Comparison of the effect of administration of Ropivacaine-Fentanyl and Ropivacaine-Sufentanil combination on the characteristics of sensory and motor block in lower limb surgery under spinal anesthesia

Comparison of the effects of Fentanyl-Bbupivacaine and Sufentanil-Bbupivacaine

Clinical trial with a control group, with parallel groups, three blinded, randomized, phase 2 on 105 patients. A lottery will be used for randomization.

This is a three-blind randomized clinical trial conducted on 105 patients candidate for lower limb surgery under spinal anesthesia in Kashani and Al-Zahra hospitals in Isfahan. After the ethics committee's approval and obtaining the patient's consent, the patients are randomly assigned into groups, the desired intervention is applied in each group, and the patient's clinical symptoms are recorded. The researcher who registers and collects data and the data analyst are not aware of the type of intervention applied. although the patients are included in the study, they are not aware of the type of intervention applied and therefore they are all blind.

Inclusion criteria: patients over 18 years old, candidate for lower limb surgery under spinal anesthesia, ASA anesthesia class I and II, informed consent to participate in the study Non-entry criteria: infection at the injection site, coagulation disorders, high intracranial pressure, drug addiction, and BMI over 30.

Intervention group A: Patients in this group receive 3 ml of Ropivacaine 0.5% along with 25 micrograms of Fentanyl (0.5 CC from the ampoule) for spinal anesthesia. Intervention group B: Patients in this group receive 3 ml of Ropivacaine 0.5% along with 25 micrograms of Sufentanil (0.5 CC from the ampoule) for spinal anesthesia. Control group C: Patients in this group receive 3 ml of 0.5% Ropivacaine along with 0.5 CC of distilled Water for spinal anesthesia.

Time of sensory and motor block effect; the time to reach the maximum sensory and motor block; Duration of sensory and motor block

This is a simple randomized clinical trial in which patients enter the study groups by lottery; The medicines and placebo are placed in the sealed, opaque, and similar form packets coded. Each code is also written on a piece of paper, folded, and placed inside a box. After entering the operating room, each patient takes one of the papers out of the box; The pocket with the same number is the intervention that will apply to him. This process continues till the number of patients reaches the desired one.

This is a three-blind clinical trial; In this way, before obtaining consent, the patients will be included in the study, but they do not know which group they will be in, and therefore they are blind. The researcher who records the patient's symptoms and collects the data related to the outcome variables, and also the person who analyzes the data collected during the study, do not know the type of intervention applied and therefore they are all blind.