What is the procedure for exchange transfusion in neonates?

Exchange Transfusion in Neonates: Procedural Guidelines

Exchange transfusion must be performed only by trained personnel in a neonatal intensive care unit with full monitoring and resuscitation capabilities, as this is a high-risk procedure with mortality of approximately 3 per 1000 cases and significant morbidity in up to 5% of procedures. 1

Pre-Procedure Preparation

Blood Product Selection and Crossmatching

• Send blood immediately for type and crossmatch when total serum bilirubin reaches or approaches exchange transfusion threshold levels 2
• Use modified whole blood (red cells and plasma) crossmatched against the mother and compatible with the infant 2
• Ensure blood products are available before initiating the procedure 1

Laboratory Assessment

• Measure serum albumin level and calculate the bilirubin/albumin (B/A) ratio to use in conjunction with total serum bilirubin when determining need for exchange 1, 2
• Obtain complete blood count with differential and peripheral smear for red cell morphology 1
• Check blood type (ABO, Rh) and direct antibody test (Coombs') 1
• Measure reticulocyte count 1
• Test for G6PD deficiency if suggested by ethnic/geographic origin or poor response to phototherapy 1
• If sepsis is suspected, perform blood culture, urine culture, and cerebrospinal fluid analysis 1

Indications for Exchange Transfusion

Bilirubin-Based Thresholds

• Exchange is indicated when total serum bilirubin rises to threshold levels despite intensive phototherapy during birth hospitalization 2
• For readmitted infants with total serum bilirubin above exchange level, consider exchange if levels remain elevated after 6 hours of intensive phototherapy 2
• Immediate exchange is mandatory for any jaundiced infant manifesting intermediate to advanced acute bilirubin encephalopathy, regardless of whether total serum bilirubin is falling 2

Risk-Stratified B/A Ratio Thresholds

The following bilirubin/albumin ratios should trigger consideration of exchange alongside total serum bilirubin levels 2:

• Infants ≥38 weeks: B/A ratio 8.0 mg/dL per g/dL (or 0.94 mmol/L per mmol/L)
• Infants 35-36 6/7 weeks (well) or ≥38 weeks with higher risk: B/A ratio 7.2 (or 0.84)
• Infants 35-37 6/7 weeks with higher risk/isoimmune hemolytic disease/G6PD deficiency: B/A ratio 6.8 (or 0.80)

Adjunctive Therapy Before Exchange

Intravenous Immunoglobulin

• In isoimmune hemolytic disease, administer intravenous immunoglobulin (0.5-1 g/kg over 2 hours) if total serum bilirubin is rising despite intensive phototherapy or is within 2-3 mg/dL of the exchange level 1
• Repeat dose in 12 hours if necessary 1
• This intervention reduces the need for exchange transfusions in Rh and ABO hemolytic disease 1

Procedural Monitoring

During Exchange Transfusion

• Maintain continuous cardiorespiratory monitoring throughout the procedure 3
• Monitor for immediate complications including apnea, bradycardia, cyanosis, vasospasm, and thrombosis 1, 4
• Check calcium levels during and after the procedure, as large blood volume shifts can affect calcium homeostasis 3
• Monitor blood glucose, as neonates have limited capacity for glycogenolysis and gluconeogenesis 3

Post-Exchange Monitoring

• Repeat total serum bilirubin within 2-3 hours if pre-exchange level was ≥25 mg/dL 1
• Repeat within 3-4 hours if pre-exchange level was 20-25 mg/dL 1
• Continue intensive phototherapy after exchange transfusion 1
• Monitor for rebound hyperbilirubinemia, particularly in cases of hemolytic disease 1

Common Complications and Management

Metabolic Complications

The most frequent adverse events include 4, 5, 6:

• Hypocalcemia (48.3% of cases) - monitor and replace calcium as needed
• Hyperglycemia (51.7%) - adjust glucose infusion rates
• Anemia (89.7%) - may require subsequent transfusion
• Electrolyte disturbances including hypernatremia (13.8%) and hyperkalaemia (6.9%)

Cardiorespiratory Complications

• Bradycardia and apnea occur in approximately 6.9% of cases 4
• These complications are more common in preterm and sick infants 5, 6
• All require immediate intervention with full resuscitation capabilities available 1

Infectious and Thrombotic Risks

• Sepsis occurs in approximately 10.3% of cases 4
• Necrotizing enterocolitis is a recognized complication 1, 3
• Thrombosis and vasospasm can occur during the procedure 1
• Blood product-associated risks must always be considered 1

Critical Safety Considerations

High-Risk Populations

• Preterm infants and sick neonates have significantly higher complication rates 5, 6
• Preterm infants require longer phototherapy after exchange (5.3 vs 3.3 days for term infants) 6
• Complications occur more frequently in unstable neonates (those <1500g or with medical problems beyond jaundice) 7

Procedural Expertise

• The procedure should never be performed in an emergency department, as this delays treatment and increases risk 1
• Exchange transfusion using peripheral arteries and veins is as effective as umbilical vein access and may have fewer severe adverse events in stable neonates 7
• Trained personnel must be immediately available, as the rarity of the procedure in modern practice may affect complication rates 1