Abstract
ABSTRACT: We wished to determine in a laboratory animal model how much residual lung was needed to sustain total gas exchange. In a series of young, healthy lambs weighing approximately 10 kg that were sedated and paralyzed, we progressively excluded from gas exchange all the left lung (a total of 43%), plus the right lower and cardiac lobes (81%), plus the right middle lobe (87.5%). In some studies, the respective lobes were surgically removed; in others, the bronchi and the pulmonary arteries to the respective lobes were ligated. We provided pulmonary ventilation using the pressure control mode (Servo 900 C) at a tidal volume of 20 mL/kg multiplied by the fraction of the remaining lungs, a respiratory rate up to 120/min, a peak inspiratory pressure of 12–15 cm H2O, and a positive end-expiratory pressure of 3 cm H2O. Those lambs with at least both the right upper lobe (RUL) and right middle lobe remaining (19% of total lungs) were weaned to room air on mechanical ventilation within 48 h. Ventilating RUL (12.5% of remaining lung) with the same ventilator required a substantially higher tidal volume and peak inspiratory pressure to result in adequate alveolar ventilation but led to respiratory failure and death within 8 h. We then applied a newly developed system of intratracheal pulmonary ventilation to ventilate the RUL (12.5% of remaining lung) alone. A continuous flow of humidified mixture of air and oxygen was directly passed into the trachea at the level of the carina through a diffuser at a tidal volume of 2.5 mL/kg. A single valve controlled expiration and respiratory rate. Lambs with only RUL remaining were weaned to room air within 2 h, at a respiratory rate of 60–120/min and peak inspiratory pressure of 14–9 cm H2O, inspiration to expiration ratio of 1:1, and positive end-expiratory pressure of 3 cm H2O. Initial mean pulmonary artery pressure progressively decreased from 40 ± 5 to 25 ± 7 mm Hg within 6 h after surgery.
Similar content being viewed by others
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Müller, E., Kolobow, T., Mandava, S. et al. How to Ventilate Lungs as Small as 12.5% of Normal: The New Technique of Intratracheal Pulmonary Ventilation. Pediatr Res 34, 606–610 (1993). https://doi.org/10.1203/00006450-199311000-00010
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1203/00006450-199311000-00010
This article is cited by
-
Theoretical interactions between ventilator settings and proximal deadspace ventilation during tracheal gas insufflation
Intensive Care Medicine (1996)