Meconium Aspiration Syndrome: A Narrative Review

Intratracheal instillation of budesonide suspension versus normal saline on oxidative stress in neonates with meconium aspiration syndrome

BACKGROUND

Presently, the efficacy of neonatal resuscitation techniques via interventions such as oral, nasal, and endotracheal suction for preventing meconium aspiration syndrome (MAS) after delivery has not been satisfactory.

OBJECTIVE

This study aimed to investigate the role of intratracheal instillation of budesonide on oxidative stress in MAS.

METHODS

Sixty-two neonates with MAS admitted to Huai'an Maternity and Child Healthcare Hospital from January 2018 to June 2020 were divided into a study group (intratracheal instillation of 2 ml budesonide suspension; n = 31) and a control group (intratracheal instillation of 2 ml normal saline; n = 31). Collect data from two groups of patients and evaluate clinical outcomes, including oxygenation index (OI), as well as serum total oxidant status (TOS), total antioxidant capacity (TAC), oxidative stress index (OSI) and 8-Isoprostane before treatment and 72h after admission.

RESULTS

We found no statistical differences in mortality, complication rate, total oxygen inhalation time, OI before treatment and 72h after admission between the two groups of neonates with MAS, while the duration of invasive respiratory support in the study group was significantly shorter than in the control group. Also, serum TAC, TOS, OSI and 8-isoprostane levels were not statistically different before treatment between the two groups. After 72h of admission, OSI and 8-Isoprostane in neonates with MAS in the study group were much lower than those in the control group. TOS, OSI, 8-Isoprostane in the control group and 8-Isoprostane in the study group were significantly higher than those before treatment. As for TAC and TOS, no significant differences were observed between the two groups.

CONCLUSION

Intratracheal instillation of budesonide was shown to alleviate oxidative stress and shorten invasive ventilation time in neonates with MAS.

Time, cause of early neonatal death, and its predictors among neonates admitted to neonatal intensive care units at Bahir Dar City public hospitals, northwest Ethiopia: a prospective follow-up study

Background

Globally, 75% of neonatal deaths occur during the first weeks of life and more than 43% of deaths are covered by sub-Saharan Africa. Health-related policymakers and decision-makers need to use evidence-based treatments to reduce the time to early neonatal death and associated predictors. However, there are limited studies on median survival time, cause, incidence, and predictors in the study area as well as the country. Therefore, the aim of the present study was to assess time, the cause of early neonatal death, and its predictors among neonates admitted to neonatal intensive care units at Bahir Dar City public hospitals in northwest Ethiopia.

Methods

An institution-based prospective follow-up study design was conducted among 387 early neonates selected by systematic sampling between 22 February and 22 April 2023. Statistical software, Epi Data version 4.6 and Stata version 14, was used for entry and analysis, respectively. Proportional hazard assumption and model fitness were checked by the Schoenfeld residual test and the Cox-Snell residual test, respectively. Descriptive statistics, the Kaplan-Meier curve, and the life table were used to describe variables. The Cox regression analysis model was fitted to identify the predictors of early neonatal death.

Result

During the follow-up time, 59 (15.25%) early neonates died, with an incidence of 31.79 per 1,000 early neonate days [95% confidence interval (CI): 0.024-0.041]. The leading causes of early neonatal death were prematurity complications, asphyxia, sepsis, meconium aspiration syndrome, and necrotizing enterocolitis. The mean survival time was 2.72 days. Being born from a multigravida mother [adjusted hazard ratio (AHR) 4.34; 95% CI: 1.63-11.55], a grand multigravida mother (AHR 3.50; 95% CI: 1.12-10.95), respiratory distress syndrome (AHR 2.60; 95% CI: 1.03-6.58), birth asphyxia (AHR 7.51; 95% CI: 2.30-24.51), a small gestational age (AHR 2.05; 95% CI: 1.08-4.92), and being unable to exclusively breastfeed (AHR 3.46; 95% CI: 1.52-7.88) were significantly associated predictors for time to early neonatal death.

