A combination of Fentanyl and Propofol are the preferred drugs for analgesia and sedation. Fentanyl is to be given as single or double strength, as solutions of 10 or 20 g / ml through the Infuserite controller. Propofol should be given as a separate infusion of no more than 5 mg / kg / hour, for the first 24 hours, and then no more than 2.5 mg / kg / hour thereafter. Propofol infusion syndrome, typified by progressive CVS failure and metabolic acidosis, has been associated with sustained doses in excess of 4-5 mg/kg. Propofol generally should not exceed 1.5-2 mg / kg if sedation is required for more than four days. Nurses control agitation by using bolus Fentanyl through the Infuserite. If there is difficulty controlling agitation, then switch to the double strength, 20 g / ml, solution. Occasionally where there is extreme agitation causing the patient or staff to be at immediate risk, a manual bolus of Propofol 20-50mg can be given. If this happens the overall amount of sedation given is probably insufficient for that patient at that time. The Propofol infusion should be run at the maximal allowable rate and adjunct sedation such as a midazolam infusion or intermittent bolus diazepam should be considered. This may be a useful time to also consider adding haloperidol or a later generation antipsychotic agent such as olanzapine or quetiapine. Psychosis and thought disorders, which may be a driver for agitation, are part of the spectrum of delirium seen in critically ill patients.
The Infuserite also has an option to give bolus Fentanyl for uncomfortable procedures, such as inserting a central line. This option has no upper limit; however the extra Fentanyl given is not incorporated into the algorithm, which updates the background rate. Routine procedures such as turning and tracheal suction should be managed in the usual way by using the infusion bolus button.
Dexmeditomidine is a new α2 agonist, similar to Clonidine, but it induces sleep more readily. It is to be used on selected patients following discussion with the consultant on call. It may be particularly useful where there is severe agitation and hypertension in a patient who is likely to be extubated within 24 hours. The 4 µg solution is made up by the addition of one ampoule of 200 µg to 50 ml of saline. The infusion should be run at between 0.2 and 1.0 µg/kg/h. The maximum rate is equal to the patient's bodyweight / 4, e.g., the maximum infusion for 80kg patient is 20 ml per hour. A useful approach to loading the patient safely is to give the maximum dose for 2 hours (the half life) and then reduce this by half. Continue to titrate all other sedation according to the RASS.