Blood Propofol Concentrations in Children During Spinal Surgery

Idiopathic Scoliosis Clinical Trial

Official title:

Comparison of Measured Versus Predicted Blood Propofol Concentrations During Total Intravenous Anaesthesia in Children Undergoing Spinal Surgery

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01932424
• Other study ID #: 12AR04
• Status: Completed
• Phase: Phase 4
• First received: August 13, 2013
• Last updated: August 29, 2013
• Start date: January 2013
• Est. completion date: July 2013

Study information

• Verified date: August 2013
• Source: Great Ormond Street Hospital for Children NHS Foundation Trust
• Contact: n/a
• Is FDA regulated: No
• Health authority: United Kingdom: Medicines and Healthcare Products Regulatory Agency
• Study type: Interventional

Clinical Trial Summary

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 20
• Est. completion date: July 2013
• Est. primary completion date: July 2013
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 5 Years to 18 Years

Eligibility

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

Study Design

Endpoint Classification: Pharmacokinetics Study, Intervention Model: Single Group Assignment, Masking: Double Blind (Subject, Caregiver)

Related Conditions & MeSH terms

• Idiopathic Scoliosis
• Neuromuscular Dystrophy
• Spine Deformities

Intervention

Device:
• Pelorus 1500
a bedside blood propofol measurement device

Drug:
• Propofol 2% (Diprivan 2%, Astra Zeneca UK)

Locations

Country	Name	City	State
United Kingdom	Great Ormond Street Hospital for Children NHS trust	London

Sponsors (1)

Lead Sponsor	Collaborator
Great Ormond Street Hospital for Children NHS Foundation Trust

Country where clinical trial is conducted

United Kingdom, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	The absolute difference between the measured and predicted concentrations of propofol in micrograms per ml of blood.		Up to 5 hours during the maintenance phase of anaesthesia, to allow a maximum of 10 samples at 20 to 30 min intervals.	No
Secondary	Median Performance Error (MDPE)	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.	Up to 5 hours during the maintenance phase of anaesthesia, to allow a maximum of 10 samples at 20 to 30 min intervals.	No
Secondary	Median Absolute Performance Error (MDAPE)	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.	Up to 5 hours during the maintenance phase of anaesthesia	No
Secondary	Wobble	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.	Up to 5 hours during the maintenance phase of anaesthesia	No
Secondary	Divergence	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.	Up to 5 hours during the maintenance phase of anaesthesia	No