Risk factors and clinical outcomes of pulmonary interstitial emphysema in extremely low birth weight infants

Persistent Pulmonary Interstitial Emphysema With Respiratory Infection: A Clinicopathological Analysis of Six Cases and Detection of Infectious Pathogens by Metagenomic Next-Generation Sequencing (mNGS)

BACKGROUND

Persistent pulmonary interstitial emphysema (PPIE) is known to be related to mechanical ventilation and preterm. However, PPIE is also reported rarely in non-ventilated and full-term infants. Its relationship with respiratory infection is rarely reported in the literature. PPIE is difficult to diagnose and always mimics other congenital thoracic malformations (CTMs), such as congenital cystic adenomatoid malformation (CCAM).

OBJECTIVE

The objective of this study was to evaluate clinicopathological and radiographic features of PPIE with respiratory infection and to detect the possible infectious pathogens.

METHODS

From January 2011 to December 2019, six cases were confirmed pathologically with PPIE from a large cohort of 477 resected CTMs in West China Hospital of Sichuan University. Clinical and radiographic features were obtained from patients' medical records and follow-up. The present study aimed to analyze clinicopathological and radiographic features and to detect the infectious pathogens by metagenomic next-generation sequencing (mNGS).

RESULTS

The six PPIE cases included four girls and two boys, ranging from 2 months to 5 years; 100% (5/5) of the available cases were full-term and without mechanical ventilation. CCAM were suspected in 66.7% (4/6) patients; 66.7% (4/6) cases affected a single lobe, and 33.3% (2/6) cases affected both lung lobes. Clinically, all six PPIEs were presented with symptoms of respiratory infection and diagnosed with pneumonia. All six patients were treated by surgery after anti-infective treatment. The pathologic characteristics showed lung cysts with variable size along the bronchovascular bundles, the cysts had a discontinuous fibrotic wall with a smooth inner surface lined with uninucleated and/or multinucleated macrophages. Streptococcus pneumoniae was detected in patient No. 1. Human beta-herpesvirus 5 was detected in patient No. 2. Neisseria mucosa, Neisseria sicca, Prevotella melaninogenica, Prevotella histicola, and Fusobacterium nucleatum were detected in patient No. 5, and no infectious pathogen was detected in 50% (3/6, No. 3, No. 4, and No. 6) of cases.

CONCLUSION

Six rare cases of PPIE with respiratory infection were treated by surgery after anti-infective treatment. All five available cases were full-term infants without mechanical ventilation. The histological characteristics of PPIE were the wall of cysts composed of a thin layer of discontinuous fibrous tissue and lined with uninucleated or/and multinucleated macrophages.

Refractory Pulmonary Interstitial Emphysema in Extreme Premature Newborn

Pulmonary interstitial emphysema (PIE) occurs when air leaks into the pulmonary interstitium due to overdistension of distal airways, it occurs mainly in neonates with respiratory distress syndrome who need positive pressure ventilation but has also been reported in spontaneously breathing infants. Herein, we report on an extremely low birth weight infant with severe persistent PIE, while on invasive mechanical ventilation (high-frequency oscillatory ventilation, high-frequency jet ventilation, and neurally adjust ventilator assist) managed successfully with 2 weeks of selective right lung ventilation after failure of more conservative measures, including shorter periods of right mainstem intubation, before the prolonged trial that was successful.

Preeclampsia was a risk factor for pulmonary interstitial emphysema in preterm infants born ≤32 weeks of gestational age

AIM

This study determined the prenatal and postnatal risk factors for pulmonary interstitial emphysema (PIE) in preterm infants born at up to 32 weeks of gestational age (GA) and their contribution to severe complications.

METHODS

We studied 179 preterm infants, who had undergone chest X-rays during the first five days of life at Justus Liebig University Giessen, Germany, between 2016 and 2017. Of these, 33 were retrospectively classified as PIE and 146 as non-PIE. The PIE cases were also matched with 33 non-PIE cases by GA and gender. Risk factors were identified by univariate analyses and multivariable logistic regression.

