- Occurs d/t the introduction of an allergen in the body
- Leads to mast cells or basophils to release histamine & other chemicals system-wide
- Will decrease tissue perfusion causing shock to occur
Anaphylactic shock is a form of ___ shock
The other types are ___ and ___ shock
distributive
neurogenic; septic
How does an allergen enter the body to cause anaphylactic shock?
An allergen can enter various ways such as via an injection, inhalation, oral, or contact w/the skin
Known Substances that can cause anaphylactic shock
! Foods (shellfish, peanuts, eggs, milk)
! Rx’s (vaccines, contrast dye, NSAIDs, abx [penicillin])
! Insect venom
! Latex
! Physical exercise
! Unknown cause (idiopathic)
- Can occur either d/t an immune response where IgE ab’s are created or d/t a non-immune response
- Regardless of the reaction, both cause the same s/s, & occur b/c mast cells or basophils release histamine & other mediators
Anaphylactic reaction: IgE related (immunological)
Pt has to experience ____ for reaction to occur
> Is where the pt has a first-time exposure to an allergen that causes the creation of IgE ab’s
Ab’s attach to the mast cell or basophil & hang out waiting for the 2nd exposure
When the 2nd exposure to the allergen occurs, it causes the mast cells or basophils to release histamine & other substances; this leads to the anaphylactic reaction
sensitization
It’s a Type I Hypersensitivity Reaction
- This means the allergen attaches to IgE ab’s on mast cells and basophils
- This leads to a system-wide release of histamine & other mediators
Anaphylactoid Reaction: NON-IgE related (non-immunological)
- Pt doesn’t have to be sensitized for the reaction to happen… but can happen w/first-time exposure
- Causes same rxn as anaphylactic, but it’s not via Ig IgE ab’s on the mast cells or basophils
> Allergens for this type of rxn incl contrast dyes, chemo, NSAIDs - These agents directly cause the mast cells & basophils to break down & release histamine
Histamine will cause
- Dilatation of vessels (lowers BP & tissue perfusion)
- Bronchoconstriction (narrow airways & resp fail)
- Inc HR
- Inc permeability of vessels (leads to swelling & depletes intravascular space of fluid that shifts to the interstitial space)
- Itching
- Incr contraction of GI stomach muscles & incr gastric secretions (→ n/v/d, GI pain)
s/s of Histamine: Respiratory
✦ dyspnea, wheezing (bronchoconstriction)
✦ swelling of upper airways d/t edema, “tightness”
✦ can’t speak, coughing, stuffy nose, watery eyes
Cardiac
✦ tachycardia, hypotension [vasodilation] (may lose consciousness or become dizzy)
GI
✦ n/v/d
✦ GI pain
Skin
✦ red, swollen, itchy, hives (vasodilation)
Nursing Interventions & Treatments
✔️ Prevention!
> Know pt allergies
> Consider facility’s prevention measure system
ACT FAST!
Allergen (remove it) & Airway (manage w/high flow O2 & continuous VS monitoring)
Call Rapid Response (start CPR, if needed, until help arrives)
Trendelenburg Positon
> will help incr venous return to the heart & incr CO & BP
First-line drug is epinephrine
> Given IM or SC
> May be needed IV if severe hypotension persists
* Causes vasoconstriction which will incr the BP, reduce swelling, & cause bronchodilation
Administer other medications per MD order (these meds may be ordered depending on the pt’s status)
> IV fluids
> breathing treatment of albuterol
> antihistamines to target H1 (diphenhydramine) & H2 (ranitidine)
> corticosteroids to prevent a recurrent attack
Stay & monitor pt very closely
! @ risk biphasic anaphylaxis (s/s occur again even if not exposed to allergen; can happen hrs >initial attack; may be less, worse, or same as initial attack)
Teach!
- Pt education
> Importance of avoiding allergen (may need allergy tests)
> Wearing bracelets & letting others know about allergen
> ALWAYS carry an Epi-Pen; administered in middle of outer thigh (replace when expired)
> Have pt demonstration on how to use
