Bartter syndrome as natural experiment if furosemide (re)opens the ductus arteriosus.

Furosemide increases renal prostaglandin synthesis and animal studies show reopening of the ductus arteriosus in rats exposed to furosemide. Nevertheless, large cohort studies in preterm infants do not support this hypothesis. Bartter syndrome, a rare genetic renal disorder with excessive fluid and salt-loss, is similar to continuous furosemide exposure. We hypothesize that Bartter syndrome could be considered as a natural experiment. Although most infants with Bartter syndrome are born prematurely, there are no cases found in literature with a patent ductus arteriosus which suggest that the contribution of furosemide to (re)opening of the ductus arteriosus in humans might be negligible.