This is a study to check the effect of blood flow to the brain after increase in blood pressure when using a drug called Dexmedetomidine in patients with brain tumours.
- Conditions
- patients with intracranial tumour and patients posted for spinal cord procedures (no intracranial pathology)
- Registration Number
- CTRI/2016/02/006680
- Lead Sponsor
- Sri Chitra Tirunal Institute for Medical Science and Technology
- Brief Summary
Cerebralautoregulation is the intrinsic ability of the brain to maintain stable cerebralblood flow while mean arterial blood pressure and cerebral perfusion pressureare changing. It constitutes a regulatory mechanism to provide metabolicsubstrates under physiological and pathological conditions.
Impairedautoregulation is demonstrated in the scenario of decreased perfusion pressurewith the use of inj. Dexmedetomidine (dynamic autoregulation). On the otherhand when there is increase in perfusion pressure preliminary studies showedthat autoregulation is maintained but the clinical and statistical significancewas not discussed (static autoregulation).
Thus our study is designed to assess the effectof initial dose Dexmedetomidine (1mcg/Kg over 10 minutes) in static cerebral bloodflow autoregulation. Infusion of Inj.Phenylephrine (0.01%) will be used and cerebralblood flow velocities will be measured with the use of transcranial Doppler. As there is scarcity of data on this phenomenon especially in patients with intracranial pathology, this study is designed to address this issue in patients with intracranial tumours.
**Proposedstudy protocol:**
· Informedconsent will be taken from Patients satisfying inclusion criteria. Consentingpatients will be included in the study protocol.
· Patientwill be shifted in to operating room. Monitors will be attached and baselineHeart rate(HR), non invasive blood pressure(BP), respiratory rate (RR), SpO2,End tidal Carbon dioxide (EtCO2) will berecorded.
· BilateralTranscranial colour Doppler imaging to ensure adequate temporal bone window andadequate insonation of middle cerebral arteries.
· UnderLignocaine (2%) skin infiltration I.V access and arterial access will beobtained.
· Inj.Glycopyrrolate0.2mg will be given by intravenous route.
**Baselineanalysis :**
· Rightand left Middle cerebral artery (MCA) flow velocities will be recorded withTranscranial colour Doppler twice with 1 minute interval (Right MCA, Left MCA →1 minute → Right MCA, Left MCA).
· Meanarterial pressure will be increased gradually by 20mmHg with infusion ofInj.Phenylephrine (0.01%). After achieving steady state of blood pressure,infusion will be stopped.
· TranscranialDoppler analysis of Right MCA and Left MCA flow velocities after steady state increasein blood pressure (Right MCA, Left MCA → 1 minute → Right MCA, Left MCA).
Inj.Dexmedetomidinewill be given as infusion (1mcg/Kg/10 min) by infusion pump.
Vital parameters (HR/IBP/RR/SpO2/EtCO2)will be monitored continuously during administration of Inj.Dexmedetomidine.
**Analysisafter administration of Dexmedetomidine :**
· Vitalparameters monitoring ( HR/IBP/RR/SpO2/EtCO2 ) will be continued.
· Rightand left Middle cerebral artery (MCA) flow velocities will be recorded withTranscranial colour Doppler twice with 1 minute interval (Right MCA, Left MCA →1 minute → Right MCA, Left MCA).
· Meanarterial pressure will be increased gradually by 20mmHg with infusion ofInj.Phenylephrine (0.01%). Afterachieving steady state of blood pressure, infusion will be stopped.
· TranscranialDoppler analysis of Right MCA and Left MCA flow velocities after steady stateincrease in blood pressure (Right MCA, Left MCA → 1 minute → Right MCA, LeftMCA).
After study period Inj.Dexmedetomidine will be continued introperatively in the dose of 0.4 to 0.6mcg/Kg/Hour as an adjuvant to anaesthetic agents.
Average flow velocityof MCA will be calculated from the repeated measurements and used for analysis.
Static rate ofautoregulation (sROR) will be calculated during baseline and after infusion ofInj.Dexmedetomidien (1mcg/Kg /10min).
**sROR = ([i]Vmca/[f]Vmca -[i]MABP/[f]MABP) / (1- [i]MABP/[f]MABP) X 100%.**
*[i] Vmca- baseline MCA flow velocity*
*[f] Vmca - MCA flow velocity after mean bloodpressure increase of 20mmHg*
*[i] MABP - baseline Mean arterial blood pressurebefore Inj.Phenylephrine.*
*[f] MABP - Mean arterial blood pressure after steadystate ( 20mmHg increase)*
An sROR of 100% implies perfect autoregulation and 0% implies absent autoregulation. Forclinical application less than 50% or adecreasing trend towards 0% signifiesimpaired autoregulation.
- Detailed Description
Not available
Recruitment & Eligibility
- Status
- Open to Recruitment
- Sex
- All
- Target Recruitment
- 20
- Two groups of patients will be included (10 patients in each group) •Group I – patient with unilateral supra tentorial tumours •Group II – patients with no intra cranial pathology (lumbar spinal cord procedures) Inclusion criteria: •Patients categorized as American society of Anesthesiology (ASA) class 1 and 2.
- •Age 18-40 years.
- •Glasgow coma scale 15.
- •patients with unilateral tumour in supratentorial compartment like glioma and meningioma (GroupI) •Patients posted for lumbar spinal cord procedures including laminectomy, discectomy and spinal cord tumour excision (Group II).
- •Patient refusal •American society of Anesthesiology (ASA) class III and above •Age less than 18 years and more than 40 years.
- •Emergency surgery •Presence of intracranial vascular abnormalities ( Aneurysm, Arterio venous malformation) •Known allergy to Dexmedetomidine or any α2 agonists.
- •Known allergy to Inj.
- Phenylephrine •Preoperative heart rate <50 bpm, Presence of Heart block.
- •Systemic hypertension stage III & above •Antihypertensive medication with α-methyldopa or Clonidine.
- •Patient on beta blockers •Presence of Coronary artery disease, Left ventricular dysfunction, •Pregnant or Nursing woman.
- •Abnormal temporal bone window for transcranial Doppler insonation •Difficulty in localizing intracranial vasculature by Transcranial color Doppler •Participation in another drug study during the preceding 1 month period.
Study & Design
- Study Type
- Interventional
- Study Design
- Not specified
- Primary Outcome Measures
Name Time Method static cerebral vascular autoregulation 1. Baseline and | 2.After administration of Dexmedetomidine (10 minutes after baseline)
- Secondary Outcome Measures
Name Time Method mean flow velocity of middle cerebral artery and Pulsatility index, cerebral perfusion pressure derived from flow velocity data. 1. baseline
Trial Locations
- Locations (1)
Room No:600, Neuro OT complex, Fourth floor, Department of Anaesthesiology
🇮🇳Thiruvananthapuram, KERALA, India
Room No:600, Neuro OT complex, Fourth floor, Department of Anaesthesiology🇮🇳Thiruvananthapuram, KERALA, IndiaArulvelanPrincipal investigator9048842282drarulvelan@gmail.com