Intrathecal Injection of Hyperbaric Bupivacaine Versus a Mixture of Hyperbaric and Isobaric Bupivacaine in Patients Undergoing Lower Abdominal Surgery

Study Overview
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Brief Summary
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The aim of this study is to compare the effects of intrathecal injection of hyperbaric bupivacaine versus injection of hyperbaric and isobaric bupivacaine in patients undergoing lower abdominal surgery.

Detailed Description
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Spinal anesthesia is one of the most commonly used nerve block procedures for surgical operations involving the lower abdomen, the perineum, and the lower limbs, owing to its quick effect and cost-effectiveness. Spinal anesthesia is advantageous in that it uses a small dose of anesthesia, is simple to perform, and offers a rapid onset of action, reliable surgical analgesia, and good muscle relaxation. The Baricity of a solution is defined as the ratio of the density of the solution to that of the cerebrospinal fluid (CSF). The most common anesthetic used for SA in obstetric and non-obstetric surgery is bupivacaine, which can be formulated as an isobaric or hyperbaric solution. Baricity differences between spinal anesthetic solutions are thought to affect hemodynamic parameters and distribution within the subarachnoid space, which may, in turn, affect the onset, extent, and duration of sensory block as well as side effects. Spinal anesthesia has been linked to different adverse effects, out of which hypotension is most common complication. The incidence of hypotension is 25-75% in general population. Factors that increase the risk of hypotension include patient factors (advanced age, pregnancy, obesity, diabetes mellitus, hypertension, and anemia) and technical factors such as a block level at or above T5, use of opioids during premedication, and high local anesthetic dosages.

Official Title
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Intrathecal Injection of Hyperbaric Bupivacaine Versus a Mixture of Hyperbaric and Isobaric Bupivacaine in Patients Undergoing Lower Abdominal Surgery: A Randomized Controlled Trial

Conditions
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Spinal Anesthesia, Hyperbaric Bupivacaine, Isobaric Bupivacaine, Lower Abdominal Surgery

Intervention / Treatment
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* Drug: Group A (hyperbaric bupivacaine)
* Drug: Group B (Mixture of Hyperbaric and Isobaric Bupivacaine)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age between 18-65 years old. Both sexes. American Society of Anaesthesia (ASA) I to II. Undergoing lower abdominal or urological surgery under spinal anesthesia Exclusion Criteria: Allergy to amide. Patients with a significant history of substance abuse. Patients with diabetes mellitus, neurological or cardiovascular diseases. Patients with neuromuscular diseases. Pregnant patients.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Group A (hyperbaric bupivacaine)<br>Patients were injected intrathecally with 20 mg hyperbaric bupivacaine 0.5% solution. | Drug: Group A (hyperbaric bupivacaine)<br>* Patients were injected intrathecally with 20 mg hyperbaric bupivacaine 0.5% solution<br>|
| Experimental: Group B (Mixture of Hyperbaric and Isobaric Bupivacaine)<br>Patients received 10 mg hyperbaric bupivacaine and 10 mg isobaric bupivacaine 0,5 % solution. | Drug: Group B (Mixture of Hyperbaric and Isobaric Bupivacaine)<br>* Patients received 10 mg hyperbaric bupivacaine and 10 mg isobaric bupivacaine 0,5 % solution<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of hypotension | Blood pressure was recorded using standard non-invasive monitors at 5, 10, 15, 20, 25, 30, 45, and 60 min, then hourly until 3 h post-injection. Hypotension was defined as a decrease in mean arterial pressure of more than 30% from baseline. | 3 hours post-injection | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Heart rate | Heart rate was recorded using standard non-invasive monitors at 5, 10, 15, 20, 25, 30, 45, and 60 min, then hourly until 3 h post-injection. | 3 hours post-injection | 
| Mean arterial pressure (MAP) | Mean arterial pressure was recorded using standard non-invasive monitors at 5, 10, 15, 20, 25, 30, 45, and 60 min, then hourly until 3 h post-injection. | 3 hours post-injection |