Sat27November0445PM 3

Is it true or false that the following can cause a right shift of the oxygen-haemoglobin dissociation curve?

True / False

Pregnancy Correct

Hypothermia Correct

Raised 2,3 DPG Correct

Carboxyhaemoglobin Correct

Acidosis Correct

Explanation

The oxygen-haemoglobin dissociation curve (OHDC) is shifted to the right to promote oxygen dissociation by:

Increased temperature

Reduced pH

Raised PCO2

Raised 2,3 DPG

Pregnancy

Anaemia, and

Post-acclimatisation at altitude.

Increase in temperature, carbon dioxide, 2,3 DPG (product of glycolysis) and hydrogen ion concentrations (reduced pH), for example in exercising muscle, increase the release of oxygen from haemogoblin to favour oxygen delivery to tissues.

Carbon monoxide has high affinity for haemoglobin. When bound the oxy-Hb dissociation curve shifts to left.

Fetal haemoglobin (HbF) binds 2,3 DPG less avidly than adult haemoglobin, therefore shifts the OHDC to the left. 2,3DPG is increased during pregnancy and thus shifts the OHDC to the right.

Reference:

Power I, Kam P. Principles of Physiology for the Anaesthetist. 2nd ed. London: Hodder Arnold; 2008.

Yentis S, Hirsch N, Smith G. Anaesthesia and Intensive Care A-Z. 4th ed. London: Churchill Livingstone; 2009.

Answer Statistics

Not enough data to display the statistics

Average score: 75.84%

Times answered: 245