1 0 1 8 Editorial correspondence The Journal of Pediatrics June 1995

Comparison of fiberoptic and conventional phototherapy for neonatal hyperbilirubinemia To the Editor:

We were interested in the comparison of fiberoptic and conven- tional phototherapy for neonatal hyperbilirubinemia reported by Tan.1 He reported that fluid intake was increased during photother- apy to offset the increased fluid loss during exposure but did not in- dicate whether the extent of this problem varied according to the mode of phototherapy. Increased fluid loss during phototherapy is a significant clinical problem in the term infant when the mother is trying to establish breast-feeding and in very low birth weight in- fants, in whom dehydration may leacl to hypernatrenia. Transdermal water loss, respiratory water loss, and gastrointestinal water loss can all be involved. 2, 3

Because it is possible to give fiberoptic phototherapy (using the Biliblanket; Ohmeda Critical Care, Columbia, Md.) with the infant clothed, we hypothesized that transdermal water loss would be less because the presence of clothing would create a microclimate with increased local humidity. We also had surmised that there might be less heating of the skin because the fiberoptic light plate is not hot. We have compared fluid loss during fiberoptic phototherapy and conventional phototherapy. Twenty-four infants (birth weight 831 to 4520 gm) with a clinical indication for phototherapy were ran- domly assigned in a crossover trial design; each infant received 12 hours of treatment with the Biliblanket and 12 hours of conventional phototherapy (blue/white lamps; Air-Shields Vickers, Hatboro, Pa.) 40 cm distance from the infant's abdomen. Total fluid loss (trans- dermal, respiratory, urinary, and gastrointestinal) and insensible fluid loss (transdermal plus respiratory) were measured by repeated weighing before and after each treatment, careful recording of fluid input during each treatment, and weighing of diapers (to measure gastrointestinal and urinary losses).

Total fluid loss was 138.7 gin/12 hours (SD 2 59.0) during Bili- blanket treatment and 140.9 grrdl2 hours (SD _+ 78.1) during con- ventional phototherapy (p =0.78). Insensible fluid loss during Bili- blanket treatment was 55.1 gin/12 hours (SD _+ 39.3) compared with 43.8 gin/12 hours (SD -+ 35.2) during conventional photo- therapy (p =0.129). Total fluid loss in 10 infants with birth weights (1500 gm during Biliblanket treatment was 111.5 grrdl2 hours compared with 105.4 gm/12 hours during conventional photother- apy (p =0.61). Insensible loss during Biliblanket treatment was 47 gin/12 hours (SD + 45.2) compared with 29.7 gin/12 hours (SD -+ 35.6) during conventional phototherapy (confidence interval for difference between means 4.5 to 29.9, p 0.026).

These results show that term infants had no overall difference in fluid loss with the two modes of phototherapy, but there was evi- dence of increased insensible water loss during Biliblanket treat- ment in the infants <1500 gin. They appear to have compensated by decreasing urine volume. Although some nurses believed that the fiberoptic plate caused local warming, axillary temperature mea- surements did not show a significant difference between the two treatments. The opinions of our nurses in the neonatal intensive care unit were substantially different from those reported in Tan's arti-

cle. They commented that the noise of the fan was troublesome and the light plate was uncomfortable for preterm infants to lie on. In contrast, the nurses and mothers on the postnatal wards were enthusiastic about the Biliblanket because it is much easier for the mother to breast-feed during phototherapy; the lack of eyepads was also viewed as very positive.

We conclude that the Biliblanket is a useful alternative (or adjunc0 to conventional phototherapy, but attention to adequate hydration is just as important during Biliblanket treatment as with conventional phototherapy.

Jakob Larsen, MD Andrew Whitelaw, MD, FRCP

Department of Pediatrics University of Oslo

Oslo, Norway 9/35/63487

R E F E R E N C E S

1. Tan KL. Comparison of the efficacy of fiberoptic and conven- tional phototherapy for neonatal hyperbilirubinemia. J PEDIATR 1994;125:607-12.

2. Oh W, Karechi H. Phototherapy and sensible water loss in the newborn infant. Am J Dis Child 1972;124:230-2.

3. Wu PYK, Moosa A. Effect of phototherapy on nitrogen and electrolyte levels and water balance in jaundiced preterm infants. Pediatrics 1978;61:193-8.

Reply To the Editor:

Increased fluid intake was necessary to offset increased fluid loss during phototherapy. No attempt was made to evaluate the amount of fluid loss during this particular study. However, to maintain ad- equate hydration (as assessed clinically and by regular weight ob- servations and the use of biochemical measurements), we had to increase fluid intake almost equally in preterm babies exposed to flbreoptic or conventional phototherapy. Intake was further in- creased in those who had combination phototherapy. Similarly, we found that increased fluid intake was also needed in term infants exposed to conventional or fiberoptic phototherapy, again with a fimher increase required for those who received combination pho- totherapy but less than in preterm infants.

Our nurses in both the neonatal intensive care unit and those in the normal nurseries gave favorable responses to the use of fiberoptic phototherapy from the point of ease of usage and freedom from obsmaction. Parents were also enthusiastic about this device. Our neonatal intensive care nurses did not find the fan noise from the fiberopfic device significantly disturbing; they became accus- tomed to it shortly after fiberoptic phototherapy was started.

K. L. Tan, MBBS, FRCPE, FRACP, DCH Department of Neonatology

National University Hospital Singapore, Republic of Singapore

9/35/63488