Persisting blood propofol in the critically ill and levels of sedation
Research type
Research Study
Full title
Persisting blood propofol levels in the critically ill and levels of sedation following the termination of a long term (>72 hours)infusion
IRAS ID
123583
Contact name
David Brealey
Contact email
Sponsor organisation
University College London
Research summary
Patients who are critically ill, frequently require intravenous sedtion to allow them to tolerate the interventions they are receiving e.g. mechanical ventilation. Propofol is commonly used for this purpose as it is easily titrateable and after short infusions rapidly reversible. However the side effects of propofol are significant; low blood pressure, respiratory depression, suppression of the immune system and an association with delirium. The physical properties of the drug allow it to distribute widely throughout the body including areas with poor blood supply such as fat. After prlonged infusions these poorly perfused areas may become saturated with propofol. On cessation of the infusion they may then act as a reservoir slowly leaking propofol back into the circulation thus prolonging the clinical effect. The concern to the clinician is differentiating the clinical side effects of residual propofol from other pathologies such as sepsis.
There is little data in this area, as measuring blood propofol levels has been technically difficult and expensive to perform, however the literature can demonstrate propofol in individuals days after a prolonged infusion has stopped. This study aims to use the Pelorus 1500 (Sphere), which now allows a rapid assay (5 minutes)of propofol levels in whole blood on the ward. The device itself will sit within the laboratory area of the critical care unit and is not attached to the patient in any way. Propofol levels will be compared to the patient’s level of sedation as assessed by both a depth of sedation monitor (BIS)and a routine clincal score (Richmond Agitation Scoring System). The BIS monitor is available within our unit and measures a composite of an electroencephalogram via a sticker applied to the forehead. The presence or absence of delirium will be assessed by the routinely applied Confusion Assessment Method for the Intensive Care Unit score.
REC name
London - Harrow Research Ethics Committee
REC reference
13/LO/1114
Date of REC Opinion
23 Sep 2013
REC opinion
Further Information Favourable Opinion