View Full Version : Respiratory Failure ( Causes - C/P - Investigations - Treatment )

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03-18-2009, 10:33 AM
Respiratory Failure

Definition: It is a decline in the respiratory performance leading to:

Po2 < 60 (normally around 100 mm Hg)
Pco2 > 50 or > 55 (normally around 40)

Provided with normal atmospheric O2 tension and absence of A- V shunts.


Type l: Hypoxic normocapnic or hypocapnic as Co2 may be washed due to hyperventilation, it is mainly diffusion defect.

Causes emphysema (pure) Chronic
interstitial. Pulmonary fibrosis.
Acute pulmonary edema - ARDS
Pneumonia Acute
Type II: Hypoxic hypercapnic
It is mainly due to ventilation defect so O2 and Co2 ­

Causes: Respiratory muscle paralysis
acute severe asthma. Acute
Obstructive hypoventilation. e.g. GOAD
restrictive e.g. pulmonary fibrosis Chronic

N.B. Patient with chronic bronchitis + emphysema will suffer from Ventilation +diffusion defect + perfusion defect O2 + ­ Co2 (type II) respiratory failure.

Treatment of respiratory failure:
1- ttt of the cause
2- according to the type

Type I
O2 with no ­ Co2
So we can give
-O2 with ­ concentration
-ttt of the cause
-Mechanical Ventilation
If necessary

So, In ttt of type II give low concentration of O2 to preserve this hypoxic drive, also, ttt the cause, mechanical ventilation if necessary.
Also we can use Doxapram as a respiratory center stimulant

Source: Internal Medicine Book of Dr.Osama Mahmoud (Ain Shams University)