Ultrasound of Diaphragmatic Musculature in Mechanically Ventilated Patients.

Ultrasound Evaluation of the Diaphragmatic Musculature in Mechanically Ventilated Patients in Intensive Care Unit

Muscle weakness and dysfunction are common problems in patients hospitalized in the intensive care unit. Respiratory muscle weakness during mechanical ventilation was recognized a state of muscular fatigue. The terminology 'ventilator-induced diaphragmatic dysfunction' (VIDD) originally was introduced to describe these effects of mechanical ventilation and respiratory muscle unloading on the diaphragm.

Ultrasonography is becoming increasingly popular management of ICU patients. It is a simple, non-invasive and safe imaging technique that can be used for the assessment of distinctive diaphragmatic characteristics.

Parameters such as amplitude and velocity of contraction, which can be assessed using M-mode ultrasound. In addition, static and dynamic (thickening fraction during inspiration) diaphragmatic thickness can also be measured by ultrasonography.

The aim of this study is to evaluate the effect of different modes of mechanical ventilation on diaphragmatic thickness using ultrasonography and the relation between time of mechanical ventilation and the percentage of change of diaphragmatic thickness in head trauma patients subjected for mechanical ventilation (>2 days) intensive care unit.

Modes of ventilation will be used in the study are:

• Pressure controlled mandatory ventilation mode (P-CMV).
• Pressure synchronized intermittent mandatory ventilation mode (P-SIMV).
• Pressure support (PS) mode.

Inclusion Criteria:

• American Society of Anesthesiologists (ASA) physical status grades I and II.
• Glasgow coma scale < 8.
• Selections of patients need mechanical ventilation (>2 days).
• Head trauma patients.

Exclusion Criteria:

• History of diaphragmatic disease
• Neuromuscular disease
• Anatomical malformation of the diaphragm.
• Patients with chest disease
• Diabetic patients.
• Chest trauma
• Chest malignancy.
• Use of non-invasive ventilation before the start of invasive ventilation.
• Selection of patients of short period of mechanical ventilation (< 2 days).
• Hemodynamic instability.
• Morbid obesity (body mass index > 40 kg/m2).