Diaphragmatic Ultrasound as a Guide Tool During Weaning From Mechanical Ventilation

Diaphragmatic Ultrasound as a Guide Tool During Weaning From Mechanical Ventilation (Randomized Controlled Trial)

To assess value of adding ultrasound derived variables to the usual parameters on success rate of weaning from mechanical ventilation in critically ill patients and to validate sensitivity and specificity of ultrasound derived variables (thickening fraction /diaphragmatic excursion)

Difficult weaning from mechanical ventilation (MV) is a common problem in critically ill patients. Many parameters have been developed to aid weaning from MV such as P/F ratio (PO2/FiO2) and rapid shallow breathing index (respiratory rate/tidal volume), however, sensitivity and specificity for most variables are still variable in literature.

Multiple studies have found that patients tolerantof SBTs were found to have successful discontinuationsat least 77% of the time.

Causes of weaning failure include: airway and lung dysfunction, brain dysfunction, cardiac dysfunction, diaphragm dysfunction, and endocrine dysfunction .

Diaphragmatic dysfunction is a common cause of weaning failure , however most of the traditional methods used for evaluation of diaphragmatic function (fluoroscopy, trans-diaphragmatic pressure measurement) are invasive and not available.

Ultrasound assessment of diaphragmatic function has been developed recently providing an easy and safe method for evaluation of diaphragmatic excursion and thickening.

It was found that weaning failure (Re-intubation within 48 hours) was associated with diaphragmatic excursion <1 cm and thickening fraction <28% several studies reported the value of diaphragmatic ultrasound to predict weaning failure ,however no one of them used diaphragmatic ultrasound to guide weaning.

previous studies showed that failure rate of weaning from mechanical ventilation was 27% ,however failure rate in our department was 43% adding ultrasound derived values aims for improving success rate of weaning from mechanical ventilation.

Inclusion Criteria:

• Critically ill patients intubated for more than 48 hours who are ready for weaning

Exclusion Criteria:

• • Age < 18 years

  • surgical dressings over the right lower rib cage which would preclude ultrasound examination
  • patients with chest trauma, thoracotomy, diaphragmatic paralysis, diaphragmatic injury and diaphragmatic surgery
  • patients with neuromuscular diseases ( myasthenia gravis ,Muscular dystrophies ,Multiple sclerosis and Amyotrophic lateral sclerosis)