Neonatal surfactant therapy beyond respiratory distress syndrome

Whilst exogenous surfactant therapy is central to the management of newborn infants with respiratory distress syndrome, its use in other neonatal lung diseases remains inconsistent and controversial. Here we discuss the evidence and experience in relation to surfactant therapy in newborns with other lung conditions in which surfactant may be deficient or dysfunctional, including meconium aspiration syndrome, pneumonia, congenital diaphragmatic hernia and pulmonary haemorrhage. We find that, for all of these diseases, administration of exogenous surfactant as bolus therapy is frequently associated with transient improvement in oxygenation, likely related to temporary mitigation of surfactant inhibition in the airspaces. However, for none of them is there a lasting clinical benefit of surfactant therapy. By virtue of interrupting disease pathogenesis, lavage therapy with dilute surfactant in MAS offers the greatest possibility of a more pronounced therapeutic effect, but this has yet to be definitively proven. Lavage therapy also involves a greater degree of procedural risk.

Postnatal causes and severity of persistent pulmonary Hypertension of Newborn

Background & Objective:

Persistent pulmonary hypertension of the newborn (PPHN) is described as severe respiratory failure along with hypoxaemia. PPHN is known to be linked with high morbidity and mortality around the world. This study was planned to determine the postnatal causes and assess the severity of persistent pulmonary hypertension of newborn in babies presenting to the Children’s Hospital, Multan.

Methods:

This observational study was conducted at the Department of Paediatric Cardiology, The Children Hospital &Institute of Child Health, Multan, Pakistan from July to December 2019. A total of 122 confirmed cases of PPHN admitted having gestational age above 34 weeks were enrolled. Demographic data of the newborns was recorded along with maternal medical history, pregnancy status and postnatal causes of PPHN. Severity of PPHN was also recorded.

Results:

Out of a total of 122 cases of PPHN, 81 (66.3%) were male. Majority, 78 (64.0%) had gestational age above 37 weeks. Mode of delivery as cesarean section was noted in 70 (57.4%). Meconium aspiration syndrome 52 (42.6%), birth asphyxia 48 (39.3%), respiratory distress syndrome 23 (18.8%) and sepsis 33 (27.0%) were found to be the commonest causes of PPHN. Severe PPHN was found to be the most frequent, noted among 63 (51.6%) while Moderate PPHN was observed in 40 (32.8%) and Mild PPHN in 19 (15.6%). Morality was noted among 26 (21.3%) of cases.

Conclusion:

Meconium aspiration syndrome, birth asphyxia and respiratory distress syndrome were the commonest postnatal causes of PPHN. Severe PPHN was found to be the most frequent form of PPHN.

Morbidity of conversion from venovenous to venoarterial ECMO in neonates with meconium aspiration or persistent pulmonary hypertension

BACKGROUND

Outcomes in neonates receiving extracorporeal membrane oxygenation (ECMO) for meconium aspiration syndrome (MAS) and/or persistent pulmonary hypertension (PPHN) are favorable. Infants with preserved perfusion are often offered venovenous (VV) support to spare morbidities of venoarterial (VA) ECMO. Worsening perfusion or circuit complications can prompt conversion from VV-to-VA support. We examined whether outcomes in infants requiring VA ECMO for MAS/PPHN differed if they underwent VA support initially versus converting to VA after a VV trial, and what factors predicted conversion.

METHODS

We reviewed the Extracorporeal Life Support Organization registry from 2007 to 2017 for neonates with primary diagnoses of MAS/PPHN. Propensity score analysis matched VA single-runs (controls) 4:1 against VV-to-VA conversions based on age, pre-ECMO pH, and precannulation arrests. Primary outcomes were complications and survival. Data were analyzed using Mann-Whitney U and Fisher's exact testing. Multivariate regression identified independent predictors of conversion for VV patients.

