Sepideh Nassabeh-Montazami

49 Phototherapy

Phototherapy is the most common therapeutic intervention

used for the treatment of hyperbilirubinemia (1).

Phototherapy causes three reactions: configurational and

structural isomerization of the bilirubin molecule and

photo-oxidation, leading to polar, water-soluble photoproducts that can be excreted in bile and urine without the need

for conjugation or further metabolism (2).

The aim of phototherapy is to reduce serum bilirubin

levels to decrease the risk of acute bilirubin encephalopathy

and the more chronic sequel of bilirubin toxicity, kernicterus (1). High-intensity phototherapy significantly reduces

the total serum bilirubin (TSB) and decreases the need for

exchange transfusion (3).

A. Indications

1. Clinically significant indirect hyperbilirubinemia.

Indications to start phototherapy in babies with hyperbilirubinemia vary depending on gestational age, birthweight, hours of life, presence of hemolysis, and other

risk factors such as acidosis and sepsis (1,4).

2. The TSB level must be considered when making the

decision to commence treatment, as there is significant

variability in laboratory measurement of direct bilirubin levels (5).

3. The American Academy of Pediatrics has published

clinical practice guidelines for phototherapy in

newborn infants at 35 weeks’ or more gestation (1)

(Fig. 49.1).

4. These guidelines do not apply to preterm infants <35

weeks’ gestation. Preterm infants are at higher risk of

developing hyperbilirubinemia compared to term

infants. Although guidelines have been proposed, the

decision to initiate phototherapy in this group of infants

remains variable and highly individualized (4,6)

(Table 49.1).

B. Contraindications

1. Congenital porphyria or a family history of porphyria is

an absolute contraindication to the use of phototherapy. Severe purpuric bullous eruptions have been

described in neonates with congenital erythropoietic

porphyria treated with phototherapy (7).

2. Concomitant use of drugs or agents that are photosensitizers is also an absolute contraindication (8).

3. Concurrent therapy with metalloporphyrin heme oxygenase inhibitors has been reported to result in mild

transient erythema (9).