The aim of the study is to and compare classical sitting and crossed leg sitting positions in patients undergoing below umbilical surgeries according to lumbar anatomical measurements calculated using ultrasonography.

       A prospective, randomized clinical study will be conducted after obtaining institutional ethical committee approval, written and informed consent from the patients admitted for surgery and satisfying inclusion criteria.

         The study will be conducted in 45 patients in each group between 18 to 60 years of age, ASA-I and ASA-II of either gender undergoing elective lower abdominal and lower limb surgeries. Patients will be informed about the proposed position for the procedure during the pre-anesthetic visit.

          Patients will be randomly allocated into one of the following groups of 45 each patients.

Group 1-CSP – Patients in classical sitting position

Group2- CLSP - Patients in crossed leg sitting position

         Randomization is done using a computer-generated random number table.

  All the patients in the study will be subjected to a thorough pre-anesthetic evaluation which includes a detailed history taking, complete general physical examination and necessary relevant investigations like complete blood count, HIV, HBsAG etc.

       Tab Alprazolam 0.5mg and Cap Pantoprazole 40mg are given orally at night on the day before surgery. All the patients are kept nil per oral as per standard guidelines.

      Patients will be taken on the operation table and standard ASA monitors will be connected. Preoperative heart rate and systolic blood pressure, diastolic blood pressure, mean arterial pressure, respiratory rate, oxygen saturation, electrocardiogram are recorded. Intravenous line will be secured and appropriate intravenous fluid is started.

       Group CSP patients are made to sit with legs extended, the forearms held on laps and hands on the knees. In Group CLSP, the patients legs are crossed, the forearms on the laps , the hands are positioned on knees.

       All the examinations are done by experienced anesthesiologist. All sonographic examinations are done using USG machine (FUJIFILM SonoSite M.Turbo) or (Wipro GE/Logic C-5) after applying hydrophilic anti allergic ultrasound transmission gel.  A curved array transducer will be initially placed longitudinally over the spine in the midline to get a median sagittal spinous process view. The crescent shaped hyperechoic reflections of the spinous processes and the Inter spinous space (ISS) is identified. The transducer will be moved caudally to visualize the sacrum, and a gap seen between the sacrum and the spinous process of the L5 vertebra is L5–S1 ISS. The L4–L5 and L3–L4 ISSs will be located by counting upwards while moving the transducer in a cranial direction. Inter spinous space will be measured as the distance between the lower border of the upper spinous process and the upper border of the lower spinous process and is measured in the median sagittal interspinous view.

        The transducer will be then placed in the paramedian sagittal oblique plane to visualize the L5–S1, L4–L5 and L3–L4 spaces. The L5–S1, L4–L5 and L3–L4 Inter laminar spaces will be located by counting upwards after identifying the sacrum. The interlaminar space (ILS) will be measured from the upper lamina’s lower border to the lower lamina’s upper border. Skin to Ligamentum Flavum(S-LF) distance will be measured from the skin to the outer border of the LF–dura mater unit. All the measurements will be taken with the aid of a built in caliper.

         After the anatomical measurement calculations using ultra sonography, under strict aseptic precautions lumbar spinous process and interspinous spaces will be  palpated and identified in CSP and CLSP respectively. After infiltration of local anesthetic 2% lignocaine at the selected site and the Spinal needle will be introduced in the midline remaining perpendicular to the patient’s back and needle is slowly inserted, piercing the skin, subcutaneous tissue, supraspinous ligament, interspinous ligament, ligamentum flavum, dura matter, subdural space, then the arachnoid matter, into the subarachnoid space, which will be confirmed by free flow of CSF. The needle will be fixed on the patient’s back and then connected to a syringe containing the drug is deposited into intrathecal space using the 0.5% hyperbaric bupivacaine administrated through 25G Quinke Babcock Spinal needle and patient made to lie.

     Ease of landmark palpation, Number of attempts for successful spinal needle placement and number of bone needle contacts are assessed.

               Level and onset of the neuraxial blockade is assessed by temperature change which is detected by wetted alcohol sponge, and the level of sensory loss by ability to detect sensation of pinpricks and motor block by the Modified Bromage scale.

Modified Bromage scale:

Grade 0-able to move the hip, knee, and ankle

Grade 1- unable to move the hip but is able to move the knee and ankle

Grade 2- unable to move the hip and knee but is able to move ankle

Grade 3- unable to move the hip, knee, and ankle.