Liquid ventilation: an adjunct for respiratory management

Abstract

Although significant advances in respiratory care have reduced mortality of patients with respiratory failure, morbidity persists, often resulting from iatrogenic mechanisms. Mechanical ventilation with gas has been shown to initiate as well as exacerbate underlying lung injury, resulting in progressive structural damage and release of inflammatory mediators within the lung. Alternative means to support pulmonary gas exchange while preserving lung structure and function are therefore required. Perfluorochemical (PFC) liquids are currently used clinically in a number of ways, such as intravascular PFC emulsions for volume expansion/oxygen carrying/angiography and intracavitary neat PFC liquid for image contrast enhancement or vitreous fluid replacement. As a novel approach to replace gas as the respiratory medium, liquid assisted ventilation (LAV) with PFC liquids has been investigated as an alternative respiratory modality for over 30 years. Currently, there are several theoretical and practical applications of LAV in the immature or mature lung at risk for acute respiratory distress and injury associated with mechanical ventilation.

Liquid ventilation with perfluorocarbons facilitates resumption of spontaneous circulation in a swine cardiac arrest model

“…8 Liquid ventilation has been associated with a reduction in the amounts and types of mediators released by pulmonary inflammatory cells. 9 Abella et al 10 described a murine model of KCl induced cardiac arrest. Mice that received rapid intra-arrest cooling by external ice application to 30°C had greater initial and 72 hour survival following resuscitation than those mice with delayed cooling or normothermia.…”

Anti-inflammatory effects of perfluorocarbon compounds

“…PFCs are clinically used as contrast agents [1][2][3]. Due to their high solubility for gases such as oxygen, PFCs have been investigated as artificial blood substitutes [4][5][6][7][8] and as oxygen carriers during liquid ventilation [9][10][11][12][13][14], organ preservation [15,16] and transintestinal systemic oxygenation [17]. Recent studies have suggested the use of vaporized [18][19][20][21][22] or aerosolized PFCs [23][24][25][26][27][28] as a treatment modality for acute lung injury.…”

“…Several PFCs, in particular perfluorooctyl bromide (PFOB), have been studied as respiratory media in both animal and clinical studies [9][10][11][12][13][14][42][43][44][45]. Partial liquid ventilation (PLV) and tidal (or total) liquid ventilation (TLV) are the most important liquid-assisted ventilation techniques employed in laboratory studies; however, only PLV with PFOB has been investigated in clinical studies.…”

A prototype of a liquid ventilator using a novel hollow-fiber oxygenator in a rabbit model

“…Countercurrent sweep gas flow (indicated by filled arrows), 5 L·min Ϫ1 of 100% of oxygen from an oxygen tank (15) is passed through the oxygenator from the gas inlet (11), sited on the top of the oxygenator, to the gas outlet (12) at the bottom. PFC tidal volume and end-expiratory and end-inspiratory volume are recorded by a scale (18). then at 60-min intervals for the 3 hrs of TLV to assess the efficiency of carbon dioxide (CO 2 ) removal by the prototype oxygenator.…”