DundeeChest 3.0

Posts Tagged ‘Respiratory Failure’

Inquisitive user El on the AskDundeeChest page has asked another question!

Would you be able to explain the difference between types 1 and 2 respiratory failure and the pink puffers and blue bloaters?Books are very unclear about this!

Here’s my response, as it might be of use to more students out there:

OK. This is the question I get asked about the most, the concept people get wrong most often, and is consistently poorly understood.

Type 1 respiratory failure is hypoxaemia. The pO2 is low, the pCO2 may be low (due to hyper-ventilation to compensate for hypoxaemia) or normal.

Acute type 2 respiratory failure is hypoxaemia with hypercarbia. The pO2 is low, the pCO2 is high. pH is usually low. This follows type 1 failure, usually because of exhaustion, and consequent hypoventilation.

Chronic type 2 respiratory failure is hypoxaemia, long standing hypercarbia with metabolic compensation. The pO2 is low, the pCO2 is high, the HCO3 is high. pH is normal. This can occur in any disease that causes chronic hypoventilation.

Acute on chronic type 2 respiratory failure is hypoxaemia, long standing hypercarbia with metabolic compensation, and an acute event leading to a further hypercarbia, and consequently, acidaemia. The pO2 is low, the pCO2 is very high, HCO3 is high, the pH is low. Think acute exacerbation of any cause of chronic type 2 respiratory failure.

Forget blue bloaters and pink puffers, the concept is not useful, to my mind.

I hope that helps you all out there!