Ultrasound-guided Inferior Vena Cava Diameter Dependent Colloid Challenge Versus Routine Crystalloid Strategy Fluid Replacement in Transurethral Resection Prostate (TURP) Under Spinal Anesthesia; A Prospective Randomized Controlled Study.

Background: Intravenous fluid replacement during transurethral resection of the prostate is still unclear. Ultrasonography of the inferior vena cava (IVC) has been recently used to assess the volume status and predict fluid responsiveness. In this double-blind, randomized controlled study, we will assess the IVC at baseline and at subsequent time points after spinal anesthesia, and according to IVC diameter will give the replacement challenge colloid. Potential problems during TURP are mostly due to either fluid overload or bleeding: Intraoperative TURP syndrome, Hemorrhage, Myocardial ischemia, Hypothermia, Prostatic capsular perforation, Bladder or urethral perforation. Postoperative TURP syndrome, myocardial ischemia/infarction, Postoperative cognitive impairment. Study Hypothesis: Strict colloid volume optimization using US-guided IVC diameter calculation aiming decrease the total IV fluid volume and accommodate the transurethral inevitable absorption of currently used irrigation crystalloid fluid (Nacl0.9%) that accidentally absorbed and change it from a circulatory overload to a complementary part of the replacement IV fluids preventing fluid overload and TURP syndrome. Aim of the work: To reduce Intraoperative and postoperative fluid overload during TURP surgery with hemodynamic stability relaying up on US-guided IVC diameter dependent Strict IV Colloid replacement volume optimization. Methods: A prospective randomized controlled trial on ASAI-III male patient aged 40-80 years old subjected to transurethral endoscopic resection of the prostate (TURP) surgery. Then patients will be divided into 2 groups according to the IV infusion fluid type as follow: Crystalloid -control group: (preload plus continuous IO Ringer acetate crystalloid 4/2/1 rule infusion) according to the usual 4/2/1 rule. Not guided by IVC diameter but IVC diameter will be calculated using the US and recorded at baseline just after spinal anesthesia and then every 30 minutes till the end of surgery. Loop Diuretic (Furosemide) will be given according to the maximum diameter of the IVC as follow; 10mg if IVC>2.5Cm. Colloid- study group: (preload plus colloid challenge only); Fluid challenge boluses of 250 mL (over 5 minutes using a pressurizer) 6% hydroxyethyl starch 130/0.4 in 0.9% sodium chloride (voluven®) if the IVC<1.7(higher limit of normal) will be given guided by IVC diameter at baseline just after spinal anesthesia and then every 30 minutes till the end of surgery.