Cargando…

Alternative protocol to initiate high-frequency oscillatory ventilation: an experimental study

INTRODUCTION: The objective was to study the effects of a novel lung volume optimization procedure (LVOP) using high-frequency oscillatory ventilation (HFOV) upon gas exchange, the transpulmonary pressure (TPP), and hemodynamics in a porcine model of surfactant depletion. METHODS: With institutional...

Descripción completa

Detalles Bibliográficos
Autores principales: Karmrodt, Jens, David, Matthias, Yuan, Shying, Markstaller, Klaus
Formato: Texto
Lenguaje:English
Publicado: BioMed Central 2006
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1751068/
https://www.ncbi.nlm.nih.gov/pubmed/16999870
http://dx.doi.org/10.1186/cc5052
_version_ 1782131417669435392
author Karmrodt, Jens
David, Matthias
Yuan, Shying
Markstaller, Klaus
author_facet Karmrodt, Jens
David, Matthias
Yuan, Shying
Markstaller, Klaus
author_sort Karmrodt, Jens
collection PubMed
description INTRODUCTION: The objective was to study the effects of a novel lung volume optimization procedure (LVOP) using high-frequency oscillatory ventilation (HFOV) upon gas exchange, the transpulmonary pressure (TPP), and hemodynamics in a porcine model of surfactant depletion. METHODS: With institutional review board approval, the hemodynamics, blood gas analysis, TPP, and pulmonary shunt fraction were obtained in six anesthetized pigs before and after saline lung lavage. Measurements were acquired during pressure-controlled ventilation (PCV) prior to and after lung damage, and during a LVOP with HFOV. The LVOP comprised a recruitment maneuver with a continuous distending pressure (CDP) of 45 mbar for 2.5 minutes, and a stepwise decrease of the CDP (5 mbar every 5 minute) from 45 to 20 mbar. The TPP level was identified during the decrease in CDP, which assured a change of the P(a)O(2)/F(I)O(2 )ratio < 25% compared with maximum lung recruitment at CDP of 45 mbar (CDP45). Data are presented as the median (25th–75th percentile); differences between measurements are determined by Friedman repeated-measures analysis on ranks and multiple comparisons (Tukey's test). The level of significance was set at P < 0.05. RESULTS: The PaO(2)/FiO(2 )ratio increased from 99.1 (56.2–128) Torr at PCV post-lavage to 621 (619.4–660.3) Torr at CDP45 (CDP45) (P < 0.031). The pulmonary shunt fraction decreased from 51.8% (49–55%) at PCV post-lavage to 1.03% (0.4–3%) at CDP45 (P < 0.05). The cardiac output and stroke volume decreased at CDP45 (P < 0.05) compared with PCV, whereas the heart rate, mean arterial pressure, and intrathoracic blood volume remained unchanged. A TPP of 25.5 (17–32) mbar was required to preserve a difference in P(a)O(2)/F(I)O(2 )ratio < 25% related to CDP45; this TPP was achieved at a CDP of 35 (25–40) mbar. CONCLUSION: This HFOV protocol is easy to perform, and allows a fast determination of an adequate TPP level that preserves oxygenation. Systemic hemodynamics, as a measure of safety, showed no relevant deterioration throughout the procedure.
format Text
id pubmed-1751068
institution National Center for Biotechnology Information
language English
publishDate 2006
publisher BioMed Central
record_format MEDLINE/PubMed
spelling pubmed-17510682006-12-27 Alternative protocol to initiate high-frequency oscillatory ventilation: an experimental study Karmrodt, Jens David, Matthias Yuan, Shying Markstaller, Klaus Crit Care Research INTRODUCTION: The objective was to study the effects of a novel lung volume optimization procedure (LVOP) using high-frequency oscillatory ventilation (HFOV) upon gas exchange, the transpulmonary pressure (TPP), and hemodynamics in a porcine model of surfactant depletion. METHODS: With institutional review board approval, the hemodynamics, blood gas analysis, TPP, and pulmonary shunt fraction were obtained in six anesthetized pigs before and after saline lung lavage. Measurements were acquired during pressure-controlled ventilation (PCV) prior to and after lung damage, and during a LVOP with HFOV. The LVOP comprised a recruitment maneuver with a continuous distending pressure (CDP) of 45 mbar for 2.5 minutes, and a stepwise decrease of the CDP (5 mbar every 5 minute) from 45 to 20 mbar. The TPP level was identified during the decrease in CDP, which assured a change of the P(a)O(2)/F(I)O(2 )ratio < 25% compared with maximum lung recruitment at CDP of 45 mbar (CDP45). Data are presented as the median (25th–75th percentile); differences between measurements are determined by Friedman repeated-measures analysis on ranks and multiple comparisons (Tukey's test). The level of significance was set at P < 0.05. RESULTS: The PaO(2)/FiO(2 )ratio increased from 99.1 (56.2–128) Torr at PCV post-lavage to 621 (619.4–660.3) Torr at CDP45 (CDP45) (P < 0.031). The pulmonary shunt fraction decreased from 51.8% (49–55%) at PCV post-lavage to 1.03% (0.4–3%) at CDP45 (P < 0.05). The cardiac output and stroke volume decreased at CDP45 (P < 0.05) compared with PCV, whereas the heart rate, mean arterial pressure, and intrathoracic blood volume remained unchanged. A TPP of 25.5 (17–32) mbar was required to preserve a difference in P(a)O(2)/F(I)O(2 )ratio < 25% related to CDP45; this TPP was achieved at a CDP of 35 (25–40) mbar. CONCLUSION: This HFOV protocol is easy to perform, and allows a fast determination of an adequate TPP level that preserves oxygenation. Systemic hemodynamics, as a measure of safety, showed no relevant deterioration throughout the procedure. BioMed Central 2006 2006-09-25 /pmc/articles/PMC1751068/ /pubmed/16999870 http://dx.doi.org/10.1186/cc5052 Text en Copyright © 2006 Karmrodt et al.; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an open access article distributed under the terms of the Creative Commons Attribution License ( (http://creativecommons.org/licenses/by/2.0) ), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research
Karmrodt, Jens
David, Matthias
Yuan, Shying
Markstaller, Klaus
Alternative protocol to initiate high-frequency oscillatory ventilation: an experimental study
title Alternative protocol to initiate high-frequency oscillatory ventilation: an experimental study
title_full Alternative protocol to initiate high-frequency oscillatory ventilation: an experimental study
title_fullStr Alternative protocol to initiate high-frequency oscillatory ventilation: an experimental study
title_full_unstemmed Alternative protocol to initiate high-frequency oscillatory ventilation: an experimental study
title_short Alternative protocol to initiate high-frequency oscillatory ventilation: an experimental study
title_sort alternative protocol to initiate high-frequency oscillatory ventilation: an experimental study
topic Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1751068/
https://www.ncbi.nlm.nih.gov/pubmed/16999870
http://dx.doi.org/10.1186/cc5052
work_keys_str_mv AT karmrodtjens alternativeprotocoltoinitiatehighfrequencyoscillatoryventilationanexperimentalstudy
AT davidmatthias alternativeprotocoltoinitiatehighfrequencyoscillatoryventilationanexperimentalstudy
AT yuanshying alternativeprotocoltoinitiatehighfrequencyoscillatoryventilationanexperimentalstudy
AT markstallerklaus alternativeprotocoltoinitiatehighfrequencyoscillatoryventilationanexperimentalstudy