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 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)