This study aims to evaluate clinical application of electrical cardiometry EC in patients admitted to respiratory ICU. It will evaluate the reliability of EC in assessment of hemodynamic changes in these patients. It will estimate the effect of mechanical ventilation either invasive or non invasive hemodynamic parameters in patients admitted to ICU with respirator disorders

Mechanical ventilation MV is a life saving intervention in intensive care units. Access to lower airways is achieved either through tracheostomy or endotracheal intubation. More recently non invasive ventilation NIV techniques were introduced that do not require an endotracheal airway but using patient ventilator interfaces in the form of facial masks have been designed.

The haemodynamic consequences of MV are multiple and complex and may affect all the determinants of cardiac performance such as heart rate.preload.contractility .and afterload. These consequences affect both right and left ventricle and are also related to the biventricular interdependence .

Mechanically ventilated patients are considered Critically ill.and they are often hemodynamically unstable or at risk of becoming unstable owing to hypovolemia. cardiac dysfunction. or alterations of vasomotor function. leading to organ dysfunction.deterioration into multiorgan failure .and eventually death .Socardiopulmonary monitoring is crucial to ensure successful evaluation and management of these patients . With hemodynamic monitoring. The investigators aim to guide our medical management to prevent or treat organ failure and improve the outcomes of our patients. Therapeutic measures may include fluid resuscitation.vasopressors or inotropic agents .

Hemodynamic monitoring can be done by different techniques which ranges from invasive to less invasive and completely noninvasive methods to assess Cardiac output BP oxygen saturation. Some hemodynamic parameters are easy to be measured like blood pressure and heart rate but do not give a complete picture of a patient's hemodynamics .

Measuring CO and its components preload afterload and contractility will tell us if there is ongoing need for fluid resuscitation vasopressors or inotropic agents . It can be used as a diagnostic tool to determine the type of shock hypovolemic cardiogenic obstructive or distributive according to the hemodynamic profile .

Traditional invasive methods incorporate thermodilution which requires that a transvenous catheter pushed forward to the pulmonary artery PAC Swan Ganz catheter. Other invasive methods require an arterial line to measure the blood pressure signal waveform . Due to the invasiveness the associated risk invasive methods are usually employed at an advanced stage of illness .

Non invasive hemodynamic methods have less complications. Recent techniques advances led to continuous non invasive monitoring that allow for data obtaining at bedside of critically ill patients in ICU these advances help to monitor changes and allow for management before complications .

A portable Electro Cardiometer ICON Osypka Medical GmbH Berlin Germany is a Hand held Portable battery operated non invasive cardiometer for continuous measurement of different hemodynamic parameters stroke volume SV cardiac output CO contractility fluid status and oxygen status in neonate children or adults Applied to the patients through 4 ECG electrodes. It is based on the measurement of changes in thoracic impedance to an electrical current that is produced by fluctuations in thoracic blood volume with each cardiac cycle .

Newer generation Thoracic Electrical Bioimpedence methods have overcome some of the limitations that was present in old models by having faster signal processing better signal filters improved ECG triggering and respiratory filtering .

Up till now there is limited research about ICON device and it's reliability in monitoring hemodynamics specially in respiratory ICU patients.

Inclusion Criteria:

• All patients admitted to respiratory intensive care unit (ICU) among both sexes Age >18 years Old.

Exclusion Criteria:

1. Patients less than 18 years old .
2. Pregnant women.
3. Patients with injuries, burns, or wounds which precluded the proper application of the device electrodes will be also excluded from the study.
4. those with uncontrollable fits.
5. Patients who need electrical direct current (DC) shock.
6. Patients who refuse to participate in the study.

Patients admitted to respiratory intensive care unit (ICU)