RESULTS

Previously known risk factors for pulmonary interstitial emphysema were confirmed, including GA and birthweight and the associations with adverse outcomes like intraventricular haemorrhage and mortality. We identified preeclampsia and haemolysis, elevated liver enzymes and low platelet count (HELLP) syndrome as additional risk factors for PIE (P = .027), and lung impairment was associated with respiratory distress syndrome (P = .001), higher maximum inspired oxygen (P = .014) and needing surfactant (P = .006).

CONCLUSION

Preeclampsia and HELLP syndrome were identified as possible additional risk factors for PIE in preterm infants. These conditions should be included in future studies, to identify preterm infants at risk of PIE straight after birth.

Pulmonary pneumatoceles in neonates

Pulmonary pneumatoceles were relatively common in neonates in the pre-surfactant era. In the current era of surfactant, noninvasive and gentle invasive ventilation there is a paucity of data on clinical characteristics and outcomes of pneumatoceles in neonates. The lesion generally resolves spontaneously, but a few cases follow a complicated course with formation of extensive and expanding lesions. To better understand the pathophysiology, clinical significance, natural history, complications, treatment options and prognosis of pulmonary pneumatoceles in neonates, an extensive research was performed on the databases of medical literature. The information collected in this review is important for the clinicians in decision-making, especially in the most difficult cases.

Antenatal magnesium sulphate and adverse neonatal outcomes: A systematic review and meta-analysis

BACKGROUND

There is widespread, increasing use of magnesium sulphate in obstetric practice for pre-eclampsia, eclampsia, and preterm fetal neuroprotection; benefit for preventing preterm labour and birth (tocolysis) is unproven. We conducted a systematic review and meta-analysis to assess whether antenatal magnesium sulphate is associated with unintended adverse neonatal outcomes.

METHODS AND FINDINGS

CINAHL, Cochrane Library, LILACS, MEDLINE, Embase, TOXLINE, and Web of Science, were searched (inceptions to 3 September 2019). Randomised, quasi-randomised, and non-randomised trials, cohort and case-control studies, and case reports assessing antenatal magnesium sulphate for pre-eclampsia, eclampsia, fetal neuroprotection, or tocolysis, compared with placebo/no treatment or a different magnesium sulphate regimen, were included. The primary outcome was perinatal death. Secondary outcomes included pre-specified and non-pre-specified adverse neonatal outcomes. Two reviewers screened 5,890 articles, extracted data, and assessed risk of bias following Cochrane Handbook and RTI Item Bank guidance. For randomised trials, pooled risk ratios (RRs) or mean differences, with 95% confidence intervals (CIs), were calculated using fixed- or random-effects meta-analysis. Non-randomised data were tabulated and narratively summarised. We included 197 studies (40 randomised trials, 138 non-randomised studies, and 19 case reports), of mixed quality. The 40 trials (randomising 19,265 women and their babies) were conducted from 1987 to 2018 across high- (16 trials) and low/middle-income countries (23 trials) (1 mixed). Indications included pre-eclampsia/eclampsia (24 trials), fetal neuroprotection (7 trials), and tocolysis (9 trials); 18 trials compared magnesium sulphate with placebo/no treatment, and 22 compared different regimens. For perinatal death, no clear difference in randomised trials was observed between magnesium sulphate and placebo/no treatment (RR 1.01; 95% CI 0.92 to 1.10; 8 trials, 13,654 babies), nor between regimens. Eleven of 138 non-randomised studies reported on perinatal death. Only 1 cohort (127 babies; moderate to high risk of bias) observed an increased risk of perinatal death with >48 versus ≤48 grams magnesium sulphate exposure for tocolysis. No clear secondary adverse neonatal outcomes were observed in randomised trials, and a very limited number of possible adverse outcomes warranting further consideration were identified in non-randomised studies. Where non-randomised studies observed possible harms, often no or few confounders were controlled for (moderate to high risk of bias), samples were small (200 babies or fewer), and/or results were from subgroup analyses. Limitations include missing data for important outcomes across most studies, heterogeneity of included studies, and inclusion of published data only.

