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Influence of Ventilatory Frequencies and Ventilator Volume/Pressure Quotients on Pulmonary Ventilation Using a Tidal Volume Ventilator
Author(s) -
Lindahl S.,
Arborelius M.,
Okmian L.
Publication year - 1979
Publication title -
acta anaesthesiologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.738
H-Index - 107
eISSN - 1399-6576
pISSN - 0001-5172
DOI - 10.1111/j.1399-6576.1979.tb01465.x
Subject(s) - medicine , tidal volume , ventilation (architecture) , mean airway pressure , anesthesia , airway obstruction , airway , peak inspiratory pressure , perfusion , volume (thermodynamics) , lung , respiratory system , cardiology , meteorology , physics , quantum mechanics
The influence of ventilatory frequency and the ventilator's “internal state of gas compression” (C vent ) on mechanics of ventilation, pulmonary ventilation, gas distribution, gas exchange and lung perfusion was studied with free airway and experimental regional airway obstruction in 10 piglets (7–12 kg b.w.), using a tidal volume ventilator. The V Dphys /V Texp ratio was greater at f = 30 than at f = 10.3 cycles/min. This could be related to a significant increase in the V Danat /V Texp ratio at f = 30, while V Dc /V Texp and V Dlav /V Texp were unchanged at both frequencies. With regional bronchial obstruction and f = 30, the regional ventilation and perfusion within the obstructed pulmonary field were reduced, compared to the values at f = 10.3 cycles/min. With C vent 20 ml/kPa, the tidal volumes were insufflated in a shorter time and with a higher initial tracheal peak pressure than with C vent 80 ml/kPa. Following bronchial obstruction, V A , RQ and Pao 2 were greater with C vent 20 than with C vent 80 ml/kPa. With C vent 20, the ventilation of the lung bases was reduced, which was compensated for by a large increase in ventilation within the apical areas of the lungs, while gas distribution within the unobstructed areas was more evenly distributed with C vent 80. Ventilation at C vent 20 showed no essential advantage over C vent 80. Only in lungs extremely difficult to ventilate and with ventilatory frequencies over 50 cycles/min could possible indications for C vent 20 be seen.