Blood propofol concentrations in children undergoing spinal surgery

• Research type

  Research Study

• Full title

  Comparison of measured versus predicted blood propofol concentration in children undergoing spinal surgery

• IRAS ID

  107096

• Contact name

  Michael R J Sury

• Sponsor organisation

  London School of Hygiene and Tropical Medicine

• Eudract number

  2012-003790-25

• Research summary

  Major spinal surgery requires intra-operative evoked potential monitoring to detect spinal cord ischaemia. Inhalational anaesthetic agents suppress evoked potentials and therefore total intra-venous anaesthesia (TIVA) with propofol is used. Propofol is administered by a syringe infusion pump which has an algorithm within its microprocessor designed to achieve a set blood level. This system is called a target controlled infusion (TCI). The TCI algorithm is based on pharmacokinetic data, previously collected in a relatively small number of patients, and is derived from a ??best fit? relationship between blood levels, infusion rates and other factors (such as the age and weight). Several factors make it possible for a wide discrepancy between the predicted target and actual blood levels. In children, pharmacokinetic inter-patient variability is a problem and performance errors in published pharmacokinetic models are high. Spinal surgery in children is a prolonged procedure lasting up to 5 hours and often has major blood loss. In these patients the difference between predicted and actual propofol blood levels could be appreciable and may have serious consequences. Low and high blood propofol levels can cause intraoperative awareness and cardiovascular depression respectively. No data are available in children having spinal surgery. Furthermore measurement of blood propofol takes too long and is expensive. The Pelorus 1500 Propofol analyser is a new bedside tool that measures blood propofol in a few minutes from less than 1ml of blood. This observational study will investigate the difference between the measured and predicted blood propofol concentrations in children having spinal surgery and determine the need for measurement of propofol blood levels at the bedside.

• REC name

  London - Bloomsbury Research Ethics Committee

• REC reference

  12/LO/1847

• Date of REC Opinion

  21 Dec 2012

• REC opinion

  Further Information Favourable Opinion