Transesophageal Echocardiology Measured Left Ventricular End Diastolic Area As Guide for Fluid Therapy in Major Oncosurgeries

Overview

Intraoperative fluid management is pivotal to successful outcome of major oncosurgeries . Adequate volume replacement to achieve optimal cardiac performance is critical to prevent any deleterious consequences of under resuscitation or fluid overload . Traditionally CVP monitoring has been tool to guide intraoperative fluid therapy and has poor reliability as indicator of volume status . Transesophageal Echocardiography measured LVEDA is more reliable and sensitive measure of left ventricular volume to guide intraoperative fluid therapy . Investigators plan the study comparing total fluid requirement and postoperative outcomes in two groups of patients receiving central venous pressure (CVP) guided Conventional Fluid Therapy (CFT) and Left ventricular end diastolic area( LVEDA) guided fluids for major oncosurgeries.

Adult patients undergoing major oncosurgeries will be included in the study ,with Alpha Error(%) = 5 ,Power(%)= 80 ,required sample size per group is 29.Investigators will include 30 patients in each group. Patients will be randomly allotted to Central Venous Pressure CVP Group (Control Group) or Transesophageal Echocardiography TEE Group (Study Group) according to computer generated randomization. In the OR 5 lead Electrocardiogram ( ECG ), Oxygen saturation (SPO2 ), Noninvasive blood Pressure (NIBP) , End tidal carbon di oxide (ETCO2 )monitors will be attached .Under local anesthesia 16Gauge peripheral intravenous and Radial artery cannulation will be performed . Anesthesia will be induced with Fentanyl 1mcg/kg-1, Morphine 0.05mg/kg-1, Propofol titrated dosage 1-2 mg/kg-1 and neuromuscular blockade with Atracurium 0.5mg/kg-1.Trachea will be intubated with oral cuffed endotracheal tube of appropriate size. Anaesthesia will be maintained with O2 / Air mixture 40:60 % Intermittent Positive Pressure Ventilation with Sevoflurane , intermittent boluses of Fentanyl and Train of Four ratio guided Atracurium . Postintubation ultrasound guided internal jugular vein will be cannulated with B.Braun 7French 20cm, 16 G Triple lumen central venous catheter in both CVP and TEE Group patients . My Lab Five ESAOTE TEE 022 multiplane probe ,frequency 3 to7MHz (Providian Medical Equipment ,OH) will be placed in TEE Group patients.Intraoperative all patients will be given one-third starvation fluid in first hour of surgery , maintenance fluid 2ml/hour crystalloid . Target is to maintain CVP between 10 -16 cms of water (H20) in CVP Group , values will be recorded every 30 minutes if CVP decreases \< 10 then 200 ml colloid bolus will be given and increase in CVP value noted . In the TEE Group TEE probe will be inserted in the oesophagus (40-45 cms) adjusted to obtain mid-papillary transgastric short axis view ,the desired view will be freezed at end-diastole and the left ventricular cavity will be traced including the papillary muscles to obtain left ventricular end diastolic area in cm2 , the average of three readings at particular interval will be noted . Every half hourly values will be measured and also if systolic blood pressure \< 90 mm Hg . Fluid therapy will be given with the target to maintain LVEDA ≥ 10 cm2 (ranging between 10-18 cm2). For readings \< 10 cm2 colloid bolus 200 ml will be given and increase in the LVEDA will be noted.For same readings Left Ventricular Outflow trac ( LVOT) view will be obtained to measure aortic diameter at the cusps and LVOT VTI , Stroke volume ( SV) will be calculated as LVOT area { Pi (LVOT diameter /2 } 2 × LVOT VTI and Cardiac Outpt will be calculated as SV x Heart Rate . Increase in stoke volume and cardiac output with colloid boluses will be noted.Urine output will be recorded every 30 minutes in all the patients.Titrated noradrenaline infusion (conc 0.08mg/ml ) will be started if Mean Arterial Pressure (MAP) \< 70 mmHg with optimal fluid administration in CVP and TEE group .Serum lactate levels will be measured on completion of surgery and postoperative at 24 and 48 hours, neuromuscular blockade will be reversed and trachea extubated . In PACU both groups will receive CVP guided intravenous fluids, monitoring will include heart rate , Blood Pressure ,SPO2 , CVP , urine output. Note will be made of any patient requiring postoperative ventilator support, inotropic support,return of bowel sounds, serum lactate levels and serum creatinine levels at 24 and 48 hours and length of ICU stay.