Monitor SimulatorAnaphylaxis simulation scenario
The patient is fine, then gets an IV antibiotic, then is not fine. This one runs on a clock: the team either gives intramuscular adrenaline within a few minutes or watches the pressure fall away.
Brief
- Patient
- Daniel, 35, admitted for cellulitis of the lower leg. The first dose of IV cefuroxime went in four minutes ago.
- Setting
- Medical ward or day unit. The scenario starts when he rings the bell saying he feels strange and itchy.
- History
- Mild asthma. No known drug allergies.
- Learners
- Ward nurses, junior doctors, rapid response teams.
- Time
- About 10 minutes plus debrief.
Learning goals
- Recognise anaphylaxis early from airway, breathing and circulation signs together.
- Stop the infusion and give IM adrenaline 0.5 mg without waiting for a second opinion.
- Lie the patient flat, give oxygen and a fluid bolus, and repeat adrenaline after 5 minutes if needed.
Monitor values
| Phase | Rhythm | HR | SBP | SpO2 | RR | EtCO2 | Change over |
|---|---|---|---|---|---|---|---|
| 0. Before the antibioticBaseline | Sinus rhythm | 82 | 128 | 98 | 14 | 38 | Set before the start |
| 1. OnsetItching, flushing, wheeze | Sinus tachycardia | 124 | 92 | 94 | 24 | 34 | 2 min trend at the start |
| 2. No adrenalineFrom minute 3 | Sinus tachycardia | 142 | 64 | 87 | 30 | 24 | 5 min trend, Poor perfusion on |
| 3. After IM adrenalineAnd fluids | Sinus tachycardia | 112 | 108 | 95 | 20 | 35 | 5 min trend, Poor perfusion off |
| 4. Still no adrenalineOptional | PEA – pulseless electrical activity | 130 | – | – | – | – | Instant |
SBP is systolic in mmHg; the app sets the diastolic. EtCO2 in mmHg. In PEA the monitor blanks pressure, saturation and EtCO2 by itself, so you only change the rhythm.
Running it in the app
- Start on phase 0 so the room sees a normal monitor. When the actor rings the bell, apply phase 1 with a 2 minute trend.
- If no one has given adrenaline by minute 3, apply phase 2 over 5 minutes. The pulse tone helps here: turn it on by tapping the ECG on the monitor and the pitch drops as the saturation falls.
- Once IM adrenaline is given, apply phase 3. If the team repeats the dose at 5 minutes, let the last few points of recovery happen then.
- Phase 4 is for groups that freeze. The ECG still shows a fast organised rhythm, but there is no pressure and no pleth. Someone has to feel for a pulse and start compressions. It is a hard lesson but a memorable one.
What learners tend to miss
- Antihistamines and steroids are not first-line. Teams that start there lose minutes.
- The infusion is often left running while everyone looks at the monitor.
- EtCO2 falls as cardiac output falls, so it is a second warning next to the pressure.
Debrief questions
- What was the first sign, and how long until someone said anaphylaxis out loud?
- Where is the adrenaline kept on your ward, and who can give it without a prescription?
- What would you have done if he had not improved after the second dose?
Questions
What does anaphylaxis look like on a patient monitor?
A sudden rise in heart rate and fall in blood pressure within minutes of the trigger, a rising respiratory rate and a falling saturation if there is bronchospasm or airway swelling. EtCO2 drops as cardiac output falls.
How fast should the vital signs change in an anaphylaxis simulation?
Fast. Onset over one to two minutes is realistic after an IV drug, and the slide into severe hypotension should take only a few more minutes if no adrenaline is given.
What should the debrief focus on?
Time to IM adrenaline. Most teams recognise the problem, but many spend minutes on antihistamines, steroids or calling someone before giving the one drug that matters.