Gas exchange in saline-filled lungs of man.

Kylstra, J A; Schoenfisch, Warren H.; Herron, John M.; Blenkarn, G D

doi:10.1152/jappl.1973.35.1.136

Cited by 12 publications

(5 citation statements)

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“…These animal experiments were followed up by a study in patients undergoing therapeutic lung lavage for alveolar proteinosis and a human volunteer, using a double-lumen endotracheal tube. Saline was cycled in and out of one lung while the contralateral lung was ventilated with oxygen (48). In these humans there was no evidence for incomplete diffusive equilibrium between alveoli and capillary blood.…”

Section: Gas Mixing and Diffusionmentioning

confidence: 99%

Pulmonary gas exchange in diving

Moon

Cherry²,

Stolp³

et al. 2009

Journal of Applied Physiology

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Moon RE, Cherry AD, Stolp BW, Camporesi EM. Pulmonary gas exchange in diving. J Appl Physiol 106: 668 -677, 2009. First published November 13, 2008 doi:10.1152/japplphysiol.91104.2008.-Diving-related pulmonary effects are due mostly to increased gas density, immersion-related increase in pulmonary blood volume, and (usually) a higher inspired PO 2. Higher gas density produces an increase in airways resistance and work of breathing, and a reduced maximum breathing capacity. An additional mechanical load is due to immersion, which can impose a static transrespiratory pressure load as well as a decrease in pulmonary compliance. The combination of resistive and elastic loads is largely responsible for the reduction in ventilation during underwater exercise. Additionally, there is a density-related increase in dead space/tidal volume ratio (VD/VT), possibly due to impairment of intrapulmonary gas phase diffusion and distribution of ventilation. The net result of relative hypoventilation and increased VD/VT is hypercapnia. The effect of high inspired PO 2 and inert gas narcosis on respiratory drive appear to be minimal. Exchange of oxygen by the lung is not impaired, at least up to a gas density of 25 g/l. There are few effects of pressure per se, other than a reduction in the P50 of hemoglobin, probably due to either a conformational change or an effect of inert gas binding. respiratory dead space; ventilation-perfusion ratio; respiratory mechanics DESPITE HAVING EVOLVED in and adapted to an atmosphere with gas density close to 1 g/l, the performance of the human lung in the diving environment is remarkable. Adequate ventilation and gas exchange have been achieved at an ambient pressure up to 71 atmospheres absolute (ATA) [701 m of sea water (msw); 2,310 ft of sea water (fsw)] with an ambient PO 2 of 0.39 ATA (49), and with a PO 2 of 0.2 ATA up to a gas density of 25 g/l (50). Adequate exchange of oxygen and carbon dioxide while diving requires the ability to maintain ventilation in the face of significantly increased resistive and elastic loads. Resistance is increased primarily by the increase in breathing gas density. Elastic load is enhanced primarily by changes in transrespiratory pressure (P TR ). Inertial mechanical load is also increased, although this has a minimal effect on the diver. Added challenges include blunted respiratory drive due to elevated partial pressures of inert gas and oxygen, and possibly impaired diffusion within the alveolus (7). While in most dives the breathing gas is hyperoxic, thus precluding hypoxemia, hypercapnia is common. Hyperoxia, particularly in the venous blood, can induce a small reduction in CO 2 solubility, and hence an increase in venous PCO 2 via the Haldane effect (27,122). Arterial PCO 2 (Pa CO 2 ) is not affected by the Haldane effect because of regulation of breathing via the chemoreceptors, although hypercapnia does occur for other reasons as discussed below.Studies of pulmonary gas exchange under hyperbaric conditions designed to simulate diving have been performed...

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Section: Gas Mixing and Diffusionmentioning

confidence: 99%

Pulmonary gas exchange in diving

Moon

Cherry²,

Stolp³

et al. 2009

Journal of Applied Physiology

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show abstract

“…Low respiratory gas solubility and excessive diffusion gradients at atmospheric conditions have limited the applicability of saline to exchange oxygen and remove carbon dioxide. 16 Investigators applied the method of hyperbarically oxygenating saline to overcome the limiting factor of low oxygen solubility and studied submerged animals. 17 While obtaining adequate oxygenation, carbon dioxide retention and profound acidosis developed, resulting in nonphysiologic conditions during both normobaric and hyperbaric saline ventilation.…”

Section: Saline-filled Lungmentioning

confidence: 99%

Liquid-assisted ventilation: An alternative respiratory modality

1998

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“…Also, the arterial and mixed venous P0 2 and PC02 remained essentially the same, suggesting that diffusive gas tension equilibrium between alveolar capillary blood and alveolar contents was established within 30 sec in these saline filled human lungs (9).…”

Section: * (A) Gah Exchangementioning

confidence: 70%

“…By increasing the inspiratory flow rate, as the saline breathing dog did, the 49 year old volunteer's maximum minute volume of saline ventilation could be 4.3 liters. The maximum minute volume of ventilation in the 28 year old patient with alveolnr proteinosis, if he werc breathing saline, could Diffusive mixing in saline filled gas exchange units of the human lung appears to be complete within 30 sec and teventilation and perfusion of saline filled lungs appears to be matched adequately (9).…”

Section: (B) Venttlationmentioning

confidence: 99%

The Feasibility of Liquid Breathing in Man

Kylstra¹

1977

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Gas exchange in saline-filled lungs of man.

Cited by 12 publications

References 0 publications

Pulmonary gas exchange in diving

Pulmonary gas exchange in diving

Liquid-assisted ventilation: An alternative respiratory modality

The Feasibility of Liquid Breathing in Man

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