Comparison of Analgesic Effectiveness of Intravenous Ketamine and Fentanyl for Spinal Anesthesia is Sitting Position in Patients With Proximal Femur Fracture

Femur fracture is a common orthopedic problem following trauma in patients of all ages. It is a painful bone injury and is associated with severe pain and distress during preoperative period. Surgical repair is most commonly done in subarachnoid block. However, moving the patient for optimal positioning for spinal needle placement in subarachnoid space leads to severe pain. Adequate analgesia not only improves patient's comfort but has also been shown to improve positioning for subarachnoid block. Several analgesic modalities have been used to decrease movement evoked pain in these patients including the use of intravenous analgesics and blocks. However, there are only few studies comparing intravenous analgesics that alleviated the pain that occurs when changing position for subarachnoid block.

Patient enrollment will be done by the primary investigator one day prior to the surgery. All eligible patients with American Society of Anesthesiologist Physical Status I, II fulfilling the inclusion criteria will be informed about the study and written consent will be obtained in pre operative visit, one day prior to the surgery, in the orthopedic in-patient ward.

All patients will be kept nil per oral for 6 hours for solid, heavy meal, 4 hours for light meal and 2 hours for clear liquid. All the patients will be pre-medicated with Tab Lorazepam 1mg (<50kg) and 2mg (>50kg) orally the night before and in the morning of the surgery.

On the day of surgery, randomization will be done in pre operative holding area and the patient will be transferred to the operation theatre in trolley maintaining the skeletal traction. All standard monitoring devices like electrocardiogram, non-invasive blood pressure monitoring and pulse oximeter will be attached. Standard anesthesia monitoring including 3-lead electrocardiography, oxygen saturation(Spo2), blood pressure(BP) and heart rate(HR) will be done.Baseline Numeric Rating Scale(NRS) for pain at rest and movement will be assessed (movement is defined at 5 cm active vertical movement of the limb).

An intravenous line will be secured with 18 gauge intavenous cannula in the dorsum of hand. Pre-hydration will be started with Ringer's Lactate solution at 5ml/kg/hour.

Dose of the drug required according to the body weight will be calculated and prepared by the anesthetist not involved in the study. It will be labelled as study drug and will be delivered by the investigator.

Group A will receive Inj Ketamine 0.30mg/kg bolus dose. Group B will receive Inj Fentanyl 1.5mcg/kg bolus dose. The drug will be prepared in an identical sterile syringe as a clear fluid and will be labelled as "study drug".

Patient will receive the study drug according to randomization.Then, 10 minutes after delivery of the study drug, the patients will be kept in sitting position with the help of operation theatre assistant while maintaining the skeletal traction. Numeric Rating Scale will be enquired and noted. If the patient will report Numeric Rating Scale of 5 or more during placement in the sitting position, procedure will be stopped and fentanyl 20 microgram will given intravenously in the form of rescue analgesia before attempting to reposition again. Once the patient will be in sitting position subarachnoid will be performed in L 3-4 inter space using 2.4ml of 0.5% hyperbaric bupivacaine maintaining strict asepsis. The patient will be laid down back to supine position. The level of sensory block and motor block will assessed. After ascertaining adequate block, patient will be shifted to fracture table for operation. The number attempts required for successful subarachnoid block will be noted. The quality of patient positioning will subjectively be rated as good, satisfactory and optimal depending upon the ease of positioning for subarachnoid block by the anesthetist. Sedation scoring will be noted for 30 minutes after delivery of the study drug. All the vital parameters will be monitored continuously and recorded every 3 minutes for first 15 minutes then every 10 minutes throughout the surgery and once in Post Anesthesia Care Unit. Patient will be assessed for the presence any adverse effect of the study drug throughout the surgery. The level of satisfaction regarding the analgesia during positioning will be questioned to the patient using Likert Scale in PACU. The time required for the patients to be discharged from PACU will be noted.

Data management Data handling- Data will be entered in Microsoft Excel 2016 and converted into Statistical package for social sciences (SPSS 11.5) for statistical analysis Coding-Alpha numerical code will be used Monitoring-Data will be entered after every day of work. Data will be reported to guide and co-guides every week.

Statistical Methods Collected data will be entered in Microsoft Excel 2010 and be converted into SPSS software 11.5 version for statistical analysis.

For descriptive statistics percentage, mean, Standard deviation, median, interquartile range will be calculated along with graphical and tabular presentation. For inferential statistics Chi square test, independent t test, Mann Whitney U test will be applied to find out the significant difference between Fentanyl and Ketamine with selected clinical and demographic parameter at 95% confidence interval where level of significance is considered p <0.05.