当前位置： SCI文献检索 > AMERICAN JOURNAL OF RESPIRATORY AND CRITICAL CARE MEDICINE期刊下所有文献 > The tension-time index and the frequency/tidal volume ratio are the major pathophysiologic determinants of weaning failure and success.

The tension-time index and the frequency/tidal volume ratio are the major pathophysiologic determinants of weaning failure and success.

Abstract：

:We have previously shown (Am. J. Respir. Crit. Care Med. 1995;152:1248-1255) that in patients needing mechanical ventilation, the load imposed on the inspiratory muscles is excessive relative to their neuromuscular capacity. We have therefore hypothesized that weaning failure may occur because at the time of the trial of spontaneous breathing there is insufficient reduction of the inspiratory load. We therefore prospectively studied patients who initially had failed to wean from mechanical ventilation (F) but had successful weaning (S) on a later occasion. Compared with S, during F patients had greater intrinsic positive end-expiratory pressure (6. 10 +/- 2.45 versus 3.83 +/- 2.69 cm H2O), dynamic hyperinflation (327 +/- 180 versus 213 +/- 175 ml), total resistance (Rmax, 14.14 +/- 4.95 versus 11.19 +/- 4.01 cm H2O/L/s), ratio of mean to maximum inspiratory pressure (0.46 +/- 0.1 versus 0.31 +/- 0.08), tension time index (TTI, 0.162 +/- 0.032 versus 0.102 +/- 0.023) and power (315 +/- 153 versus 215 +/- 75 cm H2O x L/min), less maximum inspiratory pressure (42.3 +/- 12.7 versus 53.8 +/- 15.1 cm H2O), and a breathing pattern that was more rapid and shallow (ratio of frequency to tidal volume, f/VT 98 +/- 38 versus 62 +/- 21 breaths/min/L). To clarify on pathophysiologic grounds what determines inability to wean from mechanical ventilation, we performed multiple logistic regression analysis with the weaning outcome as the dependent variable. The TTI and the f/VT ratio were the only significant variables in the model. We conclude that the TTI and the f/VT are the major pathophysiologic determinants underlying the transition from weaning failure to weaning success.

journal_name

Am J Respir Crit Care Med

journal_title

American journal of respiratory and critical care medicine

authors

Vassilakopoulos T,Zakynthinos S,Roussos C

doi

10.1164/ajrccm.158.2.9710084

subject

Has Abstract

pub_date

1998-08-01 00:00:00

pages

378-85

issue

eissn

1073-449X

issn

1535-4970

journal_volume

158

pub_type

杂志文章

在线工具

The tension-time index and the frequency/tidal volume ratio are the major pathophysiologic determinants of weaning failure and success.