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An integrated framework for teaching oxygen delivery
Author(s) -
Wittmers Lorentz E.,
Mohrman David E.
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.767.4
Subject(s) - oxygen–haemoglobin dissociation curve , oxygen , dissociation (chemistry) , oxygen delivery , oxygen transport , computer science , oxygen metabolism , biochemical engineering , chemistry , biological system , environmental science , biology , engineering , organic chemistry
The historical development of the process by which oxygen makes its way from the atmosphere to the tissue has numerous elements: pressures, ventilation, dissociation curves, blood flows, O 2 contents, curve shifts, % saturation, metabolism, etc. Students of physiology are left to assimilate these bits and pieces into some understanding of the overall process. Our goal is to integrate the aforementioned “bits” and formulate a “bottom line“ model focusing on oxygen availability to cells as judged by the P O2 around them. Whereas the latter cannot be directly measured, it can be inferred from changes in the venous P O2 . Our approach includes the constraint of conservation of mass to the overall oxygen delivery, as well as addressing the interactions of cardiovascular, respiratory, and metabolic physiology. Another major component in our approach is to combine the individual influences of P CO2 , pH, temperature, 2,3‐DPG, and CO on the oxyhemoglobin dissociation curve. This allows the development of a “normal operating curve” that helps predict the loss of oxygen from the blood as it passes through the tissue. The model presented here makes it possible for the student to grasp the consequences of commonly encountered pathophysiologies of oxygen availability. It provides a convenient framework for discussing physiologic responses to problems such as hypoventilation, shock, and CO poisoning.