CONCLUSIONS

Our findings do not support clear associations between antenatal magnesium sulphate for beneficial indications and adverse neonatal outcomes. Further large, high-quality studies (prospective cohorts or individual participant data meta-analyses) assessing specific outcomes, or the impact of regimen, pregnancy, or birth characteristics on these outcomes, would further inform safety recommendations. PROSPERO: CRD42013004451.

Positional treatment without mechanical ventilation in a very preterm infant with unilateral pulmonary interstitial emphysema: case report and review of the literature

Background

Pulmonary interstitial emphysema (PIE) in very low birth weight infants is a rare but severe complication. Although most of these air leaks develop in mechanically ventilated infants, they have also been reported in infants exposed only to nasal continuous positive airway pressure (CPAP). The optimal treatment for PIE is still under discussion and includes different approaches such as unilateral intubation, high frequency oscillation ventilation and even surgical lobectomy. However, as yet, there has been no report on complete resolution of unilateral PIE by positioning therapy without mechanical ventilation.

Case presentation

We report the case of a 28⁺¹gestational week twin, 990 g birth weight, Apgar 9–10-10. After stabilization with nasal CPAP the baby received surfactant by less invasive surfactant application (LISA) technique in the delivery room after 35 min of life, and continued respiratory support with nasal CPAP. At day 5 X-ray presented unilateral PIE, while pCO₂ increased from 40 mmHg to 55 mmHg and FiO₂ from 0.21 to 0.28 to achieve SpO₂ in the target range of 89–94%. The baby was treated by strict positioning on the affected hemithorax in a special splint while spontaneously breathing on High Flow Nasal Cannula (HFNC). Complete resolution of the unilateral PIE was observed after 96 h. No chronic lung disease developed.

Conclusion

For unilateral PIE in very preterm infants, positioning on the affected hemithorax without mechanical ventilation is a therapeutic option.

Lobectomy with ECMO Support in an Infant Who Developed Pulmonary Interstitial Emphysema Following Repair of Hypoplastic Aortic Arch

Pulmonary interstitial emphysema (PIE) is a common problem in premature neonates with respiratory distress syndrome. This condition is often related to barotrauma caused by mechanical ventilation or continuous positive airway pressure applied to low birth weight neonates. The clinical diagnosis can be challenging. However, after proper diagnosis, several interventions are available for successful management. We describe an infant who developed severe PIE with recurrent pneumothoraces and development of a persistent bronchopleural fistula shortly after repair of a hypoplastic aortic arch and description of successful lobectomy with the assistance of extracorporeal support (ECMO).

Early Pulmonary Interstitial Emphysema in Preterm Neonates-Respiratory Management and Case Report in Nonventilated Very Low Birth Weight Twins

Early pulmonary interstitial emphysema in extreme preterm neonates is closely linked with respiratory distress syndrome and exposure to mechanical ventilation. In severe cases, maintaining adequate gas exchange aiming to avoid further lung damage and other neonatal morbidities associated with systemic/pulmonary hypoperfusion, prolonged hypoxia, and respiratory acidosis can be challenging and requires in-depth knowledge into the pathophysiology of the disease. Herein, we report on very low birth weight twins who developed early pulmonary interstitial emphysema during noninvasive respiratory support. We further review the current evidence from the literature, specifically addressing on possible preventive measures and the respiratory management options of this acute pulmonary disease in high-risk neonates.

Diffuse pulmonary interstitial emphysema in a late preterm neonate without mechanical ventilation

Pulmonary interstitial emphysema (PIE) is most commonly seen in the setting of preterm, low birth weight neonates with lung disease. It exists on a spectrum with pneumomediastinum and pneumothorax and is often a transient phenomenon. This condition has been rarely reported in neonates while only on nasal continuous positive airway pressure (CPAP) without mechanical ventilation, but only as a localized presentation. We present a case of a late preterm neonate with diffuse PIE complicated by bilateral pneumothoraces, requiring chest tubes, with congenital thyroid aplasia as well.

