Annual Scientific Meeting - 2001

Patient controlled Propofol Sedation

Dr Laurence Cook

Self administered sedation is not new.  For thousands of years surgery has been performed with the aid of ethyl alcohol, cocaine, cannabis, opium etc.  Inhaled volatile agents have been self administered for sedation and analgesia since their discovery. 

Patient-controlled intra-venous analgesia has been used for many years.  Substitute a sedative for the opioid and patients can control their own sedation for many procedures. 

There are advantages in allowing patient-controlled iv sedation (PCS).  Medical staff are freed from the task.  Patients generally like it.  Patients find being in control of their own sedation immensely reassuring, are less anxious and choose to take less drug.  And it may be safer.

There are differences between patient controlled sedation and the more familiar patient controlled analgesia (PCA).  The time scale is shorter and the volumes to be infused generally larger, especially if 1% propofol is used.   The infusion device must be capable of the necessary high flow rates. 

There is great variation in the doses of propofol required for sedation.  How can one regime allow patients to be adequately sedated without allowing any to become anaesthetised?  A partial answer is that when patients become sedated they slow down their demands for sedation.  And, when they fall asleep, drug delivery ceases.  However, if drug delivery is sufficiently high then it might be possible to self-administer an overdose before consciousness was lost.