Michèle Germain

Publications (3)6.04 Total impact

• Article: Comparison of Alpha 200 and CoughAssist as intermittent positive pressure breathing devices: a bench study.

  Gaël Bourdin, Claude Guérin, Véronique Leray, Bertrand Delannoy, Sophie Debord, Frédérique Bayle, Michèle Germain, Jean-Christophe Richard
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  ABSTRACT: Intermittent positive pressure breathing (IPPB) is used in non-intubated patients to increase lung volume and to enhance coughing. Alpha 200 (Salvia Lifetec, Kronberg, Germany) is a specific IPPB device. CoughAssist (Respironics France, Carquefou, France) is a mechanical insufflator-exsufflator used to remove secretions in patients with inefficient cough. Both can also be used for intubated or tracheotomized patients. We assessed the impact of various artificial airways on the ability of the Alpha 200 and CoughAssist to generate insufflated volume. We measured the insufflated volume and pressure at the airway opening in a lung model under 2 conditions of compliance (30 or 60 mL/cm H(2)O) at single resistance of 5 cm H(2)O/L/s. The devices were used at 2 set pressures: 30 and 40 cm H(2)O. The Alpha 200 was set at 2 inflation flows: 0.5 and 1 L/s, whereas CoughAssist was set at its highest value of 10 L/s. Measurements were done without (control) and with different size endotracheal tubes and tracheostomy cannulae. The relationships between insufflated volume and measured pressure were analyzed using linear regressions. The slopes and intercepts of the control relationship between insufflated volume and pressure were significantly greater with Alpha 200 at each set flow than with CoughAssist. As artificial airways were used, the insufflated volume did not differ from the control with CoughAssist, while with Alpha 200 it increased at each flow setting and for all mechanical conditions. The largest differences in insufflated volume between the 2 devices were observed for the largest endotracheal tubes and tracheostomy cannulas and for the lowest inflation flow setting in Alpha 200. These results can be explained in terms of how the devices function, as CoughAssist adapts by increasing flow, while Alpha 200 adapts by increasing inspiratory time. This bench study has shown that in the presence of artificial airways the value of the insufflated volume generated by the CoughAssist device was significantly lower than that generated by the Alpha 200 device.
  Respiratory care 01/2012; 57(7):1129-36. · 2.01 Impact Factor
• Article: Performance of the coughassist insufflation-exsufflation device in the presence of an endotracheal tube or tracheostomy tube: a bench study.

  Claude Guérin, Gaël Bourdin, Véronique Leray, Bertrand Delannoy, Frédérique Bayle, Michèle Germain, Jean-Christophe Richard
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  ABSTRACT: The CoughAssist is a mechanical insufflator-exsufflator designed to assist airway secretion clearance in patients with ineffective cough. The device may benefit intubated and tracheotomized patients. We assessed the impact of various artificial airways on peak expiratory flow (PEF) with the CoughAssist. We measured PEF and pressure at the airway opening in a lung model during insufflation-exsufflation with the CoughAssist, at 3 set pressures: 30/-30, 40/-40, and 50/-50 cm H(2)O, first without (control), and then with different sizes (6.5 to 8.5 mm inner diameter) of endotracheal tube (ETT) and tracheostomy tube (6, 7, and 8 mm inner diameter), compliance settings of 30 and 60 mL/cm H(2)O, and resistance settings of 0 and 5 cm H(2)O/L/s). We analyzed the relationship between PEF and pressure with linear regression. With compliance of 30 mL/cm H(2)O and 0 resistance the slope of the control relationship between PEF and pressure was statistically significantly greater than during any conditions with ETT or tracheostomy tube. Therefore, in comparison to the control, the relationship of PEF to pressure significantly went in the direction from top to bottom as the ETT or tracheostomy tube became narrower. The findings were the same with compliance of 30 mL/cm H(2)O and resistance of 5 cm H(2)O/L/s. With compliance of 60 mL/cm H(2)O the highest set pressure values were not achieved and some relationships departed from linearity. The control slope of the relationship between PEF and pressure with compliance of 60 mL/cm H(2)O and 0 resistance did not significantly differ with any ETT or tracheostomy tube. The artificial airways significantly reduced PEF during insufflation-exsufflation with CoughAssist; the narrower the inner diameter of the artificial airway, the lower the PEF for a given expiratory pressure.
  Respiratory care 08/2011; 56(8):1108-14. · 2.01 Impact Factor
• Source

  Available from: Florent Wallet

  Article: Quantitative analysis of acid-base disorders in patients with chronic respiratory failure in stable or unstable respiratory condition.

  Claude Guérin, Pascale Nesme, Véronique Leray, Florent Wallet, Gael Bourdin, Frédérique Bayle, Michèle Germain, Jean-Christophe Richard
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  ABSTRACT: The Stewart approach theorizes that plasma pH depends on P(aCO₂), the strong ion difference, and the plasma total concentration of non-volatile weak acids (A(tot)). The conventional approach measures standardized base excess, bicarbonate (HCO₃⁻), and the anion gap. To describe acid-base disorders with the Stewart approach and the conventional approach in patients with chronic respiratory failure. This was an observational prospective study in a medical intensive care unit and a pneumology ward of a university hospital. There were 128 patients included in the study, of which 14 had more than one admission, resulting in 145 admissions. These were allocated to 4 groups: stable respiratory condition and elevated HCO₃⁻ (Group 1, n = 23), stable respiratory condition and non-elevated HCO₃⁻ (Group 2, n = 41), unstable respiratory condition and elevated HCO₃⁻ (Group 3, n = 44), and unstable respiratory condition and non-elevated HCO₃⁻ (Group 4, n = 37). Elevated HCO₃⁻ was defined as ≥ 3 standard deviations higher than the mean value we found in 8 healthy volunteers. Measurements were taken on admission. In groups 1, 2, 3, and 4, the respective mean ± SD values were: HCO₃⁻ 33 ± 3 mM, 26 ± 3 mM, 37 ± 4 mM, and 27 ± 3 mM (P < .001); strong ion difference 45 ± 3 mM, 38 ± 4 mM, 46 ± 4 mM, and 36 ± 4 mM (P < .001); and A(tot) 12 ± 1 mM, 12 ± 1 mM, 10 ± 1 mM, 10 ± 2 mM (P < .001). Non-respiratory disorders related to high strong ion difference were observed in 12% of patients with elevated HCO₃⁻, and in none of those with non-elevated HCO₃⁻ (P = .003). Non-respiratory disorders related to low strong ion difference were observed in 9% of patients with non-elevated HCO₃⁻, and in none of those with elevated HCO₃⁻ (P = .02). Hypoalbuminemia was common, especially in unstable patients (group 3, 66%; group 4, 65%). Normal standardized base excess (16%), HCO₃⁻ (28%), and anion gap (30%) values were common. The Stewart approach detected high effective strong ion difference in 13% of normal standardized base excess, and in 20% of normal anion gap corrected for albuminemia, and low effective strong ion difference in 22% of non-elevated HCO₃⁻. In patients with chronic respiratory failure the acid-base pattern is complex, metabolic alkalosis is present in some patients with elevated HCO₃⁻, and metabolic acidosis is present in some with non-elevated HCO₃⁻. The diagnostic performance of the Stewart approach was better than that of the conventional approach, even when corrected anion gap was taken into account.
  Respiratory care 11/2010; 55(11):1453-63. · 2.01 Impact Factor