Liquid breathing

Liquid ventilation ( engl. liquid ventilation ) is a form of ventilation, breathing an oxygen-enriched liquid from the family of perfluorocarbons in the patient instead of breathing air.

History of development

Early experiments took place in the mid-1960s at the State University of New York. Since then, research on mice showed keep making progress in the application. Since 1990 will be held clinical studies in humans. Here Perflubron LiquiVent alias is used.

Pros and Cons

The most important advantage of liquid ventilation is the down -cutting of the surface tension of the pulmonary alveoli; the reduced surface tension prevents the collapse of alveoli, so that larger areas of the lung are again involved in gas exchange. Disadvantage is the difficult act exhalation of carbon dioxide and the damage to the lung tissue through the medium, so grab liquids the protective mucosa and make it so much more susceptible to respiratory infections ( eg pneumonia ). Due to the higher density and viscosity of Perfluorkarbons to airway resistance and thus increase the work of breathing.

Application

Overview

Liquid breathing is used in preterm infants and adults with severe lung damage.

Another possible application could be to dive. The breathing of liquid overcomes the known printing problems here.

Although perfluorocarbons in many case reports have a persuasive effect on the respiration of patients with Acute Respiratory Distress Syndrome (ARDS), no standard application for perfluorocarbon (PFC ) has been established. Due to the high technical complexity and the risks to the patient is considerable concern both to the total liquid ventilation and partial liquid ventilation.

Various forms of liquid ventilation ( ventilation with perfluorocarbon ) are currently described:

Complete liquid ventilation

The total liquid ventilation ( TLV ) with complete PFC filling the lungs a special ventilator is used. This includes liquid pump, a membrane oxygenator, a heater and a liquid-filled tube system. For ventilation pure Flüssigkeitsatemhübe be applied. (This is why TLV is also sometimes translated as " Tidal Liquid Ventilation", is derived from tidal tide ) Although theoretically speaking a clear concept for the successful application of this ventilator, the practicality of the TLV is previously qualified by the complicated structure and the technically complex procedure.

Partial liquid ventilation

Partial liquid ventilation ( PLV ) can be carried out with a standard ventilator and breathing gas filled tube system. The functional residual capacity of the lung (ie, the volume after exhaling normally remains filled with air ) is filled with perfluorocarbon, and administered it as in conventional gas ventilation gas tidal volumes to the intrapulmonary Perfluorcabon levels. The influence of PLV on gas exchange and lung mechanics has been studied in several animal studies in different models of lung injury. Clinical application of PLV observations are for the ARDS Mekoniumaspirations syndrome (MAS ), congenital diaphragmatic hernia and respiratory distress syndrome in premature infants ( IRDS ) ago. The application of PLV, in particular the maintenance of the PFC filling volume, requires extreme care. In a 2002 aborted Phase 3 study in adults with ARDS (320 included patients with PLV, unpublished ) were found both in particular the filling process and the monitoring of the fill volume to be highly difficult. In addition, there are significant uncertainties about the setting of the ventilation parameters. For example, changes in the PFC Respiratorparameter filling other effects on the lungs as it is known from the gas ventilation. Moreover, there are different effects on gas-or liquid-filled areas of the lung of a patient.

Perfluorcarbondampfbeatmung

An alternative ventilation with perfluorocarbon is possible through the use of highly volatile substances. Perfluorohexane evaporated at room temperature and can be modified with an anesthetic vaporizer controls the breathing air can be admixed. The effects of these applications seem to correspond to those of the PLV. However, the strict limitation on perfluorocarbons with very high vapor pressure limits the choice of suitable substances considerably. Ambiguity currently extraalveolärer about the importance of vacuolar inclusions after experimental ventilation with perfluorohexane.