Conclusion and recommendations

The incidence of early neonatal death was high, and the mean survival time was 2.72 days. Gravidity, respiratory distress syndrome, birth asphyxia, and being unable to exclusively breastfeed were identified as predictors of early neonatal death. Therefore, future research will consist of long-term prospective follow-up studies at a multicenter, nationwide level.

Employing digital PCR for enhanced detection of perinatal Toxoplasma gondii infection: A cross-sectional surveillance and maternal-infant outcomes study in El Salvador

Toxoplasma gondii is a parasitic infection that can be transmitted in utero, resulting in fetal chorioretinitis and other long-term neurological outcomes. If diagnosed early, pregnancy-safe chemotherapeutics can prevent vertical transmission. Unfortunately, diagnosis of acute, primary infection among pregnant women remains neglected, particularly in low-and-middle-income countries. Clinically actionable diagnosis is complex due to the commonality of infection during childhood and early adulthood which spawn long-last antibody titers and historically unreliable direct molecular diagnostics. The current study employed a cross-sectional T. gondii perinatal surveillance study using digital PCR, a next generation molecular diagnostic platform, and a maternal-fetal outcomes survey to ascertain the risk of vertical toxoplasmosis transmission in the Western Region of El Salvador. Of 198 enrolled mothers at the time of childbirth, 6.6% had evidence of recent T. gondii infection-85% of these cases were identified using digital PCR. Neonates born to these acutely infected mothers were significantly more likely to meconium aspiration syndrome and mothers were more likely to experience labor and delivery complications. Multivariable logistic regression found higher maternal T. gondii infection odds were associated with the presence of pet cats, the definitive T. gondii host. In closing, this study provides evidence of maternal T. gondii infection, vertical transmission and deleterious fetal outcomes in a vulnerable population near the El Salvador-Guatemala border. Further, this is the first published study to show clinical utility potential of digital PCR for accurate diagnosis of congenital toxoplasmosis cases.

Notch RGB-camera based SpO2 estimation: a clinical trial in a neonatal intensive care unit

Regular and narrow-band RGB cameras are recently explored for contactless SpO2 monitoring. Regular RGB cameras with cross-band overlap provide a high signal-to-noise-ratio (SNR) in measuring the photoplethysmographic signals but possess high dependency on the spectra of incident light, whereas narrow-band RGB cameras have better spectral independence but lower SNR especially in dim lighting conditions, such as in the neonatal intensive care unit (NICU). This paper proposes a notch RGB camera based SpO2 measurement approach that uses an optical notch filter to attenuate the wavelengths of 580-605 nm of a regular RGB camera to improve the spectral independence while maintaining high SNR in signal measurement. The proposed setup was validated in the lab condition (e.g. dark chamber) against the existing solutions for visible-light based camera-SpO2 measurement and further verified in the NICU on preterm infants. The clinical trial conducted in the NICU with 22 preterm infants shows that the notch RGB camera can achieve a mean absolute error (MAE) less than 4% for SpO2 measurement. This is the first showcase of continuous monitoring of absolute camera-SpO2 values in the NICU.

Recent Advances in Pediatric Pulmonary Hypertension: Implications for Diagnosis and Treatment

PURPOSE

Pediatric pulmonary hypertension (PH) is a condition characterized by elevated pulmonary arterial pressure, which has the potential to be life-limiting. The etiology of pediatric PH varies. When compared with adult cohorts, the etiology is often multifactorial, with contributions from prenatal, genetic, and developmental factors. This review aims to provide an up-to-date overview of the causes and classification of pediatric PH, describe current therapeutics in pediatric PH, and discuss upcoming and necessary research in pediatric PH.

METHODS

PubMed was searched for articles relating to pediatric pulmonary hypertension, with a particular focus on articles published within the past 10 years. Literature was reviewed for pertinent areas related to this topic.

FINDINGS

The evaluation and approach to pediatric PH are unique when compared with that of adults, in large part because of the different, often multifactorial, causes of the disease in children. Collaborative registry studies have found that the most common disease causes include developmental lung disease and subsets of pulmonary arterial hypertension, which includes genetic variants and PH associated with congenital heart disease. Treatment with PH-targeted therapies in pediatrics is often guided by extrapolation of adult data, small clinical studies in pediatrics, and/or expert consensus opinion. We review diagnostic considerations and treatment in some of the more common pediatric subpopulations of patients with PH, including developmental lung diseases, congenital heart disease, and trisomy 21.

