Pre-emptive Dexamethasone in Hip Arthroplasty

- This randomized controlled prospective study will be carried out on 70 adult patients aged 21 to 75 years admitted to orthopedic operating rooms in Tanta University Hospital for hip surgery under spinal anesthesia. I

Patients will be randomly distributed into two equal groups using the computer-generated software. An anesthesia resident who will be blinded to the study groups and not participating in it will help in the preparation of uniform 10-ml syringes that contain normal saline in the control group and 16 mg dexamethasone in the other group.

• Control Group: (35 patients) Those patients will receive 10 ml of normal saline before surgery.
• Dexamethasone Group: (35 patients) Those patients will receive 16 mg dexamethasone in 10 ml of normal saline before surgery.

All the patients will undergo standardized preoperative assessment consisted of history taking, general and regional examination, and requesting preoperative investigations including (complete blood count (CBC), coagulation profile, and renal function tests). Upon patient admission to the operating theater, they will be attached to a monitor consisting of pulse oximetry, 5 lead ECG, non-invasive blood pressure, end-tidal carbon dioxide (Co2), and temperature. Then, intravenous access will be established through the insertion of an 18-gauge peripheral venous cannula, then, lactated ringer solution 7ml/kg over 30 minutes will be started. All the equipment required for spinal anesthesia, general anesthesia, and nerve block will be prepared by an expert anesthesiologist who will not be participating in this research. Also, the resuscitation equipment will be prepared before starting anesthesia.

Under complete aseptic precautions and local anesthetic skin infiltration with 3 ml lidocaine 1% at L3-L4 or L4-L5 intervertebral space, midline approach spinal anesthesia will be performed using a 25 G spinal needle. Once intrathecal placement will be confirmed, a mixture of 2 ml of hyperbaric bupivacaine (10 mg) and 0.5 ml of fentanyl (25 ugs) will be injected. The patient will be monitored for the hemodynamic parameters including the heart rate and the mean arterial pressure every 3 minutes. Moreover, the sensory and motor blockade will be assessed.

Oxygen will be applied to the patient with the aid of an oxygen mask at a flow rate of 4 L/min. The pinprick test from caudal to cephalic direction using a 26-gauge needle will be used to evaluate the sensory block until the sensory level reached the level of T11 or higher. The motor block will be assessed every 5 minutes by the Bromage score (grade 3: no movement, grade 2: unable to flex knees and can flex ankle, grade 1: unable to raise an extended leg but able to move the knees and ankles, grade 0: no paralysis) until reaching a score of 2 or 3. If no adequate sensory or motor blockade will be obtained within 20 minutes, the patient will receive general anesthesia and be excluded from the study. A decrease in the heart rate below 50 b/min will be managed by atropine 0.3 mg i.v, while a decrease in the mean arterial pressure below 65 mmHg will be managed by 10 mg ephedrine i.v and intravenous fluids.

Primary outcome will be postoperative morphine consumption and the secondary outcome will be the postoperative pain score