TY - JOUR
T1 - Ventilation-Perfusion Distribution Related to Different Inspiratory Flow Patterns in Experimental Lung Injury
AU - Dembinski, Rolf
AU - Henzler, Dietrich
AU - Bensberg, Ralf
AU - Prüsse, Berit
AU - Rossaint, Rolf
AU - Kuhlen, Ralf
PY - 2004/1
Y1 - 2004/1
N2 - In acute lung injury (ALI), controlled mechanical ventilation with decelerating inspiratory flow (Vdec) has been suggested to improve oxygenation when compared with constant flow (Vcon) by improving the distribution of ventilation and perfusion (VA/Q). We performed the present study to test this hypothesis in an animal model of ALI. Furthermore, the effects of combined decelerating and constant flow (Vdeco) were evaluated. Thus, 18 pigs with experimental ALI were randomized to receive mechanical ventilation with either Vcon, Vdec or a fixed combination of both flow wave forms (Vdeco) at the same tidal volume and positive end-expiratory pressure level for 6 h. Hemodynamics, gas exchange, and VA/Q distribution were determined. The results revealed an improvement of oxygenation resulting from a decrease of pulmonary shunt within each group (P < 0.05). However, blood flow to lung areas with a normal V A/Q distribution increased only during ventilation with V con (P < 0.05). Accordingly, PaO2 was higher with Vcon than with Vdec and Vdeco (P < 0.05). We conclude that contrary to the hypothesis, Vcon provides a more favorable VA/Q distribution, and hence better oxygenation, when compared with Vdec and Vdeco in this model of ALI.
AB - In acute lung injury (ALI), controlled mechanical ventilation with decelerating inspiratory flow (Vdec) has been suggested to improve oxygenation when compared with constant flow (Vcon) by improving the distribution of ventilation and perfusion (VA/Q). We performed the present study to test this hypothesis in an animal model of ALI. Furthermore, the effects of combined decelerating and constant flow (Vdeco) were evaluated. Thus, 18 pigs with experimental ALI were randomized to receive mechanical ventilation with either Vcon, Vdec or a fixed combination of both flow wave forms (Vdeco) at the same tidal volume and positive end-expiratory pressure level for 6 h. Hemodynamics, gas exchange, and VA/Q distribution were determined. The results revealed an improvement of oxygenation resulting from a decrease of pulmonary shunt within each group (P < 0.05). However, blood flow to lung areas with a normal V A/Q distribution increased only during ventilation with V con (P < 0.05). Accordingly, PaO2 was higher with Vcon than with Vdec and Vdeco (P < 0.05). We conclude that contrary to the hypothesis, Vcon provides a more favorable VA/Q distribution, and hence better oxygenation, when compared with Vdec and Vdeco in this model of ALI.
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U2 - 10.1213/01.ANE.0000090319.21491.91
DO - 10.1213/01.ANE.0000090319.21491.91
M3 - Article
C2 - 14693621
AN - SCOPUS:0346102650
SN - 0003-2999
VL - 98
SP - 211
EP - 219
JO - Anesthesia and Analgesia
JF - Anesthesia and Analgesia
IS - 1
ER -