RESULTS

3831 neonates underwent ECMO for MAS/PPHN, including 2129 (55%) initially requiring VA support. Of 1702 patients placed on VV ECMO, 98 (5.8%) required VV-to-VA conversion. Compared with 364 propensity-matched isolated VA controls, conversion runs were longer (190 vs. 127 h, P < 0.001), were associated with more complications, and decreased survival to discharge (70% vs. 83%, P = 0.01). On multivariate regression, conversion was more likely if neonates on VV ECMO did not receive surfactant (OR = 1.7;95%CI = 1.1-2.7;P = 0.03) or required high-frequency ventilation (OR = 1.9;95%CI = 1.2-3.3;P = 0.01) before ECMO.

CONCLUSION

Conversion from VV-to-VA ECMO in infants with MAS/PPHN conveys increased morbidity and mortality compared to similar patients placed initially onto VA ECMO. VV patients not receiving surfactant or requiring high-frequency ventilation before cannulation may have increased risk of conversion. While conversions remain rare, decisions to offer VV ECMO for MAS/PPHN must be informed by inferior outcomes observed should conversion be required.

LEVEL OF EVIDENCE

Level of evidence 3 Retrospective comparative study.

Time needed to intubate and suction a manikin prior to instituting positive pressure ventilation: a simulation trial

Tracheal suctioning in non-vigorous newborn delivered through meconium-stained amniotic fluid (MSAF) is supposed to delay initiation of positive pressure ventilation (PPV), but the magnitude of such delay is unknown. To compare the time of PPV initiation when performing immediate laryngoscopy with intubation and suctioning vs. performing immediate PPV without intubation in a manikin model. Randomized controlled crossover (AB/BA) trial comparing PPV initiation with or without endotracheal suctioning in a manikin model of non-vigorous neonates born through MSAF. Participants were 20 neonatologists and 20 pediatric residents trained in advanced airway management. Timing of PPV initiation was longer with vs. without endotracheal suctioning in both pediatric residents (mean difference 13 s, 95% confidence interval 8 to 18 s; p < 0.0001) and neonatologists (mean difference 12 s, 95% confidence interval 8 to 16 s; p < 0.0001). The difference in timing of PPV initiation was similar between pediatric residents and neonatologists (mean difference - 1 s, 95% confidence interval - 7 to 6 s; p = 0.85).Conclusions: Performing immediate laryngoscopy with intubation and suctioning was associated with longer-but not clinically relevant-time of initiation of PPV compared with immediate PPV without intubation in a manikin model. While suggesting negligible delay in starting PPV, further studies in a clinical setting are warranted.Registration: clinicaltrial.gov NCT04076189. What is Known: • Management of the non-vigorous newborn delivered through meconium-stained amniotic fluid remains still controversial. • Tracheal suctioning in non-vigorous newborn delivered through meconium-stained amniotic fluid is supposed to delay initiation of positive pressure ventilation, but the magnitude of such delay is unknown. What is New: • Performing immediate ventilation without intubation was associated with shorter-but not clinically relevant-time of initiation of ventilation compared to immediate laryngoscopy with intubation and suctioning in a manikin model. • Further studies in a clinical setting are warranted.

Perinatal characteristics and delivery room management of infants born through MSAF

The immediate delivery room (DR) management of non-vigorous (NV) infants with meconium stained amniotic fluid (MSAF) is controversial. A recent ILCOR suggestion is not to perform routine direct laryngoscopy (DL) with or without tracheal suctioning in NV infants. Our practice is to perform DL and endotracheal (ET) suctioning in targeted NV infants. The study objective was to describe the perinatal characteristics and DR Management of infants born through MSAF and admitted to the neonatal intensive care unit (NICU).

METHODS

Retrospective study evaluating the DR management of infants >35 weeks delivered through MSAF. Data retrieved included fetal heart rate abnormalities (FTHR), presence of thick/thin MSAF, DR management and postnatal course.

