title: Positive pressure ventilation using a semiclosed system: a reassessment.
mesh_terms: D000769:Anesthesia, Inhalation; D001049:Apnea / Q000209:etiology; D002245:Carbon Dioxide / Q000097:blood; D006801:Humans; D008722:Methods; D011175:Positive-Pressure Respiration / Q000009:adverse effects / Q000295:instrumentation / Q000706:statistics & numerical data*
chemical_list: D002245:Carbon Dioxide