Syllabus · Historical · V4 (2023) · Respiratory System
F12 · Respiratory Measurement
F12.ii · Respiratory Measurement
Describe the principles of capnography, including calibration, sources of errors limitations.
Written examination
SAQ history
Carbon Dioxide Monitoring — Capnography Principles
5 exam appearances
a) Outline the scientific principles that apply to the measurement of end-tidal carbon dioxide using capnography. Include the techniques of sampling in your answer (30% of marks).
b) Describe a normal capnograph waveform and its features (20% of marks). A diagram may assist you with your answer.
c) Outline the ventilation and perfusion information that can be derived from the capnograph waveform (50% of marks).
48.2%
Outline the principles of measurement of end-tidal CO2 using infrared radiation (25% of Marks). Describe the potential sources of error when using this modality and how they may be mitigated (75% of Marks).
21%
Describe the principles of capnography, including calibration, sources of error and limitations.
31%
Describe the principles of measurement of end-tidal CO2, including the sources of error.
19%
Describe the underlying principles involved in the measurement of end tidal CO2 (by infrared analysis), including sources of error and interference.
10%
Carbon Dioxide Monitoring — EtCO2–PaCO2 Gap
4 exam appearances
Explain the causes of the differences between measured end tidal and arterial partial pressures of carbon dioxide (CO2).
29%
Explain the potential causes of a difference between the measured end tidal CO2 and the arterial partial pressure of CO2.
30%
Explain the causes of the difference between measured end tidal and arterial partial pressures of carbon dioxide.
10%
Explain the causes of the differences between measured end tidal and arterial partial pressures of carbon dioxide.
—
Carbon Dioxide Monitoring — Mixed Venous CO2
2 exam appearances
Briefly describe the factors that affect the partial pressure of carbon dioxide in mixed venous blood.
8%
Carbon Dioxide Monitoring — PaCO2 Determinants
1 exam appearance
Oral examination
VIVA history
-
2021B · Day 2 · VIVA 2
This viva will assess your knowledge on end-tidal CO2 and pulmonary vasculature. What are the factors that lead to increase in the difference between PaCO2 and PETCO2?
-
2017A · Day 2 · VIVA 2
This viva is about carbon dioxide. What are the features of a capnograph? (Image removed.)
-
2016A · Day 2 · VIVA 2
This viva discussed arterial blood gases, dead space, the measurement of carbon dioxide and capnography.
-
2015A · VIVA 2
This Viva tested knowledge of respiratory physiology. It explored the understanding of ventilation and perfusion of the lung, dead space and moved on to discuss capnography.
-
2014B · VIVA 2
This Viva tested knowledge of respiratory physiology and measurement. It explored understanding of capnography and moved on to discuss dead space.
-
2008B · VIVA 1
The initial information given to the candidates was - In this station you will be asked to draw and discuss a capnograph tracing. Draw a graph of partial pressure of CO2 versus time, from a ventilated patient, i.e. a ‘capnograph tracing’. This viva explored the candidates’ knowledge in relation to the following points Capnograph trace and information that can be ascertained from it Methods used to measure partial pressure of CO2 and the underlying principles ETCO2 and PaCO2 relationships and factors that influence it Capnograph and deadspace Examination feedback: General there was a lack of depth in the understanding of the capnograph. Specifically what it measures, principles of measurements and an understanding of deadspace.
Sources: objective text from the relevant CICM syllabus; historical SAQ and VIVA wording from CICM examiner reports.