Abstract
Background: Diagnostic laboratory testing (DLT) is a source of blood loss in critically ill patients. Approximately half of patients admitted to the intensive care unit (ICU) present with anemia, with the remainder developing a multifactorial anemia with etiologies including central venous catheter (CVC) placement. Consequently, about a third of ICU patients require red blood cell (RBC) transfusion, a practice associated with poorer clinical outcomes. Our objectives were to characterize DLT blood loss in the surgical intensive care unit (SICU), and its relationship with anemia, RBC transfusion, and CVC placement.Methods: An observational study was performed by retrospective chart review of patients admitted to a SICU over 1-year. The number of DLT blood draws, average volume of blood drawn, and estimated discard volume were recorded along with clinical and laboratory findings. Results: A cohort of 292 patients (mean age 62.2 years, male to female ratio 1.5) underwent 299 hospitalizations with an average daily DLT blood loss of 14.3 mL (229.5 mL per admission). Among admissions, 51.2% presented with anemia and 95.3% were anemic at discharge, with 32% of patients receiving an RBC transfusion. Patients with greater DLT-associated blood loss had lower discharge hemoglobin (p=<0.001). Admissions requiring CVC (49.8%), demonstrated a significantly greater number of DLT blood draws, increased DLT-associated blood loss, higher rates of RBC transfusion, and an increased length of stay.Conclusions: Findings from this study suggest that DLT blood loss contributes to anemia in the SICU and the presence and duration of CVC leads to increased testing, blood loss, anemia, and is predictive of RBC transfusion.
Central Line Access is Predictive of Diagnostic Blood Loss and Transfusion in the Surgical Intensive Care Unit