Effects of propofol versus methohexital on neutrophil function and immune status in critically ill patients

Introduction

Sedatives (i.e. propofol and methohexital) have a variety of negative side effects on neutrophil leukocytes, lymphocytes and monocytes, which all play a vital role in the defense against invading microorganisms [1]. In this study, we investigated these effects in critically ill patients with long-term sedation.

Patients and methods

In this observative clinical study, we analyzed 21 critically ill patients with long-term sedation who either received propofol (n = 12, APACHE II score 26 ± 4) or methohexital (n = 9, APACHE II score 28 ± 6) after ICU admission. Patients in the propofol group (P) (nine males, three females) had a mean age of 55 ± 15 years. In the methohexital group (M) (eight males, one female) the mean age was 48 ± 18 years. Both sedatives were administered according to clinical requirements. Neutrophil leukocyte function was assessed as phagocytosis and respiratory oxidative burst activity. Furthermore, cellular markers of monocytes and lymphocytes (CD3, CD4, CD8, CD19, CD57, CD122) were assessed. Measurements were made on ICU admission, day 3, day 7 and day 14 of drug administration. Patients' demographics and results were compared by Mann–Whitney U test and one-way repeated-measures analysis of variance with an all pair-wise multiple comparison procedure.

Results

Both groups were well matched in terms of age, height and body weight. ICU length of stay was comparable (22 ± 7 days vs 20 ± 9 days). Mortality was 0/12 and 2/9, respectively. Absolute numbers of leukocytes and subpopulations were comparable between both groups at each time point. We found no difference in neutrophil oxidative burst and phagocytosis within and between both groups at the different time points. With respect to lymphocyte and monocyte CD marker expression, no differences within each group and between the time points were found.

Conclusion

Effects of methohexital and propofol on neutrophil leukocyte function, expression of lymphocyte and monocyte markers were not different in critically ill patients with long-term sedation.