Timed Inspiratory Effort Index, a New Diagnostic Method to Assess Endurance and Inspiratory Muscle Strength in Patients under Mechanical Ventilation

Abstract

Introduction: Mechanical ventilation is a critical component of modern intensive care medicine, but the process of discontinuing mechanical ventilation could be difficult in some cases. Several studies demonstrated that the combination of diaphragmatic inactivity and mechanical ventilation periods over than 18 hours is associated with atrophy of human diaphragm myofibers. Thus, the disuse atrophy of human diaphragm myofibers could be a major contributor for weaning failures. Indeed, its proper assessment of the respiratory muscle impairment depends on the use of appropriate tests. The predicting weaning indexes are still the most commonly used tests in clinical practice at ICUs around the world, because they are more widely known and easy to use in different diseases. Objective: The aim of the present article is to describe advantages, procedures, and clinical applicability of a new method called timed inspiratory effort index, or TIE index, to assess inspiratory muscle strength and specifically address the diagnosis of muscle fatigue in patients under mechanical ventilation. Methods: This short review about a new method to assess endurance and inspiratory muscle strength of patients with respiratory weakness and undergoing weaning from mechanical ventilation. Main recommendations: The analysis of respiratory muscle function through the TIE method translates a new feature to the intensive care fast, easy, accurate, reproducible and secure. In addition, to aid in the differential diagnosis of respiratory muscle fatigue directly predict weaning, may lead the most appropriate respiratory muscle training in prolonged weaning patients. Conclusion: In summary, nowadays, the TIE index can be considered one of the most appropriate methods to evaluate the various interactions in a critical patient under mechanical ventilation. Therefore, TIE index performance as a weaning predictor is among the best rates ever reported in literature.