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Anaphylaxis
Dr. S. Parthasarathy MD., DA., DNB(anaes), MD (Acu),
Dip. Diab. DCA, Dip. Software statistics PhD (physio)
Mahatma Gandhi medical college and research institute , puducherry – India
Definition • Anaphylaxis is an acute reaction leading to
severe physiologic derangements of multiple systems.
• Follows the administration of allergen to a sensitized individual
• True anaphylaxis denotes an IgE antibody- mediated reaction• Non IgE antibody- mediated reaction
resembling anaphylaxis is anaphylactoid reaction
Why should there be a name like that ??
• Inj TT – protects further tetanus disease • This is prophylaxis • Portier and Richet in 1902 reported that the
second injection of sea anemone extract into dogs resulted in a fatal systemic reaction• Iron inj. -- First time – ok – on second injection
It is fatal = antagonistic of prophylaxis – anaphylaxis
Histamine release but not anaphylaxis
• Morphine• Skin alone ??
• Atracurium • Skin and lungs also ??
Why are some of us destined for a lifeof allergy and others not?
• Low grade responders • Ige antibodies less with interferons
• High grade responders • Ige antibodies more with cytokines
Incidence in anaesthesia
• It varies
• 2 in 10,000 to 4.5 in 10000
• In france single institution study – 16 in 10000
Clinical manifestationsof anaphylaxis
• IV antigen ----= starts in 5 minutes
• Other routes like oral • Slower and less rapid progression
Grades of clinical signs
• Grade I presence of cutaneous signs; (10%)• Grade II as presence of measurable but not life-
threatening symptoms including cutaneous effects, arterial hypotension(22%)
• Grade III as presence of a life-threatening reaction, collapse , severe bronchospasm, arrhythmias ,(66 %)
• Grade IV cardiac and/or respiratory arrest (4%)
Anaesthesia • symptoms -- Cutaneous, respiratory, CVS, GI • Single system involvement – overlooked
• During general and regional anesthesia or during deep sedation, cardiovascular signs
predominate
Epidural hypotension –give colloids – anaphylaxis to colloids --- Gloom ??
Anaphylaxis under anaesthesia is not routine — most common triggers
• It is not community anaphylaxis like – • Food stuff• Bee sting • Wasps • Snake bites • What happens in anaesthesia ?? • Unconscious !!
Anaesthesia – confounding
• During general anaesthesia, early symptoms of anaphylaxis such as tongue swelling, itch, breathing difficulty and wheeze
• Skin lesions under the drapes
Differential diagnosis
• In a conscious patient, anaphylaxis is most easily confused with a vasovagal reaction, which may occur when a patient collapses after an injection or painful procedure
• But there is a bradycardia in a vasovagal reaction
Differential diagnosis
• cold urticaria (especially if generalized), idiopathic urticaria, carcinoid tumors, and systemic mastocytosis.
• Symptom based DD
Who are prone ??
• Females• Previous anaphylaxis • patients with spina bifida or allergy to some
fruit- latex allergy • IgA deficiency- blood and colloids
Initial
• Remove the offender• Venous tourniquet • Airway maintenance with 100% oxygen• laryngeal edema -- aerosolized epinephrine epinephrine by nebulizer (8–15 drops of
2.25% epinephrine in 2 mL normal saline)• Large bore IV lines• intravascular volume should be maintained
with administration of isotonic crystalloid
• Rapid infusion of an initial bolus of 1–2 L intravenous fluid initially (20 mL/kg initially in
children) before reassessment.• Adults may require 2–5 L.
severe hypotension or airway obstruction
• 0.1-mL (100μ g of a 1:1000 dilution) increments of epinephrine should be given intravenously, usually not exceeding 0.5 mg total.
• Beware – halothane, stroke, infarction
NO IV access
• 0.3 mL of 1:1000 epinephrine can be given subcutaneously or intramuscularly, or 10 mL of 1:10,000 epinephrine can be administered through the endotracheal tube.
• Hypotension and bronchospasm
• Norad, dopamine infusions to follow
Secondary • Antihistaminics – diphenhydramine • Ranitidine 1 mg/ kg • Steroids : hydrocortisone- 5 mg/kg (up to 200
mg initial dose) and then 2.5 mg/kg every 6 hours- methylprednisolone 1 mg/ kg
initially and every 6 hours IV aminophylline infusion • Bicarbonate – controversial
Refractory hypotension
• Glucagon may be administered as a 1–5 mg (20–30 μg/kg in children, maximum 1 mg)
dose over 5 min followed by an infusion of 5–15 μg/ min
Recently – vasopressin
Diagnosis
• Mast cell tryptase• Postmortem collection of samples for assay is
also possible• 2 tubes 5 – 10 ml – 6 hours gap within 48
hours means 4 deg • Or – 20 deg.
Diagnosis
• Immunodiagnostic Tests• Intradermal skin tests still are the most readily
available and generally useful diagnostic tests for drug allergy. Total Serum IgE Levels• Assays to Measure Complement Activation • Blood and urine assay of histamine mediators• Radioallergosorbent Testing
Opioids
• Histamine release is common Morphine and pethidine
• anaphylaxis are rare
• NSAIDs
• Penicillin and betalactams, cephalosporins, septran
• Skin test is almost foolproof to avoid it.
Radiocontrast
• Urticaria, angioedema, wheezing, dyspnea, hypotension, or death occurs in 2–3% of
patients receiving intravenous or intraarterial infusions.
Oral prednisolone, with AH prior to IV contrast
Local anaesthetics
• Genuine allergic reactions to local anaesthetic agents are extremely rare
• Preservatives
Colloids
• Clinical anaphylaxis to all groups of colloids is
possible, including gelatins (such as
Haemaccel® and Gelofusine®), albumin,
dextrans and starches.
• Dextrans proved
Methylmethacrylate
• Episodes of hypotension , tachycardia reported
• Whether anaphylaxis – proved ??
• Protamine • Diabetics – use insulin protamine
Induction agents • Propofol was originally formulated in a vehicle
containing Cremophor® EL but was reformulated
as a lipid emulsion following reports of severe
allergic reactions.
Egg allergy ??
Thiopentone reported , methohexital – no
Natural Rubber Latex
• Children with spina bifida and urogenital anomalies
• Gloves • Ambu bag • Reservoir bags • Masks • Latex injection ports • Tourniquets • Blood pressure cuffs
Summary
• Definition ,mechanism , incidence • Clinical manifestations • Differential diagnosis • Lab • Treatment • Anaesthetic factors and tips