IMPLICATIONS

The care of pediatric patients with PH requires consideration of unique pediatric-specific factors. With significant variability in disease etiology, ongoing efforts are needed to optimize treatment strategies based on disease phenotype and guide evidence-based practices.

Outcomes of neonates born through meconium-stained amniotic fluid pre and post 2015 NRP guideline implementation

A shift in the Neonatal Resuscitation Program (NRP) guidelines occurred in 2015 from routine intubation and endotracheal suctioning of all meconium-stained non-vigorous infants towards less aggressive interventions based on response to initial resuscitation. This study aims to examine the impact of this change on outcomes of non-vigorous infants born through meconium-stained amniotic fluid at a level III academic NICU encompassing years before and after the change in guideline. This single-center retrospective study compared NICU therapies and clinical outcomes of 117 non-vigorous newborns pre-guideline implementation to 106 non-vigorous newborns post-guideline implementation. Nearly two thirds of infants in the pre-guideline cohort received endotracheal suctioning with recovery of meconium compared to less than a third of infants in the post-guideline cohort (p<0.01). Though a higher proportion of the pre-guideline cohort were admitted to the NICU for respiratory issues compared to the post-guideline cohort, the two groups did not differ significantly with regard to morbidity and therapies. Despite a marked reduction in rates of intubation and endotracheal suctioning, there is no difference in outcomes between pre-guideline implementation vs post-guideline implementation in non-vigorous meconium-stained infants, supporting the recent NRP guideline change and highlighting the benefit of expectant management.

Clinical Importance of Serum BDNF (Brain-Derived Neurotrophic Factor) Level for the Management of Pregnancies Complicated With Meconium-Stained Amniotic Fluid

Objective The aim of this study was to investigate the association between poor neonatal outcomes and BDNF (brain-derived neurotrophic factor) levels. We aimed to predict the need for an emergency cesarean and prevent unnecessary interventions in cases complicated with meconium-stained amniotic fluid (MSAF). Methods This study was designed as a case-control study including three groups. Group A included pregnant women who underwent cesarean due to fetal distress. Group B included the women who delivered vaginally. Groups A and B had cases with the presence of meconium in the amniotic fluid. Group C as a control group had clear amniotic fluid. Demographic features, fetal outcomes, and maternal serum and fetal cord blood BDNF levels (Human BDNF ELISA Kit; Synonyms: ANON2, BULN2; Catalog no: E-EL-H0010 96T) were evaluated. Results No significant difference was found between patients with meconium and without meconium in terms of BDNF levels. However, the BDNF level was found to be significantly lower if fetal distress had occurred with MSAF. Conclusions In conclusion, the study demonstrated that the level of maternal and fetal cord blood BDNF are both significantly lower when fetal distress occurs with the presence of MSAF.

Assessment of Vitality, Blood Profile, and Degree of Meconium Staining on the Skin in Newborn Dogs According to Its Birth Weight

Neonatal mortality in dogs reaches up to 40%. Due to the high rates, promptly detecting the causes and preventing newborns from dying are extremely important. Vitality evaluation, blood parameters, and the degree of meconium staining on the skin are valuable resources in canine perinatology. In this study, 435 puppies from 85 bitches close to parturition were recruited and divided into four quartiles according to the puppy's birth weight: Q₁ (127-200 g) n = 110 puppies, Q₂ (201-269 g) n = 108 puppies, Q₃ (270-388 g) n = 108 puppies, and Q₄ (389-464 g) n = 109 puppies. This experimental article aimed to report the effect of birth weight on the blood profile variables, the vitality of newborn puppies, and the meconium staining degree, integrating these three aspects. It was concluded that the weight of newborns was correlated with the degree of meconium staining, presenting more cases of severe meconium staining in the puppies of the highest birth weight group. The weight of the newborns was correlated with a higher number of stillbirths and alterations in the blood variables, showing the most severe cases of metabolic acidosis, hypoxia, and hypoglycemia in the puppies of the Q₄ quartile. On the contrary, no statistically significant correlations were found between the weight of newborns and vitality. Nevertheless, the analysis of the results showed that the most vigorous puppies were found at Q_1; however, at minute 60 after birth (AB), all the puppies in the four quartiles standardized their vitality scores.

