Diaphragmatic dysfunction in Intensive Care Unit: physiopathology, diagnosis and treatment

Abstract

The diaphragm is particularly involved in critically ill patients and diaphragm dysfunction is associated with a heavy burden in terms of morbidity and mortality. Beyond the well-established deleterious effect of mechanical ventilation on diaphragmatic function, other risk factors (notably sepsis) are involved. Therefore, the term “ventilator induced diaphragm dysfunction” might be substituted by the term “intensive care unit associated diaphragm weakness”. The prevalence of diaphragmatic dysfunction is high since it is encountered in 60% of the patients upon admission and up to 80% at later stages. In routine, diaphragm dysfunction can be suspected at the time of liberation from mechanical ventilation, especially in case of repeated weaning attempt failures. The diagnosis is based on the evaluation of the generating pressure capacity of the diaphragm, but such an evaluation is not performed routinely. Therefore, diaphragm ultrasound which allows a non-invasive approach and a real-time examination of diaphragm displacement and diaphragm thickening, can be viewed as the preferred technique, but acquisition modalities and validity remain to be determined. Nowadays, there is no curative treatment of diaphragm dysfunction. Promotion of spontaneous inspiratory efforts maintained within physiological ranges constitutes the best strategy.