NICU

NICU

The Neonatal Intensive Care Unit (NICU) is one of the most clinically and emotionally challenging departments in any hospital. Children are not small adults, instead, they are individuals with their own set of physiological, anatomical and clinical needs distinct from any other patient group. One of the most striking differences between the neonatal population and any other group of patients is the relative inability that neonates have in the first few weeks of life to produce their own red blood cells. This is seen most commonly in preterm babies. One of the biggest contributors to anemia seen in the neonatal period is the inability to produce red blood cells coupled with the clinician’s need to closely monitor a critically ill baby in the first few weeks of life. Anemia In NICU As babies adapt to life in the outside world, hemoglobin concentration falls from approximately 17 g/dL at birth to 11 g/dL by 2 months of age. This anemia is most severe in premature babies, causing a phenomenon known as the ‘anemia of prematurity’. This predisposition to anemia among premature infants can be exacerbated by blood drawn for testing. Very low-birth-weight infants are often critically ill and, consequently, there is a clinical need for frequent blood testing. However, their circulating blood volume is very small. The blood volume of a neonate is approximately 80-90 mL/kg. Very small babies may have a total blood volume as low as 50 mL. This means drawing just 1 ml of blood from a baby could reduce his or her blood volume by up to 2%. During the first six weeks of life, blood drawn for laboratory testing has been reported to range from 11 to 22 mL/kg per week, which is equivalent to 15%–30% of the circulating blood volume of a neonate. As the baby is unable to replace blood drawn for diagnostic testing, blood must be replaced via blood transfusions. Very-low-birth-weight (<1500 g) babies are often the most critically ill babies and require many weeks of intensive monitoring and care. Approximately 70% of all blood transfusions given to very-low-birth-weight infants occur during the first month of life. However, transfusions are not benign. Transfusions are associated with risks of transmission of infection, immune-related hypersensitivity reactions, as well as the disruption of the baby’s feeding patterns around the time of administration. In addition, during conventional laboratory testing, as much as 67% of the blood drawn from a baby is discarded as, on average, only 33% is needed by the laboratory. Iatrogenic Anemia Should Be One Of The Most Important Factors A Clinician Considers When Treating Neonates There are many ways in which clinicians can reduce the volume of blood loss due to laboratory testing: Avoid Unnecessary Testing There is some evidence suggesting that laboratory testing in the critical care setting can be excessive. Care should be taken to avoid ordering tests as a matter of routine rather than necessity. Reduce The Volume Of Blood Drawn Bearing in mind the risks of iatrogenic anemia it is important to ensure that no more blood is sampled than is actually required to perform the analysis. Point-Of-Care Testing The majority of the common blood tests used to monitor critically ill neonates can now be performed at the point of care, potentially reducing iatrogenic anemia amongst this population. Point-of-care testing requires smaller blood volumes compared to laboratory analysis, creating the opportunity for decreased blood loss and improved turnaround time. A US study showed that the installation in a NICU of a bedside, handheld, POC analyzer improved the volume of blood drawn and resulted in a 46% reduction in the number of transfusions administered. The i-STAT POC analyzer measures blood gases, ionised calcium, hemoglobin, hematocrit, sodium, and potassium. These tests are measured simultaneously using just 100 μL of whole blood compared to 1000 μL when the same tests were performed in the central laboratory. Summary For neonates, blood volume conservation is of paramount importance and the blood losses associated with diagnostic testing is clinically significant. Neonates are predisposed to anemia, and the relatively large blood loss associated with diagnostic testing can exacerbate this leading to the increased need for blood transfusion. To reduce the likelihood of anemia and decrease the number of transfusions required during the neonatal period it is important to reduce the number of unnecessary tests performed and the volume of blood drawn. The introduction of point-of-care testing has been shown to reduce the incidence of anemia and a reduction in the number of transfusions that are required during the neonatal period.