Lung Ultrasound in the Early Diagnosis and Management of the Mild Form of Meconium Aspiration Syndrome: A Case Report

MAS is a common cause of neonatal respiratory distress in term and post-term neonates. Meconium staining of the amniotic fluid occurs in about 10-13% of normal pregnancies, and about 4% of these infants develop respiratory distress. In the past, MAS was diagnosed mainly on the basis of history, clinical symptoms, and chest radiography. Several authors have addressed the ultrasonographic assessment of the most common respiratory patterns in neonates. In particular, MAS is characterised by a heterogeneous alveolointerstitial syndrome, subpleural abnormalities with multiple lung consolidations, characterised by a hepatisation aspect. We present six cases of infants with a clinical history of meconium-stained fluid who presented with respiratory distress at birth. Lung ultrasound allowed the diagnosis of MAS in all the studied cases, despite the mild clinical picture. All children had the same ultrasound pattern with diffuse and coalescing B-lines, pleural line anomalies, air bronchograms, and subpleural consolidations with irregular shapes. These patterns were distributed in different areas of the lungs. These signs are specific enough to distinguish between MAS and other causes of neonatal respiratory distress, allowing the clinician to optimise therapeutic management.

Impact of Thin Meconium on Delivery and Early Neonatal Outcomes

Several reports regarding the effects of thin meconium on maternal and neonatal outcomes are contradictory. This study evaluated the risk factors and obstetrical outcomes during deliveries complicated with thin meconium. This retrospective cohort study included all women with a singleton pregnancy, who underwent trial of labor >24 weeks of gestation, in a single tertiary center, over a six-year period. Obstetrical, delivery, and neonatal outcomes were compared between deliveries with thin meconium (thin meconium group) to deliveries with clear amniotic fluid (control group). Included in the study were 31,536 deliveries. Among them 1946 (6.2%) were in the thin meconium group and 29,590 (93.8%) were controls. Meconium aspiration syndrome was diagnosed in eight neonates in the thin meconium group and in none of the controls (0.41%, p < 0.001). In multivariate logistic regression analysis, the following adverse outcomes were found to be independently associated with increased odds ratio (OR) for thin meconium: intrapartum fever (OR 1.37, 95% CI 1.1-1.7), instrumental delivery (OR 1.26, 95% CI 1.09-1.46), cesarean delivery for non-reassuring fetal heart rate (OR 2.0, 95% CI 1.68-2.46), and respiratory distress requiring mechanical ventilation (OR 2.06, 95% CI 1.19-3.56). Thin meconium was associated with adverse obstetrical, delivery, and neonatal outcomes that should receive extra neonatal care and alert the pediatrician.

Clinical characteristics of meconium aspiration syndrome in neonates with different gestational ages and the risk factors for neurological injury and death: A 9-year cohort study

Background

The presence of meconium is associated with gestational age, and the incidence of meconium aspiration syndrome (MAS) increases with gestational age. Our study compared the differences in the clinical characteristics of patients with MAS at different gestational ages and discussed the risk factors for neurological injury and death from MAS.

Methods

A total of 294 neonates diagnosed with MAS between 2013 and 2021 were included. Patients were divided into preterm, early-term, full-term, and late-term groups according to gestational age. We compared the patients' basic demographic, treatment, complications, and clinical outcomes in the different groups. We also analyzed the risk factors of neurological injury and death in patients with MAS.

Results

The mean age at admission (0.55 ± 0.9 h) was lower and the proportion of cesarean deliveries (90.00%, 27/30) was higher in the preterm group than in the other three groups. There was no statistically significant difference among the four groups regarding 1- and 5-min Apgar scores and the need for delivery room resuscitation. In terms of complications, early-term infants had the highest incidence of neurological injury (52.9%, 27/51), and late-term infants had the highest incidence of pneumothorax (37.8%, 17/45). The overall mortality rate of children with MAS was 7.80% (23/294), and the difference in mortality rates among the four groups was not significant. Low 1-min Apgar score and gestational age, metabolic acidosis, and respiratory failure were independent risk factors for neurological injury; metabolic acidosis, respiratory failure, and sepsis were independent risk factors for death in neonates with MAS.

