Impaired red blood cell deformability after transfusion of stored allogeneic blood but not autologous salvaged blood in cardiac surgery patients.

BACKGROUND: Both cardiopulmonary bypass (CPB) and red blood cell (RBC) storage are associated with detrimental changes in RBC structure and function that may adversely affect tissue oxygen delivery. We tested the hypothesis that in cardiac surgery patients, RBC deformability and aggregation are minimally affected by CPB with autologous salvaged blood alone but are negatively affected by the addition of stored allogeneic blood. METHODS: In this prospective cohort study, 32 patients undergoing cardiac surgery with CPB were divided into 3 groups by transfusion status: autologous salvaged RBCs alone (Auto; n = 12), autologous salvaged RBCs + minimal (<5 units) stored allogeneic RBCs (Auto+Allo min; n = 10), and autologous salvaged RBCs + moderate (≥5 units) stored allogeneic RBCs (Auto+Allo mod; n = 10). Ektacytometry was used to measure RBC elongation index (deformability) and critical shear stress (aggregation) before, during, and for 3 days after surgery. RESULTS: In the Auto group, RBC elongation index did not change significantly from the preoperative baseline. In the Auto+Allo min group, mean elongation index decreased from 32.31 ± 0.02 (baseline) to 30.47 ± 0.02 (nadir on postoperative day 1) (P = 0.003, representing a 6% change). In the Auto+Allo mod group, mean elongation index decreased from 32.7 ± 0.02 (baseline) to 28.14 ± 0.01 (nadir on postoperative day 1) (P = 0.0001, representing a 14% change). Deformability then dose-dependently recovered toward baseline over the first 3 postoperative days. Changes in aggregation were unrelated to transfusion (no difference among groups). For the 3 groups combined, mean critical shear stress decreased from 359 ± 174 mPa to 170 ± 141 mPa (P = 0.01, representing a 54% change), with the nadir at the end of surgery and returned to baseline by postoperative day 1. CONCLUSIONS: In cardiac surgery patients, transfusion with stored allogeneic RBCs, but not autologous salvaged RBCs, is associated with a decrease in RBC cell membrane deformability that is dose-dependent and may persist beyond 3 postoperative days. These findings suggest that autologous salvaged RBCs may be of higher quality than stored RBCs, since the latter are subject to the so-called storage lesions.

Diabetes mellitus and decompensated cirrhosis: risk of hepatic encephalopathy in different age groups.

BACKGROUND: The aim of the present study was to examine the association of diabetes mellitus (DM) with the prevalence and severity of hepatic encephalopathy (HE) in patients with decompensated cirrhosis (DC) and determine the impact of age and gender on this relationship. METHODS: West Haven criteria was used to prospectively evaluate 352 consecutive patients with DC for the presence of HE. Detailed clinicobiochemical profiling of patients was performed. Categorical data and ordered categorical variables were evaluated using the Chi-squared test for independence and trend, respectively. Continuous normal and non-parametric data were evaluated using the t-test and Mann-Whitney U-test, respectively. RESULTS: At the time of admission, HE was present in 50.3% of patients. In all, 118 patients had DM (33.5%). Patients with DM had a significantly higher prevalence (58.5% vs 42.6%; P = 0.03) and severity of HE (P(trend) = 0.01) than patients without DM. However, there were no significant differences between the two groups in terms of Child-Pugh class, MELD scores, the presence of ascites and esophageal varices. Patients with DM had higher platelet counts than those without DM (P(trend) = 0.003). In age and gender subgroup analyses, older patients and men with DM had significantly greater evidence of HE (P = 0.02 and 0.03, respectively). Multivariate analysis showed that DM (P = 0.03) and older age (P = 0.006) were independently related to HE, whereas the association of gender was non-significant. CONCLUSION: Both DM and older age are independently associated with HE in patients with cirrhosis.