12th January 2024

Treatment of chronic and acute-on-chronic Respiratory Failure 

COPD has been identified as the most common cause leading to chronic type 2 respiratory failure. Body compensates for persistently raised PaCO2 by retaining bicarbonate and hence correcting acidaemia. In acute-on-chronic respiratory failure, this balance is disturbed, resulting in an acidic pH followed by drowsiness and coma. These patients lose their chemosensitivity to raised PaCO2 and, hence, paradoxically depend on hypoxia for respiratory drive and are at risk of respiratory depression if given high concentrations of oxygen. Such patients may not appear distressed despite being critically ill. Attention must, therefore, be paid to serial ABGs and signs of CO2 narcosis (flapping tremors, bounding pulse, confusion).

The key to treatment is to identify and treat the precipitating cause while trying to achieve a safe PaO2 (>7.0 kPa) without increasing PaCO2 and acidosis. Patients who are conscious and have adequate respiratory drive may benefit from non-invasive ventilation. Patients on the other side of the spectrum who are drowsy with low respiratory effort will need an urgent decision regarding intubation and ventilation. The decision is sometimes challenging and factors like patient’s and family wishes, functional status and quality of life must be considered.

Domiciliary care for Chronic Respiratory Failure 

Advanced lung conditions like COPD, cystic fibrosis or certain neuromuscular deformities / central alveolar hypoventilation can lead to chronic respiratory failure. NIV can be of great value in such patients. In initial stages, patients may only require ventilatory support during the night when there is a physiological decline in ventilatory drive. However, over time, CO2 retention becomes chronic with renal compensation of acidosis, and in advanced cases, daytime NIV can also be helpful.

Single/double lung transplantation is reserved for patients with advanced chronic disease after exhaustion of all available medical treatment.