Use of Inhaled Nitric Oxide (iNO) in Preterm Infants

Dear Appeals Coordinator, 

K was a newborn infant at the time of his admission to (Name of Hospital). K was admitted shortly after his birth to our NICU due to episodes of apnea, respiratory distress, and decreased heart rate. Initially K received positive pressure ventilation via Neopuff, then was placed on continuous positive airway pressure (CPAP) ventilation via Neopuff. He eventually required intubation with 30% of FiO2 at 7 minutes of life. On day 2 of life, K was extubated and placed on CPAP for an hour before he developed apnea and acute respiratory distress requiring increase oxygen despite non-invasive neurally adjusted ventilation assist (NAVA) and subsequently was reintubated and placed on a high frequency oscillating ventilation. A STAT echo was ordered which confirmed the diagnosis of persistent pulmonary hypertension and a patent duct arteriosus. The medical team immediately initiated iNO treatment to which he quickly responded. The medical team was able to wean down the FiO2 to 25% and his respiratory acidosis was improving. He was weaned off the iNO treatment on (date). 

It was imperative that inhaled nitric oxide be administered to improve K’s oxygenation given his sudden deterioration despite the ventilation support. Nitric oxide has long been an accepted treatment for pulmonary hypertension due to it being a potent pulmonary vasodilator. There is much evidence supporting its use, even in infants less than 34 weeks of gestational age. See, for example: 

Studies have shown that inhaled nitric oxide successfully doubled systemic oxygenation in 16 of 30 infants (53 percent), whereas conventional therapy without inhaled nitric oxide increased oxygenation in only 2 of 28 infants (7 percent). Long-term therapy with inhaled nitric oxide sustained systemic oxygenation in 75 percent of the infants who had initial improvement. Extracorporeal membrane oxygenation was required in 71 percent of the control group and 40 percent of the nitric oxide group (P = 0.02). The number of deaths was similar in the two groups. Inhaled nitric oxide did not cause systemic hypotension or increase methemoglobin levels. Conclusions: Inhaled nitric oxide improves systemic oxygenation in infants with persistent pulmonary hypertension and may reduce the need for more invasive treatments. Roberts, J.D., Finerman, J.R., et al, Inhaled Nitric Oxide and Persistent Pulmonary Hypertension of the Newborn, N Engl J Med 1997; 336:605-610, 1997. 

NO significantly decreased OI (P < 0.0001) and improved the arterial/alveolar (a/A) oxygen ratio (P < 0.0001) within the first 2 h of NO therapy in 61.1% of the responders. Al-Aliyan, S and Neiley, E, Inhaled Nitric Oxide in Persistent Pulmonary Hypertension of the Newborn Refractory to High-Frequency Ventilation; Crit Care; 3(1): 7-10, 1999. 

We examined the effects on systemic oxygenation and blood pressure of inhaling up to 80 parts per million by volume of NO at FO2 0·9 for up to 30 minutes by 6 infants with persistent pulmonary hypertension of the newborn (PPHN). In all infants this treatment rapidly and significantly increased preductal oxygen saturation (SpO2); in 5 infants postductal SpO2 and oxygen tensions also increased. Inhalation of NO did not cause systemic hypotension or raise methaemoglobin. These data suggest that low levels of inhaled NO have an important role in the reversal of hypoxaemia due to PPHN. Roberts, J.D., Polaner, D.M., Zapol W.M., and Lang, P., Inhaled Nitric Oxide in Persistent Pulmonary Hypertension of the Newborn, The Lancet, 340: 8823, 818-819; 1992. 

Although the literature does not currently support the use of inhaled nitric oxide in premature infants for the indication of hypoxia of prematurity, there is plenty of support (and growing) for the use of inhaled nitric oxide in premature infants with pulmonary hypertension such as this patient. See, for example: 

Infants < 34 weeks' gestational age, admitted during 2010-2016 to two neonatal units, having treated with iNO for confirmed PHT. A positive response was defined by FiO2 reduction ≥20% within 3-h post iNO initiation. Early PHT was defined when developed within the first 72 h of age. 

Outcome measures: The primary outcome was the evaluation of the acute response to iNO administration. Secondary outcomes included the comparison of neonatal characteristics and outcomes between positive and negative responders, and early or late PHT infants. 

