Red blood cell transfusion in non-bleeding critically ill patients with moderate anemia: is there a benefit?

PURPOSE: This study was undertaken to investigate the efficacy of red blood cell transfusion (RBCT) at reversing the deleterious effects of moderate anemia in critically ill, non-bleeding patients. METHODS: This was a retrospective, pair-matched (ratio 1:1) cohort study. Non-bleeding critically ill patients with moderate anemia (nadir hemoglobin level between 70 and 95 g/l), admitted to the ICU over a 27-month period, were included. Anemic patients were included upon meeting five matching criteria of having the same nadir hemoglobin (±5 g/l), APACHE II score (±5), SOFA score (±2), admission diagnostic group, and age (±5 years). Outcome events occurring over the whole ICU stay and after RBCT were collected. After hospital discharge, all patients had a 2-year follow-up period. RESULTS: Two hundred fourteen non-transfused anemic patients (NTAPs) were successfully matched with 214 transfused anemic patients (TAPs). In addition to the matching criteria, at baseline, both groups were homogenous with respect to multiple comorbidities. Compared with TAPs, NTAPs showed significantly lower rates of hospital mortality (21 vs.13 %, respectively; p < 0.05) and ICU re-admission (7.4 vs. 1.9 %, respectively; p < 0.05). Additionally, NTAPs had significantly lower rates of nosocomial infection (12.9 vs. 6.7 %, respectively; p < 0.05) and acute kidney injury (24.8 vs. 16.7 %, respectively; p < 0.05). Similar results were obtained in subgroup analysis where only more anemic patients (68 matched pairs) or patients with cardiovascular comorbidities (63 matched pairs) were considered. CONCLUSIONS: RBCT does not improve the clinical outcome in non-bleeding critically ill patients with moderate anemia.

Influence of red blood cell transfusion on CD4+ T-helper cells immune response in patients undergoing cardiac surgery.

BACKGROUND: Both surgical insult and red blood cell transfusion (RBCT) induce alterations in type-1/type-2, CD4T-helper cell balance. This study was aimed to determine the influence of RBCT on Th1 and Th2 function immune response in cardiac surgery patients. MATERIAL AND METHODS: Three blood samples were prospectively drawn from 81 cardiac surgery patients with cardiopulmonary bypass (CPB): preoperatively (preOP), during CPB, before RBCT (intraOP), and on postoperative day 1 (postOP). Immune response was assessed by flow cytometry measurement of the proportion of CD4(+)T-helper cells producing tumor necrosis factor (TNF)-α [Th1 response] and interleukin (IL)-10 [Th2 response]. RESULTS: Sixty-two patients were transfused (3.4 ± 2.3 units/patient), whereas 19 did not. Both groups were homogeneous, both at baseline and during surgery, regarding multiple perioperative clinical and laboratory variables, but postoperative blood loss and transfused RBC units were significantly higher in transfused versus nontransfused patients. In contrast, preoperative hemoglobin was significantly higher in nontransfused patients. CD4(+)T-helper cells significantly decreased in both groups of patients from preOP to intraOP 1 and from intraOP to postOP. In nontransfused patients, there were no significant changes in CD4(+)T-helper cells expressing TNFα or IL-10 among different sampling times. In contrast, RBCT resulted in a significant increment in Th2 response from intraOP to postOP (P=0.01), without affecting Th1 response. CONCLUSION: RBCT, but not surgery or CPB, induces a shift of the Th1/Th2 balance toward Th2 dominance.