High-Frequency Positive Pressure Ventilation as Primary Rescue Strategy for Patients with Congenital Diaphragmatic Hernia: A Comparison to High-Frequency Oscillatory Ventilation.

OBJECTIVE: The aim of this article was to evaluate high-frequency positive pressure ventilation (HFPPV) compared with high-frequency oscillatory ventilation (HFOV) as a rescue ventilation strategy for patients with congenital diaphragmatic hernia (CDH). HFPPV is a pressure-controlled conventional ventilation method utilizing high respiratory rate and low positive end-expiratory pressure. STUDY DESIGN: Seventy-seven patients diagnosed with CDH from January 2005 to September 2019 who were treated with stepwise progression from HFPPV to HFOV versus only HFOV were included. Fisher's exact test and the Kruskal-Wallis test were used to compare outcomes. RESULTS: Patients treated with HFPPV + HFOV had higher survival to discharge (80 vs. 50%, p = 0.007) and to surgical intervention (95.6 vs. 68.8%, p = 0.003), with average age at repair 2 days earlier (p = 0.004). Need for extracorporeal membrane oxygenation (p = 0.490), inhaled nitric oxide (p = 0.585), supplemental oxygen (p = 0.341), and pulmonary hypertension medications (p = 0.381) were similar. CONCLUSION: In CDH patients who fail respiratory support with conventional ventilation, HFPPV may be used as an intermediary mode of rescue ventilation prior to HFOV without adverse effects. KEY POINTS: · HFPPV may be used as an intermediary mode of rescue ventilation prior to HFOV without adverse effect.. · HFPPV is more widely available and can mitigate the limitations faced when using HFOV.. · HFPPV allows for intra- or interhospital transfer of neonates with CDH..

Revisiting the definition of bronchopulmonary dysplasia in premature infants at a single center quaternary neonatal intensive care unit.

OBJECTIVE: To compare the incidence of bronchopulmonary dysplasia (BPD) based on the 1988 Vermont Oxford Network (VON) criteria, National Institutes of Health (NIH) 2001 definition, and NIH 2018 definition. METHODS: BPD incidence by each definition was compared in premature infants born at a single center between 2016 and 2018. Comorbidities were compared between those with and without BPD according to the newest definition. RESULTS: Among 352 survivors, BPD incidence was significantly different at 9%, 28% and 34% according to VON, NIH 2001 and NIH 2018 definitions, respectively (p < 0.05). According to the newest definition, any grade of BPD was associated with more co-morbidities than those without BPD (P < 0.001). CONCLUSION: At a center that emphasizes use of early noninvasive respiratory support, the incidence of BPD was significantly higher according to the NIH 2018 definition compared to other two definitions. The relationship between BPD diagnosis and long-term clinical outcomes remains unclear.

Surfactant and continuous positive airway pressure for the prevention of chronic lung disease: History, reality, and new challenges.

The discovery of surfactant was one of the most significant research events to occur in the history of neonatology. Certainly, surfactant saved lives for premature infants who were otherwise considered non-viable. However, the prevention of chronic lung disease did not progress and it became clear that a significant portion of the help surfactant provides to the premature lung is counteracted by mechanical ventilation. A dilemma exists over the priorities in premature management to intubate and administer surfactant or not to intubate and support these infants non-invasively with the use of continuous positive airway pressure. A new hydrophilic surfactant preparation has been developed with the hope to enable the introduction of surfactant therapy without the need for tracheal intubation. Clinical trials on this product are currently in progress. This article provides the history and prospect of respiratory distress management in premature infants and evaluates the current evidence for non-invasive practices.

Is mechanical ventilation associated with intraventricular hemorrhage in preterm infants?

