Study design and population
pain, drug addiction, chronic diseases, allergies
STERILE, CHRONIC DISEASES, ALLERGIES
This prospective randomized controlled clinical study was carried out on American Society of Anesthesiologists (ASA) physical status I and II (ASA I and II) patients scheduled for lower limb orthopedic surgeries of both sexes aged 21 – 60 years old at Zagazig University Hospitals during the period from October 1, 2021 to April 30, 2022 after approval from the institutional review board (Research ethical committee of Faculty of Medicine, Zagazig University) with reference number (ZU-IRB#7045-15-8-2021) and obtaining written informed consent from all patients before their enrollment. This study was registered under clinicaltrials.gov (NCT05041270) on registration date 13/09/2021.Patients with known allergies to any of the study drugs or suffering from severe chronic diseases (cardiac, renal, hepatic, or neurological), presence of contraindications to neuraxial block, drug addiction or patient refusal were excluded from the study. If the spinal sensory block level did not reach T10 the patient was excluded from this study.Preoperative history taking, clinical examination, routine investigations, and baseline measurements of patients (heart rate, mean arterial blood pressure (MAP), oxygen saturation) were recorded. Patients were instructed on how to express their pain, which was assessed by visual analog scale (VAS). The patient put a mark on a horizontal line at which 0 reads “no pain at all” at one end, and 10 means “worst imaginable pain” at the other end [An intravenous line was secured, and patients were preloaded with (10 ml/kg) ringer lactate solution over 15–20 min. Patients sat on the operative table with their back curved and flexed forward. After cleaning and draping the back with a sterile sheet, the intervertebral space (L2-L3) was identified, and skin wheal was raised using a 26-gauge needle with 2% lidocaine. Tuohy needle number 18 was introduced and advanced slowly until the epidural space was identified by loss of resistance to air technique, with the bevel in the cephalic direction, an epidural catheter was inserted 5 cm into the epidural space and secured. Three milliliters of lidocaine (2%) with adrenaline (1/200,000) were injected through the epidural catheter as test dose. Then, L3-L4 intervertebral space was identified, and a 25-gauge spinal needle was introduced and 15 mg of 0.5% heavy bupivacaine was injected intrathecally. Surgery started under spinal anesthesia.Patients were allocated randomly into three groups using computer generated randomization tables. A trained nurse who was blinded to the patient allocation and the study purpose prepared the study drugs.