AGREEMENT OF TWO METHODS FOR ASSESSING PRESSURE/TIME CURVE PROFILE (STRESS INDEX) IN ARDS
Contributo in Atti di convegno
Data di Pubblicazione:
2011
Citazione:
AGREEMENT OF TWO METHODS FOR ASSESSING PRESSURE/TIME CURVE PROFILE (STRESS INDEX) IN ARDS / Terragni, Pierpaolo; L., Mascia; A., Birocco; C., Faggiano; T., Tenaglia; G., Maiolo; J., Pernechele; E., Degiovanni; E., Viscomi; V. M., Ranieri. - In: INTENSIVE CARE MEDICINE. - ISSN 0342-4642. - 37:(2011), pp. 195-195. ( 24th ESICM Annual Congress Berlin, Germany 1-5 October 2011).
Abstract:
INTRODUCTION. Analysis of the shape of the airway pressure/time curve (Paw-t) during
constant flow mechanical ventilation (Stress Index = SI) has been used to predict mechanical
stress. The mathematical coefficient describing the shape of the Paw-t curve may therefore
identify and quantify mechanical stress during ventilation. In experimental studies, the
threshold values for SI that best discriminated lungs with and without morphological, histological
signs and biological markers of Ventilator Induced Lung Injury ranged between 0.9 and
1.1. The implementation of a SI monitoring software on ventilator would allow an easier use
and bedside access.
OBJECTIVES. We compared Stress Index values collected on the ventilator using a dedicated
software with the values obtained using experimental device.
METHODS. The experimental device (KleisTEK Engineering, Bari, Italy) measures the flow
with a pneumotacograph connected to a differential pressure transducer inserted between theY
piece of the ventilator circuit and the Endotracheal Tube (ET). The Paw is measured proximal
to ET. All variables are collected and the mean portion of Paw-t curve was analyzed trough the
algorithm of Levemberg-Marquardt. SI is represented by the b factor of the equation:
Pao=a 9 t^(b) + c. Servo-i (Maquet) have been implemented by a real time SI analysis
software using measurements of flow and Paw as performed by the ventilator.
Multiples measurements on different ventilation settings have been performed at the same time
with the two devices (Servo-i and KleisTEK) on 10 ARDS patients. Data have been compared
with the statistical analysis proposed by Bland&Altman in order to assess agreement between
two SI measurement techniques.
RESULTS. The strength of the relation between two variables is r = 0.92 (CI 0.9–0.93; p\0.0001).
CONCLUSIONS. Statistical analysis show a good correlation and agreement in the measurements
taken by the ventilator’s software than those of the reference device.
constant flow mechanical ventilation (Stress Index = SI) has been used to predict mechanical
stress. The mathematical coefficient describing the shape of the Paw-t curve may therefore
identify and quantify mechanical stress during ventilation. In experimental studies, the
threshold values for SI that best discriminated lungs with and without morphological, histological
signs and biological markers of Ventilator Induced Lung Injury ranged between 0.9 and
1.1. The implementation of a SI monitoring software on ventilator would allow an easier use
and bedside access.
OBJECTIVES. We compared Stress Index values collected on the ventilator using a dedicated
software with the values obtained using experimental device.
METHODS. The experimental device (KleisTEK Engineering, Bari, Italy) measures the flow
with a pneumotacograph connected to a differential pressure transducer inserted between theY
piece of the ventilator circuit and the Endotracheal Tube (ET). The Paw is measured proximal
to ET. All variables are collected and the mean portion of Paw-t curve was analyzed trough the
algorithm of Levemberg-Marquardt. SI is represented by the b factor of the equation:
Pao=a 9 t^(b) + c. Servo-i (Maquet) have been implemented by a real time SI analysis
software using measurements of flow and Paw as performed by the ventilator.
Multiples measurements on different ventilation settings have been performed at the same time
with the two devices (Servo-i and KleisTEK) on 10 ARDS patients. Data have been compared
with the statistical analysis proposed by Bland&Altman in order to assess agreement between
two SI measurement techniques.
RESULTS. The strength of the relation between two variables is r = 0.92 (CI 0.9–0.93; p\0.0001).
CONCLUSIONS. Statistical analysis show a good correlation and agreement in the measurements
taken by the ventilator’s software than those of the reference device.
Tipologia CRIS:
4.1 Contributo in Atti di convegno
Elenco autori:
Terragni, Pierpaolo; L., Mascia; A., Birocco; C., Faggiano; T., Tenaglia; G., Maiolo; J., Pernechele; E., Degiovanni; E., Viscomi; V. M., Ranieri
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