Thoracic Fluid Content by Electrical Cardiometry Versus Lung Ultrasound in Mechanically Ventilated Patients

Study Overview
=================
Brief Summary
-----------------
This study aims to compare the accuracy of the total thoracic fluid content (TFC) measured by electrical cardiometry with accuracy of lung ultrasound score in prediction of weaning outcome in mechanically ventilated patients.

Detailed Description
-----------------
Weaning of patients from mechanical ventilation remains one of the critical decisions in the intensive care unit. Earlier patient weaning from mechanical ventilation is recommended to avoid complications of prolonged mechanical ventilation; however, premature weaning might result in extubation failure which is, independently, associated with poor outcomes. Screening for eligibility is the first step in the weaning process, followed by the spontaneous breathing trial (SBT). Various indices should be checked carefully before starting a spontaneous breathing trial to ensure adequate oxygenation, ventilation, and airway reflexes. However, nearly one-third of patients fail and are reintubated despite fulfillment of all the current weaning pre-requisites.

Official Title
-----------------
Thoracic Fluid Content by Electrical Cardiometry Versus Lung Ultrasound Score as Predictors of Weaning Outcome in Mechanically Ventilated Intensive Care Patients

Conditions
-----------------
Thoracic Fluid Content, Electrical Cardiometry, Lung Ultrasound, Mechanical Ventilation, Intensive Care Unit

Intervention / Treatment
-----------------
* Diagnostic Test: Thoracic fluid content by electrical cardiometry group
* Diagnostic Test: Ultrasound examination group


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: 85 mechanically ventilated patients for ≥ 48 hours Aged 18-65 years Both sex Fulfilled the weaning readiness criteria Scheduled for spontaneous breathing trial (SBT) using pressure support ventilation. Exclusion Criteria: Acute respiratory distress syndrome (ARDS) patients. Interstitial lung fibrosis. Patients with lung resection. Pulmonary embolism. Patients with fluid overload due to heart, renal or hepatic failure. Cardiac patients with ejection fraction less than 40%, cardiomyopathy, congenital or valvular heart diseases. Pneumothorax. Pleural or pericardial effusion. Pregnancy. Patients with injuries, burns, or wounds which precluded the proper application of the device electrodes or the ultrasound transducer.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
-----------------
All

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Successful weaning group<br>Criteria of weaning included resolution of the primary cause of intubation, adequate cough without excessive tracheobronchial secretions, PaO2 > 60 mmHg with positive end-expiratory pressure ≤ 8 cmH2O, fraction of inspired oxygen ≤ 0.4, respiratory rate < 30 per minute, appropriate pH for patients' baseline respiratory status, and stable cardiovascular status. | Diagnostic Test: Thoracic fluid content by electrical cardiometry group<br>* Thoracic fluid content will be measured using electrical cardiometry device (ICON ® Cardiotronics, Inc., La Jolla, CA 92307; Osyka Medical GmbH, Berlin, and Germany, model C3, Serial no: 1725303). The ICON device will be connected to four electrocardiogram electrodes which will be placed over patients' skin after cleaning with alcohol at the neck below the left ear, just above the left clavicular midpoint, and two electrodes at left mid-axillary line one at the level of the xiphoid process, and the other electrode 5 cm below this point. The thoracic fluid content will be observed for 30 s and the average of the highest and lowest values will be recorded.<br>Diagnostic Test: Ultrasound examination group<br>* The 12-region technique for lung assessment will be performed using Philips ® (CX50 - Extreme edition) equipped with phased array transducer. B-line will be defined as laser like vertical hyperechoic artefact which extends between the pleural line and the bottom of the screen and moves with respiratory movements. Two types of B-lines will be evaluated.<br>|
| Failed weaning group<br>Weaning failure will be defined as a patient need for reintubation or noninvasive ventilation within 48 h after extubation due to the presence of one or more of the following criteria: altered mental status tachypnea (respiratory rate more than 35 breaths per minute), oxygen saturation less than 90% or PaO2 less than 60 mmHg on a fraction of inspired oxygen of 40%, an apparent increase in accessory respiratory muscle activity, evident facial signs of respiratory distress and hemodynamic instability (Heart rate >140 b/min, systolic blood pressure >180 or < 90mmHg ) | Diagnostic Test: Thoracic fluid content by electrical cardiometry group<br>* Thoracic fluid content will be measured using electrical cardiometry device (ICON ® Cardiotronics, Inc., La Jolla, CA 92307; Osyka Medical GmbH, Berlin, and Germany, model C3, Serial no: 1725303). The ICON device will be connected to four electrocardiogram electrodes which will be placed over patients' skin after cleaning with alcohol at the neck below the left ear, just above the left clavicular midpoint, and two electrodes at left mid-axillary line one at the level of the xiphoid process, and the other electrode 5 cm below this point. The thoracic fluid content will be observed for 30 s and the average of the highest and lowest values will be recorded.<br>Diagnostic Test: Ultrasound examination group<br>* The 12-region technique for lung assessment will be performed using Philips ® (CX50 - Extreme edition) equipped with phased array transducer. B-line will be defined as laser like vertical hyperechoic artefact which extends between the pleural line and the bottom of the screen and moves with respiratory movements. Two types of B-lines will be evaluated.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Comparing the area under the curve (AUC) of receiver operating characteristic (ROC) for thoracic fluid content (TFC) and lung ultrasound score. | Comparing the area under the curve (AUC) of receiver operating characteristic (ROC) for thoracic fluid content (TFC) and lung ultrasound score (minimum score, normal lungs: 0; maximum score, both consolidated lungs: 36) in prediction of weaning outcome in mechanically ventilated patients. | Two days after the extubation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Prediction of weaning through rapid shallow breathing index (RSBI) | Rapid shallow breathing index (RSBI) [respiratory rate/tidal volume (in liters)] will be recorded before the initiation of spontaneous breathing trial (SBT) and before extubation. | Two days after the extubation | 
| The degree of lung compliance | Lung compliance will be recorded before initiation of spontaneous breathing trial and before extubation. It is defined as the measure of the lung's ability to stretch and expand (distensibility of elastic tissue) and is calculated using the equation (V/ΔP; where ΔV is the change in volume, and ΔP is the change in pleural pressure. | Before initiation of spontaneous breathing trial and before extubation. | 
| Cumulative fluid balance | Cumulative fluid balance at the day of spontaneous breathing trial (equals the total fluid intake minus the fluid output) will be recorded. | within 24 hours of spontaneous breathing trial |