Hemodynamic Monitoring and Correlation Between Electrical Cardiometry and Esophageal Doppler in Patients Undergoing Major Abdominal Surgery
Condition: Electrical Cardiometry VS Esophageal Doppler
Study type: Observational [Patient Registry]

Summary: 
      The aim of this study is to correlate hemodynamic monitoring between noninvasive Electrical
      Cardiometry and minimally invasive Esophageal Doppler in patients undergoing major abdominal
      surgery
    

Detailed description: 
      Cardiac output (CO) and Stroke Volume (SV) can be used as markers for global cardiovascular
      functions and can assess fluid responsiveness to ensure adequate tissue perfusion which is
      one of the essential concerns of anesthestists and intensivists The gold standard is the
      thermodilution procedure by pulmonary artery catheter (PAC), yet, cannot be considered as a
      routine owing to potential difficulty and virtual complications The development of safe,
      simple, minimally invasive or non-invasive techniques which estimate CO, SV and systemic
      vascular resistance (SVR) without invasive intravascular catheterization or dye injection is
      important for clinical decision-making and research in anesthesia and critical care medicine
      Echocardiography in comparison with other Doppler modalities is a potent diagnostic mean that
      has the superiority above the traditional PAC for both diagnostic precision and rapidity
      However, the use of echocardiography needs good training and relatively expensive. Another
      ultrasound based device is Esophageal Doppler(ED) which looks more suitable for prolonged
      hemodynamic monitoring. This technique is minimally invasive which calculates the blood flow
      velocity in descending aorta and can determine SV and CO with sound trustworthiness. Such
      technique needs less training than standard echocardiography or PAC Thoracic Electric
      Bioimpedance (TEB) is a noninvasive monitoring which correlates differences in thoracic
      electrical conductivity to thoracic aortic blood volume and flow. It is a simple method for
      detection of SV, CO, contractility, SVR, and thoracic fluid content (TFC) for continuous
      monitoring. The results of previous studies comparing impedance cardiography with thermo
      dilution and other methods like transoesophageal echocardiography (TEE) have been largely
      inconclusive which may referred to higher thorax fluid content and consequently higher
      conductivity after surgical procedure To overcome these problems, upgraded computer equipment
      and advanced algorithms are used in the newer model; electrical cardiometry (EC), that
      interprets the maximum changes in TEB and can calculate CO accurately in adults and neonates
      Although other study compared between two devices in patients undergoing major abdominal and
      pelvic surgeries , but the sample size was small rather than our study , also it included
      laparoscopic surgeries which affect hemodynamics (blood pressure , heart rate and other
      cardiac parameters ) in such points . In addition investigators used the old version of
      thoracic bio-impedance (NICOM) which is different from our device as we will us (ICON) , Like
      another study comparing between two devices used also the old version of thoracic
      bio-impedance and didn't specify the type of surgery at which the study was done . There are
      also other studies comparing the two devices one of them in paediatrics undergoing kasai
      operation and the second in patients during liver transplantation , these two studies contain
      two types of patients not included in the present study .
    

Intervention name(s): Esophageal doppler
Intervention type(s): Diagnostic Test
Intervention description(s): It is a prospective observational clinical study to correlate hemodynamic monitoring between non-invasive Electrical Cardiometry and minimally invasive Esophageal Doppler during major abdominal surgery.
Other intervention name(s): Electrical cardiometry
Observational model: Case-Control
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Demographic data, hemodynamic parameters as heart rate (HR), and mean arterial blood
        pressure (MAP), and urine output will be registered.

        Cardiac data derived from EC and ED including: CO ,cardiac index( CI), SV, stroke volume
        index( SVI),systemic vasculare resistance (SVR), and oxygen delivery index (DO2I) will be
        also recorded.

        Cardiac data will be recorded at the following time:

          1. T1 baseline: prior to skin incision.

          2. T2: one hour after induction.

          3. T3: half an hour after organ resection.

          4. T4: at the end of surgical procedure. During arrhythmias or hemodynamic instability,
             measurements will not be recorded.

        After the end of surgery, muscle relaxation will be reversed with 0.05 mg/kg neostigmine
        and 0.02 mg/kg atropine. Postoperative pain relief will be achieved by intravenous
        administration of 1mg/kg mepridine and 1gm acetaminophen every 12 hours.