Use of Pediatric Size Phlebotomy Tubes in Adult Critically Ill Patients to Reduce Red Blood Cell Transfusions

Inclusion Criteria: * New admission to the medical or transplant ICU at Memorial Hermann Hospital in Houston * ICU admission hemoglobin level of at least 7 g/dL. The ICU admission hemoglobin will be the most recent hemoglobin value available at the time of screening for inclusion in the study. * Randomization is expected within 12 hour of admission to the ICU Exclusion Criteria: * Clinical bleeding. Defined as menstrual bleeding, bleeding leading to a change in the frequency of hemoglobin monitoring or to an order for a medication, transfusion, procedure, or consultation intended to prevent or treat bleeding. * Known hemolytic disorder (e.g. sickle cell disease, hereditary spherocytosis, autoimmune hemolytic anemia) * Bone marrow disorder (e.g. aplastic anemia, marrow infiltration disorder, chemotherapy within the last 8 weeks) * Jehovah's Witnesses * Patient is comfort care measures only * Refractory shock: mean arterial blood pressure below 60 mmHg despite maximal doses of 3 vasopressors. Maximal dose of vasopressors are as follows: Norepinephrine 70 mcg/min; vasopressin 0.04 units/min; epinephrine 35 mcg/min; dopamine 20 mcg/kg/min; phenylephrine 350 mcg/min * Severe acidosis: potential of hydrogen (pH) below 7 in more than one arterial blood gas within 24 hours of ICU admission in the absence of diabetic ketoacidosis Surgical admission diagnosis * Pregnancy * Current prisoner