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TYK41: Difference between revisions
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The storage of red blood cells (RBC) in the blood bank leads to a progressively lower oxygen carrying capacity over time. Once these RBC are transfused to a patient, how long does it take before normal oxygen carrying capacity is restored? | The storage of red blood cells (RBC) in the blood bank leads to a progressively lower oxygen carrying capacity over time. Once these RBC are transfused to a patient, how long does it take before normal oxygen carrying capacity is restored? | ||
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D. > 24 hours but < 48 hours after transfusion | D. > 24 hours but < 48 hours after transfusion | ||
E. > 48 hours after transfusion | E. > 48 hours after transfusion<div class="mw-customtoggle-TYK_Answer" style="text-align: right; color:#0000ff">Click for Answer</div> | ||
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==Answer== | ==Answer== | ||
The correct answer is D. There are several things that occur with ex vivo storage of RBC's - collectively referred to as the "storage lesion." First, ATP is depleted and membrane lipids and cytoskeletal elements are damaged (oxidant injury) - this leads to decreased deformability of the red cell in the microcirculation (it gets "clogged up" in the capillaries). Second, the levels of 2,3-DPG are essentially depleted to zero after a week of storage. Fortunately, 2,3-DPG levels return to normal within 24 hours or so following transfusion. Hence, normal oxygen carrying capacity is back to normal somewhere between 24-48 hours after transfusion. Until that time, RBC are essentially a good volume expander, but you may not necessarily get all the oxygen delivery benefits! | The correct answer is D. There are several things that occur with ex vivo storage of RBC's - collectively referred to as the "storage lesion." First, ATP is depleted and membrane lipids and cytoskeletal elements are damaged (oxidant injury) - this leads to decreased deformability of the red cell in the microcirculation (it gets "clogged up" in the capillaries). Second, the levels of 2,3-DPG are essentially depleted to zero after a week of storage. Fortunately, 2,3-DPG levels return to normal within 24 hours or so following transfusion. Hence, normal oxygen carrying capacity is back to normal somewhere between 24-48 hours after transfusion. Until that time, RBC are essentially a good volume expander, but you may not necessarily get all the oxygen delivery benefits! | ||
==Notes== | ==Notes== | ||
<references /> | <references /> | ||
==Keywords== | ==Keywords== | ||
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