Intravenous Dexamethasone for Prolonging Sensory Block in Spinal Anesthesia

Tunis University120 enrolled

Overview

The goal of this clinical trial is to learn if intravenous dexamethasone can help prolong the effect of spinal anesthesia in adults having elective pelvic, urologic, or proctologic surgery. The study also looks at whether dexamethasone improves pain control after surgery and whether it causes any side effects. The main questions it aims to answer are: Does intravenous dexamethasone increase how long the spinal anesthesia lasts? Does it reduce the need for pain medications after surgery? Does it cause more or fewer side effects compared to a placebo? In this study: Participants were randomly assigned to receive either 8 mg of intravenous dexamethasone or a placebo (salt water). All participants received standard spinal anesthesia with bupivacaine and sufentanil. Researchers measured how long the spinal anesthesia lasted and when the first pain medication was needed after surgery. Participants were monitored for side effects such as low blood pressure, nausea, vomiting, and slow heart rate. Surgeon satisfaction with anesthesia quality was also recorded. Participants did not receive any additional procedures beyond routine care. The study found that dexamethasone helped prolong the spinal anesthesia and delayed the need for pain relief, without increasing side effects.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

TRIPLE

Enrollment

120

Conditions

Spinal Anesthesia Postoperative Pain Management

Interventions

DexamethasoneDRUG

Single intravenous injection of 8 mg dexamethasone (2 mL) administered 5 minutes before spinal anesthesia. This intervention was tested for its effect on prolonging the duration of sensory and motor blocks induced by hyperbaric bupivacaine combined with sufentanil. The drug was administered under sterile conditions by an anesthesiologist blinded to group allocation.

PlaceboDRUG

Single intravenous injection of 2 mL isotonic saline (0.9% NaCl) administered 5 minutes before spinal anesthesia. This placebo was used to mimic the dexamethasone injection in the control group. The preparation, volume, and timing were identical to the intervention group to maintain blinding. The saline was administered under sterile conditions by an anesthesiologist blinded to group allocation.

Eligibility

Sex: ALLMin age: 18 YearsMax age: 80 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Adult patients aged 18 to 80 years ASA physical status I or II Scheduled for elective pelvic surgery under spinal anesthesia (urologic, inguinal, or proctologic procedures) Provided informed consent Exclusion Criteria: * Known allergy to dexamethasone or local anaesthetics Contraindications to spinal anesthesia Neurological diseases Chronic use of corticosteroids or immunosuppressants BMI \> 40 kg/m² Refusal to participate

Outcomes

Primary Outcomes

Duration of sensory block

The duration of the sensory block was defined as the time from intrathecal injection of the local anesthetic until regression of sensory level to the L1 dermatome, as assessed by pinprick test every 15 minutes postoperatively. This endpoint was selected to evaluate the effect of intravenous dexamethasone on prolonging the duration of spinal anesthesia.

Time frame: From the time of spinal injection until sensory regression to L1 dermatome (up to 4 hours postoperatively)

Secondary Outcomes

Duration of motor block

The duration of the motor block was defined as the time from intrathecal injection until achieving a modified Bromage score of 3, which corresponds to partial motor recovery (able to move knees). The modified Bromage score was assessed every 15 minutes postoperatively. This measure was used to assess whether intravenous dexamethasone prolongs motor block following spinal anesthesia.

Time frame: From the time of spinal injection until modified Bromage score = 3 (up to 4 hours postoperatively)

Time to first analgesic request

Time from intrathecal injection to the first request for postoperative analgesia, defined as the moment when the patient reported a pain score ≥ 3 on a visual analog scale (VAS, 0-10). This was recorded in minutes starting from the time of spinal anesthesia. The aim was to assess whether intravenous dexamethasone prolongs the duration of effective postoperative analgesia.

Time frame: From spinal injection until VAS score ≥ 3 and first analgesic request (up to 6 hours postoperatively)

Incidence of adverse events

Adverse events occurring during the surgical procedure were systematically recorded. These included hypotension (systolic BP \< 90 mmHg), bradycardia (HR \< 50 bpm), nausea, vomiting, pruritus, and any signs of discomfort or neurological complications. All events were recorded as present or absent and compared between the dexamethasone and placebo groups to assess the safety profile of intravenous dexamethasone during spinal anesthesia.

Time frame: From spinal injection until the end of surgery

Surgeon satisfaction score

Surgeon satisfaction with the quality of intraoperative anesthesia was assessed using a binary score (Satisfied / Not satisfied). The evaluation was based on intraoperative conditions such as patient immobility, comfort, and adequacy of anesthesia. The rating was collected at the end of surgery to compare the perceived quality between the dexamethasone and placebo groups.

Time frame: Immediately after the end of surgery