Effects of inotropes on human leucocyte numbers, neutrophil function and lymphocyte subtypes

We have investigated the effects of inotropes with different adrenergicreceptor specificity on differential white cell count, lymphocyte subtypesand neutrophil function in healthy volunteers. Six healthy, male volunteerswere enrolled into this randomized, placebo-controlled pilot study. Eachvolunteer was studied on four separate occasions during a 2-h infusion ofvarious agents, and for 2 h after stopping the infusion. The agentsinvestigated were adrenaline 0.1 microgram kg-1 min-1, dobutamine 5micrograms kg-1 min-1, dopexamine 2 micrograms kg-1 min-1 and 5% glucose0.5 ml kg-1 h-1. Venous blood was sampled at 0, 30, 120 and 240 min.Haemodynamic monitoring was continued throughout the study. Full bloodcount, white cell differential count and enumeration of lymphocyte subtypeswere performed. Neutrophil function tests included chemoluminescence, andassessment of neutrophil chemotaxis, phagocytosis and adhesion. TheWilcoxon signed rank test was used to compare differences between placeboand active drugs at each time compared with baseline. There was asignificant increase in white cell count, lymphocyte count and neutrophilcount with adrenaline, and a small but significant decrease in thesevariables with dobutamine and dopexamine. These changes were also apparentfor absolute CD3+, CD4+ and CD8+ lymphocyte counts. Neutrophil respiratoryburst in response to f-methionyl-leucyl-phenylalanine increasedsignificantly only with adrenaline at 30 min (P = 0.046). There were noother significant changes in tests of neutrophil function. Infusion ofinotropes was associated with changes in white cell numbers, lymphocytesubtypes and neutrophil respiratory burst. In healthy volunteers,adrenaline had effects different from those of dobutamine and dopexamine.The clinical relevance of such effects requires further investigation incritically ill patients.