RESULTS

118 infants were resuscitated and directly admitted to the NICU, including 58 intubated for meconium, 29 receiving immediate PPV (n = 25) or CPAP (n = 4) and 31 (17%) initially stable developed delayed respiratory symptoms and administered CPAP. Sixty-four (35.2%) infants initially stable in the DR were subsequently admitted to NICU. ET suctioning was performed in 58/182 infants with meconium obtained in 41/58; meconium aspiration syndrome (MAS) was diagnosed in 21 infants. ET suctioning was positive in 10/21 cases. FHRT abnormalities (n = 50) were noted with thick meconium and associated with a 2.8-fold increased risk for meconium below the cords, and 3.1-fold increased risk of MAS.

CONCLUSION

NV infants delivered through thick versus thin meconium were more likely to be intubated with a high yield of recovery. Serious pulmonary morbidity was uncommon. Most respiratory symptomatology were not related to MAS.

Tracheal suctioning of meconium at birth for non-vigorous infants: a systematic review and meta-analysis

CONTEXT

The International Liaison Committee on Resuscitation sought to review the initial management of non-vigorous newborns delivered through meconium stained amniotic fluid (MSAF).

OBJECTIVE

To complete a systematic review and meta-analysis comparing endotracheal intubation and suctioning to immediate resuscitation without intubation for non-vigorous infants born at ≥34 weeks gestation delivered through MSAF.

DATA SOURCES

Medline, EMBASE, the Cochrane Database of Systematic Reviews, and other registries were searched from 1966 to November 7, 2019.

STUDY SELECTION

Studies were selected by pairs of independent reviewers in 2 stages.

DATA EXTRACTION

Reviewers extracted data, appraised risk of bias, and assessed Grading of Recommendations Assessment, Development and Evaluation certainty of evidence for each outcome.

RESULTS

Four randomized controlled trials (RCTs) included 581 patients and one observational study included 231 patients. No significant differences were observed between the group treated with tracheal suctioning compared with immediate resuscitation for survival at discharge (4 RCTs; risk ratio [RR] = 1.01; 95 % CI, 0.96-1.06; p = 0.69; observational study; no deaths), hypoxic ischemic encephalopathy and meconium aspiration syndrome.

LIMITATIONS

The certainty of evidence was low for survival at discharge and very low for all other outcomes.

CONCLUSIONS

For non-vigorous newborns delivered through MSAF, there is insufficient evidence to suggest routine immediate direct laryngoscopy with tracheal suctioning.

PROSPERO

CRD42019122778.

CLINICAL TRIALS REGISTRATION

PROSPERO; CRD42019122778.

Pregnancy-induced hypertension is an independent risk factor for meconium aspiration syndrome: A retrospective population based cohort study

OBJECTIVE

Meconium aspiration syndrome (MAS), possibly resulting from fetal hypoxia, is a respiratory distress disorder in the infant. Pregnancy-induced hypertension (PIH) can cause placental dysfunction and lead to fetal hypoxia, which may induce the development of MAS. Therefore, the aim of this study was to determine the association between PIH and MAS and to identify the predictive risk factors.

MATERIALS AND METHODS

This was a retrospective cohort study. We selected patients with newly diagnosed PIH and a matched cohort group from the Taiwan National Health Insurance Research Database (NHIRD), from January 1, 2000 till December 31, 2013. For each patient in the PIH cohort, 4 subjects without PIH, matched for age and year of delivery, were randomly selected as the comparison cohort. The incidence of meconium aspiration syndrome was assessed in both groups.

RESULTS

Among the 23.3 million individuals registered in the NHIRD, 29,013 patients with PIH and 116,052 matched controls were identified. Patients who experienced PIH had a higher incidence of MAS than did those without PIH. According to a multivariate analysis, PIH (odds ratio [OR] = 1.70, 95% confidence interval [CI] = 1.49-1.93, p < 0.0001) was independently associated with increased risk of MAS. Additionally, age ≥30 years (OR = 1.26, 95% CI = 1.12-1.42, p = 0.0001), nulliparity (OR = 1.13, 95% CI = 1.01-1.27, p = 0.0367) and patients with diabetes mellitus (OR = 3.09, 95% CI = 1.35-7.09, p = 0.0078) were also independent risk factors of MAS.

