oxygen dissociation curve

  • It is sigmoidal because of positive cooperativity
  • *Deranged Physiology:* once an oxygen molecule is bound to it, the oxygenated subunit increases the oxygen affinity of the three remaining subunits

LEFT shift = higher affinity to oxygen = ↓ oxygen delivery

  • Lower acidity (alkalosis)
  • Lower 2,3-DPG (produced in response to hypoxia/anaemia)
  • Lower temperature
  • Carbon monoxide
  • HbF
  • metHb
  • COHb
  • Carboxyhaemoglobin

RIGHT shift = reduced affinity to oxygen = ↑ oxygen delivery to tissues

  • Higher temperature
  • Higher concentration 2,3-DPG
  • Higher [H+] i.e. acidosis
  • Hypercapnia

Haldane effect

  • deoxygenated hemoglobin (Hb) binds CO2 with greater affinity than oxygenated hemoglobin (HbO2)
  • hence oxygen induces a rightward shift of the CO2 dissociation curve, which is called the Haldane effect
  • in patients with severe COPD who cannot increase minute ventilation, the Haldane effect accounts for about 25% of the total PaCO2 increase due to O2 administration

#physiology #resp-physiology

https://derangedphysiology.com/main/cicm-primary-exam/respiratory-system/Chapter-1142/haldane-effect