Objective: To evaluate the efficiency of continuous positive airway pressure through a face mask in acute respiratory insufficiency (ARI) secondary to Pneumocystis carinii pneumonia.
Design: Prospective study.
Setting: Multidisciplinary ICU.
Patients: Fifteen patients with ARI secondary to Pneumocystis carinii pneumonia were studied.
Interventions: Initially al patients received high flow oxygen therapy through a face mask for 60 minutes (Pre-CPAP phase); then CPAP through a face mask, with identical FiO2 and for a similar period of time (Pst-CPAP phase). At the end of each phase the following parameters were evaluated: respiratory rate, heart rate, arterial gases, acid-base balance, and respiratory muscle motility.
Measurements: After oxygen therapy all fifteen patients had similar variables. After 60 minutes with CPAP through a face mask, significant improvements were noted for respiratory rate, heart rate, muscular effort, PaO2, SaO2, and PaO2/FiO2 (p < 0.001) in eleven patients, who survived after a mean stay of 8.5 days in the ICU with no evidence of major complications. In contrast, CPAP failed in four patients as respiratory rate, heart rate and vigorous muscle effort remained unchanged and, although PaO2 and SaO2 increased, the obtained values were significantly lower than in the remaining patients. Consequently, they underwent intubation and mechanical ventilation and after a mean stay of fourteen days with this ventilatory option died.
Conclusions: These results confirm that CPAP through a face mask is an effective means to improve oxygenation in patients with Pneumocystis carinii pneumonia who develop hypoxemic respiratory insufficiency. Its early introduction in hospital protocols can help improving the prognosis in certain patients with severe PCP and avoid their admission to ICU, which would be thus preserved for those patients requiring mechanical ventilation.