1 / 9

Effects of Acid-Base on Oxygenation?

Effects of Acid-Base on Oxygenation?. James Barnett, RN, MSN Clinical Educator – Neuroscience PCC Vanderbilt University Medical Center May, 2007. Affinity. Affinity is defined as the ability of hemoglobin to combine with oxygen In other words – how much does the hemoglobin love the oxygen?

chadrick
Download Presentation

Effects of Acid-Base on Oxygenation?

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Effects of Acid-Base onOxygenation? James Barnett, RN, MSN Clinical Educator – Neuroscience PCC Vanderbilt University Medical Center May, 2007

  2. Affinity • Affinity is defined as the ability of hemoglobin to combine with oxygen • In other words – how much does the hemoglobin love the oxygen? • High affinity – they love to be together • Low affinity – they hate to be together

  3. Affinity • High affinity means that… • Hemoglobin and oxygen readily combine • Hemoglobin doesn’t like to give its oxygen up – it is like a child with its blanket • Low affinity means that… • Hemoglobin doesn’t want to combine with oxygen • Hemoglobin is only too happy to give up its oxygen

  4. OxyhemoglobinDissociation Curve (ODC) • The ODC represents the ability of hemoglobin to hold onto oxygen at various PaO2 levels • When PaO2 is high, hemoglobin is able to saturate itself with oxygen easily • When PaO2 is low, hemoglobin has a hard time holding onto oxygen

  5. OxyhemoglobinDissociation Curve (ODC) • When PaO2 drops below 40 mmHg, hemoglobin has a hard time holding onto oxygen • The ODC is not a linear function Graphic from: http://www.rnceus.com/abgs/abgcurve.html

  6. OxyhemoglobinDissociation Curve • So I’m sure you’re asking, “what does this have to do with acid-base balance”? • Alterations in the blood’s pH can change hemoglobin’s affinity for oxygen!!!

  7. OxyhemoglobinDissociation Curve • Acidosis • Causes the oxyhemoglobin curve to advance to the right (remember: acid = advance) • This is known as a “shift to the right” • Affinity is reduced • More oxygen is released to the tissues, BUT • Hemoglobin is less likely to bind with oxygen in the lungs, so there is not as much to give up • De-saturation occurs at higher PaO2 than normal http://www.readylinkhealthcare.net/newsletters/0602/page2.asp

  8. OxyhemoglobinDissociation Curve • Alkalosis • Causes the oxyhemoglobin curve to move backward to the left (remember: base = back) • This is known as a “shift to the left” • Affinity is increased • More oxygen is taken up by hgb in the lungs, BUT • Hgb is less likely to give up its oxygen to the tissues • Tissue hypoxia can occur even if PaO2 is WNL http://www.readylinkhealthcare.net/newsletters/0602/page2.asp

  9. Finished • You have finished this inservice • Please proceed to the ABG Interpretation Post-Test at the following website

More Related