Cuirass ventilation

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The cuirass ventilation ( cuirass ventilation ; English biphasic cuirass ventilation , BCV) is an aid for home ventilation or respiratory support. Like the historic iron lung , it is a non-invasive procedure. The thorax is expanded ( non-invasive negative pressure ventilation , NINPV) by external negative pressure in a cuirass encompassing the chest (French cuirasse " leather armor ", from cuir "leather" ).

application areas

Cuirass ventilation is not a procedure used in acute intensive care medicine , but is used for long-term respiratory support in patients who cannot guarantee adequate ventilation of their lungs without aids. The principle of external negative pressure ventilation represents an alternative to the non-invasive mask ventilation with positive ventilation pressures. It is used to a certain extent, for example, in spinal muscular atrophy . For structural reasons, this breathing support is a therapy option, especially in childhood. However, it is not a routine procedure; mask ventilation is also much more widespread here. A comparison of the two methods is not possible due to the study situation.

External negative pressure ventilation has the advantage that it is based on physiological breathing, i.e. it does not blow air into the lungs by means of positive pressure, but creates negative pressure in the lungs by expanding the thorax, which causes air to passively flow into the lungs. Furthermore, the nose and throat are freely accessible during ventilation, so that z. B. the suction of mucus is easily possible. Disadvantages are the volume of the compressor, which sometimes reaches 50 dB, as well as pressure points on the thorax and abdomen caused by the cuirass.

Structure of the device

The cuirass ventilation is practiced using a type of vest made of a transparent, relatively elastic material. It surrounds the patient's chest and partially the abdomen and closes the edges as tightly as possible so that no major leaks occur. Air can be pumped into and out of the vest via a hose that is connected to the vest. A compressor connected to the hose takes over this pumping function.

functionality

The cuirass ventilation can be carried out in different modes. The compressor can either create a constant negative pressure in the cuirass; or a negative pressure that alternates cyclically with ambient pressure; or alternating negative and positive pressure for inspiration and expiration support. If there is overpressure in the cuirass, the chest is compressed, if it is underpressure it expands. The changes in the volume of the chest and lungs that are brought about in this way lead to inhalation and exhalation and thus ventilation of the lungs. A connected control unit can be used to set various parameters, the most important of which are the pressure limits for inspiration / expiration and the breathing rate. The vest can be used almost permanently or, for example, only during sleep phases, depending on requirements. Often, using the fan at night is sufficient to prevent nocturnal apneas and the associated wake-up reactions ( arousals ).

Individual evidence

  1. a b case report , annual conference of the Saxon-Thuringian Society for Pediatric and Adolescent Medicine and Pediatric Surgery, 4th – 5th April 2003 in Dresden
  2. a b J. M. Shneerson: Assisted ventilation. 5. Non-invasive and domiciliary ventilation: negative pressure techniques. In: Thorax. Volume 46, No. 2, February 1991, pp. 131-135. PMID 2014494
  3. ^ R. Larsen, T. Ziegenfuß : Ventilation: Basics and practice. Springer, Heidelberg 2009, ISBN 978-3-540-88811-6 , pp. 245 f. (books.google.de)

literature

  • Heinrich Becker, Hilmar Burchardi, Bernd Schönhofer (eds.): Non-invasive ventilation. Thieme, Stuttgart 2005, ISBN 3-13-137852-2 , p. 172.