INHALED
NITRIC OXIDE THERAPY FOR HYPOXIC RESPIRATORY FAILURE IN NEONATES
Zhou Beihua,
Zhang Xudong, Chen Chao, Shao Xiaomei, Huang Guoying, Fan Shaozeng, Sun Bo
Division of
Neonatology, Department of Pediatrics Children¡¯s Hospital, Fudan
University, Shanghai 200032, China
Objective: This study was to evaluate the
effects of a low dose of inhaled nitric oxide (iNO) for treatment of
hypoxic respiratory failure in neonates.
Patients
and Methods: Ten near or full-term and 18 preterm (gestation 31 week-) newborns
requiring mechanical ventilation for hypoxic respiratory failure, received
iNO at a concentration of 3~15 ppm. The original causes of respiratory
failure were respiratory distress syndrome (n=9), meconium aspiration
syndrome (n=6), pneumonia (n=3), and asphyxia associated persistent
pulmonary hypertension (n=7). They were mechanically ventilated with FiO2
>0.65 along with clinical and echocardiographic evidence of pulmonary
hypertension.
Results: Before iNO, mean FiO2
was 0.80?.15 , SpO2 was 74%?2.9% and oxygenation index (OI) was 25.9?6.4.
At 3 and 24 h after iNO, FiO2 decreased to 0.72?.15 and 0.52?.11 (both
P<0.001), SpO2 increased to 91.3%?.4% and 92.7%?.8%(P<0.001), and
mean OI decreased to 16.5?.6 (P<0.05) and 11.5?.8 (P<0.01), respectively.
Pumonary arterial pressure decreased from 7.3?.5 kPa before iNO to 5.2?.1
kPa 24 h after iNO (p< 0.001), along with reversal of right-to-left
shunting to bilateral or left-to-right shunting. 16 patients recovered and
discharged successfully, 3 with partial recovery, and 9 died (in which 4
had improved oxygenation but were given up by the parents). No adverse
effect of iNO was detected in respect to methemoglobin level and nitrogen
dioxide formation.
Conclusion: Inhaled NO effectively
alleviated hypoxic respiratory failure in the term and preterm neonates
mainly through selective pulmonary vasodilation, without causing
methemoglobinemia and other potential complications.
Key words: nitric oxide, respiratory failure