The effect of dexmedetomidine on the control of the brains blood flow in children, as assessed by doppler ultrasound of the blood vessels in the brain when under anaesthesia
- Registration Number
- CTRI/2024/05/066764
- Lead Sponsor
- Dr Mathew George
- Brief Summary
Dexmedetomidine is a widely used anaesthetic adjunct and sedative agent, that has been touted to offer numerous benefits to both neurosurgical patients and children undergoing surgery.
The transient hyperaemic response (THR) test is a simple, non-invasive technique to evaluate cerebral auto-regulation using transcranial doppler.
The purpose of this study is to assess the effect of dexmedetomidine on cerebral autoregulation in children under anaesthesia using the THRR (Transient hyperaemic response ratio) in otherwise normal children undergoing spine surgery.
We are planning to conduct the study on patients of <14 years of age, of ASA Grade I, II of either gender who are undergoing spine surgery
We will exclude - 1)Age <3 months and >14years
2)Patients with known allergy to any of the drugs used in the study (general anaesthetics, dexmedetomidine)
3)Disturbed intracranial dynamics that may affect TCD readings –untreated hydrocephalus, craniosynostosis
Patients randomly allotted to Group D or Group S based on computer generated random sequence of numbers
Following a standardized induction of anaesthesia, they will be intubated and ventilated with sevoflurane at an end-tidal concentration of 1% or age adjusted 0.5% MAC in a 50% air-oxygen mixture and ventilated using volume control ventilation with a tidal volume of 8 ml/kg and a rate adjusted to an EtCO2 of 35 mm of Hg. The patient will receive the test drug according to the group they have been enrolled in.The syringe will be labelled as "Test Drug" and will be infused at a rate of (bodyweight \*1.5) ml per hour. Patients enrolled in group D, the drug will be dexmedetomidine, while patients in group S the drug will be normal saline.
Following the loading dose, TCD recordings will be taken (upto 3 sets). Transcranial doppler measurement of the right Middle Cerebral Artery M1 segment (rMCA) ill be insonated through the temporal bone window. Transcranial doppler measurements will be made using a portable RIMED Digi-One TCD system using a 2MHz probe
After noting the baseline value of rMCA peak flow, the patient will be subjected to upto 3 compressions of the right carotid artery in the neck for 10 seconds, to produce a maximum decrease in the rMCA velocity, with at least 1 minute elapsing between each compression.
The peak flow velocities of rMCA
1. before compression(F1),
2. during compression (F2),
3. immediately following release (F3)
will be noted and stored digitally as screenshots.
Transient Hyperaemic Response Ratio=F3/F1
a value of more than 1.09 indicates intact autoregulation.
Strength of Autoregulation (SA) :
SA= (F3xP2)/(MAPxF1)
P2 –denotes the MCA pressure at the beginning of compression, calculated as
MAPxF2/F1 or taken as 60 mm of Hg.
SA will be calculated only in patients in whom an arterial line is placed as indicated for patient management.
- Detailed Description
Not available
Recruitment & Eligibility
- Status
- Open to Recruitment
- Sex
- All
- Target Recruitment
- 30
Patients undergoing spine surgery under Motor Evoked Potential monitoring.
1)Age <3 months and >14years 2)Patients with known allergy to any of the drugs used in the study (general anaesthetics, dexmedetomidine) 3)Disturbed intracranial dynamics that may affect TCD readings –untreated hydrocephalus, craniosynostosis.
Study & Design
- Study Type
- Interventional
- Study Design
- Not specified
- Primary Outcome Measures
Name Time Method Transient Hyperaemic Response Ratio (THRR) measured from the right middle cerebral artery measurements of THRR will be made 10 minutues after induction of anaesthesia, before the commencement of the surgery
- Secondary Outcome Measures
Name Time Method Strength of Autoregulation(SA) will be calculated as a secondary outcome Measurements will be taken 10 minutes after the induction of anaesthesia, & before the commencement of surgery
Trial Locations
- Locations (1)
Amrita Institute of Medical Sciences and Research Center, Kochi
🇮🇳Ernakulam, KERALA, India
Amrita Institute of Medical Sciences and Research Center, Kochi🇮🇳Ernakulam, KERALA, IndiaDr Mathew GeorgePrincipal investigator9447841795mathew.doc@gmail.com