USE OF 2-PERCENT-PROPOFOL TO PRODUCE DIURNAL SEDATION IN CRITICALLY-ILL PATIENTS

Objective:The assessment of propofol to produce diurnal sedation in cr itically ill patients Design: Prospective clinical study Setting: Inte nsive Care Unit, University Hospital Patients and participants: Thirty consecutive patients admitted to the Intensive Care Unit older than 1 8 years who were expected to be sedated for more than 50 h Interventio ns: The patients were randomised into two groups. All received sedatio n with a constant background infusion of morphine and a variable infus ion rate of propofol, which was altered hourly to maintain the intende d sedation score. The first group received constant light sedation (CL S) over 50 h aiming for a Ramsay score of 2-3. The second group receiv ed CLS between 0600 h and 2200 h and additional night sedation (ANS) w ith propofol between 2200 h and 0600 h, aiming for a sedation score of 4-5. Measurements and results: Patients were studied for 50 h from 18 00 h on the first day of admission. Recordings of heart rate, blood pr essure, sedation scores and propofol and morphine infusion rates were made hourly. An APACHE II score was recorded for each patient. Sedatio n scores were analysed by blind visual assessment and cosinor analysis , which is used in chronobiology to examine the correlation of data wi th a cosine curve. Patients in the ANS group had significantly better rhythmicity of sedation levels using cosinor analysis (r = 26 % v 8 %) p < 0.01. There was no difference between the CLS and ANS groups with respect to age, sex or APACHE II scores. Nine out of 15 patients in t he ANS group achieved diurnal sedation. Three patients in the CLS grou p showed diurnal rhythmicity of sedation, which can be attributed to n atural sleep, and had a median APACHE II score of 12. Five patients in the CLS group and three in the ANS group showed a deep constant sedat ion pattern. They had high APACHE II scores (median 21.5) and an obtun ded conscious level on admission due to severe sepsis. Conclusion: Pro pofol can safely provide diurnal sedation in the critically ill when t itrated against the Ramsay score. Sedation levels cannot be manipulate d in some severely ill patients.