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

In this retrospective study employing chart reviews, 75 open heart surgery patients (OHSPs) were divided into 3 groups of 25 patients. Group 1 received no intravenous (i.v.) norepinephrine (NE) after surgery. Group 2 and group 3 received a minimum of 0.028 mcg/kg/min of i.v. NE for 6-24 h and greater than 24 h, respectively. In the 3 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 h or more, compared to subjects of the other groups who received no NE or 6-24 h 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. Furthermore, postoperative infections were more prevalent in group 3 than the other 2 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 i.v. NE administration on the lymphocyte counts of OHSPs and to reduce infections in those receiving NE.