subject: Clinical features and management of respiratory failure [print this page] Although it is correct to exercise caution when administering oxygen tohypercapnic patients, it should be remembered that severehypoxaemia - Pao2 less than 5kPa (38mmHg) - is lifethreateningand must be relieved, and hypoxaemic patientswithout CO2 retention (a common situation in fibrotic lungdisease, for example) can receive high inspired oxygenconcentrations without developing hypercapnia.If, with the proper use of oxygen supplements, the Paco2continues to rise, and particularly if the respiratory acidosisworsens, a respiratory stimulant such as doxapram may,in the short term, occasionally be helpful. This may allowthe use of a higher inspired oxygen concentration withoutprecipitating a rise in Paco2. However, some patients willcontinue to deteriorate, and the point may come when adecision will have to be made about whether to offerassisted mechanical ventilation. In this group of patients,above all, their background in terms of respiratory function,exercise tolerance, and when they were last reasonablywell, must be taken into consideration. Discussions should involve the patient's family and, very often, thepatient.For selected patients with ventilatory failure, including those with chronic bronchitis, the technique of noninvasive intermittent nasal positive pressure ventilation may obviate the need for intubation and reduce mortality.
Clinical features and management of respiratory failure
