Preoperative Use of Peripheral Nerve Blocks in Elderly Patients With Hip Fractures

The aging of the population is a global trend. In the elderly population, hip fractures are among the leading reasons for hospitalization and in most cases require surgical treatment. When we talk about hip fractures, we actually mean fractures of the proximal femur, which are classified according to the AO school as extracapsular (trochanteric region) and intracapsular (femoral neck area). Articular fractures (femoral head area) are very rare and not the subject of this study.

Patients with hip fractures, in addition to their advanced age, have numerous comorbidities. That is why mortality rate is high, up to 36% within a year of surgery, and perioperative care of such patients is a challenge for everyone involved in their treatment, especially surgeons and anesthesiologists. Despite this, to this date our institution has no protocol that would ensure standardization of the care in perioperative period, although this is recommended by professional societies. That is why we designed this study, in which we emphasize use of regional anesthesia in elderly patients.

The goal of this clinical trial is to promote usage of peripheral nerve blocks. Based on our clinical experience, peripheral nerve blocks act as aids for spinal anesthesia positioning and are a crucial part of peri-operative multimodal analgesia protocols in elderly patients scheduled for hip fracture surgery.

We believe that our results will show that peripheral nerve blocks decrease pain and amount of analgesics used in perioperative period, per mouth as well as intravenously. However, in order to include their use into standard operating protocols, we need to determine which block is the best for our group of patients, considering different types of fractures and types of surgeries. We also need to determine which block provides the best analgesia, both for positioning for spinal anesthesia and postoperatively, which block lasts the longest, while not interfering with the start of physical therapy and not prolonging hospital stay.

Primary outcome of this research is to determine pain. It will be determined using visual analogue scale, at rest and dynamically, while leg is being passively raised for 15˚.

Secondary outcomes are: patient reported outcome using EQ-5D-5L, time for the performance of blocks, ease of positioning and time to positioning to spinal, as well as time for the performance of spinal anesthesia, time until the first rescue analgesia and total analgesics used, total duration of blocks, level of motor blockade and time of the initiation of physical therapy, as well as any adverse effects until hospital discharge.

After meeting our inclusion and exclusion criteria, patients will be offered to participate in the research, as respondents. After signing informative consent, they will be randomized into one of four groups, 3 interventional and one control group. Each group will have an equal number of subjects with intracapsular and extracapsular hip fractures. Respondents will not know to which group they have been randomized, nor will the surgeons, nurses and anesthesiology residents. Anesthesiologists will therefore be considered as the study supervisors. Respondents will be closely monitored until hospital discharge.

Anesthesiologist's examination before the surgery will consist of recording body weight and height, determining BMI, noting down history and comorbidities using ASA status, frailty score (Clinical Frailty Test), cognitive status (Mini Mental State Exam), laboratory results (L, WBC, CRP, IL-6, Hb, Htc, ferritin, TSAT, urea, creatinine, eGFR, PLT, PV, INR, APTV, electrolytes) and introducing EQ-5D-5L to respondents. Preoperative fasting will be ensured (6 - 8 hours), clear liquids allowed up to 2 hours before surgery. Upon arrival to the operating block, in the preparation room, respondents will be analgosedated with esketamine 5mg and fentanyl 50 mcg for the administration of peripheral nerve block. Application of peripheral nerve block will be made using ultrasound (linear or curvilinear probe, depending on the block) and regional needles (Pajunk, 21G, length 100 mm). Respondents will be monitored all the time and 20 minutes after administration of the block they will be asked to answer EQ-5D-5L for the second time. After that, they will be positioned for spinal in sitting position. 5 minutes after the spinal they will be asked EQ-5D-5L for the third time and then transported to the operating room. Before the incision, cefazoline and tranexamic acid will be administered. Respondents will be lightly to moderately sedated during surgery (RASS -2 to -3), with propofol and esketamine, sequenced. Normovolemia will be maintained. Intraoperative hypotension will be treated with ephedrine, phenylephrine or norepinephrine. Normothermia will be maintained using passive heating (active if necessary) and body temperature will be measured. Multimodal analgesia will be continued with paracetamol, ketoprofen, dexamethasone and MgSO4. Granisetron will be given as well. Postoperatively, they will answer EQ-5D-5L 4 more times: upon leaving recovery room and operative block, 6 hours after the surgery, 24h and 48h after.

Postoperatively, time until the rescue dose of analgesics will be noted. Analgesics, when necessary, will be introduced in this order: Paracetamol 1 g iv., Diclofenac 75 mg im., Tramadol 50 mg iv., Morphine 2 - 5 mg sc. or iv. After respondents start taking fluids and food per mouth (after 1 hour of receiving fluids, food can be given, or according to the patient's tolerance, but as soon as possible), they can start using analgesics orally. Laboratory results will be done 24h after the surgery, as well as MMSE.

Bromage test for motor blockade will be performed 20 minutes after the block, upon exit from the recovery room, 6h, 24h and 48h after the surgery. Respondents' ability to participate in physical therapy will also be monitored.