Results: Of the 55 infants of our cohort, 39 (71%) had a positive response to iNO administration. No differences noted regarding bronchopulmonary dysplasia, intraventricular haemorrhage or other morbidities; however, positive responders had significantly higher survival rate in overall (77 vs 21%, p = 0.001) and within early PHT subgroup (74 vs 33%, p = 0.044). Regression analysis revealed that oligohydramnios (OR 2.834, 95%CI 1.652-6.070) and early PHT (OR 1.953, 95%CI 1.377-2.930) were significantly related with a positive response. 

Conclusions: Preterm infants with confirmed acute PHT respond in significant proportion to the iNO administration, especially in the background of oligohydramnios or the development of early PHT. 

Rallis D, Deierl A, Atreja G, Chaban B, Banerjee J. The efficacy of inhaled nitric oxide treatment in premature infants with acute pulmonary hypertension. Early Hum Dev. 2018;127:1‐5. doi:10.1016/j.earlhumdev.2018.09.004 

Other study authors concluded: 

In conclusion, our experience confirms that treatment with iNO should be considered as a rescue therapy in preterm newborns with acute hypoxic respiratory failure caused by severe pulmonary hypertension. 
Buse M, Graziano F, Lunetta F; et al. Inhaled nitric oxide as a rescue therapy in a preterm neonate with severe pulmonary hypertension: a case report. Ital J Pediatr. 2018; 44: 55.

Published online 2018 May 15. doi: 10.1186/s13052-018-0494-9

This study looked at long term outcomes of premature infants with pulmonary hypertension who were treated with inhaled nitric oxide:

Abstract

Objective: To describe short-term and long-term outcomes of preterm neonates with severe acute pulmonary hypertension (aPHT) in relation to response to rescue inhaled nitric oxide (iNO) therapy. 

Design: Retrospective cohort studyover a 6 year period. 

Setting: Tertiary neonatal intensive care unit.

Patients: 89 neonates <35 weeks gestational age (GA) who received rescue iNO for aPHT, including 62 treated at ≤3 days of age (early aPHT).

Interventions: iNO ≥ 1 hour.

Main outcome measures: Positive responders (reduction in fraction of inspired oxygen (FiO2) ≥0.20 within 1 hour of iNO) were compared with non-responders. Primary outcome was survival without moderate-to-severe disability at 18 months of age. 

Results: Mean (SD) GA and birth weight was 27.7 (3.0) weeks and 1077 (473) gm, respectively. Median (IQR) pre-iNO FiO2 was 1.0 (1.0, 1.0). Positive response rate to iNO was 46%. Responders showed improved survival without disability (51% vs 15%; p<0.01), lower mortality (34% vs 71%; p<0.01) and disability among survivors (17% vs 50%; p=0.06). Higher GA (adjusted OR: 1.44 (95% CI 1.10 to 1.89)), aPHT in context of preterm prolonged rupture of membranes (6.26 (95% CI 1.44 to 27.20)) and positive response to rescue iNO (5.81 (95% CI 1.29 to, 26.18)) were independently associated with the primary outcome. Compared with late cases (>3 days of age), early aPHT had a higher response rate to iNO (61% vs 11%; p<0.01) and lower mortality (43% vs 78%; p<0.01). 

Conclusion: A positive response to rescue iNO in preterm infants with aPHT is associated with survival benefit, which is not offset by long-term disability. 

Baczynski M, Ginty S, Weisz DE, et al. Short-term and long-term outcomes of preterm neonates with acute severe pulmonary hypertension following rescue treatment with inhaled nitric oxide. Arch Dis Child Fetal Neonatal Ed. 2017;102(6):F508‐F514. doi:10.1136/archdischild-2016-312409 

We have reviewed your denial of these Inpatient services from to during which iNO was given and we are appealing because iNO was imperative to help treat this newborn’s respiratory failure due to severe pulmonary hypertension. As the above references (and others) show, K was treated with evidence-based medicine, specifically the use of inhaled Nitric Oxide to treat pulmonary hypertension. K was in respiratory distress due to pulmonary hypertension and responded immediately to treatment. In the attempt to save his life and give him the best possible care, inhaled nitric oxide was used with success. At the time of this letter K’s need for supplemental oxygen has greatly decreased, and he was rapidly weaned off the iNO. Thanks to the nitric oxide, K is now stable on CPAP. 

The literature supports the use of inhaled nitric oxide in premature infants with pulmonary hypertension such as K, and fortunately, this infant has demonstrated the same positive response as has been seen in other premature infants with pulmonary hypertension. It is possible the information stated in this appeal may not have been available to the reviewer initially. Because of that possibility, we look forward to your overturning this denial and adjusting your guidelines to support the use of inhaled nitric oxide in premature infants with pulmonary hypertension. 

Sincerely,