Neonatal pulmonary hypertension treated with inhaled nitric oxide and high-frequency ventilation

Abstract

Term and near-term infants with pulmonary hypertension are frequently treated with inhaled nitric oxide. This therapy can be delivered with highfrequency ventilation, but there has been limited study of the relative effectiveness of high-frequency jet ventilation and high-frequency oscillatory ventilation.Objective: To compare short-term clinical outcomes of neonates with pulmonary hypertension treated with inhaled nitric oxide plus either high-frequency jet ventilation or high-frequency oscillatory ventilation.Study Design: Study infants met the following criteria: X35 weeks gestation, respiratory failure with pulmonary hypertension, no congenital malformations and treatment in the first week of life with inhaled nitric oxide plus either high-frequency jet ventilation (n ¼ 22) or high-frequency oscillatory ventilation (n ¼ 43). Data were collected from medical records. Result:The jet ventilation and oscillatory ventilation groups were similar in terms of gestational age, but the jet ventilation group had less severe respiratory illness (that is, lower oxygenation index) just prior to initiation of the combination of nitric oxide and high-frequency ventilation. The jet ventilation group spent more hours on inhaled nitric oxide (71.4 versus 40.8; P ¼ 0.004) but was less likely to require extracorporeal membrane oxygenation (2(9%) versus 19(44%); P ¼ 0.004). No difference was found in the ages at which oxygen and high-frequency ventilation were discontinued. Keywords: persistent pulmonary hypertension; inhaled nitric oxide; hypoxic respiratory failure; high-frequency ventilation; high-frequency oscillatory ventilation; high-frequency jet ventilation Introduction Persistent pulmonary hypertension of the newborn (PPHN) refers to a lack of normal cardiopulmonary adaptation following delivery, 1 including persistence of the elevated pulmonary vascular resistance that is characteristic of fetuses. 2 Most often PPHN occurs in infants with meconium aspiration syndrome (34 to 51%), pneumonia/sepsis (20 to 23%), idiopathic PPHN (17 to 25%), congenital diaphragmatic hernia (10 to 15%) or respiratory distress syndrome (9 to 12%). 3,4 Prior to the introduction, in the late 1990s, of inhaled nitric oxide (iNO), therapies for PPHN included induced alkalosis, supplemental oxygen, mechanical ventilation and neuromuscular blockade; and patients who failed to respond to these measures were treated with extracorporeal membrane oxygenation (ECMO). 5 iNO has been shown to reduce the need for ECMO in term and near-term neonates with pulmonary hypertension. 3,4,6,7 High-frequency ventilation (HFV) has been used with increasing frequency for PPHN, 8 and when combined with iNO results in an acute rise in arterial oxygen saturation, 9 and reduces the likelihood of ECMO treatment. 10 Studies of iNO delivered by HFV have, to date, utilized high-frequency oscillatory ventilation (HFOV). However, since patients treated with high-frequency jet ventilation (HFJV), as compared to conventional ventilation, require lower peak pressures to achieve t...

High-frequency oscillatory ventilation: A narrative review

“…This method uses permissive hypercapnia to provide ventilatory support and maintain normal cellular function, allowing PaCO 2 to rise while maintaining an arterial pH between 7.25 and 7.30. This strategy minimizes VILI, reduces the incidence of secondary chronic lung disease, improves ventilation/perfusion (V/Q) mismatch, does not impair cardiac output, and improves lung recruitment without overdistension [1, 4, 5, 9, 11, 13, 17, 18, 25, 26, 30, 31, 34, 40, 42].…”

Caracteristics, Diagnosis, Management and Output of Persistent Pulmonary Hypertension of the Newborn at Dr. Soetomo Hospital

“…The ECMO and HFO ventilation also can provide improvement for the lung oxygenation up to 53%, compared to regular mechanical ventilation in PPHN infants, with recovery rates from 81-82% 11,27 . The combination of HFO and iNO also give the advantage, because with low pressure it can quickly corrected arterial oxygenation saturation 1,3 .…”

The use of high frequency jet ventilation to treat suspected pulmonary hypoplasia

“…In a published retrospective case control study of infants with hypoxemic respiratory failure who required inhaled nitric oxide (iNO), both HFOV and HFJV were equally effective at delivering iNO, but HFJV was associated with a lower mean airway pressure. [17] Lower mean airway pressure also resulted from the use of HFJV in a randomized study [18] and in a case control study [19] comparing HFJV to CMV in supporting infants with hypoxemic respiratory failure. These clinical reports support the animal models of respiratory failure, which demonstrate that adequate gas exchange can be achieved with a lower mean airway pressure using HFJV compared to either CMV or HFOV [20].…”