ANEMIA OF PREMATURITY MEDICAL CARE

anemia of prematurity medical care:
The medical care options available to the clinician treating an infant with AOP are prevention, blood transfusion, and recombinant EPO treatment.

anemia of prematurity prevention
• Reducing the amount of blood taken from the premature infant diminishes the need to replace blood. When caring for the premature infant, carefully consider the need for each laboratory study obtained. Hospitals with care for premature infants should have the ability to determine laboratory values using very small volumes of serum.
• Manufacturers are developing an array of technologies that require extremely small amounts of blood for a steadily increasing number of tests. Likewise, devices that allow blood gases and serum chemistries to be determined at bedside via an analyzer attached to the umbilical artery catheter without loss of blood recently have been developed. The impact of such devices on the development of anemia and/or the need for transfusions has yet to be determined.
• The use of noninvasive monitoring devices, such as transcutaneous hemoglobin oxygen saturation, partial pressure of oxygen, and partial pressure of carbon dioxide, may allow clinicians to decrease blood drawing; however, no data currently support such an impact of these devices.

Blood transfusion
• Packed red blood cell (PRBC) transfusions: Despite disagreement regarding timing and efficacy, PRBC transfusions continue to be the mainstay of therapy for the individual with AOP. The frequency of blood transfusions varies with gestational age, degree of illness, and, interestingly, the hospital evaluated.
• Reducing the number of transfusions: Studies derived from individual centers document a marked decrease in the administration of PRBC transfusions over the past 2 decades, even before the use of EPO. This decrease in transfusions is almost certainly multifactorial in origin. One frequently mentioned component is the adoption of transfusion protocols that take a variety of factors into account, including hemoglobin levels, degree of cardiorespiratory disease, and traditional signs and symptoms of pathologic anemia.

Using various audit criteria and indications for transfusions suggested by Canadian, American, and British authorities, the Medical University of South Carolina has instituted the following transfusion guidelines:
o Do not transfuse for phlebotomy losses alone.
o Do not transfuse for hematocrit alone, unless the hematocrit level is less than 21% with a reticulocyte count less than 100,000.
o Transfuse for shock associated with acute blood loss.
o For an infant with cyanotic heart disease, maintain a hemoglobin level that provides an equivalent fully saturated level of 11-12 g.
o Transfuse for hematocrit levels less than 35-40% in the following situations:
􀂃 Infant with severe pulmonary disease (defined as requiring >35% supplemental hood oxygen or continuous positive airway pressure [CPAP] or mechanical ventilation with a mean airway pressure of >6 cm water)
􀂃 Infant in whom anemia may be contributing to congestive heart failure
o In the following situations, transfuse for a hematocrit level that is 25-30% or less:
􀂃 The patient requires nasal CPAP of 6 cm water or less (supplemental hood oxygen of <35% by hood or nasal cannulae).
􀂃 The patient has significant apnea and bradycardia (defined as >9 episodes in 12 h or 2 episodes in 24 h, requiring bag-mask ventilation while receiving therapeutic doses of methylxanthines).
􀂃 The patient has persistent tachycardia or tachypnea without other explanation for 24h.
􀂃 Weight gain of patient is deemed unacceptable in light of adequate caloric intake without other explanation, such as known increases in metabolic demands or known losses in metabolic demands (malabsorption).
􀂃 The patient is scheduled for surgery; transfuse in consultation with the surgery team.
• Reducing the number of donor exposures: In addition to reducing the number of transfusions, reducing the number of donor exposures is important. This can be accomplished as follows:
o Use PRBCs stored in preservatives (eg, citrate-phosphate-dextrose-adenine [CPDA-1]) and additive systems (eg, Adsol). Preservatives and additive systems allow blood to be stored safely for up to 35-42 days. Infants may be assigned a specific unit of blood, which may suffice for treatment during their entire hospitalization.
o Use volunteer-donated blood and all available screening techniques. The risk of cytomegalovirus (CMV) transmission can be reduced dramatically (but not entirely) through the use of CMV-safe blood. This can be accomplished by using either CMV serology-negative cells or blood processed through leukocyte-reduction filters. This latter method also reduces other WBC-associated infectious agents (eg, Epstein-Barr virus, retroviruses, Yersinia enterocolitica). The American Red Cross now is providing exclusively leukocyte-reduced blood to hospitals in the United States.

anemia of prematurity - Recombinant erythropoietin treatment
• Multiple investigations have established that premature infants respond to exogenously administered recombinant human EPO with a brisk reticulocytosis. Modest decreases in the frequency of PRBC transfusions have been documented primarily in premature infants who are relatively large.
• Recent trials have evaluated the impact of EPO treatment in populations of the most immature neonates. These studies likewise have demonstrated that infants with VLBW are capable of responding to EPO with a reticulocytosis and that the drug appears to be safe. Conversely, the hemoglobin level of infants treated with EPO falls to at or below the hemoglobin level of the control group within 1 week of treatment cessation, and the impact on transfusion requirements ranges from nonexistent to small.
• No agreement regarding timing, dosing, route, or duration of therapy exists. In short, the cost-benefit ratio for EPO has yet to be clearly established, and this medication is not accepted universally as a standard therapy for the individual with AOP. When the family has religious objections to transfusions, the use of EPO is advisable.

Consultations: Neonatology and Pediatric hematology

Diet: Provision of adequate amounts of vitamin E, vitamin B-12, folate, and iron are important to avoid exacerbating the expected decline in hemoglobin levels in the premature infant.

anemia of prematurity - MEDICATION
Drug Category: Growth factors -- Hormones that stimulate production of red cells from the erythroid tissues in the bone marrow.

Drug Category: Vitamins and minerals -- Organic substances required by the body in small amounts for various metabolic processes. Used clinically for the prevention and treatment of specific deficiency states

anemia of prematurity - FOLLOW-UP
Further Outpatient Care: After discharge from the hospital, ensure regular determination of hematocrit levels in infants with APO. Once a steady increase in the hematocrit level has been established, only routine checks are required.

In/Out Patient Meds: Administer and/or prescribe iron supplementation according to standard guidelines.

Transfer: Transfer generally is not required unless transfusions cannot be carried out in the hospital's nursery.

Deterrence/Prevention: Limit diagnostic blood draws to a minimum.

anemia of prematurity - Complications:
• Transfusion-acquired infections (eg, hepatitis, CMV, HIV, syphilis)
• Transfusion-associated fluid overload and electrolyte imbalances
• Transfusion-associated exposure to plasticizers
• Transfusion-associated hemolysis
• Posttransfusion graft versus host disease

Prognosis: Spontaneous recovery in the individual with AOP occurs by age 3-6 months.

anemia of prematurity - Patient Education:
• Explain the normal course of anemia.
• Explain criteria for and risks of transfusions.
• Explain advantages and disadvantages of EPO adminis