Intrapulmonary gas transport and perfusion during high-frequency oscillation

1981 ◽  
Vol 51 (6) ◽  
pp. 1507-1514 ◽  
Author(s):  
E. R. Schmid ◽  
T. J. Knopp ◽  
K. Rehder
Keyword(s):  
Gas Exchange ◽  
High Frequency ◽  
Regional Distribution ◽  
Pulmonary Gas Exchange ◽  
Right Atrial ◽  
High Frequency Oscillation ◽  
Dependent Lung ◽  
Frequency Oscillation ◽  
133Xe Clearance ◽  
The Right

The effects of high-frequency oscillation (HFO) on 1) regional pulmonary 133Xe clearance after equilibration, 2) regional distribution and subsequent clearance of 133Xe after right atrial bolus injection, and 3) pulmonary gas exchange were examined in anesthetized supine dogs. After equilibration 133Xe cleared similarly from all lung regions with HFO at 16 and 30 Hz and a stroke volume of 2.6 ml/kg. Pulmonary gas exchange was adequate. 133Xe, injected as a bolus into the right atrium, was preferentially distributed to dependent lung regions during both HFO and apnea, indicating vertical gradients in pulmonary perfusion. During the subsequent pulmonary clearance of 133Xe, regional 133Xe concentrations (CrXe) increased initially in nondependent regions. By contrast, CrXe decreased immediately in the dependent lung region; after CrXe's became similar in dependent and nondependent regions, all lung regions started to clear at similar rates. The initial increases of CrXe in nondependent regions were attributed to interregional mixing, which may contribute to the uniformity in regional pulmonary 133Xe clearance after equilibration.

PULMONARY GAS EXCHANGE DURING HIGH FREQUENCY OSCILLATION

1980 ◽  
Vol 53 (3 Suppl) ◽  
pp. S402-S402 ◽  
Author(s):  
E. R. Schmid ◽  
T. J. Knopp ◽  
K. Rehder
Keyword(s):  
Gas Exchange ◽  
High Frequency ◽  
Pulmonary Gas Exchange ◽  
High Frequency Oscillation ◽  
Frequency Oscillation

Aerosol deposition in the human lung: Effect of high-frequency oscillation on the deposition characteristics of an inhaled nebulized aerosol

1988 ◽  
Vol 75 (5) ◽  
pp. 535-542 ◽  
Author(s):  
Simon H. L. Thomas ◽  
Jackie A. Langford ◽  
Robert J. D. George ◽  
Duncan M. Geddes
Keyword(s):  
Deposition Rate ◽  
High Frequency ◽  
Regional Distribution ◽  
Normal Subjects ◽  
Aerosol Deposition ◽  
High Frequency Oscillation ◽  
Particle Sizes ◽  
Frequency Oscillation ◽  
Regional Deposition ◽  
Peripheral Lung

1. Oral high-frequency oscillation (OHFO) may have important effects on aerosol deposition in the lungs. In order to investigate these, a technique was devised to measure regional deposition rates of a nebulized radio-labelled aerosol in the lungs during normal tidal breathing. 2. The effect of three frequencies of OHFO on pulmonary aerosol deposition rate (PADR) in four normal subjects and five patients with chronic airways obstruction (CAO) were assessed using the technique. 3. In separate experiments employing three normal subjects, the effect of OHFO was studied on the deposition rate of aerosol on the oropharynx and delivery apparatus, and on the amount and characteristics of aerosol inhaled by the subjects. 4. Total PADR was significantly reduced by OHFO at 8 Hz and 16 Hz in the normal subjects, and by all three frequencies of OHFO in the CAO patients. In the normal subjects, the regional distribution of aerosol deposition was unchanged, but in the CAO patients a larger proportion of total aerosol deposition occurred in peripheral lung. 5. OHFO reduced the oropharyngeal aerosol deposition rate, increased the loss of aerosol to the atmosphere before inhalation, and increased the deposition of aerosol on the delivery apparatus. The end result was a reduction in the amount of aerosol inhaled, and in the particle sizes measured at the mouthpiece. 6. We conclude that OHFO reduces the amount of aerosol inhaled, but may improve peripheral deposition of inhaled aerosol in patients with CAO. This effect may be of value in the clinical administration of nebulized drugs.

