probable lack of cooperation with patient; severe disease disease, eg generalized neoplastic disease; concomitant pulmonary diseases (eg, fibrosis lungs); respiratory acidosis - ph <7.3 with pco2> 50 mmhg; disturbances of consciousness - gcs < 12;

probable lack of cooperation with patient; severe disease disease, eg generalized neoplastic disease; concomitant pulmonary diseases (eg, fibrosis lungs); respiratory acidosis - ph <7.3 with pco2> 50 mmhg; disturbances of consciousness - gcs < 12;