Sacral ESPB vs. PENG Block for Hip Hemiarthroplasty Analgesia

Study design This double-blinded, prospective, randomized comparative study will be conducted in Fayoum University hospital after the approval of local Institutional Ethics Committee and local institutional review board. Written informed consent will be obtained from all patients for these scientific contributions before recruitment and randomization.

Randomization, Allocation Concealment and blinding Patients will be randomly allocated into one of 2 parallel groups (40 in each group) based on sample size. Randomization will be achieved using computer-generated random numbering of each study patient. Allocation concealment will be insured using Sequentially Numbered, Opaque, Sealed Envelopes (SNOSE), prepared by a researcher not involved in patient recruitment or outcome assessment. The block tray and necessary equipment will be prepared by an independent anesthesiologist not involved in patient assessment. The patient and researcher who collects the data after the block will be blinded to the study group. All study outcomes will be evaluated by a dedicated anesthesiologist who will be blinded to the group allocation.Patients will be randomized into 2 groups.

Group (S) patients who will receive sacral erector spinae plane block. Group (G) patients who will receive pericapsular nerve group block. Anesthesia procedure

* The study protocol, sacral erector plane block, PENG block and the numerical pain rating score (NPRS) will be explained to each patient during the preanesthetic counselling. The (NPRS) is 11-point numeric scale ranges from 0 to 10, (where score 0 =no pain and 10 =worst pain imaginable) . * . Before the participants will be admitted in this study, the purpose and nature of the study, as well as the risk-benefit assessment will be explained to them. An informed consent will be obtained from participants. Patients will fast for about 6 to 8 hours for solid meals, for 4 hours for non-clear liquids and for 2 hours for clear liquids before surgery .

Anesthetic technique

* Perioperative anesthesia management will be according to our hospital routine protocol. * An intravenous cannula will be inserted in the hand and standard monitoring (noninvasive blood pressure, electrocardiography, and pulse oximetry) will be applied. * In all patients, spinal anesthesia will be performed in the sitting position. The midline at level of the L3-4 and L4-5 intervertebral spaces will be identified, and spinal anesthesia will be administered using 25-gauge Quincke needle. * Patients will be immediately placed in the supine position. Spinal anesthesia will be considered successful when a bilateral block to T12, as assessed by loss of cold (cold ice) and pain (a 23-gauge needle) sensations, will be established 10 minutes after the intrathecal injection, the surgery will be done using a lateral approach and a lateral decubitus position. Local Anesthetic Dose, Safety, and Emergency Preparedness

1. Sacral ESPB: 30 mL of 0.25% bupivacaine HCl (plain), equivalent to 75 mg. PENG block: 20 mL of 0.25% bupivacaine HCl (plain), equivalent to 50 mg . Both doses fall well within the recommended maximum safe dose for elderly patients and selected per anatomical requirements and RCT evidence. The maximum safe dose of plain bupivacaine will be strictly adhered to, defined as 2 mg/kg, not exceeding an absolute maximum of 150 mg. 2. Slow Incremental Injection: The standard practice is to inject the local anesthetic under ultrasound guidance in small boluses, commonly 5-10 mL at a time, followed by aspiration to rule out intravascular placement and systemic toxicity. 3. Emergency preparedness measures included:

(i) Lipid rescue protocol availability: 20% Intralipid solution will be readily available for immediate intravenous administration in the event of local anesthetic systemic toxicity (LAST), according to ASRA guidelines.

(ii) Monitoring for LAST: Continuous monitoring of neurological status (e.g., dizziness, perioral numbness, seizures) and cardiovascular parameters (ECG, blood pressure, heart rate) will be performed throughout the procedure and during the immediate post-block period.

(iii) Allergic/anaphylaxis management: Emergency medications (adrenaline, antihistamines, corticosteroids) and resuscitation equipment will be available, with a predefined protocol for prompt management of any hypersensitivity reactions.

(iv)Emergency airway management equipment will be available at the bed side. (V) Stop rule will be applied if unexpected adverse events (e.g., severe hypotension, arrhythmia, LA toxicity). Postoperative analgesia protocol All patients will receive standardized multimodal analgesia. Paracetamol (1 g every 6 hours) and NSAIDs (unless contraindicated) will be administered as routine analgesics. Opioids will be used as rescue medication according to a unified protocol for both groups. This standardized regimen aims to minimize confounding and ensure that differences in pain scores are attributable to the regional techniques.

• Numerical Pain Rating Scale(NPRS) during movement and at rest in 24 h after surgery at (2,4,6,8,12,18,24) [Срок оценки: At 2, 4, 6, 8, 12, 18, and 24 hours postoperatively.]
• Cumulative morphine consumption in 24 hours in mg [Срок оценки: During the first 24 hours postoperatively]
• Time for first rescue analgesia (hours), standard rescue analgesia (Morphine PCA or IV (dose specified) [Срок оценки: In the first 24 hours postoperatively]
• Intraoperative opioids consumption. [Срок оценки: Intraoperative peroid]
• Inability to perform physiotherapy at 24 hours. [Срок оценки: At 24 hours postoperatively.]
• Delirium assessment (CAM score), a diagnosis of delirium is made if the patient has both (Acute onset and fluctuating course) and (Inattention), plus either (Disorganized thinking) or (Altered level of f consciousness) 20 [Срок оценки: Twice daily (every 12 hours) for the first 72 hours postoperatively.]
• The incidence of block-related adverse events (ie, vascular puncture, LA toxicity). [Срок оценки: For Vascular Puncture: "Intraoperatively, during the performance of the nerve block. For LA Toxicity (LAST): "From the time of injection until 60 minutes post-procedure.]
• Incidence of quadriceps motor block at 3,6,12,24 hours postoperatively [Срок оценки: At 3, 6, 12, and 24 hours postoperatively.]
• Opioid related side effects (ie, nausea, vomiting, urine retention, respiratory depression) [Срок оценки: From the time of the first dose up to 24 hours post-administration.]
• Length of stay in hospital. [Срок оценки: From the day of surgery until hospital discharge, assessed up to 30 days.]