Effect of High-Frequency Oscillation on Gas Exchange and Pulmonary Phospholipids in Experimental Hyaline Membrane Disease1–3

1983 ◽  
Vol 127 (5) ◽  
pp. 585-589 ◽  
Author(s):  
W. E. Truog ◽  
T. A. Standaert ◽  
J. Murphy ◽  
S. Palmer ◽  
D. E. Woodrum ◽  
...  
Keyword(s):  
Gas Exchange ◽  
High Frequency ◽  
High Frequency Oscillation ◽  
Frequency Oscillation ◽  
Hyaline Membrane

scholarly journals Partial Liquid Ventilation Using High Frequency Oscillation: Effects of Changes in Frequency on Gas Exchange. † 1593

1997 ◽  
Vol 41 ◽  
pp. 268-268
Author(s):  
Kendra M. Smith ◽  
Jamie S. Clink ◽  
Don W. Jung ◽  
M. Dale Prince ◽  
Morley A. Herbert ◽  
...  
Keyword(s):  
Gas Exchange ◽  
High Frequency ◽  
High Frequency Oscillation ◽  
Partial Liquid Ventilation ◽  
Frequency Oscillation ◽  
Liquid Ventilation

Gas transport and pulmonary perfusion during high-frequency ventilation in humans

1984 ◽  
Vol 57 (4) ◽  
pp. 1231-1237 ◽  
Author(s):  
K. Rehder ◽  
E. P. Didier
Keyword(s):  
Gas Exchange ◽  
High Frequency ◽  
Regional Distribution ◽  
Vertical Gradient ◽  
Conventional Mechanical Ventilation ◽  
Pulmonary Gas Exchange ◽  
High Frequency Ventilation ◽  
Pulmonary Perfusion ◽  
Volume Ventilation ◽  
Frequency Ventilation

Regional pulmonary 133Xe clearances, regional 133Xe washins, regional distribution of pulmonary blood flow, and pulmonary gas exchange were determined during high-frequency small-volume ventilation (HFV, oscillation frequencies 12 or 18 Hz, stroke volumes 1.2–0.8 ml/kg) in six healthy anesthetized-paralyzed volunteers lying supine. Adequate pulmonary gas exchange was maintained by HFV; the efficiency of oxygenation during HFV did not differ significantly from that during conventional mechanical ventilation at similar mean lung volumes. During HFV regional pulmonary clearances and washins of tracer gas were different among regions. Apical nondependent lung regions cleared faster and had greater regional longitudinal gas conductances than did basal nondependent or dependent regions. The vertical gradient for pulmonary perfusion was preserved during HFV. Apparently the rate of interregional gas mixing is small during HFV at 12 and 18 Hz in anesthetized-paralyzed humans.

Iloprost in persistent pulmonary hypertension of the newborn

2003 ◽  
Vol 13 (4) ◽  
pp. 361-363 ◽  
Author(s):  
Michael Ehlen ◽  
Beatrix Wiebe
Keyword(s):  
Nitric Oxide ◽  
Pulmonary Hypertension ◽  
High Frequency ◽  
Therapeutic Option ◽  
Substantial Improvement ◽  
High Frequency Oscillation ◽  
Critically Ill Patient ◽  
Severe Pulmonary Hypertension ◽  
Frequency Oscillation ◽  
The Right

Aerosolized iloprost is now used as a therapeutic option in the treatment of pulmonary hypertension. We report on the administration of this derivative of prostacycline in treating severe pulmonary hypertension of the newborn. The combination of iloprost instilled endotracheally and inhaled was chosen as a last attempt at treatment in a critically ill patient who did not respond to advanced conventional treatments, including high frequency oscillation and inhalation of nitric oxide. The use of iloprost converted permanently the right-to-left shunting, leading to a substantial improvement in oxygenation.

Open-lung Protective Ventilation with Pressure Control Ventilation, High-frequency Oscillation, and Intratracheal Pulmonary Ventilation Results in Similar Gas Exchange, Hemodynamics, and Lung Mechanics

2003 ◽  
Vol 99 (5) ◽  
pp. 1102-1111 ◽  
Author(s):  
Khaled A. Sedeek ◽  
Muneyuki Takeuchi ◽  
Klaudiusz Suchodolski ◽  
Sara O. Vargas ◽  
Motomu Shimaoka ◽  
...  
Keyword(s):  
Gas Exchange ◽  
High Frequency ◽  
Distress Syndrome ◽  
Pulmonary Ventilation ◽  
Pressure Control ◽  
Control Ventilation ◽  
Lung Mechanics ◽  
High Frequency Oscillation ◽  
Lung Protective Ventilation ◽  
Frequency Oscillation

