Frequent Blood sampling and Anaemia in Critical Ill Patients

Frequent Blood sampling and Anaemia in Critical Ill Patients

Introduction

Anemia is not a disease but rather a clinical condition in which levels of Hgb and/or Hct are low or insufficient, which can cause the body to be inadequately oxygenated. Hgb and Hct counts in neonates vary widely depending on gestational age, chronological age, and health status. In utero, as gestation advances, Hgb and Hct levels increase. After birth, all neonates experience a decrease in Hgb and Hct levels because they have much larger amounts of available oxygen than they do in utero, which stimulates their bodies to produce fewer RBCs. If this decrease in Hgb and Hct levels is within normal limits (i.e., Hgb levels of 9-12 g/dL in term neonates, Hgb levels of 7-8 g/dL in premature neonates, and Hct levels as low as 30%) the condition is known as physiologic anemia, a normal condition that does not need to be treated. Neonatal anemia is marked by abnormal Hgb and Hct levels at least two standard deviations below the average for postnatal age.

Causes of neonatal anemia can be divided into three categories: blood loss, decreased RBC production, and increased RBC destruction. Causes of blood loss include conditions that occur before birth, such as fetomaternal hemorrhage, fetoplacental hemorrhage, and twin-twin transfusion syndrome. Conditions that develop during delivery, such as hematomas, aneurysms, nuchal cord, placenta previa, abruptio placenta, obstetric complications, placental incision during cesarean section, traumatic amniocentesis, and umbilical cord rupture; internal bleeding during or after delivery; and excessive laboratory blood sampling after birth. Causes of decreased RBC production include bone marrow disorders; infections such as parvovirus B19, HIV, syphilis, cytomegalovirus, and rubella; iron, folate, vitamin B12, and protein deficiencies; and congenital leukemia. Causes of increased RBC destruction include immune hemolytic anemia from blood group incompatibilities or maternal autoimmune disorders, RBC enzyme abnormalities, RBC membrane defects, Hgb disorders, vitamin E deficiency, bacterial or viral sepsis, anemia of prematurity, disseminated intravascular coagulation (DIC), and inherited metabolic disorders.

Treatment depends on the severity of the anemia and the overall health status of the neonate. Neonates with anemia that causes recurrent apnea and bradycardia, oxygen desaturation, hypotension, and/or shock require immediate transfusion with packed RBCs (PRBCs; see Quick Lesson About…Neonatal Anemia and Transfusion) and/or mechanical ventilation. Other treatment may include recombinant human erythropoietin (rHuEPO); vitamin E, iron, and protein supplements; supplemental oxygen; supportive care; and family member education and emotional support. Potential complications from PRBC transfusion in neonates include the need for increased respiratory support, bronchopulmonary dysplasia, necrotizing enterocolitis, and retinopathy of prematurity. When neonatal anemia does not cause severe signs and symptoms, treatment includes intensive monitoring for worsening signs and symptoms and following laboratory values closely. Keeping in view these concepts, the study aims to understand if frequent blood samples cause anaemia among critically ill patients and the guidelines to the practitioners in the haematological practices. The author will also examine what changes do the nurse's experience and skills is required in judging the frequency of blood ...