Simulated Patient Scenario

Anaphylactic Shock

Scenario Details

Scenario: Adult patient with sudden onset multi-system allergic reaction progressing to shock.

Simulated Patient: 40-year-old Female Actor/Mannequin

Actor/Actress: Patient (initially able to speak, deteriorates), Friend/Partner (provides collateral).

MDT Information

Urgent response - Allergic Reaction / Difficulty Breathing
40-year-old female, sudden onset SOB, rash
Possible Anaphylaxis
Patient conscious but distressed
Friend present

On Arrival

Paramedics arrive at a cafe. The patient is sitting at a table, appearing anxious, flushed, and audibly wheezing. She is scratching at her arms where a widespread urticarial rash is visible. Her friend reports the patient ate a pastry a few minutes ago which she thought might have contained nuts (patient has a known severe nut allergy and carries an EpiPen, but hasn't used it yet). The patient complains of throat tightness and difficulty swallowing.

Initial Impression and Primary Survey

Category	Finding
Initial Impression	Acutely unwell, distressed, audible wheeze, visible rash/flushing.
Response	Alert but anxious and struggling to speak in full sentences due to dyspnoea/throat tightness (AVPU=A).
Airway	Compromised - patient reports throat tightness/swelling, voice may be hoarse, potential for stridor (listen carefully).
Breathing	Rapid respiratory rate, increased work of breathing (accessory muscle use), audible wheeze bilaterally on auscultation. SpO2 may be dropping.
Circulation	Tachycardic, peripheral vasodilation (flushed, warm skin initially), pulse may feel weak/thready, hypotension likely developing or present. Capillary refill may become sluggish.
Disability	Alert initially but may become confused/agitated/drowsy as hypoxia/hypoperfusion worsens. GCS 15 initially.
Exposure/Environment	Cafe environment. Patient wearing normal clothes. Expose chest/skin to assess rash fully (urticaria, angioedema - especially lips, tongue, eyelids).

Secondary Survey and Simulation Progression

History (Friend collateral, Patient input limited by distress)

Allergies	Known severe allergy to Peanuts and Tree Nuts. Carries EpiPen. No other known allergies.
Medications	Salbutamol inhaler PRN (mild asthma), Oral contraceptive pill.
Past Medical History	Previous anaphylactic reaction to nuts 5 years ago requiring hospital admission and adrenaline. Mild intermittent asthma.
Last Oral Intake	Ate a pastry ~10-15 minutes ago at the cafe.
Events Preceding / History of Presenting Complaint	Within minutes of eating the pastry, started feeling itchy mouth/throat, followed rapidly by widespread rash, feeling hot, throat tightness, difficulty breathing, and wheezing. Symptoms progressed quickly. Friend confirms timeline and known allergy. Patient feels dizzy and nauseous.

Vital Signs/Assessment (Initial & Progression)

Parameter	Value (Approximate/Expected - may deteriorate rapidly)
Resp. Rate (/min.)	30-35, increased effort
Lung Sounds (L/R)	Widespread wheeze, possible stridor (inspiratory noise indicating upper airway obstruction). Air entry may decrease if severe bronchospasm/obstruction.
SpO2 (%)	88-92% on Room Air initially, dropping further without intervention.
EtCO2 (mmHg)	May be low initially due to hyperventilation, but rises if respiratory failure develops. Waveform may show 'shark fin' shape (bronchospasm).
Pulse Rate (/min.)	130-150, may become thready.
CRT (sec.)	> 3 seconds, sluggish.
ECG rhythm	Sinus Tachycardia
12-lead ECG	Sinus tachycardia. (May show ischaemic changes in severe shock/hypotension).
BP (mmHg)	75/45 (Hypotensive - crucial sign of shock).
Skin	Flushed initially, may become pale/mottled/cool as shock progresses. Urticaria widespread. Possible angioedema (lips, eyes).
Pain (/10)	May report abdominal pain/cramps. Primary complaint is dyspnoea/throat tightness.
GCS (/15: E,V,M)	15 initially, decreasing to 12-13 (confused/drowsy) if shock/hypoxia worsens.
BGL (mmol/L)	Within normal limits (e.g., 6.0).
Pupils (mmL/mmR)	Equal and reactive.
Pupil reac. (L/R)	Equal and Reactive.
Temp. (°C)	Normal.

Physical Examination (Focused)

**General:** Anxious, distressed, tachypnoeic, tachycardic, hypotensive.
**Airway:** Hoarse voice, stridor, patient reporting throat swelling/difficulty swallowing. Angioedema of lips/tongue.
**Breathing:** Increased work of breathing, accessory muscle use, audible wheeze, bilateral wheeze on auscultation, low SpO2.
**Circulation:** Tachycardia, hypotension, delayed capillary refill.
**Skin:** Widespread urticaria (hives), flushing, angioedema (face, lips, eyelids).
**Abdomen:** May be soft but patient might report cramping.
**Neurology:** Initially alert, potential for deterioration in LOC.

Assessment and Treatment

Appropriate Management

Recognise Anaphylaxis with signs of shock (hypotension, altered mental status) and airway/breathing compromise. **Life-threatening emergency.**
Primary survey (ABCDE), manage immediate life threats FIRST.
**Adrenaline (Epinephrine):** **Administer IMMEDIATELY.** First line treatment.
- Route: Intramuscular (IM) injection into anterolateral thigh (vastus lateralis).
- Dose: Adult 0.5mg (e.g., 0.5ml of 1:1000 solution). Repeat every 5 minutes if no significant improvement.
- Consider patient's own EpiPen if available while preparing own medication.
**Airway Management:** Position patient upright if airway patent and breathing allows. Monitor airway closely for obstruction. Prepare for advanced airway management (intubation) if obstruction worsens or LOC decreases significantly - this can be very difficult due to swelling.
**Oxygen:** High-flow oxygen via non-rebreather mask aiming SpO2 ≥94%. Assist ventilations with BVM if respiratory effort inadequate.
**Circulation Support:**
- Establish large bore IV access x 2 if possible.
- **Aggressive IV Fluid Resuscitation:** Administer rapid bolus of isotonic crystalloid (e.g., 1000ml Sodium Chloride 0.9% or Hartmann's solution) due to vasodilation and capillary leak causing relative hypovolaemia. Repeat boluses as needed based on BP response.
- Consider IV Adrenaline infusion if unresponsive to IM adrenaline and fluids (follow local protocols - critical care setting usually).
**Adjunctive Therapies (Secondary - AFTER Adrenaline):**
- **Antihistamines:** (e.g., IV Chlorphenamine or Promethazine) - Helps with skin symptoms but does NOT treat life-threatening features.
- **Corticosteroids:** (e.g., IV Hydrocortisone or Oral Prednisolone) - May help prevent biphasic reaction/protracted symptoms, but slow onset, not for acute life threats.
- **Bronchodilators:** Nebulised Salbutamol (+/- Ipratropium) for persistent wheeze/bronchospasm after adrenaline.
Remove allergen if possible (e.g., bee sting).
Continuous monitoring of vital signs, respiratory status, mental status.
Transport urgently to hospital, pre-notifying with "Anaphylaxis Alert".
**Pre-notify:** Inform receiving hospital about anaphylaxis, suspected trigger, vital signs (confirming airway/breathing compromise and hypotension), **Adrenaline given (dose, route, time, response)**, fluids given, other medications, ETA.
Documentation: Detailed record of symptom onset, trigger, assessment findings, timings and doses of all medications (especially adrenaline), fluid volumes, vital sign trends, response to treatment.