Physics, measurement and equipment

“Candidates should have a good understanding of the principles of physics and clinical measurement with an emphasis on the function of monitoring equipment safety and measurement techniques”.

Physics and measurement

Elements from both competency documents relating to Physics and Measurement are listed in the following section mapped to the chapter headings in Basic Physics and Measurement in Anaesthesia, by Davis, Parbrook and Kenny. Terms included in the chapter headings therefore may not appear in the College Syllabus

Chapter 1 – Pressure

Simple Mechanics: mass, force.
Absolute and relative pressure
Measurement and units of pressure.
Principles of surface tension.

Chapter 2 – Fluid flow

Density and viscosity of gases
Laminar and turbulent flow; Poiseuille’s equation, the Bernoulli principle

Chapter 3 – Volume and flow measurement

Measurement of volume and flow in gases and liquids
The pneumotachograph and other respirometers
The Fick Principle

Chapter 4 – The gas laws

Physics of gases and vapours
The gas laws; triple point; critical temperature and pressure
Vapour pressure: saturated vapour pressure

Chapter 5 – Natural exponential functions

Concepts only of exponential functions and logarithms: wash-in, wash-out and tear away
Measurement of Cardiac output by thermodilution

Chapter 7 – Diffusion and Osmosis

Colligative properties

Chapter 8 – Work, energy and power

Work and power

Chapter 9 – Temperature

Heat: freezing point, melting point
Conduction, convection, radiation
Measurement of temperature

Chapter 10 – Heat capacity and latent heat

Concept of latent heat
Mechanical equivalent of heat: laws of thermodynamics

Chapter 12 – Humidification

Measurement of humidity

Chapter 13 – The sine wave and wave patterns

Basic principles of ultrasound and the Doppler effect

Chapter 14 – Electricity

Basic concepts of electricity and magnetism
Capacitance, inductance and impedance
Bridge circuits
Sources of electrical interference
Diathermy and its safe use
Principles of defibrillators
Principles of pressure transducers

Chapter 15 – Biological electrical potentials: their display and recording

Basic measurement concepts: linearity, drift, hysteresis, signal: noise ratio, static and dynamic response
Amplifiers: band width, filters
Amplification of biological potentials: ECG, EMG, EEG
Processing, storage and display of physiological measurements
Principles of cardiac pacemakers
Measurement of neuromuscular blockade

Chapter 16 – Electrical safety

Electricity and electrocution
Electrical hazards: causes and prevention

Chapter 17 – Blood pressure measurement

Resonance and damping, frequency response
Direct and indirect methods of blood pressure measurement
Principles of pulmonary artery and wedge pressure measurement

Chapters 18, 19 and 20 – Oxygen, (H+) and co2 measurement, gas chromatography and mass spectrometry

Pulse oximetry
Measurement of gas and vapour concentrations, (oxygen, carbon dioxide, nitrous oxide, and volatile anaesthetic agents) using infra-red, paramagnetic, fuel cell, oxygen electrode and mass spectrometry methods
Measurement of pH, pCO2 , pO2
Capnography, including interpretation of the capnography trace
Interpretation and errors of capnography, oximetry and ventilatory gas analysis

Chapter 23 – Fires and explosions

Fires and explosions

Chapter 24 – Isotopes and radiation

Basic principles and safety of lasers

Chapter 25 – Presenation and handling of data

Mathematical concepts: relationships and graphs


SI units: fundamental and derived units
Other systems of units where relevant to anaesthesia (e.g. mmHg, bar, atmospheres)

Clinical Measurement (CCT III)

“The Final examination assumes knowledge of the Primary FRCA examination syllabus, with the addition of more sophisticated measurements. There is an emphasis on clinical applications of clinical measurement, such as indications, practical techniques and interpretation of acquired data. Candidates will be expected to understand the sources of error and the limitations of individual measurements”.

Anaesthesia, HDU and ICU equipment: monitoring and safety

Physical principles underlying the function of:
The anaesthetic machine
Pressure regulators
Breathing systems
Care, cleaning, disinfection, sterilization (particularly airway equipment)
Potential defects and problems
Basis for pre-use checks of anaesthetic machine, breathing systems and monitoring apparatus
Safety precautions and checking.
Manufacture and storage of oxygen, nitrous oxide, carbon dioxide, compressed air
Pipeline gas supplies and suction systems
Gas cylinders
Airways, tracheal tubes, emergency airways, laryngeal masks, fixed and variable performance oxygen therapy equipment, self-inflating bags (including the use of)
Other laryngoscopy blades and bougies
Specialised tubes
Tracheostomy tubes, types, fixation and care
Principles of lung ventilators, disconnection monitors
Humidification devices
Chemistry of absorption of carbon dioxide
An understanding of the uses and limitations of monitoring equipment
Understanding portable monitoring systems
Characteristics of intravenous cannulae, spinal and epidural needles
peripheral nerve stimulators
Peripheral nerve locators
Function and use of resuscitation equipment, transfusion devices
The content of an anaesthetic record
Principles of underwater seals on chest drains
Environmental control of the operating theatre including temperature, humidity, air changes and scavenging systems for waste anaesthetic gases and vapours

Skills listed in CCT ii: Equipment

Checking the anaesthetic machine
Checking pipelines
Changing and checking cylinders
Connecting up breathing systems
Checking breathing systems
Setting up/checking/monitoring lung ventilators
Setting up/checking alarm limits for monitoring equipment
Collecting data from monitors
Record keeping
Checking resuscitation equipment
Assembling resuscitation equipment
Selecting defibrillator settings
Recognizing machine, breathing system and equipment errors: miss-assembly and disconnections
Composing equipment checklists for: resuscitation equipment
Difficult and failed intubation
CVP monitoring
Arterial pressure monitoring
Epidural/spinal packs
Paediatric intubation set

Stephen Keay and Chris Callander
The safe use of infusion devices

Colin M Sinclair, Muthu K Thadsad, and Ian Barker
Modern anaesthetic machines

William Wellesley Mapleson
Anaesthetic breathing systems – semi-closed systems

Nadeem Sabir and Vino Ramachandra
Decontamination of anaesthetic equipment

David A Gabbott
Recent advances in airway technology

Julia Ely and Michael Clapham
Delivering oxygen to patients

Antony R. Wilkes
Breathing system filters

Phil Dalrymple and Subbiah Chelliah
Electrical nerve locators

Ian Thomas and John Anthony Carter
Occupational hazards of anaesthesia

A R Wilkes
Humidification: its importance and delivery

Steve Boumphrey and Jeremy A Langton
Electrical safety in the operating theatre

Andrew John Kitching and Christopher J Edge
Lasers and surgery