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The first 25 slides, exactly as they appear. The full deck has 83 content slides.
Anaesthesiology
Electrical safety
Built from Al-Shaikh — Essentials of Equipment in Anaesthesia, Critical Care and Peri-operative Medicine, 6e
What’s inside
7 sections · 83 slides
Overview
- What this deck will teach you
Electricity and the mains supply
- Where the electricity comes from
- Live, neutral and earth — the three wires
Principles of electricity
- Common circuit-component symbols
- Electric current (I) — the flow of electrons
- Two kinds of current: DC vs AC
- Voltage, resistance and Ohm's law
- Impedance (Z) and reactance (X)
- Storing charge and making magnetism
Classifying medical equipment
International standard IEC 60601
- Why classify — and the single-fault idea
- Class I — earthed equipment
- Protective-earth symbol
- Class II — double-insulated equipment
- Class II double-insulated symbol
- Class III — safety extra-low voltage (SELV)
- Class III equipment symbol
- The three equipment classes at a glance
- Types B, BF and CF — protecting the patient
- Type B — low leakage, but not for the heart
- Type B applied-part symbol
- Type B defibrillation-proof symbol
- Type BF — an isolated (floating) applied part
- Type BF applied-part symbol
- Type BF defibrillation-proof symbol
- Type CF — safe for direct heart connection
- Type CF applied-part symbol
- Type CF defibrillation-proof symbol
- Types B / BF / CF — leakage and heart safety
- Attention — consult the accompanying documents
- Attention / consult-documents symbol
- High-voltage and electrocution warning labels
- Protective earth vs functional earth
- Protective-earth terminal symbol
- Functional-earth symbol
- Extra earthing and equipotentiality
- Additional protective-earth symbol
- Equipotentiality symbol
- Isolated (floating) circuits
- Earth-leakage circuit breakers (COELCB)
- Water ingress and anaesthetic-proof equipment
- Drip-, splash- and water-proof symbol
- Anaesthetic-proof (AP) equipment symbol
- Anaesthetic-proof category G symbol
- Conformity marks: CE and UKCA
- CE conformity mark
- UKCA conformity mark
- Maintenance checks
Hazards of electric shock
- How an electric shock happens
- Frequency matters — why 50 Hz is so dangerous
- Impedance, skin resistance and current density
- Macroshock vs microshock
- Macroshock vs microshock: a 1000-fold difference
- Effects of electrocution by current (50 Hz)
- Two ways electricity injures tissue
- What determines how severe a shock is
- How the body joins a circuit
- Reducing the risk of electrocution
Surgical diathermy
- What diathermy is and why it uses high frequency
- Surgical diathermy circuit
- Components of a diathermy circuit
- How the heat is generated — current density
- Why diathermy does not fibrillate the heart
- Cutting vs coagulation waveforms
- Monopolar vs bipolar diathermy
- Diathermy: problems and safety features
- Why is an isolating capacitor used in a diathermy circuit?
Static electricity and lasers
- Static electricity in theatre
- Lasers — what the word means and how they work
- Types of laser
- Laser hazards and safety
- Laser safety classes
- Airway laser surgery — fire risk and the drill
- Key takeaways
- Type CF equipment can be safely connected directly to the heart — why?
- References
- Essentials of Equipment in Anaesthesia, Critical Care, and Perioperative Medicine