Conclusion

The clinical characteristics of MAS neonates of different gestational age are different mainly in complications. Early-term infants are more likely to complicate with neurological injury, and late-term infants are more likely to complicate with pneumothorax. Low 1-min Apgar score and gestational age, metabolic acidosis, and respiratory failure were established as risk factors for neurological injury; metabolic acidosis, respiratory failure, and sepsis were independent risk factors for death in neonates with MAS.

Neonates Born Through Meconium-stained Amniotic Fluid among Deliveries in a Tertiary Care Centre: A Descriptive Cross-sectional Study

Introduction

The mortality and morbidity of meconium aspiration syndrome in neonates born with meconium-stained amniotic fluid in developing countries are still high. In Nepal, few studies have estimated the prevalence of meconium-stained amniotic fluid among newborns. The study aimed to find out the prevalence of neonates born through meconium-stained amniotic fluid among deliveries in a tertiary care centre.

Methods

This descriptive cross-sectional study was conducted among neonates born in a tertiary care centre from November 2021 to March 2022. Neonates born during the study period with meconium-stained amniotic fluid were studied. Ethical approval was obtained from the Institutional Review Committee. Convenience sampling method was used. With permission from the Department of the Neonatal Intensive Care Unit, the data were collected and entered in a Microsoft Excel sheet. Point estimate and 95% Confidence Interval were calculated.

Results

Among 576 neonates, the prevalence of neonates born through meconium-stained amniotic fluid was 77 (13.37%) (10.59-16.15, 95% Confidence Interval).

Conclusions

The prevalence of neonates born through meconium-stained amniotic fluid was found to be similar to other studies done in similar settings.

Keywords

meconium; neonate; Nepal.

Meconium Aspiration Syndrome in Animal Models: Inflammatory Process, Apoptosis, and Surfactant Inactivation

Meconium Aspiration Syndrome is a condition that causes respiratory distress in newborns due to occlusion and airway inflammation, and surfactant inactivation by meconium. This condition has been described in animal species such as canids, sheep, cattle, horses, pigs, and marine mammals. In its pathogenesis, the pulmonary epithelium activates a limited inflammatory response initiated by cytokines causing leukocyte chemotaxis, inhibition of phagocytosis, and pathogen destruction. Likewise, cytokines release participates in the apoptosis processes of pneumocytes due to the interaction of angiotensin with cytokines and the caspase pathway. Due to these reactions, the prevalent signs are lung injury, hypoxia, acidosis, and pneumonia with susceptibility to infection. Given the importance of the pathophysiological mechanism of meconium aspiration syndrome, this review aims to discuss the relevance of the syndrome in veterinary medicine. The inflammatory processes caused by meconium aspiration in animal models will be analyzed, and the cellular apoptosis and biochemical processes of pulmonary surfactant inactivation will be discussed.

Determinants of meconium aspiration syndrome among neonates admitted to neonatal intensive care unit at Nigist Eleni Mohammed Memorial Comprehensive Specialized Hospital, South Ethiopia: Unmatched case-control study

Objective:

To identify determinants of meconium aspiration syndrome among neonates admitted to the neonatal intensive care unit at Nigist Eleni Mohammed Memorial Comprehensive Specialized Hospital, South Ethiopia, in 2022.

Method:

A facility-based unmatched case–control study was used to identify meconium aspiration syndrome with a total sample size of 249 from January to April 2022. Data were entered by using EpiData version 3.1 and analyzed using SPSS version 24 software. Descriptive findings were presented by frequency tables and percentages. Multicollinearity was checked and the goodness of fit test was done. To determine the independent determinants associated with meconium aspiration syndrome, bivariate analysis was done and variables with a p value of <0.05 were taken to multivariate logistic regression analysis. Adjusted odds ratio with a 95% confidence interval was calculated, and statistical significance was declared at a p value less than 0.05.

