صدق الله العظيم

1. بسم الله الرحمن الرحيم وَقُل رَّبِّ زِدْنِي عِلْمًا صدق الله العظيم سورة طه آيه 114

2. Anaphylaxis and Latex Allergy By Dr. Ibrahim Mohamed Ibrahim Lecturer of Anesthesia, M.D.

3. A case Study 30 years old female anesthetist, who worked in El-Demerdash Hospital, started to anesthize a patient in O.R of Surgery Unit. She wore disposable gloves and started induction of anesthesia After 5 minutes she developed red rashes allover her hand, then spread to both upper limps, chest and face. She neglected these symptoms and continued monitoring of the patient.

4. After a while she developed nausea and vomiting and get dyspnea She asked for help from senior staff, who continued monitoring the patient and advised her for rest and to monitor her vital data. Bp 80/50, HR120b/min, SPO2 96% Temp. 36.8C She received ondansetron 4mg IV in a peripheral cannula which is inserted in her hand. She received normal saline 0.9% 250ml and amp. hydrocortisone 100mg IV She get better after 10minutes Her medical history was free apart from being allergic to some sort of fruits like banana

5. What Happened??

6. MCQ Latex allergy is: Type I hypersensitivity. Type II hypersensitivity. Type III hypersensitivity. Type IV hypersensitivity.  Risky patient for latex allergy is: Obese patient. Patient who is sensitive to banana. Child with spina bifida. Pregnant woman. Diagnostic tests for latex allergy: Intradermal skin testing. Chest X-ray. Pelvi-abdominal ultrasound. RAST (radio-allegro - sorbent test).

7. The most important drug in treatment of anaphylaxis due to latex allergy is: Corticosteroid. Beta-blockers. Ranitidine. Adrenaline. Latex-allergy presented by: Hypertension. Hypotension. Bradycardia. Constipation.

8. Anaphylaxis and Latex Allergy Anaphylaxis is a sudden catastrophic allergic reaction that involves the whole body. It usually occurs within minutes of exposure to the offending allergen (due to insect, dust, medication being the commonest causes).

9. Latex allergy: Causes:Exposure to a latex antigen which is present in many surgical and anesthetic equipments. Example:

15. Mechanism • Type I hypersensitivity (immediate type). • Initial exposure of a susceptible person to an antigen induces CD4+ T cells to produce IL4, IL5, IL6, IL10 and granulocyte- macrophage colony stimulation factor. These lymphocytes activate and transform specific B-lymphocytes into plasma cells which produce allergen – specific IgE antibodies. The FC portion of these antibodies are fixed on the surface of tissue mast cells and circulating basophils. • During subsequent re-exposure to the antigen, it binds to the fab portion of adjacent IgE antibodies on mast cell surface, inducing deregulation and release of inflammatory lipid mediators and cytokines from mast cells.

16. The intracellular Ca++ increase leading to the release of mediators as: histamine, kinins, leukotrienes, prostaglandins serotonin, platelet activating factor. • These mediators produce the clinical picture. • It may occur without any previous exposure mostly due to immunological cross-reactivity e.,g dextran.

17. Type IV hypersensitivity (Delayed type) • It is mediated by CD4+T lymphocytes that have been sensitized to a specific antigen by a prior exposure Re-exposure to the antigen causes these lymphocytes to produce lymphokines (interleukins, interferon and tumor necrosis factor) that attract and activate inflammatory mononuclear cells over 48-72 hours. • e.g.: allergic dermatitis from topically applied drugs as local anesthetics.

18. Who is at risk? • The patients at risk are those with prolonged or frequent to latex products, especially: • Patients with neural tube defects (meningeomyelocelel, spina bifida) and congenital urological abnormalities. • Health care workers with increased exposure to latex, usually gloves. • History of atopy e.g., patients allergic to banana, kiwis have antibodies that cross react with latex. • Clinical picture • Anaphylaxis presents with • Hypotension, tachycardia, dysrhythmia up to cardiac arrest. • Rash and itching (face , scalp, palms, soles). • Bronchospasm and chest tightness. • Nausea, vomiting, diarrhea and abdominal cramps.

19. Onset: Is generally 20-60 minutes after exposure to the antigen. * Hypotension  Key signs during GA *Bronchospasm * Urticaria Key signs during awake status  sense of impending death, nausea, vomiting and dyspnea.

20. Diagnostic tests: • Intrademal skin testing. • Radioallergosorbent test (RAST) an in vitro test for IgE antibodies in the patient's seam. • Positive in 65%-95% of cases. • Expensive.

21. Prevention and prophylasix: Avoid re-exposure to the antigen (if known) is the most important. Drugs as corticosteroids, cromolyn Na, bronchodilators, H1 H2, blockers (controverse). Give all drugs and fluids slowly and diluted. Full monitoring of patient. Full resuscitation facilities should be available. N.B: Rubber stoppers be removed from drug vials before their use and injection should be made through plastic cocks and use products which are latex free as polyvinyl or neoprene gloves, silicon ETT, laryngeal masks or plastic face masks.

22. Nowadays may manufactures label their products " latex free" •  Emergency management of acute major latex allergy • Early detection is important • a- Immediate therapy: • Discontinue administration of allergen. • Call for help. • Discontinue surgery as there is an increased risk of coagulopathy. • Discontinue anesthesia as there is an increased risk of hemodynamic instability. • ABC protocol (Airway, Breathing, Circulation). • Maintain the airway with 100% O2 + tracheal intubation. • Mechanical ventilation (may be needed). • Adrenaline iv 1g/kg (0.5-1ml 1: 100 000 solution) it can be repeated if no response. • IV fluids expansion, colloids 10ml/kg are preferred because crystalloids will escape via leaky capillaries.

23. Secondary management • Salbutamal: intial dose 250ug i.v, maintenance 5-20ug/min. • Terbutaline: intial dose 250-500ug i.v, maintenance 1.5-g/min iv. • Hydrocortisone 500-1000mg i.v or methyl prednisone 1-2gm. • Aminophylline: 6mg/kg iv slowly.

24. Antihistaminic: chloro-phenaramine 20mg i.v slowly. • NaHCo3: to correct acidosis 0.5-1 mEq/kg. • Inotropes as adrenaline or noradrenaline infusion and consider vasopressin. • Anti-arrhythmics. • Consider the possibility of coagulopathy.

25. Our conclusion is: • To take latex allergy very seriously. • It is preventable, important and still potentially fatal condition. • Full resuscitation equipments should be available in each operating room. • Studying CPR is mandatory for every anesthetic doctor.

26. Thank you