Describe the principles of capnography, including calibration, sources of error and limitations.
Answers that scored well followed the structure outlined in the question and explained the principles of each component of the question.
It is hard to tell, but it seems that by "structure outlined in the question", it appears the examiners wanted something with the headings "principles", "calibration", "sources of error" and "limitations". This puts one in a position where one must identify sources of error which are not limitations, and limitations which are not sources of error, which would be hard to do over a ten-minute answer. Perhaps because of this, the pass rate was 31%. The marker's expectations are of course difficult to reconstruct from the examiner's elliptic comments. What is presented here hopefully represents a passing answer, but how would you ever know.
Ward, Kevin R., and Donald M. Yealy. "End‐tidal Carbon Dioxide Monitoring in Emergency Medicine, Part 1: Basic Principles." Academic Emergency Medicine 5.6 (1998): 628-636.
Gravenstein, Joachim S., et al., eds. Capnography. Cambridge University Press, 2011.
Kennell, Eric, Raymond Andrews, and Harry Wollman. "Correction factors for nitrous oxide in the infrared analysis of carbon dioxide." Anesthesiology 39.4 (1973): 441-443.
Rosencwaig, Allan. Photoacoustics and photoacoustic spectroscopy. Wiley, 1980.
Marriott, W. McKim. "The determination of alveolar carbon dioxid tension by a simple method." Journal of the American Medical Association 66.21 (1916): 1594-1596.
Berman, J. A., J. J. Furgiuele, and G. F. Marx. "The Einstein carbon dioxide detector." Anesthesiology (Philadelphia) 60.6 (1984): 613-614.
Puntervoll, S. A., et al. "Rapid detection of oesophageal intubation: take care when using colorimetric capnometry." Acta anaesthesiologica scandinavica 46.4 (2002): 455-457.
Westenskow, D. R., et al. "Clinical evaluation of a Raman scattering multiple gas analyzer for the operating room." Anesthesiology 70.2 (1989): 350-355.