Background Although indomethacin and ibuprofen are the standard treatments for hemodynamically significant patent ductus arteriosus (hsPDA), they are associated with renal impairment and gastrointestinal complications. Paracetamol for hsPDA closure does not provoke a peripheral vasoconstrictive effect and seems to have effects similar to those of indomethacin and ibuprofen. We have previously reported the safety of low-dose (7.5 mg/kg) intravenous paracetamol for preterm infants with hsPDA, who were indomethacin-resistant or -contraindicated but did not affect the need for surgical PDA ligation. However, reports considering the use of higher-dose (15 mg/kg) paracetamol for hsPDA have not been published in Japan. Cases In 16 premature infants in whom indomethacin or ibuprofen was contraindicated or ineffective, 15 mg/kg of paracetamol was intravenously administered every 6 hours for 3 days after obtaining parental consent. hsPDA closure or narrowing was observed in 14 infants (88%), with the need for surgical closure totally avoided in nine cases (56%). High plasma paracetamol levels were observed in three cases. No paracetamol-related side effects or adverse events were reported. Conclusion The intravenous administration of higher dose paracetamol was safe and feasible in premature infants with hsPDA. Future clinical trials to explore the optimized dose and timing of administration are needed.

Maintaining the patency of ductus arteriosus (DA) is essential for fetal circulation and normal development of the fetus. In almost-term infants, the DA constricts and causes intraluminal ischemic hypoxia, which eventually leads to the closure and remodeling of the DA a few days after birth. The occurrence of patent DA (PDA) is inversely related to gestational age and weight, with a higher incidence in preterm infants. 1 PDA is a significant cause of morbidity and mortality in preterm infants, including bronchopulmonary dysplasia, intraventricular hemorrhage, necrotizing enterocolitis, and acute renal failure due to increased pulmonary blood flow and focal organ ischemia. [2][3][4] In Japan, the AbstractBackground Although indomethacin (IND) is the standard treatment for hemodynamically significant patent ductus arteriosus (hsPDA) in Japan, it may be associated with renal impairment and gastrointestinal complications. The use of paracetamol for hsPDA closure has recently increased. Unlike IND, paracetamol does not have a peripheral vasoconstrictive effect and can be given to infants with contraindications to IND. Based on limited data available from randomized trials, paracetamol and IND seem to have similar effects. However, there have been no reports of the use of paracetamol for hsPDA in Japan. Cases Our drug administration protocol was approved by the institutional ethics committee after purchasing a clinical trial insurance. In three premature infants in whom IND was contraindicated or ineffective, a 7.5 mg/kg of paracetamol was intravenously administered every 6 hour for 3 days after obtaining parental consents. A temporary hsPDA closure was observed in two of the three infants. However, all three infants eventually needed surgical closure. No side effects, such as hepatic and renal dysfunctions, and adverse events were reported. Conclusion The intravenous administration of paracetamol was safe and feasible in premature infants with hsPDA. Future clinical trials with optimized dose and timing of administration are needed.

Septic shock is associated with impaired vasoregulation, and treatment includes vasoactive drugs. Therefore, evaluation of vasoregulatory change is important. The present report describes the successful characterization of vasoregulatory change in response to a vasoactive drug during septic shock. A male infant born at 23 weeks' gestation developed septic shock. Severe hypotension developed, and treatment with colloid fluid and dopamine failed to increase blood pressure. With continuous measurement of skin blood flow using laser Doppler, noradrenaline was started. Based on changes in the blood flow, the dose was increased. At a dose of 1 μg/kg per min, skin blood flow in the foot decreased without any change in blood pressure. Subsequent blood transfusion succeeded in increasing both blood pressure and skin blood flow. It is concluded that decrease in foot blood flow reflects the vasoconstrictive effect of noradrenaline, although this finding must be validated in larger studies.