Oxygen needs during resuscitation and surfactant to achieve stabilisation were independent risks factors for pulmonary interstitial emphysema in preterm infants

AIM

Pulmonary interstitial emphysema is a severe complication of mechanical ventilation in preterm infants that leads to air leakage and, or, chronic lung disease. We determined the associated risk factors.

METHODS

This was a retrospective case-control study from 2005 to 2014 at a regional referral centre in Valencia, Spain. The cases were 54 preterm infants up to 30 weeks' gestation and, or, born weighing less than 1500 g, who were diagnosed with pulmonary interstitial emphysema (PIE). The 54 controls were preterm infants without PIE matched by gestational age. Univariate analysis and multivariate analysis were performed to assess the independent predicting factors.

RESULTS

Infants with PIE had been resuscitated with higher mean fractional inspired oxygen concentration (FiO₂ ) (p = 0.008), had received higher peak mean positive end expiratory pressure (p = 0.00) and higher mean airway pressure (p = 0.026) 24 hours before diagnosis. PIE patients also received more surfactant (p = 0.00) and had higher mortality (p = 0.034). A Cox regression model identified that independent risk factors were the total amount of surfactant administered and the mean FiO₂ during the 24 hours before diagnosis.

CONCLUSION

Independent risk factors for pulmonary interstitial emphysema in preterm infants were higher oxygen during resuscitation and a higher need for surfactant and ventilatory pressures before diagnosis.

A Case of Pulmonary Interstitial Emphysema Treated by Percutaneous Catheter Insertion in Extremely Low Birth Weight Infant

The pulmonary interstitial emphysema (PIE) is a life-threatening illness in premature infants with mechanical ventilation. While most are managed conservatively, decompression would be necessary. Here, we report the first case of PIE treated by percutaneous catheter insertion in an extremely low birth weight (ELBW) infant in Korea. The patient, born with 660 g in 23+2 weeks of gestation, showed PIE in left lower lung on postnatal day 12. Percutaneous catheter insertion was performed on postnatal day 25. The size of PIE decreased, but didn't disappear completely. On postnatal day 42, we exchanged catheter and inserted additional catheter in pleural space. However, sudden desaturation and pneumothorax occurred on postnatal day 44. We changed catheter in pleural space, and pneumothorax and PIE improved. Finally, we successfully removed catheters, and weaned patient out. As in our case, percutaneous catheter insertion would be a useful option for ELBW infants with PIE.

Steroid-induced resolution of refractory pulmonary interstitial emphysema

Pulmonary interstitial emphysema (PIE) is a familiar complication of mechanical ventilation in premature infants. Its most severe form, marked by life-threatening respiratory and cardiovascular compromise, is a particularly vexing problem in neonatology. Treatment modalities rely on decubitus positioning and reduction of mean airway pressure, but refractory PIE is unresponsive to these maneuvers. Other options such as selective unilateral bronchial intubation, balloon catheter bronchial occlusion, selective lung volume reduction, and mechanical decompression each have clear limitations. In a patient with refractory, life-threatening PIE too unstable for other therapeutic modalities, we describe success with steroid therapy at a familiar dosing regimen.

Isolated Placental Inflammation and Vasculopathy: Clinical Implications in the Extremely Low Birth Weight Infants

The predictive values of placental histopathologies are compromised by a non-segregation of common anomalies. The effects of isolated pure placental inflammation (PI) and vasculopathy-coagulopathy (PV) were compared with normal (NL) placentas in extremely premature infants (ELBW, birth weight < 1000 g). PI infants required lower peak inspiratory pressure on day 3. More infants in PV were oxygen dependence on day 28. PV had an increased risk of intraventricular-periventricular hemorrhage (IVH, OR 4.9, 95% CI 1-24.7, p = 0.05). NL infants were unexposed to PPROM or maternal hypertension, had highest requirement for surfactant, did not develop IVH and periventricular leukomalacia (PVL) and none of them were Caucasian.

