Expansion of CD14+CD16+ monocytes in critically ill cardiac surgery patients

We have asked whether critically ill cardiac valve surgery patients identified by a high APACHE II score exhibit an increase in the number of proinflammatory CD14(+) CD16(+) monocytes. A group of 12 patients was studied over a period of 5 days post cardiac valve surgery for changes in blood monocyte populations. Patients were selected on day 1 post surgery to either be in good clinical condition (APACHE II Score of less than or equal to 14; N = 9) or to be critically ill (APACHE II score of greater than or equal to 24; N = 3). The less than or equal to 14 patients had an uneventful course and could leave the ICU after 2-3 days. Among the greater than or equal to 24 patients two showed a decrease of the score to less than or equal to 14 within the 5 days of observation and they could leave the ICU thereafter. One greater than or equal to 24 patient (patient #2) had a persistently high score and finally died on day 28. Analysis of blood monocytes on day 1 post surgery revealed that the less than or equal to 14 patients had normal values of CD14(+)CD16(+) monocytes (44 +/- 9/mu l). By contrast the greater than or equal to 24 patients had increased values of these cells with 243 +/- 106 cells per mu l on day 1. The numbers of CD14(+) CD16(+) monocytes returned to the control range over the 5 days of observation in 2 of the greater than or equal to 24 patients concomitant with the improvement of the APACHE II score. CD14(+)CD16(+) monocytes remained, however, at a high level in patient #2, the patient with persistently high APACHE II score.