med 18

 

faced with a vast array of equipment to choose from and

must be aware of advantages and disadvantages of each

type. Table 49.2 describes some of the phototherapy

devices commonly used in the United States.

4. Fluorescent tubes

a. “Special blue” tubes, such as F20 T12/BB, provide

more irradiance in the blue spectrum than other

tubes and are the most effective fluorescent light

source. (2). The “special blue F20 T12/BB” tubes

provide much greater irradiance than regular blue

tubes, labeled F20T12/B. The flickering glare of the

blue light has been reported to cause giddiness,

nausea, and temporary blurring of vision in nursing

personnel (11). One way to overcome this has been

to use cool white light in conjunction with the special blue, but this combination can decrease efficacy by as much as 50%, depending on the proportion of cool white light used (12).

b. Green/turquoise lamps penetrate the skin to a

greater depth, but the advantage over blue light is

unclear (13–15).

c. Cool white lamps may be inadequate in sufficiently

decreasing total bilirubin levels unless the lights are

positioned in close proximity to the infant (13). As

mentioned previously, this type of light has also

been used together with special blue tubes.

d. Daylight lamps, like cool white lamps, have a wider

wavelength spectrum and are less effective than

blue light (12).

5. Halogen lamps

a. Halogen spotlight systems utilize single or multiple

metal halide lamps as the light source and can

provide high irradiance over a small surface area

(>20 mW/cm2

/nm).

b. These units can generate considerable heat, with the

potential of causing thermal skin injury; therefore,

they must not be in close proximity to the patient.

c. The variable positioning with respect to the distance

from the infant as well as heterogeneity of the irradiance can lead to unreliable dosing and unpredictable clinical responses. In addition, they are more

expensive than fluorescent bulbs (2).

6. Fiberoptic systems

a. UV-filtered light from a tungsten–halogen bulb

enters a fiberoptic cable and is emitted from the

sides and end of fiberoptic fibers inside a plastic pad.

Fig. 49.1. Guidelines for phototherapy in hospitalized infants of

35 or more weeks’ gestation.

(From American Academy of

Pediatrics Subcommittee on

Hyperbilirubinemia. Management

of hyperbilirubinemia in the newborn infant 35 or more weeks of

gestation. Pediatrics. 2004;114:

297.)

Table 49.1

Guidelines for the Use of

Phototherapy and Exchange

Transfusion in Preterm Infants

Based on Gestational Age

Total Bilirubin Level (mg/dL/mmol/L)

Exchange Transfusion

Gestational Age (wk) Phototherapy Sicka Well

36 14.6 (250) 17.5 (300) 20.5 (350)

32 8.8 (150) 14.6 (250) 17.5 (300)

28 5.8 (100) 11.7 (200) 14.6 (250)

24 4.7 (80) 8.8 (150) 11.7 (200)