OSCE Anaphylaxis - Paramedic Practice: Obstetric and Paediatric Emergencies PDF

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Summary

PARA303 OSCE notes on anaphylaxis diagnosis, management (QAS Guidelines) and pathophysiology from semester 2, 2016....

Description

PARA303 OSCE – Anaphylaxis

History

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Pathophysiology

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Known allergies Exposure to known allergies or potential allergens History of prior anaphylaxis Risk factors for anaphylaxis:  Asthma  Age (teenagers/older adults)  Initial misdiagnosis  Delay to or no adrenaline administration Anaphylaxis is the outcome of a widespread hypersensitivity to an allergen that triggers a reaction Type 1 anaphylactic reactions involve an antigen/immunoglobulin E (IgE) antibody reaction on the surface of mast cells in tissues and basophils in the blood In the first exposure, IgE antibodies attach to receptor sites on these cells, where they await activation by specific antigens When an exposure to the specific antigen occurs, the antigen reacts with the IgE bound to the surface of mast cells and basophils and mast cells and basophils to cross-link and become activated and the cells rupture The cell rupture results in the release of a host of vasoactive chemicals including histamines, leukotrienes, bradykinins and prostaglandins These substances result in bronchoconstriction, peripheral vasodilation and increased capillary permeability In some cases mast cell degranulation is triggered by a mechanism that does not involve IgE (also known as anaphylactoid) Shock occurs when the peripheral dilation is massive, and a type of hyovolaemic shock is precipitated Common triggers of IgE dependent anaphylactic reactions include: Foods: Peanuts Tree nuts Crustaceans Medications: B-lactam antibiotics

Onset Signs & Symptoms

Management

Pharmacology

Other antibiotics Aspirin and other NSAIDS Venoms: Bee sting Snake bite Animal proteins: Cat Dog Horse - Common triggers of IgE independent anaphylactoid reactions include:  Radiocontrast media  Opioids  Muscle relaxants  Temperature – hot & cold  Transfusion reactions – IgG, IgM - Usually within 2-30 mins however can take several hours - Tachycardia - Tachypnoea - Anxiety - Hypotension - Difficulty/noisy breathing/stridor - Swelling of tongue - Swelling/tightness in throat (difficulty swallowing) - Difficulty talking and/or hoarse voice - Wheeze or persistent cough - Persistent dizziness or collapse - Pale and floppy (young children) - CCP backup – ETT, hydrocortisone - Adrenaline - IM >6yrs 150microg, 88% - History of bleomycin therapy with SpO2 >88% Precautions: - Paraquat poisoning or bleomycin lung injury – target SpO2 88-92% - Prolonged administration to premature neonates Side Effects: - Hypoventilation in some COPD patients with hypoxic drive

Drying of mucus membranes Salbutamol: Presentation: - Nebule – 5mg/2Ml - Ampoule, 500 microg/1mL Drug Class: Beta-adrenergic agonist Pharmacology: Salbutamol is a direct acting sympathomimetic agent which mainly effects B2 – adrenoreceptors. It primarily acts as a bronchodilator but also has inotropic and chronotropic actions. Additionally it lowers serum potassium levels through its direct stimulation of the sodium/potassium ATPase pump, drawing potassium into the cells. Indications: - Bronchospasm - Suspected hyperkalaemia (with QRS widening and/or AV dissociation Contraindications: - KSAR or hypersensitivity to salbutamol - Pts...