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

Clinical tips – may not be severe

• Already asthmatic -

• Already on beta blockers

• Ill health

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

TREATMENT OF ANAPHYLAXIS

• Initial

• Secondary

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.

Epinephrine

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

Perioperative environment

NeuromuscularBlocking Agents

• Suxamethonium

• Pancuronium, atracurium, alcuronium

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

Transfusion-RelatedAnaphylaxis

In GA

• Refractory unexplained hypotension

• Haematuria

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

Thank you all