Result:

Two hundred forty-nine (83 cases and 166 controls) mothers with their respective neonates were included in this study and that made the overall response rate 100%. Preeclampsia (adjusted odds ratio: 3.35, 95% confidence interval: 1.02, 10.97), antepartum hemorrhage (adjusted odds ratio: 3.63, 95% confidence interval: 1.50, 8.78), duration of labor (adjusted odds ratio: 4.34, 95% confidence interval: 1.83, 10.30), premature rupture of membrane (adjusted odds ratio: 16.02, 95% confidence interval: 5.66, 45.29), and obstructed labor (adjusted odds ratio: 4.57, 95% confidence interval: 1.42, 14.70) were determinants of meconium aspiration syndrome.

Conclusion:

In this study, preeclampsia, antepartum hemorrhage, duration of labor, premature rupture of membrane, and obstructed labor were determinants of meconium aspiration syndrome. Therefore, to reduce the risk of meconium aspiration syndrome, prevention, early identification, and management of these obstetrical factors may help to reduce meconium aspiration syndrome locally.

Meconium-stained Amniotic Fluid among Term Deliveries in a Tertiary Care Centre: A Descriptive Cross-sectional Study

Introduction

Although the precise aetiology of meconium-stained amniotic fluid is still unclear, risk factors include advanced gestational age at delivery, mode of delivery, the prolonged second stage of labour, and intrauterine infection. It has been associated with poor perinatal outcomes including low Apgar scores, increased incidence of neonatal intensive care admission, and a high rate of perinatal death. The objective of the study was to find out the prevalence of meconium-stained amniotic fluid in term deliveries in a tertiary care centre.

Methods

A descriptive cross-sectional study was done among term deliveries in the Department of Obstetrics and Gynaecology, in a tertiary care centre from inpatient records starting from 1 November 2019 to 1 November 2020 after obtaining ethical approval from the Institutional Review Committee (Reference number: PMG1911281316). Convenience sampling was done. Point estimate and 95% Confidence Interval were calculated.

Results

Out of 1699 term deliveries, meconium-stained amniotic fluid was seen in 91 (5.35%) (4.28-6.42, 95% Confidence Interval). Among these 69 (75.82%) newborns were delivered through lower segment caesarean section and 61 (67%) newborns had Grade II meconium-stained amniotic fluid.

Conclusions

The prevalence of meconium-stained amniotic fluid was similar to the studies done in similar settings.

Keywords

apgar score; caesarean section; gestational age; perinatal death; pregnancy.

[Clinical features of severe meconium aspiration syndrome (MAS) and early predicting factors for severe MAS in neonates with meconium-stained amniotic fluid]

OBJECTIVES

To study the clinical features of severe meconium aspiration syndrome (MAS) and early predicting factors for the development of severe MAS in neonates with meconium-stained amniotic fluid (MSAF).

METHODS

A total of 295 neonates who were hospitalized due to Ⅲ° MSAF from January 2018 to December 2019 were enrolled as subjects. The neonates were classified to a non-MAS group (n=199), a mild/moderate MAS group (n=77), and a severe MAS group (n=19). A retrospective analysis was performed for general clinical data, blood gas parameters, infection indicators, and perinatal clinical data of the mother. The respiratory support regimens after birth were compared among the three groups. The receiver operating characteristic (ROC) curve and multivariate logistic regression analysis were used to investigate predicting factors for the development of severe MAS in neonates with MSAF.

RESULTS

Among the 295 neonates with MSAF, 32.5% (96/295) experienced MAS, among whom 20% (19/96) had severe MAS. Compared with the mild/moderate MAS group and the non-MAS group, the severe MAS group had a significantly lower 5-minute Apgar score (P<0.05) and a significantly higher blood lactate level in the umbilical artery (P<0.05). Compared with the non-MAS group, the severe MAS group had a significantly higher level of interleukin-6 (IL-6) in peripheral blood at 1 hour after birth (P<0.017). In the severe MAS group, 79% (15/19) of the neonates were born inactive, among whom 13 underwent meconium suctioning, and 100% of the neonates started to receive mechanical ventilation within 24 hours. Peripheral blood IL-6 >39.02 pg/mL and white blood cell count (WBC) >30.345×109/L at 1 hour after birth were early predicting indicators for severe MAS in neonates with MSAF (P<0.05).