BACKGROUND: The impact of mechanical ventilation on the incidence of intraventricular hemorrhage (IVH) in very low birth weight (VLBW) infants is unknown, simply because the vast majority of these infants have been routinely intubated and mechanically ventilated. There is a growing interest in the use of early nasal continuous positive airway pressure (ENCPAP) and avoiding mechanical ventilation. OBJECTIVES: To examine the role of mechanical ventilation since delivery room in determining severe IVH in VLBW infants in two neonatal units that follow the same strategy of respiratory management using ENCPAP. METHODS: We collected data on delivery room intubation and mechanical ventilation during the first 3 days of life in VLBW infants. Logistic regression model was constructed to test the relationship between early mechanical ventilation and the diagnosis of severe IVH after controlling for significant confounding variables, such as BW, gender, duration of mechanical ventilation, and partial pressure of CO(2) (PCO(2)). RESULTS: Of the studied 340 VLBW, 35 infants had severe IVH; most of them received mechanical ventilation that started either in the delivery room (n=12) or during the first (n=10) and second (n=3) days of life. Severe IVH was independently associated with lower BW, mechanical ventilation in the delivery room, and the cumulative duration of mechanical ventilation during the first 3 days. The adjusted odds ratio for severe IVH in infants intubated in delivery room was (OR=2.7, CI: 1.1-6.6, P=0.03). Severe IVH was not associated with gender, prenatal steroids, early sepsis, or patent ductus arteriosus. CONCLUSIONS: Mechanical ventilation plays a role in predicting severe IVH. Both the time at which ventilation was initiated and the duration of ventilation are important determinants of severe IVH. Risk for severe IVH in infants who were never intubated in delivery room or during the first 3 days of life is miniscule.

Factors Affecting the Weaning from Nasal CPAP in Preterm Neonates.

Objective. Identification of the weight and postmenstrual age (PMA) at successful weaning of NCPAP in preterm neonates and the factors influencing the successful wean. Study Design. Retrospective review of 454 neonates ≤32 weeks of gestational age (GA) who were placed on NCPAP and successfully weaned to room air was performed. Results. Neonates had a mean birth weight (BW) of 1357 ± 392 grams with a mean GA of 29.3 ± 2.2 weeks. Neonates were weaned off NCPAP at mean weight of 1611 ± 432 grams and mean PMA of 32.9 ± 2.4 weeks. Univariate analysis showed that chorioamnionitis, intubation, surfactant use, PDA, sepsis/NEC, anemia, apnea, GER and IVH were significantly associated with the time to NCPAP wean. On multivariate analysis, among neonates that were intubated, BW was the only significant factor (P < 0.001) that was inversely related to time to successful NCPAP wean. Amongst non-intubated neonates, along with BW (P < 0.01), chorioamnionitis (P < 0.01), anemia (P < 0.0001), and GER (P < 0.02) played a significant role in weaning from NCPAP. Conclusion. Neonates were weaned off NCPAP at mean weight of 1611 ± 432 grams and mean PMA of 32.9 ± 2.4 weeks. BW significantly affects weaning among intubated and non-intubated neonates, though in neonates who were never intubated chorioamnionitis, anemia and GER also significantly affected the duration on NCPAP.

Early or late surgical ligation of medical refractory patent ductus arteriosus in premature infants.

Optimal time to surgical ligation of patent ductus arteriosus (PDA) in very-low-birth-weight (< 1500 g) premature infants remains an area of controversy. We compared the outcomes of early or late ligation of medical refractory PDA in very-low-birth-weight premature infants. Fifty-six infants underwent surgical closure of PDA after failure of or having contraindications to medical treatment. Thirteen infants were in the early ligation (< or = 14 days) and 43 in the late ligation (> 14 days) groups. Basic clinical features, major morbidity of prematurity and mortality were compared. Clinical features and major outcomes were similar. The early ligation group had earlier onset of symptomatic PDA (5.7 +/- 1.6 days vs. 8.1 +/- 3.6 days, p = 0.024), and fewer days of total parenteral nutrition (TPN) (39.6 +/- 13.9 days vs. 60.4 +/- 31.4 days, p = 0.025) and ventilator use (11.1 +/- 6.7 days vs. 18.6 +/- 10.5 days, p = 0.019). Early ligation of medical refractory PDA in very-low-birth-weight premature infants improves enteral feeding tolerance and reduces TPN and ventilator use, but long-term benefits need further investigation.

Treatment of giant pulmonary interstitial emphysema by ipsilateral bronchial occlusion with a Swan-Ganz catheter.

