Comparative Evaluation of Post-Operative Analgesic Efficacy of 15 ml of 0.375 % Ropivacaine versus 25 ml of 0.375 % Ropivacaine in patients undergoing hip fracture surgery under ultrasound guided Pericapsular Nerve Group Block: A Prospective Randomised Double Blinded Trial

Hip fracture is an increasingly common emergency surgical presentation particularly amongst elderly and a rising social and economic burden. This reflects the high morbidity and mortality of the condition , particularly among the frail elderly .PENG(Pericapsular Nerve Group) Block was first described by Phillip W.H. Peng in July, 2018 . PENG block is a novel regional anesthesia technique that has been proposed as an effective motor sparing block for total hip arthroplasty. PENG Block targets the articular branches of femoral ,obturator and accessory obturator nerves providing innervation to the anterior capsule of the hip joint. Its potential motor sparing effect is desirable for early ambulation , better physical therapy and earlier discharge . The potential analgesic benefit provided by this block, without impairing motor function , positively impact patient mood, sleep, appetite and over all well being. Ropivacaine is an amide local anesthetic with predilection for sensory blockade. We hypothesize that 15 ml of 0.375% ropivacaine would be able to achieve similar analgesic effects as 25ml of 0.375% ropivacaine. Studies conducted so far to assess the analgesic efficacy of PENG block have used local anaesthetic in a volume ranging from 8 to 30 ml and concentration 0.2% to 0.5% . Inclusion criteria: 1.Patient wo had given written informed consent 2.Patients belonging to  ASA grade I and II. 3.All genders 4.Patients in the age group of 18 yrs and above 5.Patient with hip fracture ( fracture neck of femur, intertrochanteric and subtrochanteric fractures). Exclusion criteria : 1.Patient refusal.2.ASA grade III and IV3.Emergency surgeries 4.Patient with polytrauma5.Patient who had allergy and intolerance to local anesthetics & have active skin infection.6.Patient with cognitive impairment, delirium, dementia and severe hearing impairment.7.Coexisting coagulopathy or anticoagulant or antiplatelet treatment that would be a contraindication to regional anesthesia. 8.Patient having diabetes , ischemic and valvular heart disease, pre-existing  neurologic deficits in the limb . After obtaining approval from the institutional ethics committee of SGPGIMS and written informed consent from the patients, the study will be conducted with the study population being the patients undergoing surgery for hip fracture. Patients will be randomly allocated by use of block randomization method using software ‘Sealed Envelope”.The duration of study is going to be for about 18 months.  Subjects will be placed in supine position,standard ASA monitors will be applied, oxygen will be administered via nasal cannula. Intravenous midazolam and fentanyl will be titrated for patient comfort. After skin disinfection and draping, a curvilinear low frequency probe (2-5 Hz) will be initially placed in a transverse plane over the anterior inferior iliac spine ,before being aligned with the pubic ramus by rotating the probe 45 degree counterclockwise .The skin puncture site will be anesthetized using 2% lignocaine (2-3 ml ) A 22G 100 mm echogenic needle(Pajunk or Stimuplex needle) will be inserted from lateral to medial in an in- plane approach and will be advanced to the target site i.e. between the psoas tendon anteriorly and pubis ramus posteriorly .In group A, 15 ml of 0.375 % Ropivacaine will be injected and in group B,  25 ml of 0.375% ropivacaine will be injected to the target site. In both the groups , 4 mg of injection dexamethasone will be administered intravenous at the time of block placement .[8 Negative aspiration should be observed before injection of local anesthetic into the plane and observation of fluid spread in the desired plane. Pain during positioning(i.e. sitting position or Hamstring stretch position) for spinal anesthesia will be assessed using the pain score (score 0 = calm, 1 = facial grimacing, 2 = moaning, 3 = screaming, and 4 = unable to proceed because of restlessness or agitation). 30 minutes after placement of Pericapsular Nerve Group Block, spinal anesthesia will be administered using 0.5 % hyperbaric bupivacaine with a dose range of 12-15 mg based on patient height along with 15 mcg of fentanyl. Patients in both the groups will receive same care pre and postoperatively. Post operatively subjects in both the groups will receive scheduled paracetamol (15 mg/kg) six hourly as part of a multimodal pain regimen. Static and dynamic pain assessment will be done at 2h, 4h, 12h, 18h, 24h,30h, 36 h,42h, 48h, using NRS. NRS score more than 4 will be treated as breakthrough pain and injection fentanyl  (0.5 mcg/kg) will be administered intravenous as rescue analgesic. Time at which first rescue analgesia is demanded by the patient will also be recorded.