CONCLUSIONS

Meconium suctioning cannot completely prevent the onset of severe MAS in neonates with MSAF. The neonates with severe MAS may develop severe respiratory distress and require mechanical ventilation early after birth. Close monitoring of blood lactate in the umbilical artery and peripheral blood IL-6 and WBC at 1 hour after birth may help with early prediction of the development and severity of MAS.

Bile acids-induced lung injury: update of reverse translational biology

The presence of bile acids in lung tissue is associated with some clinical features observed in various medical specialties, but it took time to understand that these are due to a "bile acid-induced lung injury" since specific translational studies and cross-disciplinary awareness were lacking. We used a reverse translational approach to update and summarize the current knowledge about the mechanisms of bile acid-induced lung injury. This has been done in a cross-disciplinary fashion since these conditions may occur in patients of various age and in different medical fields. We here define these clinical conditions, then we review the physiopathology of these conditions and the animal models used to mimic them and, finally, their pathobiology. Mechanisms of bile acid-induced lung injury have been partially clarified overtime and are represented by: 1) the interaction with secretory phospholipase A2 pathway, 2) the effect on surfactant function and structure, 3) the biological effects on inflammation and local immunity, 4) the direct cellular toxicity. These mechanisms are schematically illustrated and histological comparisons between ARDS induced by bile acids and other triggers are also provided. Based on these mechanisms we propose possible direct therapeutic applications and, finally, we discuss further research steps to improve the understanding of processes that generate pathological clinical conditions.

Pneumopericardium in a Newborn with Respiratory Distress and COVID-19

BACKGROUND: Pneumopericardium (PPC) is one of the rarest pulmonary air leak syndromes, but the incidence is the highest in the neonatal period. Risk factors include premature infants with respiratory distress (RD) syndrome, receiving active resuscitation, meconium aspiration syndrome, and aggressive mechanical ventilation. Several cases have also been reported related to COVID-19. CASE PRESENTATION: We report a case of a female newborn with a birth weight of 3300 grams a COVID-19 confirmed 35-year-old G3P2A0 mother. The baby was not crying at born and the amniotic fluid was stained green. The baby experienced RD and was intubated. A babygram was performed at the age of 5 h with the impression of a too deep endotracheal tube, neonatal pneumonia, and PPC. COVID-19 RT-PCR examination of the baby was positive. There were no signs of cardiac tamponade, so it was decided to take conservative and supportive management. CONCLUSION: Resolution of PPC was found on repeated babygram 26 h later. The baby was then discharged after 19 days of treatment.

Approach to the Connection between Meconium Consistency and Adverse Neonatal Outcomes: A Retrospective Clinical Review and Prospective In Vitro Study

Whether meconium-stained amniotic fluid (MSAF) serves as an indicator of fetal distress is under debate; however, the presence of MSAF concerns both obstetricians and pediatricians because meconium aspiration is a major contributor to neonatal morbidity and mortality, even with appropriate treatment. The present study suggested that thick meconium in infants might be associated with poor outcomes compared with thin meconium based on chart reviews. In addition, cell survival assays following the incubation of various meconium concentrations with monolayers of human epithelial and embryonic lung fibroblast cell lines were consistent with the results obtained from chart reviews. Exposure to meconium resulted in the significant release of nitrite from A549 and HEL299 cells. Medicinal agents, including dexamethasone, L-Nω-nitro-arginine methylester (L-NAME), and NS-398 significantly reduced the meconium-induced release of nitrite. These results support the hypothesis that thick meconium is a risk factor for neonates who require resuscitation, and inflammation appears to serve as the primary mechanism for meconium-associated lung injury. A better understanding of the relationship between nitrite and inflammation could result in the development of promising treatments for meconium aspiration syndrome (MAS).

