title: Helium-oxygen in the postextubation period decreases inspiratory effort.
abstract: After tracheal extubation, upper and total airway resistances may frequently be increased resulting in an increase in inspiratory effort to breathe. We tested whether breathing a helium-oxygen mixture (HeO(2)) would reduce inspiratory effort in the period after extubation. Eighteen consecutive patients with no chronic obstructive pulmonary disease who had received mechanical ventilation (> 48 h) were successively studied immediately after extubation (N(2)O(2)), 15 min after breathing HeO(2), and after return to N(2)O(2). Effort to breathe, assessed by the transdiaphragmatic pressure swings (DeltaPdi) and the pressure-time index of the diaphragm (PTI), comfort, and gas exchange, were the main end points. The mean reduction of the transdiaphragmatic pressure under HeO(2) was 19 +/- 5%. All but three patients presented a decrease in transdiaphragmatic pressure under HeO(2), ranging from - 4 to - 55%, and a significant reduction in DeltaPdi was observed between HeO(2) and N(2)O(2) (10.2 +/- 0.7 versus 8.6 +/- 1.1 versus 10.0 +/- 0.8 cm H(2)O for the three consecutive periods; p < 0.05). PTI also differed significantly between HeO(2) and N(2)O(2) (197 +/- 19 versus 166 +/- 22 versus 201 +/- 23 cm H(2)O/s/min for the three periods; p < 0.05). Breathing HeO(2) significantly improved comfort, whereas gas exchange was not modified. We conclude that the use of HeO(2) in the immediate postextubation period decreases inspiratory effort and improves comfort.
authors.affiliation: Service de Réanimation Médicale, Hôpital Henri Mondor, AP-HP, Université Paris, France.
authors.forename: S
authors.initials: S
authors.lastname: Jaber
authors.forename: A
authors.initials: A
authors.lastname: Carlucci
authors.forename: M
authors.initials: M
authors.lastname: Boussarsar
authors.forename: R
authors.initials: R
authors.lastname: Fodil
authors.forename: J
authors.initials: J
authors.lastname: Pigeot
authors.forename: S
authors.initials: S
authors.lastname: Maggiore
authors.forename: A
authors.initials: A
authors.lastname: Harf
authors.forename: D
authors.initials: D
authors.lastname: Isabey
authors.forename: L
authors.initials: L
authors.lastname: Brochard
mesh_terms: D000280:Administration, Inhalation; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001784:Blood Gas Analysis; D003964:Diaphragm / Q000187:drug effects / Q000503:physiopathology; D004359:Drug Therapy, Combination; D005260:Female; D006371:Helium / Q000494:pharmacology / Q000627:therapeutic use*; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007320:Inspiratory Capacity / Q000187:drug effects*; D007442:Intubation, Intratracheal / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D010102:Oxygen Inhalation Therapy / Q000379:methods*; D011312:Pressure; D011659:Pulmonary Gas Exchange; D012131:Respiratory Insufficiency / Q000378:metabolism / Q000503:physiopathology* / Q000628:therapy*; D013997:Time Factors; D016896:Treatment Outcome; D015300:Ventilator Weaning / Q000009:adverse effects / Q000379:methods*; D014939:Work of Breathing
chemical_list: D006371:Helium