hello,

we have noticed that when phototherapy is used on day 3-4, we get PDA opening and new murmur. Any coincidence?

have you come across this ?

selvan.r.dr

ERODE,INDIA

Yes they have an association

1) Acta Paediatr. 1999 Sep;88(9):1014-9.

Cardiac output and ductal reopening during phototherapy in preterm infants.

Benders MJ, Van Bel F, Van de Bor M.

LINK

2)J Perinatol. 1993 Sep-Oct;13(5):376-80.

Association of patent ductus arteriosus and phototherapy in infants weighing less than 1000 grams.

Barefield ES, Dwyer MD, Cassady G.

LINK

Should we shield the chest?

Acta Paediatr. 2006 Nov;95(11):1418-23.

Patent ductus arteriosus in extremely preterm infants receiving phototherapy: does shielding the chest make a difference? A randomized, controlled trial.

Travadi J, Simmer K, Ramsay J, Doherty D, Hagan R.

LINK

Thanks for the articles.

how do you avoid this or do you do anything for the opened up pdA

thanks

selvan.r

In my practice I noticed similar findings. What is the underlying mechanism? . It worth a study, but sheilding the chest may decrease the efficacy of phototherapy!.

... What is the underlying mechanism? ...

The suspected underlying mechanism seems to be that in a preterm, the light can penetrate and reach the ductus. There it causes a photorelaxation via the nitric oxide pathway (cGMP mediated) dependent relaxation of the ductus.

REF

Furchgott RF. Endothelium-dependent relaxation, endothelium-derived relaxing factor and photorelaxation of blood vessels.Sem Perinatol 1991; 15: 11–5

LINK

Clyman RI, Rudolf AM. Patent ductus arteriosus: a new light on an old problem. Pediatr Res 1978; 12: 92–4

LINK

It has long been recognised that phototherpy increases the chances of opening the duct or delaying its closure. This is thought to be due to the effect of phototherapy on ductal prostaglandins.

As simple, cost effective and evidence based way to prevent this is to cover the ductal area with a reflective (tin foil) material. [see Jack Sinclaire's book on evidence based neonatal medicine)

the PDA do open up during phototheraphy probably due to extra fluids 40-60 ml /kg given in addition to normal maintainance.

As simple, cost effective and evidence based way to prevent this is to cover the ductal area with a reflective (tin foil) material. [see Jack Sinclaire's book on evidence based neonatal medicine)

It doesnt seem to work for extreme premature infants though (see Travadi's paper). Additionally, phototherapy has changed as well as LED-powered phototherapy is being used more and more which seems to be producing less heat and is a lot more effective (Vreman et al.) - so maybe the effects seen in Rosenfeld's paper might not be applicable today.

the PDA do open up during phototheraphy probably due to extra fluids 40-60 ml /kg given in addition to normal maintainance.

We tend to give 20ml/kg additionally, but who knows what the right fluid management is?

Additionally I might want to remark that even though phototherapy is widely used, no one really knows what long-term effects might arise from phototherapy (DNA mutations?). At least it seems that aggressive therapy is better than a conservative approach (Morris et al.), but at what Bilirubin level do we have to worry about worse neurological outcome due to bilirubin toxicity?

I respect Dr Cardona's views and am aware of Tirvidi's paper. In our experience of over 30 years we have found it useful even in the very preterm and with newer generation of lights.

I admit one paper is just little evidence, but as a young member to the field of neonatology I do not have a lot of experience so I resort to the best evidence I can find. The association seen in older papers might be due to confounding as various people in this thread have pointed out. I am interested in your experience though: are all neonates covered with foil when they are subject to phototherapy. And have you seen differences in rates of PDA at your ward?

Personally, I do not feel convinced this association is a scientifically robust association.

It may well be that phototherapy is a proxy for other factors related to duct opening, rather than the phototherapy itself being part of the causal chain of events.

There are lots of preterm infants with PDA's and hyperbili.

One could easily recruit hundreds of infants to an (unblinded) RCT, comparing coverage vs no coverage, being able to control for potential confounders.