The effects of norepinephrine infusion on the circulating lymphocyte counts of post open heart surgery patients

Abstract

In this retrospective study employing chart reviews, 75 open-heart surgery patients (OHSPs) were divided into three groups of 25 patients. Group 1 received no intravenous (IV) norepinephrine (NE) after surgery. Group 2 and Group 3 received a minimum of 0.028 mcg/kg/minute of IV NE for 6-24 hour and 24-36 hour respectively. In the three groups, preoperative lymphocyte counts were compared to counts obtained on postoperative days 1 and 2. The results showed lower lymphocyte counts on postoperative day 2 in group 3 subjects, who received NE for 24 hours or more, compared to subjects of the other groups who received no NE or 6-24 hours of NE (p<0.05). There was also evidence that preoperative use of beta-blocking agents significantly affected the change in lymphocyte counts from day 1 to day 2 in both groups receiving NE. Further, postoperative infections were more prevalent in group 3 than the other two groups (p<0.05). The lower lymphocyte counts and higher infection rate, however, may be linked to lower postoperative blood pressure and increased number of intensive care unit days in group 3. Further investigation is warranted to elucidate the effects of IV NE administration on the lymphocyte counts of OHSPs and to reduce infections in those receiving NE.