Final answer:
Each unit of packed red blood cells (PRBCs) can increase the hemoglobin level by approximately 1 billion molecules of oxygen. Healthcare professionals consider the patient's current hemoglobin level, target hemoglobin level, severity of anemia, underlying cause, age, and overall health when determining the appropriate number of units to transfuse.
Step-by-step explanation:
Hemoglobin is packed into red blood cells at a rate of about 250 million molecules of hemoglobin per cell. Each hemoglobin molecule binds four oxygen molecules so that each red blood cell carries one billion molecules of oxygen. Therefore, each unit of packed red blood cells (PRBCs) can increase the hemoglobin level by approximately 1 billion molecules of oxygen.
When determining the appropriate number of units to transfuse for a patient, healthcare professionals need to consider the patient's current hemoglobin level and desired target hemoglobin level. They also take into account factors such as the severity of the anemia, the underlying cause of anemia, the patient's age and overall health condition, and any potential risks or complications associated with blood transfusions.