Validation of Electrical Cardiometry in Resuscitation of Patients Undergoing Orthotopic Liver Transplantation

Induction of anaesthesia will be by using propofol (2mg.kg) IV, fentanyl (1-2μg. kg) IV and atracurium (0.5 mg.kg) IV. Anaesthesia will be maintained with Sevoflurane adjusted between 1-2% in an air ⁄ oxygen mix (FiO2 0.6), fentanyl infusion at 1-2 μg.kg/h and atracurium infusion at 0.5 mg.kg/ h. Mechanical ventilation will be provided by using a Dräger anaesthesia machine (Dräger Primus®, Germany) using a tidal volume of 6-8 ml.kg with the respiratory rate adjusted to maintain the PaCO2 between 4-4.6 kilopascal (kPa) and positive end expiratory pressure (PEEP) of 5 cmH2O. All patients will be monitored for five lead ECG, peripheral oxygen saturation, noninvasive and invasive arterial blood pressure, temperature, end-tidal carbon dioxide tension, hourly urinary output, and central venous pressure (CVP). A 7-Fr triple lumen CVP catheter (Arrow International Inc, Reading, PA, USA) will be inserted into the right internal jugular vein.

All patients will receive 6ml /kg/h Ringer acetate solution as a maintenance intraoperative fluid. If SVV is more than 15%, the patient will be considered as fluid responder and will receive a 250-ml bolus of albumin 5% to maintain SVV ≤15%. Blood transfusion will be given based on a hemoglobin level (< 7 g/dl). Norepinephrine will be administered if the mean arterial pressure was less than 70 mmHg. Epinephrine will be administered if mean arterial blood pressure was less than 70 mm Hg and the cardiac index was less than 2.5 L/min/m2 despite sufficient volume infusion, to maintain a target cardiac index of 2.5-3.0 L/min/m2

Electrical cardiometry (EC) Examination:

1. ECG electrodes will be placed on the bare skin of patients in the following positions:

2. On the left neck below the ear;

3. Directly above the midpoint of the left clavicle;

4. Along the left mid-axillary line at the level of the xiphoid process;

5. Two inches caudal from the third electrode.

6. Patient characteristics of sex, age, height and weight will be entered into the monitor.

7. Clocks on the EC and trans esophageal echo (TEE) machine will be synchronized prior to data collection.

8. The EC monitor will be programmed to capture moving averages of variables based on the previous 10 cardiac cycles and to record those averages every10 s.

9. Only EC data with a signal quality index (SQI) of >70 will be included in the analysis.