Clinical trial NCT04403724: Sequential and Mixture Injection of Opioids and Hyperbaric Bupivacaine
Official title: Comparison of Sequential and Mixture Injection of Opioids and Hyperbaric Bupivacaine for Subarachnoid Block for Elective Caesarean Section; a Randomised Controlled Study
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE4
Conditions: Bupivacaine Adverse Reaction
Regional Anesthesia Morbidity
Cesarean Section Complications
Lead sponsor: Assiut University
Sponsor class: OTHER
First posted: 2020-05-27
Enrollment: 126
Sex: FEMALE
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: Neuraxial anesthesia, especially the subarachnoid block, is the preferred method for LSCS. The intrathecal spread of local anesthetic drugs is unpredictable. However, Baricity, which is the relative density of local anesthetics to that of CSF, is a key determinant of the local anesthetic spread within the subarachnoid space. Alterations in the baricity of a solution to the extent of 0.0006 g/ml-1 can alter the spread of local anesthetic solution in CSF. Patients features such as position, weight, height, and age, and local anaesthetic characteristics such as density, PH, and temperature may play a role as well.

Bupivacaine is the main local anaesthetic used frequently for the subarachnoid block. Hyperbaric bupivacaine has dextrose added at a concentration of 80 g/ml to increase its density to 1.0262 which is higher than that of cerebrospinal fluid (CSF), leading to a more predictable spread after intrathecal injection.

Opioids such as morphine and fentanyl are commonly injected as adjuvants to hyperbaric bupivacaine. Their synergistic role leads to satisfactory block at smaller subtherapeutic doses of bupivacaine which minimizes the associated side effects. The combination of fentanyl which is lipophilic opioid and morphine which is hydrophilic opioid results in rapid onset and prolonged course of perioperative analgesia. In an in vitro study, the mean densities of fentanyl and morphine were found to be 0.9957 and 1.0013 respectively while the mean density of CSF in term pregnant woman is 1.000306. Thus, opioids spread freely within the CSF interacting on the spinal and supraspinal opioid receptors. They have a synergistic effect to bupivacaine leading to adequate sensory blockade with lesser hemodynamic adverse effects.

Nevertheless, opioids are commonly mixed with hyperbaric bupivacaine in a single syringe before intrathecal injection. This practice alters the density and PH of the mixture which may impact the pharmacokinetics of each individual drug. Therefore, we hypothesize in this study that separate injection of opioids and hyperbaric bupivacaine may improve their intrathecal spread. This will not only improve the quality of anesthesia, but it will also decrease the associated hemodynamic adverse events and the incidence of undesired high sensory block levels, which all will increase the perioperative patient satisfaction.


Eligibility criteria: Inclusion Criteria:

* LSCS
* ASA I or II
* Single baby pregnancy of more than 32 weeks
* Elective or semi-elective surgery (category 3 and 4 Caesarean sections)

Exclusion Criteria:

* Abnormal Placentation
* PET
* Disordered coagulation
* Allergy to opioids or local anesthetic.
* BMI \> 35
* Spine surgery
* Cardiac disease
* Extremes of height; height more than 180 or less than 140
* Multiple pregnancy or polyhydramnios

Primary outcomes:
measure: duration to the maximal sensory block to light touch
timeFrame: intraoperative
Secondary outcomes:
Other outcomes:
Locations:
city: Assiut
country: Egypt
facility: Assiut University hospital
Study officials:
References: