RBC Transfusions in Newborns

Question 1

Define physiological anemia

Answer 1

• Seen in term babies, hemoglobin concentration declines between 8-12 weeks of life, remains stable for several weeks and increases progressively
• Asymptomatic

Question 2

Define non physiologic anemia

Answer 2

• Develops earlier than physiologic (4-12 weeks)
• Symptomatic (tachycardia)

Question 3

What is the most common cause of non physiologic anemia?

Answer 3

Iatrogenic (phlebotomy)

Question 4

List strategies to prevent and reduce severity of anemia

Answer 4

• Delayed umbilical cord clamping
• Restricted blood sampling
• Using recombinant human EPO to stimulate erythropoeisis
• Iron supplementation or vitamins to minimize severity of anemia
• Appropriately collected + stored multipack RBC units
• Appropriately screnned + handled RBCs from designated donors
• Collecting and transfusing umbilical cord blood

Question 5

What is the evidence for delayed cord clamping?

Answer 5

Several RCTs showed delayed cord clamping compared with early cord clamping reduced the need for transfusion without increasing adverse outcomes

Question 6

How can we restrict blood loss?

Answer 6

• Decreasing uneccessary blood work
• Returning dead space volume after art line sampling
• Microtechnique lab procedures
• Noninvasive monitoring methods

Question 7

Where is fetal and neonatal EPO produced?

Answer 7

Fetus: liver

Neonate: kidney

Question 8

Why is the infant response to hypoxia reduced?

Answer 8

• Poor sensitivity of liver oxygen sensors
• Immature renal oxygen sensors

Question 9

What is a major cause of anemia of prematurity?

Answer 9

EPO deficiency

Question 10

How effective is EPO administration?

Answer 10

Same effect as restrictive guidelines for RBC transfusion

Question 11

What is the evidence for EPO?

Answer 11

• Several studies have shown beneficial effects but in association with conservative transfusion criteria, minimizing phlebotomy and early Fe supplementation
• Meta-analysis of RCTs studying efficacy of EPO in preventing RBC transfusions showed benefits when combined with conservative RBC transfusion criteria
• Authors concluded EPO should not be a standard tx for anemia of prematurity

Question 12

Does EPO change the need for transfusions in the first two weeks of life?

Answer 12

NO!

Question 13

What dose of supplemental iron is required by prems to prevent late anemia?

Answer 13

4-4.5mg/kg

Question 14

What dose of vitamin E is required to prevent hemolytic anemia?

Answer 14

25IU

Question 15

What type of preservative is used for the preservation of RBCs since 1993?

Answer 15

• Adenine-saline anticoagulant (AS3)
• RBCs can be stored for at least 4 weeks

Question 16

What age of blood can be used for rapid and large volume tranfusions?

Answer 16

< 5 days old

Question 17

What is the advantage of having a long storage period for blood products?

Answer 17

• Increased availability of blood
• Limits donor exposure

Question 18

Why do we not use blood older than 5 days for rapid and large volume blood transfusions?

Answer 18

• Serum potassium substantially elevated
• Blood older than 5 days can still be used for slow, small volume top up transfusions

Question 19

When should babies get irradiated blood?

Answer 19

• If donated blood is obtained from first or second degree relatives
• Fetuses getting intrauterine transfusions
• Immunocompromised infants
• Infants who previously received an in utero transfusion

Question 20

When should babies get blood irradiated < 24 hours ago?

Answer 20

When clinical risk of hyperkalemia is significant

Question 21

What infectious things are blood products screened for?

Answer 21

• HIV1, HIV2
• HTLV1, HTLV2
• Hepatitis B surface antigen
• Syphilis
• CMV

Question 22

Can low birthweight infants receive CMV positive blood?

Answer 22

Uncertain whether leukodepletion is adequate for prevention of CMV, most guidelines recommend CMV negative blood

Question 23

What is the benefit of leukodepletion for newborn infants?

Answer 23

No proven benefits but probably no disadvantages

Question 24

What is the most important approach to reducing donor eposure?

Answer 24

Use of multipack collection systems

Question 25

Are directed donations safer than random donations?

Answer 25

• No
• Risk of maternal blood containing alloantibodies
• Many mothers not able to donate: anemia, ABO blood incompatibility, fever/infection, medical problems

Question 26

List issues related to directed blood donation:

Answer 26

• Finding a compatible donor
• Time delay in obtaining blood (testing)
• Needs irradiation
• Lack of available blood in bank when needed
• Ethical issues (identifying HIV in family)
• Compliance with parental wishes

Question 27

What are the problems associated with autologous blood transfusions?

Answer 27

• Bacterial contamination
• Incorrect identification
• Clotting issues
• Labour intensive, not commonly used

Question 28

What is the evidence for benefit in RBC transfusions?

Answer 28

• No studies show RBC transfusions improve clinically important outcomes in stable high risk infants

Question 29

List adverse effects caused by transfusions

Answer 29

• Transfusion reactions
• Graft vs host disease
• Toxic effects due to preservatives and anticoagulants
• Complications from use of old RBCs
• Infectious risks

Question 30

Indications for RBC transfusions? (Table 1)

Answer 30

• Hypovolemic shock associated with acute blood loss
• Hct 30-35% or Hb 100-120g/L in extreme illness conditions where RBCs may improve O2 delivery
• Hct 20-30% or Hb 60-100g/L in severely ill infants +/- mechanical ventilation with compromised O2 delivery
• Hct falling (20% or less) or Hb 60g/L or less with retics 100-150 or less in the context of:
  
  • FTT
  • No weight gain
  • Tachycardia > 180bpm
  • Tachypnea
  • Supplemental O2 needs
  • Lethargy