The Experts below are selected from a list of 588 Experts worldwide ranked by ideXlab platform

Charles G Gallagher - One of the best experts on this subject based on the ideXlab platform.

Jeanclaude Rostain - One of the best experts on this subject based on the ideXlab platform.

  • microdialysis study of striatal dopaminergic dysfunctions induced by 3 mpa of nitrogen and Helium Oxygen Breathing mixtures in freely moving rats
    Brain Research, 2004
    Co-Authors: David Dedieu, Norbert Balon, Michel Weiss, Jeanjacques Risso, Richard Kinkead, Jeanclaude Rostain
    Abstract:

    Abstract Previous studies have demonstrated opposite effects of high-pressure Helium and nitrogen on extracellular dopamine (DA) levels, which may reflect disturbances on the synthesis, release or metabolic mechanisms. Intrastriatal microdialysis was used to measure the precursor (tyrosine), DA and its metabolites (DOPAC, HVA) levels under nitrogen- or Helium- at pressure up to 3 MPa. Under 3 MPa of Helium–Oxygen Breathing mixtures, the extracellular concentration of tyrosine is decreased while the extracellular concentration of DA is increased. On the contrary, nitrogen–Oxygen Breathing mixture at the same pressure increased extracellular tyrosine concentration and decreased DA release. Under both conditions, an increment of the DOPAC and HVA levels could be noted. Our results suggest that changes in DA release and metabolism during high-pressure Helium exposure reflect the effect of the pressure per se, whereas the intrinsic effects of narcotic gases, although sensitive to pressure, would be revealed by hyperbaric nitrogen exposure.

Naoki Yahagi - One of the best experts on this subject based on the ideXlab platform.

  • Helium Oxygen Breathing improves hypoxemia after cardiac surgery
    Artificial Organs, 2008
    Co-Authors: Naoki Yahagi, Keiji Kumon, Masaki Haruna, Yasuhiko Watanabe, Junk Matsui, Hideaki Hayashi, Hironobu Tanigami, Shinichi Takamoto
    Abstract:

    : The effects of Helium/Oxygen (He/O2) on Oxygen-ation (respiratory index [Pao2,/Fio2] and inuapulmonary 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 Oxygen-ation 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., oxy-genation had improved significantly; that is, Pao2/Fio2, in creased 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 < 0.01) together with an increase in Cdyn (from 60 ml/cm H2O to 64 mVcm H2O; p < 0.05). These results suggest that HeiO2 may have improved Oxygenation by recruiting previously obstructed small airways and alveoli.

  • Helium Oxygen Breathing improved hypoxemia after cardiac surgery case reports
    Anesthesia & Analgesia, 1995
    Co-Authors: Naoki Yahagi, Keiji Kumon, Yasuhiko Watanabe, Hironobu Tanigami, Junki Matsui
    Abstract:

    14 breaths/min under volume-controlled ventilation without muscle relaxants, which was sufficient to maintain normocapnea) and Pao, did not improve. After admission to the intensive care unit (ICU), her arterial blood Oxygenation failed to improve despite vigorous therapy, including nebulization of a bronchodilator, an 1:E ratio of 0.75, and PEEP of up to 10 cm H,O. Use of high PEEP (15-20 cm H,O) was avoided in order to prevent hemodynamic deterioration. (Her cardiac index [CI] and central venous pressure were 2.0-2.3 L * min-’ * m-’ and 9-13 mm Hg, respectively, with support by intravenous dopamine and dobutamine at a rate of 5 Fg * kg-’ . min-’ each.) Bronchial secretion was not pathologic, and her chest radiograph showed no significant change (Fig. 1). On the second postoperative day, when Pao, had decreased to 56 mm Hg with a FIO, of 1.0 and the intrapulmonary shunt fraction (Qs/Qt) was calculated to be 35%, He/O, was initiated. Helium (purity, 99.9%) was connected to the compressed-air port of a Servo-ventilator 900-C. The required FIO, decreased and the fraction of Helium thus increased: Pao, was 50 mm Hg with a FIO, of 40.5 and Qs/Qt of 31% some 15 min after the initiation of He/O, (Fig. 2). Pace, was slightly decreased (42 + 37 mm Hg). Peak inspiratory pressure (PIP, 24 + 24 cm H,O), CI (2.4 + 2.5 L * min-’ * m-‘), and a systolic systemic blood pressure (127 + 129 mm Hg) showed no change. After 2 h of inhaling He/O,, Oxygenation remained good and reached the normal range after 12 h.

Bharath S Krishnan - One of the best experts on this subject based on the ideXlab platform.

Shinichi Takamoto - One of the best experts on this subject based on the ideXlab platform.

  • Helium Oxygen Breathing improves hypoxemia after cardiac surgery
    Artificial Organs, 2008
    Co-Authors: Naoki Yahagi, Keiji Kumon, Masaki Haruna, Yasuhiko Watanabe, Junk Matsui, Hideaki Hayashi, Hironobu Tanigami, Shinichi Takamoto
    Abstract:

    : The effects of Helium/Oxygen (He/O2) on Oxygen-ation (respiratory index [Pao2,/Fio2] and inuapulmonary 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 Oxygen-ation 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., oxy-genation had improved significantly; that is, Pao2/Fio2, in creased 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 < 0.01) together with an increase in Cdyn (from 60 ml/cm H2O to 64 mVcm H2O; p < 0.05). These results suggest that HeiO2 may have improved Oxygenation by recruiting previously obstructed small airways and alveoli.