Clinical Characteristics, Respiratory Functional Parameters, and Outcome of a Two-Hour T-Piece Trial in Patients Weaning from Mechanical Ventilation

Abstract

The discrepancy in results from different studies regarding outcome of weaning from mechanical ventilation may be due to several factors such as the differences in patient populations and weaning indexes used. In order to analyze the clinical characteristics and weaning indexes in patients undergoing a 2-h T-piece weaning trial and the relationship between the etiology of acute respiratory failure (ARF) and the outcome of this weaning trial, we prospectively studied 217 patients receiving mechanical ventilation who met standard weaning criteria. Successful weaning occurred in 57.6% (125 of 217) of patients: 13 of 33 (39.4%) patients with chronic obstructive pulmonary disease (COPD), 27 of 46 (58.7%) neurologic patients, and 85 of 138 (61.6%) patients with ARF. Ventilatory support was reinstituted in 31.8% (69 of 217) patients: 20 of 33 (60.6%) of patients with COPD, four of 46 (8.7%) neurologic patients, and 45 of 138 (32.6%) patients with ARF (p < 0.001). Reintubation was required in 23 of 148 (15.5%) patients: 15 of 42 (35.7%) neurologic patients, and eight of 93 (8.6%) patients with ARF, whereas no patient with COPD was reintubated (p < 0.001). Using a discriminant analysis, the following variables were selected as the best predictors of outcome: (1) in the whole population, days of mechanical ventilation before weaning trial (DMV), frequency-to-tidal volume ratio (f/VT), maximal inspiratory pressure (MIP), airway occlusion pressure (P0.1), maximal expiratory pressure (MEP), and vital capacity (VC); (2) in patients with ARF, DMV, P0.1/MIP, MIP, f/VT, and age; (3) in patients with COPD, f/VT, P0.1, P0.1/MIP, MIP, age, and DMV; (4) in neurologic patients, MIP, MEP, and f/VT.P0.1. Using these predictors, 74.6% of the whole population, 76.1% of patients with ARF, 93.9% of patients with COPD, and 73.9% of neurologic patients were accurately classified as weaning successes or failures. The highest rate of reintubation occurred in neurologic patients. In this group, the ability to cough and clear respiratory secretions, objectively reflected by MEP, may help in clinical decision-making.

Implications of extubation failure and prolonged mechanical ventilation in the postoperative period following elective intracranial surgery

“…Published November 28, 2011 Extubation failure is defined as the reinstitution of respiratory support from 24 to 72 h following the scheduled extubation. This condition occurs in 2 to 25% of extubated patients (1)(2)(3). Extubation failure increases the incidence of mortality, pneumonia, number of days in the intensive care unit (ICU) and hospital, time spent on mechanical ventilation (MV), hospital costs, and the need for a tracheostomy (4)(5).…”

“…A number of studies have demonstrated an increased incidence of reintuba-tion, pneumonia, and prolonged MV among such patients (2)(3)(4)(5)7,9,14,15).…”

Frequência respiratória como preditor de falha de desmame da ventilação mecânica

“…The current predictive indices do not distinguish patients who, after a satisfactory SBT, will be reintubated from those who will be successfully extubated 3,19 .…”

“…Extubation failure (EF) was associated with higher mortality rate (70%). Several studies show that EF is associated with increased mortality 2,3,6,[18][19][20] . According to Epstein et al 6 , the mortality rate in patients with EF was 43% compared to 12% among those with weaning success (p < 0.0001).…”

Predictors of weaning outcome in chronic obstructive pulmonary disease patients

“…Clearly, the present threshold values for weaning indices need to be tested prospectively in future studies in COPD patients, which should also take into account the effect of duration of mechanical ventilation on weaning outcome [1]. However, the results of a recent study of VALLERDU Á et al [16] suggest that the present threshold value for fR/VT, which is lower than that proposed by YANG and TOBIN [1] (84 versus 100 breaths . min -1 .…”