PCV ( engl. Biphasic Positive Airway Pressure) is a ventilation mode with two different pressure levels that are both controlled as well as a supported or optimized, unobstructed in each breathing phase, spontaneous breathing of patients in the intensive care and pneumology allows and from the CPAP Ventilation was developed. BIPAP ventilation corresponds to pressure-controlled ventilation with an inspiration-expiration ratio of 1: 2, combined with CPAP with a PEEP that changes between two levels. In contrast to pure CPAP ventilation, the second, lower pressure is applied during exhalation, which makes it easier to exhale.
BiPAP (English Bilevel Positive Airway Pressure ) must be distinguished from BIPAP , the form of ventilation used in intensive care medicine . BiPAP was developed for non-invasive home ventilation of patients with sleep apnea .
BIPAP is pressure-controlled ventilation that allows the patient to breathe independently in every phase of ventilation. The ventilator alternately generates high pressure to inhale and lower pressure to exhale. The lower pressure level is called PEEP (positive end-expiratory pressure). This change is controlled by defining the breathing rate and two time periods for the upper (T high) and the lower (T low) pressure level. The patient will notice the higher and lower back pressure at both levels.
Ideally, BIPAP should be able to achieve ventilation adapted to the patient's varying natural breathing without having to switch the ventilation mode during the entire ventilation period. BIPAP therefore covers the entire spectrum from controlled ventilation to spontaneous breathing . The patient's work of breathing is never prevented.
- Respiratory rate
- upper pressure p insp
- lower pressure PEEP
- Duration of the inspiration time (Evita 2 dura, Evita 4, Evita XL, Elisa, Sonata) or duration of the two pressure phases (T1 = P insp, or T2 = PEEP), whereby the respiratory rate results from the added times of these pressure phases (Evita , Elisa, Sonata).
- FiO 2 : oxygen fraction in the breathing gas mixture.
- Pressure rise time or ramp (Evita 2 dura, Evita 4, Evita XL, Elisa, Sonata): the time from the beginning of inhalation ( inspiration ) to reaching the p insp
- the patient's own breathing rate
- Minute ventilation and spontaneous minute ventilation
- Tidal volume inspiratory (when inhaling) and expiratory (when exhaling), also called tidal volume
- Oxygen saturation
- Blood gases
- Stress parameters such as blood pressure , pulse , sweating and restlessness
Since the procedure was developed by M. Baum and H. Benzer in 1989 , BIPAP has become one of the standard procedures in intensive therapy. In the classic ventilation modes, machine strokes are synchronized with spontaneous breaths. Patients tolerated mandatory breaths only with calming medication , spontaneous breaths were sometimes interrupted by mandatory breaths.
Terms such as BiPhase, BiLevel, BiVent and others are used synonymously with BIPAP.
The term BiPAP is protected as a US trademark by Respironics, Inc. Other companies that produce ventilators (including Dräger ) must therefore either conclude license agreements with Respironics or use other names for this form of ventilation.
- H. Benzer: Therapy of respiratory failure. In: J. Kilian, H. Benzer, FW Ahnefeld (ed.): Basic principles of ventilation. Springer, Berlin a. a. 1991, ISBN 3-540-53078-9 , 2nd, unaltered edition, ibid 1994, ISBN 3-540-57904-4 , pp. 215-278, especially pp. 251-259.
- H. Benzer: Therapy of respiratory failure. 1991 (1994), p. 251.
- H. Benzer: Therapy of respiratory failure. 1991 (1994), p. 252 f.
- Larsen, Reinhard: Ventilation: Basics and Practice, 2nd edition. Berlin 1999, pp. 380-381.