Background Pressure control ventilation (PCV), high-frequency oscillation (HFO), and intratracheal pulmonary ventilation (ITPV) may all be used to provide lung protective ventilation in acute respiratory distress syndrome, but the specific approach that is optimal remains controversial. Methods Saline lavage was used to produce acute respiratory distress syndrome in 21 sheep randomly assigned to receive PCV, HFO, or ITPV as follows: positive end-expiratory pressure (PCV and ITPV) and mean airway pressure (HFO) were set in a pressure-decreasing manner after lung recruitment that achieved a ratio of Pao2/Fio2 > 400 mmHg. Respiratory rates were 30 breaths/min, 120 breaths/min, and 8 Hz, respectively, for PCV, ITPV, and HFO. Eucapnia was targeted with peak carinal pressure of no more than 35 cm H2O. Animals were then ventilated for 4 h. Results There were no differences among groups in gas exchange, lung mechanics, or hemodynamics. Tidal volume (PCV, 8.9 +/- 2.1 ml/kg; ITPV, 2.7 +/- 0.8 ml/kg; HFO, approximately 2.0 ml/kg) and peak carinal pressure (PCV, 30.6 +/- 2.6 cm H2O; ITPV, 22.3 +/- 4.8 cm H2O; HFO, approximately 24.3 cm H2O) were higher in PCV. Pilot histologic data showed greater interstitial hemorrhage and alveolar septal expansion in PCV than in HFO or ITPV. Conclusion These data indicate that HFO, ITPV, and PCV when applied with an open-lung protective ventilatory strategy results in the same gas exchange, lung mechanics, and hemodynamic response, but pilot data indicate that lung injury may be greater with PCV.

Ventilation by high-frequency oscillation in rabbits with oleic acid lung disease

1981 ◽  
Vol 50 (5) ◽  
pp. 1056-1060 ◽  
Author(s):  
K. Wright ◽  
R. K. Lyrene ◽  
W. E. Truog ◽  
T. A. Standaert ◽  
J. Murphy ◽  
...  
Keyword(s):  
Oleic Acid ◽  
Gas Exchange ◽  
Partial Pressure ◽  
Lung Disease ◽  
High Frequency ◽  
Gas Flow ◽  
High Frequency Oscillation ◽  
Frequency Oscillation ◽  
Co2 Partial Pressure ◽  
Spontaneously Breathing

The feasibility and efficiency of ventilation by high-frequency oscillation (HFO) were examined in animals with diffuse hemorrhagic lung disease. Twenty-four hours after injection with 0.12 ml/kg oleic acid, 11 spontaneously breathing rabbits had a mean (+/- SD) arterial O2 partial pressure (PaO2) of 65 +/- 16 Torr and arterial CO2 partial pressure (PaCO2) of 38 +/- 7 Torr [inspired fractional O2 concentration (FIO2) of 0.21]. Following paralysis animals were ventilated using a high-frequency oscillator for periods of 20 min followed by three successive hyperinflations to prevent atelectasis. Maintaining a constant mean airway pressure (MAP) of 6 cmH2O and fresh gas flow (FGF) of 2 1/min (FIO2 = 0.21), all combinations of frequency (5, 10, 20, and 30 Hz) and stroke volume (Vs) 2.6, 5.0, and 8.9 ml) were tested. At each frequency, an increase in Vs tended to lower mean PaCO2. At each Vs, CO2 elimination appeared maximal at 20 Hz, an effect attributable to decreasing effective Vs with increasing frequency. With constant Vs, MAP, and frequency, increasing FGF from 1 to 2 or 61/min decreased mean PaCO2 (P less than 0.05). With constant Vs, frequency, and FGF, increases in MAP from 2 to 10 cmH2O increased mean PaO2 (P less than 0.05). HFO, coupled with periodic hyperinflation, supports satisfactory gas exchange in rabbits with oleic acid lung injury. The efficiency of gas exchange is improved by independent increases in Vs, FGF, MAP, or frequency.

High-Frequency Oscillation and Chronic Lung Disease in Very Low Birth Weight Infants

PEDIATRICS ◽  
2001 ◽  
Vol 108 (1) ◽  
pp. 212-214
Author(s):  
J. P. Shenai; ◽  
P. Rimensberger; ◽  
U. Thome ◽  
F. Pohlandt; ◽  
P. Rimensberger
Keyword(s):  
Birth Weight ◽  
Low Birth Weight ◽  
Lung Disease ◽  
Chronic Lung Disease ◽  
High Frequency ◽  
Very Low Birth Weight ◽  
High Frequency Oscillation ◽  
Frequency Oscillation ◽  
Low Birth Weight Infants
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