BACKGROUND: Unilateral giant pulmonary interstitial emphysema (PIE) can be seen as a complication of chronic ventilation in extremely low-birth-weight babies. Many can be managed by conventional pulmonary care which includes positioning, suctioning, chest physiotherapy, gentle conventional ventilation and high-frequency ventilation. Some may need invasive procedures such as lung puncture, pleurotomies and excisional surgery. This is the group in which single-lung ventilation may be beneficial and circumvent the need for an invasive procedure. OBJECTIVE: We describe the technique of single-lung ventilation using a Swan-Ganz catheter to block the main stem bronchus on the diseased side in air-leak syndromes. MATERIALS AND METHODS: A retrospective chart review was done on 17 newborns undergoing single-lung ventilation using this technique at the Children's Hospital of New York, Columbia University, from 1986 to 2000. RESULTS: The technique was successful in the management of severe, neonatal unilateral lung disease not responsive to conventional modes of therapy in all but two neonates as seen by a significant improvement in pH and a decrease in PaCO(2) levels. In one neonate malpositioning of the Swan-Ganz catheter balloon could have contributed to the development of pneumothorax. CONCLUSION: The described technique of single-lung ventilation provides a safe, minimally invasive and economically feasible method of management of unilateral giant PIE in newborns not responsive to conventional modes of therapy with minimal complications.

A comparison of a new, ultrathin-walled two-stage twin endotracheal tube and a conventional endotracheal tube in very premature infants with respiratory distress syndrome: a pilot study.

This was a pilot study to test the feasibility of use of the ultrathin-walled two-stage twin endotracheal tube (UTTS-T-ETT), with one half to one third the resistance to gas flow and one third to one seventh the dead space of a conventional tracheal tube, in very premature infants. Twenty-eight infants with gestational age 24 to 28 weeks and birthweight >/= 500 g with respiratory distress syndrome requiring intubation and mechanical ventilation were randomly assigned to be intubated with either the UTTS-T-ETT (13 infants) or with a conventional ETT (15 infants). The infants in the two groups were similar in GA, birthweight, age of entry in the study, and initial ventilator settings. Indications for intubation and extubation were standardized. To evaluate the feasibility of the UTTS-T-ETT, complications with insertion of the endotracheal tube, traumatic injury of the upper airway, number of accidental extubations, number of re-intubations after attempted extubation, number of x-ray/days of mechanical ventilation, prevalence of atelectasis, prevalence of air-leak syndrome, duration of ventilation, bronchopulmonary dysplasia, length of stay, and mortality in the two groups were compared. No significant differences in the outcomes were observed. Specifically, no complications during intubation or traumatic injury of the upper airway due to indwelling ETT were observed in either group. The proportion of failed extubation attempts was 7% in the UTTS-T-ETT V 40% in the conventional ETT group ( P = 0.08). The use of the UTTS-T-ETT is feasible in preterm infants. There was no difference in adverse events associated with its use compared with a conventional ETT. Given the proven in vitro advantages and a favorable trend toward facilitation of extubation in this pilot study, a larger randomized trial to assess clinical benefit and confirm safety is indicated.

Lung function in infants after repair of congenital diaphragmatic hernia.

BACKGROUND/PURPOSE: Congenital diaphragmatic hernia (CDH) is initially characterized by severe restrictive lung defect and low lung compliance, but survivors have relatively few abnormalities later in life. We studied the changes in lung growth and function in infants after the repair of CDH. METHODS: Retrospective analysis of pulmonary function tests was performed during the first 24 months of life in 56 infants (33 male and 23 female) after repair of CDH. Lung function (functional residual capacity [FRC], respiratory system compliance [C(rs)] and resistance [R(rs)], and maximum expiratory flow rate at FRC [V'(maxFRC)]) were compared among 4 different ages (0-3, 4-6, 7-12, and 13-24 months). RESULTS: All indices of lung function (mean +/- SD of z scores) were abnormal during the first 6 months of life but were almost normalized by 24 months (P < .0001): FRC, from -0.84 +/- 0.5 to 3.26 +/- 2.07; C(rs), from -0.87 +/- 0.4 to 1.84 +/- 1.75; R(rs), from 2.85 +/- 2.71 to -0.23 +/- 2.03, and V'(maxFRC), from -1.63 +/- 0.4 to -0.09 +/- 0.94. There was significant correlation (P < .001) between lung function and increase in age, height, and especially weight. CONCLUSIONS: Lung growth and function gradually normalize between 6 and 24 months of life after repair of CDH.

