This chapter is relevant to Section G7(iv) of the 2017 CICM Primary Syllabus, which asks the exam candidate to "describe the methods of measurement of cardiac output including calibration,
sources of errors and limitations".
Relationship of Global End-diastolic Volume (GEDV) and Intra-Thoracic Blood Volume (ITBV)
The ITBV calculation does not take into account any ort of hideous structural abnormalities in the heart, like shunts, space occupying lesions, or massive pulmonary emboli.
ITBV will be inaccurate in patients with a saddle embolus or pulmonectomy.