CONCLUSION

Patients with PIH obtained higher subsequent risk for the development of MAS than those without PIH. Besides, age ≥30 years, nulliparity and patients with diabetes mellitus are the independent risk factors of developing MAS.

Endotracheal suctioning for prevention of meconium aspiration syndrome: a randomized controlled trial

The current version of Neonatal Resuscitation Program no longer favors routine endotracheal suctioning (ETS) in non-vigorous newborns with meconium-stained amniotic fluid (MSAF) due to possibility of procedure-related harms and questionable benefits. However, it calls for additional research on this procedure to provide a definitive answer. The present study was conducted to evaluate the role of ETS in non-vigorous neonates of ≥ 34 weeks' gestation born through MSAF on the incidence of meconium aspiration syndrome (MAS). In this open-label randomized controlled trial, 132 non-vigorous neonates with MSAF were randomized to receive ETS (n = 66) or no-ETS (n = 66) during delivery room resuscitation (DRR). Primary outcome variable was incidence of MAS. Secondary outcome variables were requirement of DRR, need of respiratory support, development of complications, duration of hospitalization, and mortality. Both the groups were comparable with respect to maternal and neonatal characteristics. Incidence of MAS was 21 (31.8%) and 15 (22.7%) cases in ETS and no-ETS groups, respectively (relative risk (RR), 1.400, 95% confidence interval (CI), 0.793-2.470). The two groups did not differ with regard to DRR, need for respiratory support, and development of complications. Nine (13.6%) neonates in ETS group, and 5 (7.5%) in no-ETS group died (p > 0.05). Median (interquartile range) duration of hospital stay was 54 (31-141) h and 44 (26-102) h in ETS and no-ETS groups, respectively (p > 0.05).Conclusions: Routine ETS at birth is not useful in preventing MAS in non-vigorous neonates of ≥ 34 weeks' gestation born through MSAF.Trial registration: Clinical Trials Registry of India (CTRI/2015/04/008819).What is Known:• Routine endotracheal suctioning is of questionable benefit in non-vigorous newborns with meconium stained amniotic fluid and may have a possibility of procedure-related harms.What is New:• Routine endotracheal suctioning at birth is not useful in preventing meconium aspiration syndrome in non-vigorous newborns of ≥ 34 weeks' gestation born through meconium stained amniotic fluid.

Influence of foetal inflammation on the development of meconium aspiration syndrome in term neonates with meconium-stained amniotic fluid

Background

Meconium-stained amniotic fluid is observed in approximately 10–15% of all deliveries; however, only 5% of neonates with meconium-stained amniotic fluid develop meconium aspiration syndrome (MAS). Although foetal distress and subsequent sympathetic stimulation have been considered as the primary upstream events of MAS, this clinical complication sometimes occurs due to other pathologies, such as intraamniotic inflammation. The aim of this study was to investigate whether the incidence of MAS is associated with the presence of funisitis and chorioamnionitis in term neonates with meconium-stained amniotic fluid.

Methods

Between April 2013 and March 2015, a total of 95 term neonates with meconium-stained amniotic fluid, who were hospitalized at a neonatal intensive care unit, were enrolled in the study. The placenta and umbilical cord were histopathologically examined. Clinical variables and histopathological findings associated with the incidence of MAS were studied.

Results

A total of 36 neonates developed MAS. Univariate logistic regression analysis revealed that a heavier birth weight, male sex, 1-min Apgar score ≤ 7, funisitis (but not chorioamnionitis), and elevated acute-phase inflammatory reaction score were associated with increased incidence of MAS (all p < 0.05). The multivariate model comprised funisitis (OR = 5.03, 95% CI [1.63–15.5], 1-min Apgar score ≤ 7 (OR = 2.74, 95% CI [1.06–7.09], and male sex (OR = 3.4, 95% CI [1.24–9.34].

Conclusion

In neonates with meconium-stained amniotic fluid, funisitis, as well as low 1-min Apgar score and male sex, was identified as an independent variable for MAS development. Intraamniotic inflammation might be involved in the pathological mechanisms of MAS.

