HYPERCAPNIC RESPIRATORY FAILURE
Respiratory failure due to icreased carbon dioxide in the blood stream and decreased oxygen levels. Results in compromised gas exchange and tissue perfusion.
Normal reference values:
Oxygen PaO2 > 60 mmHg. In kPa, PaO2 values should be above 8.
Carbon dioxide PaCO2 < 45 mmHg. In kPa, PaCO2 should be less than 6.6kPa.
Hypercapnic respiratory failure: PaCO2 > 50 mmHg (i.e. 6.5kPa). This indicates inadequate alveolar ventilation
Head and neck injuries
Chronic obstructive pulmonary disease
Drug overdose, poisoning
Adult respiratory distress syndrome
Reduced breathing effort
ACUTE versus CHRONIC HYERCAPNIC RESPIRATORY FAILURE:
Chronic respiratory failure
may take several days to develop
results in increased bicarbonate concentration, and pH is slightly decreased.
Acute respiratory failure
develops over minutes to hours.
pH < 7.3.