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.
Descripción general del estudio
Estado
Intervención / Tratamiento
Tipo de estudio
Inscripción (Actual)
Fase
- Fase 4
Contactos y Ubicaciones
Ubicaciones de estudio
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London, Reino Unido, WC1N 3JH
- Great Ormond Street Hospital for Children NHS Trust
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Criterios de participación
Criterio de elegibilidad
Edades elegibles para estudiar
Acepta Voluntarios Saludables
Géneros elegibles para el estudio
Descripción
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
Plan de estudios
¿Cómo está diseñado el estudio?
Detalles de diseño
- Asignación: N / A
- Modelo Intervencionista: Asignación de un solo grupo
- Enmascaramiento: Doble
Armas e Intervenciones
Grupo de participantes/brazo |
Intervención / Tratamiento |
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Experimental: 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
Otros nombres:
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¿Qué mide el estudio?
Medidas de resultado primarias
Medida de resultado |
Periodo de tiempo |
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The absolute difference between the measured and predicted concentrations of propofol in micrograms per ml of blood.
Periodo de tiempo: 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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Medidas de resultado secundarias
Medida de resultado |
Medida Descripción |
Periodo de tiempo |
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Median Performance Error (MDPE)
Periodo de tiempo: 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)
Periodo de tiempo: 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
Periodo de tiempo: 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
Periodo de tiempo: 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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Colaboradores e Investigadores
Investigadores
- Director de estudio: Michael RJ Sury, FRCA PhD, Great Ormond Street Hospital for Children NHS Foundation Trust
- Investigador principal: Selvakumar Panchatsharam, MBBS FRCA, Great Ormond Street Hospital for Children NHS Foundation Trust
Fechas de registro del estudio
Fechas importantes del estudio
Inicio del estudio
Finalización primaria (Actual)
Finalización del estudio (Actual)
Fechas de registro del estudio
Enviado por primera vez
Primero enviado que cumplió con los criterios de control de calidad
Publicado por primera vez (Estimar)
Actualizaciones de registros de estudio
Última actualización publicada (Estimar)
Última actualización enviada que cumplió con los criterios de control de calidad
Última verificación
Más información
Términos relacionados con este estudio
Palabras clave
Términos MeSH relevantes adicionales
Otros números de identificación del estudio
- 12AR04
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