1. Total haemoglobin mass, but not haemoglobin concentration, is associated with preoperative cardiopulmonary exercise testing-derived oxygen-consumption variables
- Author
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Hugh Montgomery, Toby Richards, Walter Schmidt, Michael P.W. Grocott, Lisa Loughney, James M. Otto, Eleri Clissold, Denis J. Wakeham, and James O. M. Plumb
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medicine.medical_specialty ,business.industry ,Physical fitness ,chemistry.chemical_element ,Cardiopulmonary exercise testing ,030204 cardiovascular system & hematology ,Plasma volume ,Oxygen ,Preoperative care ,Surgery ,03 medical and health sciences ,% total haemoglobin ,0302 clinical medicine ,Anesthesiology and Pain Medicine ,chemistry ,030202 anesthesiology ,Internal medicine ,medicine ,Cardiology ,Reduced haemoglobin ,business ,Anaerobic exercise - Abstract
Background Cardiopulmonary exercise testing (CPET) measures peak exertional oxygen consumption ( V ˙ O 2 peak ) and that at the anaerobic threshold ( V ˙ O 2 at AT, i.e. the point at which anaerobic metabolism contributes substantially to overall metabolism). Lower values are associated with excess postoperative morbidity and mortality. A reduced haemoglobin concentration ([Hb]) results from a reduction in total haemoglobin mass (tHb-mass) or an increase in plasma volume. Thus, tHb-mass might be a more useful measure of oxygen-carrying capacity and might correlate better with CPET-derived fitness measures in preoperative patients than does circulating [Hb]. Methods Before major elective surgery, CPET was performed, and both tHb-mass (optimized carbon monoxide rebreathing method) and circulating [Hb] were determined. Results In 42 patients (83% male), [Hb] was unrelated to V ˙ O 2 at AT and V ˙ O 2 peak (r=0.02, P=0.89 and r=0.04, P=0.80, respectively) and explained none of the variance in either measure. In contrast, tHb-mass was related to both (r=0.661, P
- Published
- 2017
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