Meconium aspiration syndrome requiring ECMO in newborns with gastroschisis: incidence and surgical outcomes

AIM OF THE STUDY

To evaluate the incidence of respiratory failure requiring ECMO in newborns with gastroschisis (GC), compare it to the incidence in the general population, review the surgical outcomes of newborns with GC requiring ECMO and compare them to newborns with GC not requiring ECMO.

METHODS

This is a retrospective review of all neonatal admissions for GC from December 2010 to September 2015.

MAIN RESULTS

110 newborns with GC were admitted to our NICU between 12/2010 and 9/2015; 36 were term. Four cases, all term, all prenatally diagnosed, all outborn, developed respiratory failure requiring ECMO secondary to meconium aspiration syndrome (MAS). This 11% (4/36 term GC) represents a 300-fold increase in the incidence of MAS-associated respiratory failure requiring ECMO compared to the general population of term newborns (0.037%). Median time on ECMO was 12 (9-20) days. The time to achieve full enteral feedings in the GC/ECMO group was twice the time of the 106 newborns in the GC/non-ECMO group [median: 70 (48-77) vs. 35 (16-270) days, respectively]. Time to hospital discharge was three times longer in the GC/ECMO group compared to the GC/non-ECMO group (median: 42 [20-282] versus 125 [69-223] days, respectively). All patients survived.

CONCLUSION

The incidence of respiratory failure requiring ECMO is remarkably higher in patients with GC than in the general population and much higher in the subgroup of term GC. While infrequent, the possibility of this event supports the concept that fetuses with GC benefit from being delivered at tertiary centers with immediate pediatric surgery and ECMO capabilities.

Degradation of Lung Protective Angiotensin Converting Enzyme-2 by Meconium in Human Alveolar Epithelial Cells: A Potential Pathogenic Mechanism in Meconium Aspiration Syndrome

BACKGROUND

Pancreatic digestive enzymes present in meconium might be responsible for meconium-induced lung injury. The local Renin Angiotensin System plays an important role in lung injury and inflammation. Particularly, angiotensin converting enzyme-2 (ACE-2) has been identified as a protective lung enzyme against the insult. ACE-2 converts pro-apoptotic Angiotensin II to anti-apoptotic Angiotensin 1-7. However, the effect of meconium on ACE-2 has never been studied before.

OBJECTIVE

To study the effect of meconium on ACE-2, and whether inhibition of proteolytic enzymes present in the meconium reverses its effects on ACE-2.

METHODS

Alveolar epithelial A549 cells were exposed to F-12 medium, 2.5% meconium, meconium + a protease inhibitor cocktail (PIc) and PIc alone for 16 h. At the end of incubation, apoptosis was measured with a nuclear fragmentation assay and cell lysates were collected for ACE-2 immunoblotting and enzyme activity.

RESULTS

Meconium caused a fourfold increase in apoptotic nuclei (p < 0.001). The pro-apoptotic effect of meconium can be reversed by PIc. Meconium reduced ACE-2 enzyme activity by cleaving ACE-2 into a fragment detected at ~ 37 kDa by immunoblot. PIc prevented the degradation of ACE-2 and restored 50% of ACE-2 activity (p < 0.05).

CONCLUSION

These data suggest that meconium causes degradation of lung protective ACE-2 by proteolytic enzymes present in meconium, since the effects of meconium can be reversed by PIc.

Prevalence of meconium stained amniotic fluid and its associated factors among women who gave birth at term in Felege Hiwot comprehensive specialized referral hospital, North West Ethiopia: a facility based cross-sectional study

BACKGROUND

Meconium stained amniotic fluid is one of the risk factors to increase the rate of perinatal morbidity and mortality both in developed and developing countries. Due to a multitude of factors associated with socioeconomic and quality of service, the ill effect of meconium stained amniotic fluid is even worse in developing countries. But very little information is known about the situation in Ethiopia, particularly the study area to design appropriate prevention strategies. Hence, this study aimed to determine the prevalence of meconium-stained amniotic fluid and its associated factors among women who gave birth at term in Felege Hiwot Referral Hospital, North West Ethiopia.