Variables associated with the early failure of nasal CPAP in very low birth weight infants.

OBJECTIVE: To identify risk factors and neonatal outcomes associated with the early failure of "bubble" nasal continuous positive airway pressure (CPAP) in very low birth weight (VLBW) infants with respiratory distress syndrome (RDS). STUDY DESIGN: Following resuscitation and stabilization at delivery, a cohort of 261 consecutively inborn infants (birth weight < or = 1250 g) was divided into three groups based on the initial respiratory support modality and outcome at 72 hours of age: "ventilator-started" group, "CPAP-failure" group, and "CPAP-success" group. RESULTS: CPAP was successful in 76% of infants < or = 1250 g birth weight and 50% of infants < or = 750 g birth weight. In analyses adjusted for postmenstrual age (PMA) and small for gestational age (SGA), CPAP failure was associated with need for positive pressure ventilation (PPV) at delivery, alveolar-arterial oxygen tension gradient (A-a DO2) >180 mmHg on the first arterial blood gas (ABG), and severe RDS on the initial chest x-ray (adjusted odds ratio [95% CI] = 2.37 [1.02, 5.52], 2.91 [1.30, 6.55] and 6.42 [2.75, 15.0], respectively). The positive predictive value of these variables ranged from 43% to 55%. In analyses adjusted for PMA and severe RDS, rates of mortality and common premature morbidities were higher in the CPAP-failure group than in the CPAP-success group. CONCLUSION: Although several variables available near birth were strongly associated with early CPAP failure, they proved weak predictors of failure. A prospective controlled trial is needed to determine if extremely premature spontaneously breathing infants are better served by initial management with CPAP or mechanical ventilation.

Is the new definition of bronchopulmonary dysplasia more useful?

OBJECTIVE: To determine the incidence of bronchopulmonary dysplasia (BPD) in low birth weight (LBW) infants <1251 g managed with early bubble nasal continuous positive airway pressure (NCPAP) and a gentle ventilation strategy using the newly proposed definition for BPD and the previous definitions. METHODS: Needs for supplemental oxygen and positive pressure (positive pressure ventilation or NCPAP) during initial hospitalization were evaluated in 266 inborn LBW infants (birth weight <1251 g). The data were categorized in three weight groups, <751, 751 to 1000 and 1001 to 1250 g and the incidence of BPD was computed in survivors based on oxygen need at 28 days, 36 weeks postmenstrual age (PMA) and the new severity of BPD criteria, that is, mild BPD: need for supplemental oxygen > or =28 days, but not at 36 weeks PMA; moderate BPD: need for supplemental oxygen > or =28 days and <30% at 36 weeks PMA and severe BPD: need for supplemental oxygen > or =28 days, and >30% at 36 weeks PMA and/or positive pressure at 36 weeks PMA. Further, BPD-associated comorbidities and short-term outcome data during hospitalization were compared among the groups, defined by severity of BPD. RESULTS: Among LBW infants <1251 g, the incidences of BPD at 28 days and 36 weeks PMA were 21.1 and 7.4% respectively. Using the newly defined criteria, the incidences of mild, moderate and severe BPD were 13.5, 4.8 and 2.6%, respectively. In total, 64.6% of these infants had mild BPD and 70.8% weighed <751 g at birth. Associated comorbidities correlated significantly with grades of underlying pulmonary disease. Also, significantly longer hospital stay, discharge at a higher PMA and lower growth velocity was observed with increasing grades of BPD. CONCLUSIONS: The new system for grading the severity of BPD offers a better description of underlying pulmonary disease and correlates with the infant's maturity, growth and overall severity of illness. Whether it will have a role in predicting long-term outcome remains to be determined.

Inhaled nitric oxide and gentle ventilation in the treatment of pulmonary hypertension of the newborn--a single-center, 5-year experience.

