Post-Spinal Shivering
Conditions
Keywords
Intrathecal Dexmedetomidine
Brief summary
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.
Interventions
DRUGGroup P (Placebo Control Group)
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.
DRUGGroup D2.5 (Low-Dose Dexmedetomidine Group)
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.
DRUGGroup D5 (Moderate-Dose Dexmedetomidine Group)
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.
DRUGGroup D10 (Higher-Dose Dexmedetomidine Group)
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.
Sponsors
Benha University
Al-Azhar University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
DOUBLE (Subject, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 75 Years
Healthy volunteers
No
Inclusion criteria
* 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
Exclusion criteria
* 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 * Uncontrolled hypotension * Pregnancy * Chronic use of α₂-agonists or antagonists (e.g., clonidine, tizanidine) * Infection at the planned spinal puncture site * Coagulopathy or bleeding disorder * Inability to rate or communicate shivering (e.g., language barrier, cognitive impairment)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Incidence of clinically significant shivering | Throughout the intraoperative period until 60 minutes post-spinal. | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Requirement of rescue anti-shivering drug | Intraoperative period, as needed. | the number of patients required pharmacologic intervention (meperidine or tramadol) to treat severe shivering. |
| Dose of rescue anti-shivering drug | Intraoperative period, as needed. | The total amount of pharmacologic intervention (meperidine or tramadol) to treat severe shivering. |
| Time to first shivering episode | Intraoperative period, up to 60 minutes post-spinal. | The duration from the completion of the spinal injection to the onset of the first observable shivering (any grade). |
| Patient satisfaction | Postoperatively (e.g., prior to discharge from PACU). | The patient's overall satisfaction with the anesthesia experience.Using a Likert scale (e.g., 1-5 or 1-10) or a standardized satisfaction questionnaire. |
| Time to first analgesic request | 24 hours Postoperatively. | The duration from the end of surgery until the patient first requires supplemental pain medication. |
| Sedation level | Postoperative 24 hour | 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. |
Countries
Egypt
Contacts
Primary ContactNeveen A Kohaf, Ph.D
Outcome results
None listed