title: Helium/oxygen breathing improves hypoxemia after cardiac surgery.
abstract: The effects of helium/oxygen (He/O2) on oxygenation (respiratory index [PaO2/FiO2] and intrapulmonary shunt [Qs/Qt]) and on lung parameters (dynamic compliance [Cdyn] and peak inspiratory pressure [PIP]) were studied in 12 patients. After cardiac surgery, they had impairment of oxygenation without physiological findings and with normal chest radiographs despite having a positive end expiratory pressure of up to 10 cm H2O. After 90 min of inhalation of He/O2, oxygenation had improved significantly; that is, PaO2/FidO2 increased significantly (from 113 to 174 mm Hg; mean values are given; p < 0.01), and there was a significant fall in Qs/Qt (from 29 to 19%; p < 0.001) together with an increase in Cdyn (from 60 ml/cm H2O to 64 ml/cm H2O; p < 0.05). These results suggest that He/O2 may have improved oxygenation by recruiting previously obstructed small airways and alveoli.
authors.affiliation: Surgical Intensive Care Unit, Osaka University, Medical School, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Yahagi
authors.forename: K
authors.initials: K
authors.lastname: Kumon
authors.forename: M
authors.initials: M
authors.lastname: Haruna
authors.forename: Y
authors.initials: Y
authors.lastname: Watanabe
authors.forename: J
authors.initials: J
authors.lastname: Matsui
authors.forename: H
authors.initials: H
authors.lastname: Hayashi
authors.forename: H
authors.initials: H
authors.lastname: Tanigami
authors.forename: S
authors.initials: S
authors.lastname: Takamoto
mesh_terms: D000280:Administration, Inhalation; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006348:Cardiac Surgical Procedures / Q000009:adverse effects; D005260:Female; D006371:Helium / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D006801:Humans; D000860:Hypoxia / Q000188:drug therapy* / Q000503:physiopathology; D007320:Inspiratory Capacity / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology; D010366:Peak Expiratory Flow Rate / Q000187:drug effects; D011183:Postoperative Complications / Q000517:prevention & control
chemical_list: D006371:Helium; D010100:Oxygen