Blood Propofol Concentrations in Children During Spinal Surgery
Comparison of Measured Versus Predicted Blood Propofol Concentrations During Total Intravenous Anaesthesia in Children Undergoing Spinal Surgery
During major spinal surgery evoked potential monitoring is performed to detect spinal cord damage. Intra-venous anaesthesia is the preferred anaesthetic technique because volatile anaesthetic agents supress the evoked potentials. Total Intra-Venous Anaesthesia (TIVA) with propofol is commonly administered as a Target Controlled Infusion (TCI). The TCI is an automated drug delivery system which administers propofol to achieve a desired blood concentration, based on an in built pharmaco-kinetic data (TCI model) derived from previous studies. The TCI model also provides a real time predicted blood concentration to facilitate the anaesthetist to adjust the target concentration of propofol.
The TCI algorithm is based on pharmaco-kinetic data derived from previous studies in a relatively small number of patients, by a "best fit" relationship between blood levels, infusion rates and other factors (such as age and weight). Several factors make it possible for a wide discrepancy between the predicted and the true blood concentrations. This difference can be higher in children compared to adults. Also blood loss and administration of large volumes of intravenous fluids can affect the blood concentrations. This study aims to identify the difference between the predicted and true blood concentrations by using Pelorus 1500, a bedside blood propofol measurement device, in children undergoing major spinal surgery under TIVA.
Studie Overzicht
Toestand
Interventie / Behandeling
Studietype
Inschrijving (Werkelijk)
Fase
- Fase 4
Contacten en locaties
Studie Locaties
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London, Verenigd Koninkrijk, WC1N 3JH
- Great Ormond Street Hospital for Children NHS Trust
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Deelname Criteria
Geschiktheidscriteria
Leeftijden die in aanmerking komen voor studie
Accepteert gezonde vrijwilligers
Geslachten die in aanmerking komen voor studie
Beschrijving
Inclusion Criteria:
- Children undergoing major spinal surgery under propofol TCI
- Surgery expecting to last more than 3 hours.
Exclusion Criteria:
- Major hepatic or renal disease
Studie plan
Hoe is de studie opgezet?
Ontwerpdetails
- Toewijzing: NVT
- Interventioneel model: Opdracht voor een enkele groep
- Masker: Dubbele
Wapens en interventies
Deelnemersgroep / Arm |
Interventie / Behandeling |
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Experimenteel: Single arm
The intervention in this study involves taking blood sample from an existing arterial line for measurement of blood propofol levels.
The drug in evaluation is Propofol 2% (Diprivan 2%, Astra Zeneca UK) administered as a target controlled infusion using the commercially available paediatric TCI models (Paedfusor and Marsh models).
The dose range is usually between a target concentration of 3-8 mcg/ml.
However the anaesthetic management is not changed for the study.
The blood concentrations of propofol will be measured using Pelorus 1500 (Sphere Medical, UK), a CE marked device.
The anaesthetist will be blinded from the measurements, unless the measured value was outside the safe limit ( < 3 mcg/ml or > 10mcg/ml).
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a bedside blood propofol measurement device
Andere namen:
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Wat meet het onderzoek?
Primaire uitkomstmaten
Uitkomstmaat |
Tijdsspanne |
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The absolute difference between the measured and predicted concentrations of propofol in micrograms per ml of blood.
Tijdsspanne: Up to 5 hours during the maintenance phase of anaesthesia, to allow a maximum of 10 samples at 20 to 30 min intervals.
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Up to 5 hours during the maintenance phase of anaesthesia, to allow a maximum of 10 samples at 20 to 30 min intervals.
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Secundaire uitkomstmaten
Uitkomstmaat |
Maatregel Beschrijving |
Tijdsspanne |
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Median Performance Error (MDPE)
Tijdsspanne: Up to 5 hours during the maintenance phase of anaesthesia, to allow a maximum of 10 samples at 20 to 30 min intervals.
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The median value of ratio between the measured and predicted concentration of propofol to the predicted concentration (Performance error) in blood.
Expressed as a percentage.
This is a measure of overall bias of the target controlled infusion.
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Up to 5 hours during the maintenance phase of anaesthesia, to allow a maximum of 10 samples at 20 to 30 min intervals.
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Median Absolute Performance Error (MDAPE)
Tijdsspanne: Up to 5 hours during the maintenance phase of anaesthesia
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The median value of the ratio of the absolute difference (excluding the sign) between the measured and predicted concentrations to the predicted concentration (Absolute performance error) in blood.
Expressed as percentage.
This is a measure of the accuracy of the target controlled infusion.
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Up to 5 hours during the maintenance phase of anaesthesia
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Wobble
Tijdsspanne: Up to 5 hours during the maintenance phase of anaesthesia
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The median value of the difference between the individual performance errors and the Median Performance Error (MDPE).
This is a measure of the distribution of the performance errors around the median.
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Up to 5 hours during the maintenance phase of anaesthesia
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Divergence
Tijdsspanne: Up to 5 hours during the maintenance phase of anaesthesia
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The median of the regression coefficient of the performance error against time.
This is a measure of how the target controlled infusion performs with time.
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Up to 5 hours during the maintenance phase of anaesthesia
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Medewerkers en onderzoekers
Onderzoekers
- Studie directeur: Michael RJ Sury, FRCA PhD, Great Ormond Street Hospital for Children NHS Foundation Trust
- Hoofdonderzoeker: Selvakumar Panchatsharam, MBBS FRCA, Great Ormond Street Hospital for Children NHS Foundation Trust
Studie record data
Bestudeer belangrijke data
Studie start
Primaire voltooiing (Werkelijk)
Studie voltooiing (Werkelijk)
Studieregistratiedata
Eerst ingediend
Eerst ingediend dat voldeed aan de QC-criteria
Eerst geplaatst (Schatting)
Updates van studierecords
Laatste update geplaatst (Schatting)
Laatste update ingediend die voldeed aan QC-criteria
Laatst geverifieerd
Meer informatie
Termen gerelateerd aan deze studie
Trefwoorden
Aanvullende relevante MeSH-voorwaarden
Andere studie-ID-nummers
- 12AR04
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