CONCLUSIONS

In ELBW infants (1) pure placental vasculopathy-coagulopathy is a risk factor for IVH, (2) a non- pathological intrauterine environment is nonconducive to IVH and PVL, (3) pure placental inflammation is protective for acute pulmonary disease, (4) Caucasian mothers are more susceptible to adverse intrauterine environment.

Development of Localized Pulmonary Interstitial Emphysema in a Late Preterm Infant without Mechanical Ventilation

Pulmonary interstitial emphysema (PIE) is not an uncommon finding in premature infants with respiratory distress who need respiratory support by mechanical ventilation. PIE has been reported in a few cases of neonates in whom either no treatment other than room air was given or they were given continuous positive end-expiratory pressure (CPAP) support. We present a case of a premature neonate who presented with respiratory distress, in whom PIE and spontaneous pneumothorax (PTX) developed while on CPAP therapy only. The patient was treated conservatively with subsequent resolution of the radiological findings and clinical improvement. No surgical intervention was required. It is important to know that PIE may develop independently of mechanical ventilation. We would like to add this case to the literature and describe the pertinent plain film and computed tomography (CT) findings of this entity, the possible mechanism of development, and the differential diagnosis. A review of the literature is also provided.

Pulmonary interstitial emphysema: a case report and review of the literature

Pulmonary interstitial emphysema is a rare condition that generally affects low-weight preterm infants submitted to mechanical ventilation. The prognosis is variable, depending on early diagnosis and treatment. The radiologist plays a key role in this scenario. The authors report a case of persistent pulmonary interstitial emphysema, describing the main characteristics of such entity.

High-frequency oscillatory ventilation with low oscillatory frequency in pulmonary interstitial emphysema

BACKGROUND

Pulmonary interstitial emphysema (PIE) is a common respiratory illness in preterm infants associated with significant morbidity and mortality for which the ventilatory management is imperfect.

OBJECTIVES

To evaluate the impact of high-frequency oscillatory ventilation (HFOV) with a low oscillatory frequency and thus prolonged expiratory time in preterm infants with severe PIE.

METHODS

In a retrospective cohort study, preterm infants ≤30 weeks' gestation with radiological findings of severe PIE, and either high FiO2 or persistent respiratory acidosis were studied if managed on HFOV with a low frequency (5-6 Hz, inspiratory time 30%) for >24 h. Trends in physiological and ventilatory parameters were examined over the first 72 h, radiological changes noted, and in-hospital outcomes ascertained.

RESULTS

19 cases were identified and analysed in two groups: 14 with bilateral and 5 with predominantly unilateral disease. After transition to low-frequency HFOV, physiological responses were seen in both groups, in particular a rapid and sustained improvement in oxygenation in the bilateral group (mean (SD) alveolar-arterial oxygen difference at baseline: 404 ± 206 mm Hg; 4 h post-transition: 262 ± 181 mm Hg; 72 h: 155 ± 74 mm Hg; p = 0.0003). This occurred following a reduction in mean airway pressure (mean (SD) baseline: 14 ± 3.9 cm H2O; 72 h: 12 ± 2.9 cm H2O; p = 0.011). In the unilateral group, radiological resolution of PIE was observed on re-inflation following collapse of the affected lung. Overall, 15 infants survived, including 10 of the bilateral cases (71%), and all of the unilateral cases.

CONCLUSION

HFOV with a low oscillatory frequency may afford benefit in preterm babies with severe PIE.

Pulmonary complications of mechanical ventilation in neonates

Mechanical ventilation is necessary and life saving in many neonates. Most complications are inherent to this intervention and cannot be confused with iatrogenic errors in judgment or care practices by clinicians. Clinical data suggest that complications such as volutrauma and air leak syndromes can negatively affect long-term pulmonary and non-pulmonary outcomes. Careful attention to many aspects of neonatal care, such as delivery room resuscitation, ventilatory support, and routine care practices, is needed to decrease pulmonary complications of mechanical ventilation. Clinical research is needed to improve mechanical ventilator strategies to reduce pulmonary complications and improve long-term outcomes.