Hemoglobin Trend in Critically Ill Patients with Long ICU Stay

Abstract

Introduction: Critically ill patients develop anemia due to several reasons: bleeding prior or during intensive care unit (ICU) stay, frequent flebotomies, hemodilution and inflammatory status with altered erythropoiesis. The aim of this study was to assess the trend of hemoglobin (Hb) level during long ICU stay (more than 7 days) in transfused and nontransfused patients. Materials and Methods: We conducted a prospective observational study that included all patients with long ICU length of stay (LOS) admitted during 1 year in a 19-beds mixed ICU of a tertiary care university hospital. Patients were divided into two groups: never transfused (NT) and ever transfused (ET) according to their transfusional status during ICU stay. Collected data: demographic data, severity scores, Hb values during ICU stay transfusion status and outcome. Statistical analysis was conducted with SPSS 15.0. Results: 132 patients (54 NT, 78 ET) were enrolled in the study. On ICU admission, overall mean Hb level was 9.2 g% (95%CI 8.72-9.72) with a significant difference between NT and ET group (10.1 g% versus 8.5 g%; p<0.01). By the day 7 there was little change in overall mean Hb value (9.1 g%; 95%CI 8.85-9.43) as in NT group the Hb values continued to drop while in ET group raised as a result of transfusions. However, at two weeks after ICU admission there was a significant decrease in mean Hb value, from 9.2 g% in day 1 to 8.1 g% (95%CI 7.71-8.49) in day 14. The variance also had a significant decrease over time (8.94 in day 1; 1.58 in day 14) indicating a convergence of Hb values in studied patients, regardless of their transfusion status. Conclusions: Despite the fact that Hb values on ICU admission may vary widely, after 14 days of ICU stay the Hb values tend to converge. The Hb level in critically ill patients with long ICU stays decreases stadly over time no matter the transfused or non-transfused status.