METHODS

Institutional based cross-sectional study was conducted at Felege Hiwot Referral Hospital from March 02-May 27, 2018. A total of 495 mothers were included in the study. The study participants were selected by systematic random sampling technique. A combination of chart review and interview were used to collect the data. Data entry and analysis were made by using Epi-data version 3.1 and SPSS versions 23 respectively. Both descriptive & analytical statistics were computed. Statistical significance was considered at P < 0.05 and the strength of association was assessed by using adjusted odds ratio.

RESULT

The prevalence of meconium stained amniotic fluid was found to be 17.8%. Women whose age greater than 30 years [AOR =5.63, 95%CI =3.35-9.44], duration of labor greater than 24 h [AOR = 7.1, 95%Cl =1.67-29.68], induced labor [AOR = 2.60, 95% CI =1.39-4.87], preeclampsia [AOR = 3.45, 95%CI =1.26-9.37] and obstructed labor [AOR =5.9, 95%CI =1.29-29.68] were found to be associated with meconium stained amniotic fluid.

CONCLUSIONS

The prevalence of meconium stained amniotic fluid was similar as compared to the international standard. Preeclampsia, maternal age, obstructed labor, induced labor and longer duration of labor were factors associated with an increased risk for meconium-stained amniotic fluid. Thus, early detection and timely intervention are mandatory to decrease prolonged and obstructed labor.

Meconium stained liquor and its neonatal outcome

Objective:

To determine the maternal factors and neonatal outcome of pregnancy complicated by meconium stained amniotic fluid.

Methods:

This one year retrospective study was conducted at the Agha Khan Hospital for Women-Garden Campus, it is a secondary care private teaching hospital. Demographics information included gestational age, gender and birth weight of baby, medical and obstetric complications during pregnancy, mode of delivery, neonatal outcome (Meconium Aspiration Syndrome (MAS) and need for admission in nursery) were recorded on a pre-designed proforma.

Results:

In our study the frequency of meconium stained amniotic fluid (MSAF) was 7.85%, out of them 12 % babies developed MAS. There was significant association between grades of meconium and MAS, babies with thick meconium were prone to develop MAS (P = 0.02). Emergency cesarean section was significantly associated with MAS. Gestational diabetes (GDM) and pregnancy induced hypertension (PIH) were the significant factors associated with MAS.

Conclusion:

Thick Meconium stained amniotic fluid was associated with low APGAR score, high rate of emergency cesarean section and meconium aspiration syndrome. Anemia during pregnancy, PIH and GDM were important risk factor associated with MAS.

New Evidence to Support Antibiotic Prophylaxis in Meconium-Stained Amniotic Fluid in Low-Risk Women in Labor a Prospective Cohort Study

Purpose of study

To assess the maternal and perinatal complications associated with meconium-stained amniotic fluid (MSAF) in low-risk women in labor.

Methods

This prospective cohort study was conducted at CMC Hospital, Vellore, India. Two hundred low-risk women who had artificial or spontaneous rupture of membranes after admission with MSAF were included in the study. Two hundred similar women with clear liquor were taken as controls. The primary outcomes considered were the incidence of chorioamnionitis and endomyometritis in the mothers. The secondary outcomes included postpartum hemorrhage and retained placenta in the mothers and respiratory distress, meconium aspiration, sepsis, and NICU admission in the newborn. Statistical analysis was done using Fischer exact test. Odds ratio, 95% confidence interval, and P value were estimated.

Results

Compared to controls, those with MSAF had significantly higher rates of chorioamnionitis (2 vs. 8%, P = 0.006) and endomyometritis (3 vs. 9.5% P = 0.007). Among the secondary end points, only neonatal respiratory distress (8.5 vs. 1.5%; P = 0.001) and meconium aspiration (4 vs. 0%; P = 0.007) were found to be significantly increased in the meconium group.

