Trend of Maximal Inspiratory Pressure in Mechanically Ventilated Patients: Predictors

Abstract

Caruso P, Carnieli DS, Kagohara KH, Anciães A, Segarra JS, Deheinzelin D. Trend of maximal inspiratory pressure in mechanically ventilated patients: predictors. Clinics. 2008;63(1):33-8. INTRODUCTION:It is known that mechanical ventilation and many of its features may affect the evolution of inspiratory muscle strength during ventilation. However, this evolution has not been described, nor have its predictors been studied. In addition, a probable parallel between inspiratory and limb muscle strength evolution has not been investigated. OBJECTIVE: To describe the variation over time of maximal inspiratory pressure during mechanical ventilation and its predictors. We also studied the possible relationship between the evolution of maximal inspiratory pressure and limb muscle strength. METHODS: A prospective observational study was performed in consecutive patients submitted to mechanical ventilation for > 72 hours. The maximal inspiratory pressure trend was evaluated by the linear regression of the daily maximal inspiratory pressure and a logistic regression analysis was used to look for independent maximal inspiratory pressure trend predictors. Limb muscle strength was evaluated using the Medical Research Council score. RESULTS: One hundred and sixteen patients were studied, forty-four of whom (37.9%) presented a decrease in maximal inspiratory pressure over time. The members of the group in which maximal inspiratory pressure decreased underwent deeper sedation, spent less time in pressure support ventilation and were extubated less frequently. The only independent predictor of the maximal inspiratory pressure trend was the level of sedation (OR=1.55, 95% CI 1.003 -2.408; p = 0.049). There was no relationship between the maximal inspiratory pressure trend and limb muscle strength. CONCLUSIONS: Around forty percent of the mechanically ventilated patients had a decreased maximal inspiratory pressure during mechanical ventilation, which was independently associated with deeper levels of sedation. There was no relationship between the evolution of maximal inspiratory pressure and the muscular strength of the limb.

Within-Breath Analysis of Respiratory Mechanics in Asthmatic Patients by Forced Oscillation

“…The real-time identification of alterations in respiratory mechanics is of great interest in both physiopathology studies and in the diagnosis of breathing diseases 1,2. This analysis allows a detailed evaluation of the different phases of the breathing cycle, and it can be made using the interruption technique.…”

Influência da mobilização precoce na força muscular periférica e respiratória em pacientes críticos

“…Some authors have demonstrated that early mobilization is an important component in the care of critically ill patients who require prolonged MV; it facilitates improved lung and muscle function, accelerates the recovery process, and decreases T MV and T ICU ,. (1,7,22,(26)(27)(28)(29)(30) The present study has several limitations. First, there was a difference between the initial values of PImax between the CPTG and the EMG.…”

Análise da força muscular expiratória e respiração espontânea de indivíduos em ventilação mecânica: estudo transversal

“…The fault in the DVM has as one of the main causes the respiratory muscle weakness [10][11][12] , commonly evaluated by the maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) 13 ; however, there are only a few studies focusing on the function of expiratory muscles at weaning, whose focus in generally on the inspiratory ones, in particular on the diaphragm [14][15][16] . Thus, reviews and guidelines do not mention the MEP and the expiratory muscle training 10,12,17 .…”