatening hypotension persists despite IM adrenalin and aggressive fluid resuscitation.

Dilute 1mg adrenalin in 200ml normal saline, and slowly infuse at 1ml/minute (5mcg/min) with continuous ECG monitoring

Management of AnaphylaxisCrystalloidsThese should be given if hypotensive or

unresponsive to adrenalinEstablish rapid IV accessRapidly infuse 1-2 liters of crystalloid

(RL/NS)20ml/kg for childrenRepeat IV infusion prn, as large amounts

may be required

Management of AnaphylaxisGlucagonAdult: 1-2mg IM or slowly IV every 5min if

not responsive to adrenalin, and especially if on beta-blockers

Child: 20 mcg/kg (maximum 1mg)Watch out for nausea, vomiting and

hyperglycaemia

Management of Anaphylaxis

Antihistamin – H1 BlockerPromethazine (Phenergan) should be given IM

or slowly IV> 12 yrs: 25-50mg 6-12 yrs: 12.5mg2-5 yrs: 6.25mg

Management of AnaphylaxisCorticosteroidsHydrocortisone/Methylprednisolone

(Hydrocort/Solu-medrol) - IM or slowly IVFor prevention or shortening protracted

reactionsAdults and Children > 12yrs: 100mg/125mgChildren: 1mg/kg

Management of AnaphylaxisInhaled beta-agonists (Ventolin)Nebulised salbutamol (Ventolin) 5mg (1cc)

or 0.15mg/kg To be given every 15 min if bronchospasm is a measure feature or no response to given drugs, especially if the patient is on beta-blockers

Management of AnaphylaxisH2 receptor blockers Ranitidine (Zantac) Adult: 50mg IM or slowly IV (diluted in 20ml

over 2min) Child: 1mg/kg (max. 50mg)OR Cimetidine (Tagamet) Adult: 300mg IM or slowly IV (diluted in

20ml over 2min) Child: 5mg/kg (max. 300mg)

Management of AnaphylaxisAdmit for observation8-24 hrsRecurrence may occur

Management of AnaphylaxisPrevention of recurrenceIdentify the causative agentArrange for a “Medic Alert” braceletEducate patient and family on the use of

self-injectable adrenalin device (EpiPen).The EpiPen kit is a MUST for every patient

who has had a severe reaction before.