The Lowest Effective Dose of Dexmedetomidine in Attenuating the Hemodynamic Responses During Skull Pin Insertion in Patients Undergoing Elective Craniotomy

Study Overview
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Brief Summary
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Skull pins are used to immobilize the head during craniotomy. Fixation of skull pins causes acute hemodynamic changes which may affect cerebral autoregulation and hence cerebral blood flow. Therefore, maintenance of stable hemodynamic parameters during skull pin placement under general anesthesia is crucial to ensure adequate cerebral perfusion and prevention of acute rise of intracranial pressure

Detailed Description
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Many different strategies have been used to minimize the hemodynamic responses to skull pin placement with varying results. Local anesthetic infiltration at pin application sites has been used but was always unsuccessful in obtunding the hemodynamic responses to skull pin placement. Dexmedetomidine, an alpha-2 adrenoceptor agonist, has been recently introduced as a sedative for patients on mechanical ventilation. In addition to its sedative effect; Dexmedetomidine has significant analgesic qualities and has been labeled as analgesia-sparing. To the best of the investigator's knowledge, few studies investigated Dex use to suppress hemodynamic responses to skull pinning. The aim of the current study was to evaluate the lowest effective dose of Dexmedetomidine in attenuating the hemodynamic responses to skull pin placement for craniotomies. Lidocaine, administered subcutaneously at the head-holder pin sites, was more effective in preventing the blood pressure response to skull-pin than was deepening the level of anesthesia.

Official Title
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Assessment of the Lowest Effective Dose of Dexmedetomidine in Attenuating the Hemodynamic Responses During Skull Pin Insertion in Patients Undergoing Elective Craniotomy: Randomized Control Study

Conditions
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Skull Pin Insertion

Intervention / Treatment
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* Drug: Dexmedetomidine Injection [Precedex]
* Other: normal saline 0.9%


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 120 Adult patients, undergoing elective craniotomy ASA I and II patients Exclusion Criteria: patients undergoing craniotomy for emergency surgery, raised ICP, obese patients (body mass index >30 kg/m2 for males and 28 kg/m2 for females), patients having systemic comorbidities (cardiac, renal, hepatic, and endocrinal), hypertensive patients (including those detected after admission), patients undergoing intracranial aneurysm clipping

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: group I (placebo)<br>will receive intravenous normal saline (NS) | Other: normal saline 0.9%<br>* will receive intravenous normal saline 0.9%<br>|
| Experimental: group II (Dex 0.5)<br>will receive intravenous Dex 0.5 mcg/kg | Drug: Dexmedetomidine Injection [Precedex]<br>* will receive intravenous Dexmedetomidine<br>* Other names: Dexmedetomidine;|
| Experimental: group III (Dex 0.25)<br>will receive intravenous Dex 0.25 mcg/kg | Drug: Dexmedetomidine Injection [Precedex]<br>* will receive intravenous Dexmedetomidine<br>* Other names: Dexmedetomidine;|
| Experimental: group IV (Dex 0.2)<br>will receive intravenous Dex 0.2 mcg/kg. | Drug: Dexmedetomidine Injection [Precedex]<br>* will receive intravenous Dexmedetomidine<br>* Other names: Dexmedetomidine;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| arterial blood pressure change | systolic and diastolic blood pressure mmhg | before Skull Pin Insertion till 20 minutes | 
| heart rate change | heart rate beat/minute | before Skull Pin Insertion till 20 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Dexmedetomidine, Skull Pin Insertion, Hemodynamic Responses