OBJECTIVE: To evaluate the effect of inhaled nitric oxide (INO) in pulmonary hypertension of the newborn (PH) in a single center over 5 years using gentle ventilation (GV), without hyperventilation or induced alkalosis. METHODS: Data from 229 consecutive infants with PH of varied etiology treated with INO and GV, and from 67 infants with meconium aspiration syndrome (MAS) and primary PH (PPHN) treated with GV alone were reviewed over a 5-year period (86% outborn). INO was initiated at 25 ppm when PH and severe hypoxemia persisted despite maximal optimal ventilation. Hyperventilation or systemic alkalosis were not attempted. RESULTS: Mean duration of ventilation was 9.9 +/- 14 days (median 6.5 days). Average mean airway pressure (MAP) dropped from 17.7 +/- 4.3 cm H(2)O at the referral hospital to 13.2 +/- 2.5 cm H(2)O (p < 0.001) following admission to our unit using conventional settings and GV, before starting INO. Mean oxygenation index (OI) dropped from 46.8 +/- 24.5 to 22.7 +/- 21.4 within 24 hours of INO therapy (p < 0.001). Infants with higher baseline pH and lower baseline OI responded better to INO (p < 0.02). Overall survival was 72%. Patients with MAS and PPHN had the best response, 92% survived and there was a 46% reduction in need for extracorporeal membrane oxygenation (ECMO) compared to historical pre-INO period controls (23.9% vs. 12.8%, p < 0.01). In the infants treated with GV alone, the MAP dropped from 17.2 +/- 4.3 cm H2O at the referral hospital to 12.6+/-2.4 after GV was started in our unit. CONCLUSIONS: We conclude that INO is an effective and well-tolerated therapy for PH in infants receiving GV.

Subcutaneous emphysema and pneumomediastinum as presenting manifestations of neonatal tracheal injury.

Neonatal tracheal injury/perforation is an uncommon complication of traumatic deliveries or endotracheal intubation. We present a case of neonatal tracheal injury following delivery at term that presented with subcutaneous emphysema and pneumomediastinum before any attempt at intubation. The clinical course, treatment, and outcome are described.

Congenital diaphragmatic hernia in 120 infants treated consecutively with permissive hypercapnea/spontaneous respiration/elective repair.

BACKGROUND/PURPOSE: Poor prognosis (approximately 50% survival rate and significant morbidity) traditionally has been associated with congenital diaphragmatic hernia (CDH). The authors reviewed a single institution experience and challenged conventional wisdom in the context of a care strategy based on permissive hypercapnea/spontaneous respiration/elective repair. METHODS: From August 1992 through February 2000, all infants with CDH and (1) respiratory distress requiring mechanical ventilation, (2) in-born or (3) transferred preoperatively within hours of birth are reported. All respiratory care strategy used permissive hypercapnea/spontaneous respiration and combined with elective repair. Arterial blood gas values and concomitant ventilator support were recorded. Outcome markers were (1) need for extracorporeal membrane oxygenation ECMO, (2) discharge to home, (3) supplemental oxygen need at discharge, and (4) influence of non-ECMO ancillary therapies (surfactant, nitric oxide, high-frequency oscillatory ventilation). RESULTS: One hundred twenty consecutive infants were reviewed. Overall survival rate was 75.8%, but, excluding 18 of 120 not treated (6 lethal anomalies, 10 overwhelming pulmonary hypoplasia, 3 prerepair ECMO-related neurocomplications), 84.4% survived to discharge. A total of 67/120 were inborn. Non-ECMO ancillary treatments had no impact on survival rate. ECMO was used in 13.3%. Surgery was transabdominal; prosthetics were used in 7%. Tube thoracostomy was rare. Every inborn patient (n = 11) requiring a chest tube for pneumothorax died. Respiratory support before surgery was peak inspiratory pressure (PIP), 22, FIO(2),.43 with PaO(2), 66 torr; PaCO(2), 41 torr; and pH, 7.32. The survivors discharged on oxygen (n = 2) died at 4 and 7 months. CONCLUSIONS: The majority of infants with life-threatening CDH treated with permissive hypercapnea/spontaneous respiration/elective surgery survive to discharge with minimal pulmonary morbidity.