Nichtinvasive Maskenbeatmung bei akuter respiratorischer Insuffizienz

Summary

Background. Noninvasive positive pressure ventilation via face masks offers, in comparison to endotracheal intubation, advantages such as swallowing and coughing in the treatment of patients with acute respiratory failure. We report our experiences and attempt to verify the indications and the efficacy of noninvasive mask ventilation.

Patients and Methods. In the period from January 1991 to August 1996,109 patients (30 female, 79 male; mean age 61 ± 12 years) received mechanical ventilation with noninvasive mask ventilation, representing 25% of all mechanical ventilations in this term. As baseline capillary blood gases were found: pH 7, 30±0,10,pCO₂ 64 ± 19 mmHg (=8.5 ± 2.5 kPa), pO₂ 60 ± 19 mmHg (= 8 ± 2.5 kPa).All patients received supplemental oxygen. Success of noninvasive mask ventilation was determined by an improvement of the baseline capillary blood gases.

Results. Noninvasive mask ventilation was successful in 77 patients (71%). Considering the kind of respiratory insufficiency the patient population was divided into four groups: (1) acute hypoxemic respiratory failure, (2) acute hypercapnic ventilatory failure, (3) acute decompensation of chronic respiratory insufficiency, and (4) combined failure. Considering these subgroups we obtained the best results in the groups of patients with hypercapnic disturbances. In the group of patients with acute hypoxemic respiratory failure, noninvasive mask ventilation was only successful if the improvement of capillary blood gases occurred in the early stage (12 h) of noninvasive mask ventilation.

Conclusion. Our data indicate that application of noninvasive mask ventilation is an effective and safe alternative to endotracheal intubation in many patients with hypercapnic ventilatory failure. The method is also successful in patients with hypoxemic respiratory failure with a milder course.