title: [Intermittent negative pressure ventilation in patients with chronic air flow limitation: criteria for selection of patients].
abstract: To determine clinical and functional predictive criteria for use of intermittent negative pressure ventilation we evaluated 9 patients with severe chronic air flow limitation. Arterial blood gases, lung volumes, maximal inspiratory pressures and transdiaphragmatic pressure during quiet breathing were measured. patients were then ventilated once or twice a week for 3 to 10 weeks and improvement was evaluated through changes in quality of life, dyspnea, PaO2, PaCO2 and maximal inspiratory mouth pressure (PRMAX). Result was considered good when 4 or more of these indices improved. 5 patients benefitted from intermittent negative pressure ventilation. Compared to non responders, patients who improved had significantly lower PRMAX (39.4 +/- 11.6 VS 73.5 +/- 13.8 CMh20, p < 0.025), and higher percentage of their maximal inspiratory pressure during quiet breathing (31.2 +/- 7 vs 12.2 +/- 5%, p < 0.025>). Other indices were not different between groups. We conclude that a severe impairment of inspiratory muscle function characterizes patients with chronic air flow limitation who may benefit from intermittent negative pressure ventilation.
authors.affiliation: Departamento de Enfermedades Respiratorias, Escuela de Medicina, Pontificia Universidad Católica, Santiago de Chile.
authors.forename: C
authors.initials: C
authors.lastname: Lisboa
authors.forename: M
authors.initials: M
authors.lastname: Barros
authors.forename: G
authors.initials: G
authors.lastname: Contreras
authors.forename: E
authors.initials: E
authors.lastname: Cruz
mesh_terms: D000328:Adult; D000368:Aged; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012129:Respiratory Function Tests; D012131:Respiratory Insufficiency / Q000503:physiopathology / Q000628:therapy*; D015919:Ventilators, Negative-Pressure / Q000592:standards
vernacular_title: Ventilacion mecanica intermitente con presion negativa externa en pacientes con limitacion cronica del flujo aereo: criterios para seleccion de pacientes.