Abstract
Background: Anemia of critical illness and other hematological abnormalities are common among the Medical Intensive Care Unit (MICU) patients. A large number of Red Blood Cells (RBC), Fresh Frozen Plasma (FFP), and platelets (Plt) are frequently transfused to critically ill patients. Data from our 480-bed community hospital shows that more than tow thirds of all patients who were admitted to the MICU received at least 1 unit of a blood product during their stay. Transfusions carry significant acute and late complications, including risks for transmission of infectious agents and immune modulation. In addition, the RBCs survival, functions, and oxygen-carrying capacity are reduced during storage. Evidences show significant poorer outcomes with blood products transfusion in critically ill patients, who are hemodynamically stable. Although restrictive red cell transfusion practice has become the standard of care in critically ill patients since 1999, data on the use of FFP are limited. A significant number of patients with coagulopathy receive FFP transfusion without any demonstrated efficacy. In addition, very little medical evidence exists to document the effectiveness of its use. FFP transfusion is associated with important adverse affects, including transfusion-related acute lung injury, transfusion-related circulatory overload, and rarely, allergic reactions.
Methodology: We retrospectively reviewed the medical records of 63 patients, who were admitted to the MICU between October 2007 and July 2008. The primary endpoint was studying the relation of transfusing blood products to the survival of critically ill patients. The eligibility criteria were age above 18 years old and admission to the MICU with a diagnosis of septic shock. The demographic variables, length of stay (LOS) in both MICU and regular medical floor, and the number of transfused blood products were evaluated. Four patients expired before being transferred to MICU and were excluded from the analysis.
Results: Thirty six (57.1%) patients were female and 27 (42.9%) were male. Their ages ranged from 25 to 99, mean (SD) 65.6 (19.3) years. Of the 63 patients, 40 (63.5%) patients expired (group A), and 23 (36.5%) patients survived (group B). The mean LOS in the MICU and total LOS in the hospital for group A were 13.2 and 22.5 days and for group B were 8.5 and 29.5 days respectively. Among group A, 77.5% (n=31), and among group B, 65.2% (n=15) of patients received at least one unit of blood product transfusion during their admissions respectively. In an Independent Samples Test Analysis, the group A patients received a mean (SD) of 11.5 (2.0) units and group B patients received a mean (SD) of 4.6 (1.1) units of blood products during their stay in the hospital (95% CI −12.0 to −1.9, p= .008)(Figure 1). The most commonly transfused blood product was packed RBC in both groups, 75% (n=27) of group A patients and 52.2% (n=12) of group B patients received a mean (SD) of 4.2 (3.4) and 4.5 (2.6) units of PRBC respectively.
Conclusion: Anemia is common in ICU, its causes are multifactorial, and is a common complication of critical illnesses. Blood transfusion is not without risk; still, transfusion is common in critically ill patients. In this group of studied patients, more than two thirds of MICU patients received an average of 7.6 units of blood products. Our data also indicates that patients with septic shock who are transfused with more units of blood products have poorer outcome and increased mortality rate, although in majority of the cases the severity of the underlying clinical condition has necessitated the larger amount of blood product transfusions.
Figure Figure
Effect of transfusion, leukocyte-depleted blood product on onset of new septic shock and mortality in septic shock