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Comparative Dose-Response of Intrathecal Dexmedetomidine for Post-Spinal Shivering

ConditionPost-Spinal Shivering
Trial statusNot yet recruiting
Trial phasePhase 3
Trial typeInterventional
Biological sexAll
Age18-75
SponsorAl-Azhar University

About this trial

Dexmedetomidine, a highly selective α2-adrenergic agonist, when used intrathecally as an adjuvant to local anesthetics, prolongs sensory/motor block and may blunt thermoregulatory shivering mechanisms. Several randomized controlled trials and meta-analyses have demonstrated decreased shivering incidence with intrathecal dexmedetomidine, but reported doses vary (commonly 2.5, 5, and 10 µg, and in some trials up to 15-20 µg), and the balance between efficacy and adverse effects (sedation, bradycardia, and hypotension) is not fully established. Hence, a head-to-head randomized comparison of several low-to-moderate intrathecal doses is warranted.

Objective: to compare the safety and efficacy of three intrathecal dexmedetomidine doses (2.5 µg, 5 µg, 10 µg) versus placebo for the prevention of post-spinal shivering.

Eligibility criteria

This trial does not accept healthy volunteers

Qualifiers

Adult patients (age 18-75 years)

Scheduled for ureteric stone removal surgery

ASA(American Society of Anesthesiologists) physical status I, II, or III

Able to provide informed consent

Disqualifiers

Known allergy to dexmedetomidine, bupivacaine, or other study medications

Preexisting bradycardia (heart rate <50 beats per minute)

Second- or third-degree atrioventricular (AV) block without a pacemaker

Severe hepatic dysfunction

Trial design

Design model

Parallel

Treatments tested in this trial

  • Group P (Placebo Control Group)

    Drug

    Patients in this group will receive the standard spinal anesthetic consisting of hyperbaric bupivacaine 0.5% (15 mg) combined with an equivalent volume of normal saline (0.9% NaCl), containing no active dexmedetomidine. The total intrathecal injection volume will be standardized to 3.5 mL across all groups by adjusting the volume of saline added. This group serves as the control to establish the baseline incidence and characteristics of post-spinal shivering and block dynamics without the intervention of the α2-adrenergic agonist.

  • Group D2.5 (Low-Dose Dexmedetomidine Group)

    Drug

    Patients in this group will receive the standard spinal anesthetic (15 mg hyperbaric bupivacaine 0.5%) supplemented with a low dose of 2.5 µg of dexmedetomidine. Normal saline will be added to achieve the standardized total intrathecal volume of 3.5 mL.

  • Group D5 (Moderate-Dose Dexmedetomidine Group)

    Drug

    Patients in this group will receive the standard spinal anesthetic combined with a moderate dose of 5 µg of dexmedetomidine. The total volume will be adjusted to 3.5 mL with normal saline.

  • Group D10 (Higher-Dose Dexmedetomidine Group)

    Drug

    Patients in this group will receive the standard spinal anesthetic supplemented with a higher dose of 10 µg of dexmedetomidine, with normal saline used to standardize the total volume to 3.5 mL.

Treatment groups

120 Participants
are divided into 4 treatment groups
Group A: Group PPlacebo comparator 1 intervention
Group B: Group D2.5Experimental treatment 1 intervention
Group C: Group D5Experimental treatment 1 intervention
Group D: Group D10Experimental treatment 1 intervention

Trial outcomes

Primary outcomes

1

Incidence of clinically significant shivering

Incidence of clinically significant shivering within 60 minutes after spinal injection, defined as Crossley and Mahajan shivering scale grade ≥2 (scale 0-4)The highest intensity of shivering experienced by the patient, scored on the 0-4 scale. The Crossley and Mahajan shivering scale is a clinically validated, four-grade ordinal scale (0-4) used to objectively quantify the severity of post-anesthetic shivering. It is defined as follows: Grade 0 signifies no shivering; Grade 1 indicates mild, intermittent fasciculations of the face, neck, or chest; Grade 2 represents visible, intermittent shivering involving more than one muscle group; Grade 3 denotes generalized, continuous shivering of the whole body; and Grade 4 describes gross, bed-shaking tremors that interfere with monitoring or procedure. Grade ≥2 is typically considered clinically significant and often triggers therapeutic intervention. The scale is assessed through direct visual observation of the patient by trained personnel.

Time frame
Throughout the intraoperative period until 60 minutes post-spinal.

Secondary outcomes

1

Time to first shivering episode

The duration from the completion of the spinal injection to the onset of the first observable shivering (any grade).

Time frame
Intraoperative period, up to 60 minutes post-spinal.
2

Requirement of rescue anti-shivering drug

the number of patients required pharmacologic intervention (meperidine or tramadol) to treat severe shivering.

Time frame
Intraoperative period, as needed.
3

Dose of rescue anti-shivering drug

The total amount of pharmacologic intervention (meperidine or tramadol) to treat severe shivering.

Time frame
Intraoperative period, as needed.
4

Sedation level

The Ramsey Sedation Scale (RSS) is a simple, widely used six-level clinical tool (scores 1-6) for assessing a patient's level of sedation and responsiveness. It is scored as follows: 1 - Patient is anxious, agitated, or restless; 2 - Patient is cooperative, oriented, and tranquil; 3 - Patient responds only to commands; 4 - Patient exhibits a brisk response to a light glabellar tap or loud auditory stimulus; 5 - Patient exhibits a sluggish response to such a stimulus; and 6 - Patient exhibits no response to stimulus.

Time frame
Postoperative 24 hour

Other outcomes

Sponsors and contacts

Click on the lead sponsor to view all of their trials.

Al-Azhar University

Lead sponsor

Benha University

Collaborator

Source ClinicalTrials.gov

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