patients will be divided into two groups Group (C) control these are the patients with BMI less than 35 and Group (O) for patients with BMI more than 35.All patients will be sitting to receive their epidural analgesia for labor pain.~A 2.5 to 5 MHz curvilinear probe (Sonosite X-porte, Fujifilm industries) will be used to detect the desired level usually between L3-4 or L4-5. patients will be divided into two groups Group (C) control these are the patients with BMI less than 35 and Group (O) for patients with BMI more than 35. All patients will be sitting to receive their epidural analgesia for labor pain.~A 2.5 to 5 MHz curvilinear probe (Sonosite X-porte, Fujifilm industries) will be used to detect the desired level usually between L3-4 or L4-5. Initially a parasagittal oblique interlaminar view will be obtained and by tilting it medially to visualize the laminae and interlaminar spaces. Starting by the sacral image, counting will start detecting the L5-S1, L4-L5 and L3-L4 levels. After marking the level another imaging in the transverse view will be attempted at the previous levels then the anesthetist will detect the posterior complex (ligamentum flavum, epidural space and dura) and anterior epidural complexes and according to the anesthetist preference a level will be This is followed by a test dose of 10 ml 0.125% bupivacaine and patient controlled epidural analgesia will be started by the following protocol (0.0625% bupivacaine) Smith Medical ASD,Inc. in intermittent dose (10 ml will be injected by the machine every 30 minutes.
The aim of this study is to calculate the sensitivity and specificity of using color Doppler with pulsed wave Doppler to accurately detect the position of epidural catheter