The Effects of Different Types of Steroids on Clinical Outcomes in Neonates with Meconium Aspiration Syndrome: A Systematic Review, Meta-Analysis and GRADE Assessment

Background and Objectives: Meconium aspiration syndrome (MAS) is a condition caused by the aspiration of meconium-stainted amniotic fluid into the lungs, resulting in pulmonary inflammation, neonatal morbidity, and mortality. It is important that these MAS infants receive appropriate care to avoid further complications. Steroids have an anti-inflammatory effect and may be effective in the management of MAS. The objective of the this study was to evaluate the effect of different steroids on clinical outcomes in infants with MAS. Materials and Methods: We systematically searched of PubMed/Medline, Scopus, Embase, Clinical Trials.gov, and Cochrane Library databases from inception to 24 January 2021 without language restriction. Only randomized controlled trials (RCTs) evaluating the effects of steroids in neonates with MAS were included. We calculated relative risks and weighted mean differences (MDs) with 95% confidence intervals (CIs) using a random-effects model to determine the associations between MAS and steroids and GRADE approach was employed for quality of evidence. The main outcomes measures were duration of respiratory distress, oxygen requirement, hospitalization, need for mechanical ventilation, death, and adverse drug reactions. Results: Seven RCTs involving 397 patients were analyzed. Nebulized budesonide and intravenous (IV) methylprednisolone shortened the duration of respiratory distress (MD, −2.46 days; 95% CI, −3.09 to −1.83 and MD, −3.30 days; 95% CI, −4.07 to −2.52, respectively) (moderate certainty). There was a reduction in duration of oxygen requirement in nebulized budesonide use (MD, −2.40 days; 95% CI, −3.40 to −1.40) (low certainty) and IV methylprednisolone use (MD, −3.30 days; 95% CI, −4.07 to −2.52) (moderate certainty). Nebulized budesonide shortened hospitalization stay (MD, −4.47 days; 95% CI, −8.64 to −0.30 days) (low certainty) as IV methylprednisolone use (MD, −7.23 days; 95% CI, −8.19 to −6.07 days) (moderate certainty). None of steroids benefits in death (low certainty). Conclusions: Certain types of steroids may benefit the respiratory aspect, but there was no decrease in mortality in MAS infants.

Clinical features and prognosis of severe meconium aspiration syndrome with acute respiratory distress syndrome

OBJECTIVES

To study the clinical features and prognosis of neonates with severe meconium aspiration syndrome (MAS) and acute respiratory distress syndrome (ARDS).

METHODS

A retrospective analysis was performed on the medical data of 60 neonates with severe MAS who were admitted from January 2017 to December 2019. According to the presence or absence of ARDS, they were divided into two groups: ARDS (n=45) and non-ARDS (n=15). Clinical features and prognosis were compared between the two groups.

RESULTS

Among the 60 neonates with severe MAS, 45 (75%) developed ARDS. Arterial blood gas analysis showed that the ARDS group had a significantly higher median oxygenation index within 1 hour after birth than the non-ARDS group (4.7 vs 2.1, P<0.05), while there was no significant difference between the two groups in white blood cell count, C-reactive protein (CRP), and interleukin-6 (IL-6) on admission and the peak values of procalcitonin, CRP, and IL-6 during hospitalization (P>0.05). The ARDS group had a significantly higher incidence rate of shock than the non-ARDS group (84% vs 47%, P<0.05). There was no significant difference between the two groups in the incidence rates of persistent pulmonary hypertension, pneumothorax, pulmonary hemorrhage, hypoxic-ischemic encephalopathy, intracranial hemorrhage, and disseminated intravascular coagulation (P>0.05). The ARDS group required a longer median duration of mechanical ventilation than the non-ARDS group (53 hours vs 3 hours, P<0.05). In the ARDS group, 43 neonates (96%) were cured and 2 neonates (4%) died. In the non-ARDS group, all 15 neonates (100%) were cured.

CONCLUSIONS

Neonates with severe MAS and ARDS tend to develop respiratory distress earlier, require a longer duration of mechanical ventilation, and have a higher incidence rate of shock. During the management of children with severe MAS, it is recommended to closely monitor oxygenation index, give timely diagnosis and treatment of ARDS, evaluate tissue perfusion, and actively prevent and treat shock. Citation.