Study of The Analgesic Profile of Two Adjuvants Added to Low Dose Hyperbaric Bupivacaine Versus One Adjuvant in Patients Undergoing Anal Surgery Using Spinal Anesthesia

NCT ID: NCT07114263

Last Updated: 2025-08-11

Basic Information

• Recruitment Status: NOT_YET_RECRUITING
• Clinical Phase: NA
• Total Enrollment: 60 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-08-31
• Study Completion Date: 2026-02-28

Brief Summary

This study will be conducted to compare the efficacy of fentanyl and Dexmedetomidine as an additive to hyperbaric bupivacaine 0.5% in saddle block anesthesia on duration of analgesia in patients undergoing anorectal surgeries.

Detailed Description

Pilonidal sinus, hemorrhoidectomy, anal fistula or fissure repair are the main types of anorectal surgery. Various surgical and anesthetic techniques have been introduced to improve analgesia level and limit the motor blockade.Regional anesthesia is preferred for anorectal surgeries to avoid the risks of general anesthesia. Besides, providing effective post-operative analgesia, regional techniques reduce the opioid use.

Intrathecal administration of drugs to obtain anesthesia has been in use since the turn of the twelfth century. Saddle block anesthesia is a kind of low spinal block that provides anesthesia over the saddle area, i.e., perineum, perianal area, medial aspect of legs and thigh.

Saddle block anesthesia is performed by injecting a small dose of hyperbaric local anaesthetic at the level of L3, L4 after which the patient is maintained in sitting position for a few minutes to facilitate preferential impregnation of sacred roots (S1 to S5), which is responsible for innervation of perineum, external genitalia and anus. The saddle block causes a parasympathetic blockade at the bladder level which may result in bladder and rectal atony which is advantageous because of sphincteric relaxation needed for the operation.

Hyperbaric bupivacaine 0.5% is the most common local anaesthetic used for spinal anaesthesia for lower abdominal and lower limb surgeries. One disadvantage with using hyperbaric bupivacaine alone is a relatively shorter duration of action that means that early analgesic intervention is needed in postoperative period. Adjuvants are drugs that increase the efficacy or potency of other drugs when given concurrently. Neuraxial adjuvants are used to increase the speed of the onset of neural blockade (reduce latency), improve the quality and prolong the duration of neural blockade.

Fentanyl is a lipophilic short-acting opioid that exhibits close structural similarities to local anesthesia and has demonstrable local anesthetic efficacy on sensory C primary afferent nerve fibers, which may facilitate analgesic effects. It has improved spinal anesthesia and reduced the anesthetic drug related side effects including pruritus, nausea and vomiting.

Dexmedetomidine, a highly selective alpha_2 agonist, is being introduced as an adjuvant to local anesthetics with significant analgesic, sympatholytic, and sedative properties. Compared to clonidine; Dexmedetomidine is approximately eight times more selective towards α2-adrenergic receptors , which is associated with sedative and analgesic effects in supraspinal and spinal sites and also has an antinociceptive impact on both visceral and somatic pain.

This study will be conducted to compare the efficacy of fentanyl and Dexmedetomidine as an additive to hyperbaric bupivacaine 0.5% in saddle block anesthesia on duration of analgesia in patients undergoing anorectal surgeries.

Conditions

Spinal Anesthesia Administration; Analgesic; Anorectal Surgery

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: PREVENTION
• Blinding Strategy: TRIPLE

Study Groups

Group F :Fentanyl group

Patients will receive intrathecal 1.5 ml hyperbaric bupivacaine 0.5% and 0.5 ml (25 mcg) Fentanyl and 1 ml glucose 5% with total volume of 3ml.

Group Type: EXPERIMENTAL

Group F (fentanyl group)

Intervention Type: DRUG

Group F (fentanyl group):will receive intrathecal 1.5 ml hyperbaric bupivacaine 0.5% and 0.5 ml (25 mcg) Fentanyl and 1 ml glucose 5% with total volume of 3ml.

Group D: Dexmedetomidine group

Patients will receive intrathecal 1.5 ml hyperbaric bupivacaine 0.5% and 1 ml (4 mcg) Dexmedetomidine and 0.5 ml glucose 5% with total volume of 3ml.

Group Type: EXPERIMENTAL

Group D :Dexmedetomidine group

Intervention Type: DRUG

Group D :Dexmedetomidine group: will receive intrathecal 1.5 ml hyperbaric bupivacaine 0.5% and 1 ml (4 mcg) Dexmedetomidine and 0.5 ml glucose 5% with total volume of 3ml.

Group DF :Fentanyl and Dexmedetomidine

Patients will receive intrathecal 1.5 ml hyperbaric bupivacaine 0.5%, 0.5 ml (25 mcg) Fentanyl and 1 ml (4 mcg) Dexmedetomidine with total volume of 3ml.

Group Type: EXPERIMENTAL

Group DF :Fentanyl and Dexmedetomidine group

Intervention Type: DRUG

Fentanyl and Dexmedetomidine group:will receive intrathecal 1.5 ml hyperbaric bupivacaine 0.5%, 0.5 ml (25 mcg) Fentanyl and 1 ml (4 mcg) Dexmedetomidine with total volume of 3ml.

Interventions

Group F (fentanyl group)

Group F (fentanyl group):will receive intrathecal 1.5 ml hyperbaric bupivacaine 0.5% and 0.5 ml (25 mcg) Fentanyl and 1 ml glucose 5% with total volume of 3ml.

Intervention Type: DRUG

Group D :Dexmedetomidine group

Group D :Dexmedetomidine group: will receive intrathecal 1.5 ml hyperbaric bupivacaine 0.5% and 1 ml (4 mcg) Dexmedetomidine and 0.5 ml glucose 5% with total volume of 3ml.

Intervention Type: DRUG

Group DF :Fentanyl and Dexmedetomidine group

Fentanyl and Dexmedetomidine group:will receive intrathecal 1.5 ml hyperbaric bupivacaine 0.5%, 0.5 ml (25 mcg) Fentanyl and 1 ml (4 mcg) Dexmedetomidine with total volume of 3ml.

Intervention Type: DRUG

Eligibility Criteria

Inclusion Criteria

• aged from 18 to 65 years
• American Society of Anesthesiologists' physical I or II of both sexes
• Patients who will be scheduled to surgery for their uncomplicated hemorrhoids, anal fissure, or anal fistula in lithotomy position will be included in the study.

Exclusion Criteria

• Infection focus at back, history of spine surgery, coagulopathy, mental disturbance, and neurological disease.
• drug allergy.
• intake of experimental or analgesic medication within last 24 hours.
• patients receiving alpha-adrenergic antagonist will be excluded from the study.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 65 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Tanta University

OTHER

Sponsor Role: lead

Responsible Party

Ezzat Nasr Ezzat Alhelw

Resident

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

Tanta University

Tanta, Gharbia Governorate, Egypt

Countries

Egypt

Central Contacts

Ezzat Alhelw, Resident

Role: CONTACT

ezzatnasr136@gmail.com

+20 10 06489620

Facility Contacts

Ezzat Alhelw, Resident

Role: primary

ezzatnasr136@gmail.com

+20 10 06489620

Other Identifiers

36264MS785/12/24

Identifier Type: -

Identifier Source: org_study_id