Conclusion

Statistically significant increased incidence of chorioamnionitis and endomyometritis in women with MSAF in labor established in our study strongly supports the use of prophylactic antibiotics in these women to prevent immediate and long-term consequences.

HandS ECMO: Preliminary Experience With "Hub and Spoke" Model in Neonates With Meconium Aspiration Syndrome

We aim to evaluate clinical outcomes of emergent extracorporeal membrane oxygenation (ECMO) implantation in newborns with life-threatening meconium aspiration syndrome (MAS) in peripheral hospitals with Hub and Spoke (HandS) setting. We retrospectively reviewed all neonates presenting with MAS, with no other comorbidities, treated with HandS ECMO, in peripheral hospitals. Team activation time (TAT) was described as the time from first alerting call to ECMO support initiation. From May 2014 to December 2016, 4 patients met our inclusion criteria. In addition, 2 cases occurred on the same day, requiring a second simultaneous HandS ECMO team activation. All patients were younger than 8 days of life (1, 1, 4, and 7), with a mean BSA 0.21 ± 0.03m² , and TAT of 203, 265, 320, and 340 min. One patient presented ventricular fibrillation after priming administration. Veno-arterial ECMO was established in all patients after uneventful surgical neck vessels cannulation (right carotid artery and jugular vein). Mean time from skin incision to ECMO initiation was 19 ± 1.4 min. Mean length of ECMO support was 2.75 ± 1.3 days. All patients were weaned off support without complications. At a mean follow up of 20.5 ± 7.8 months, all patients are alive, with no medications, normal somatic growth, and neuropsychological development. MAS is a life-threatening condition that can be successfully managed with ECMO support. A highly trained multidisciplinary HandS ECMO team is crucial for the successful management of these severely ill newborns in peripheral hospitals.

Combined Inhibition of C5 and CD14 Attenuates Systemic Inflammation in a Piglet Model of Meconium Aspiration Syndrome

BACKGROUND

Meconium aspiration syndrome (MAS) is a severe lung condition affecting newborns and it can lead to a systemic inflammatory response. We previously documented complement activation and cytokine release in a piglet MAS model. Additionally, we showed ex vivo that meconium-induced inflammation was dependent on complement and Toll-like receptors.

OBJECTIVES

To assess the efficacy of the combined inhibition of complement (C5) and CD14 on systemic inflammation induced in a forceful piglet MAS model.

METHODS

Thirty piglets were randomly allocated to a treatment group receiving the C5-inhibitor SOBI002 and anti-CD14 (n = 15) and a nontreated control group (n = 15). MAS was induced by intratracheal meconium instillation, and the piglets were observed for 5 h. Complement, cytokines, and myeloperoxidase (MPO) were measured by ELISA.

RESULTS

SOBI002 ablated C5 activity and the formation of the terminal complement complex in vivo. The combined inhibition attenuated the inflammasome cytokines IL-1β and IL-6 by 60 (p = 0.029) and 44% (p = 0.01), respectively, and also MPO activity in the bronchoalveolar fluid by 42% (p = 0.017). Ex vivo experiments in human blood revealed that the combined regimen attenuated meconium-induced MPO release by 64% (p = 0.008), but there was only a negligible effect with single inhibition, indicating a synergic cross-talk between the key molecules C5 and CD14.

CONCLUSION

Combined inhibition of C5 and CD14 attenuates meconium-induced inflammation in vivo and this could become a future therapeutic regimen for MAS.

Meconium aspiration syndrome: risk factors and predictors of severity

PURPOSE

To identify risk factors and predictors of severity associated with meconium aspiration syndrome (MAS) in the patients admitted to the neonatal intensive care unit (NICU).

MATERIALS AND METHODS

Retrospective study including newborns admitted, between 2005 and 2015, with a diagnosis of MAS.

RESULTS

Of the newborns admitted to the NICU, 0.66% were diagnosed with MAS. These had higher prevalence of caesarean delivery (p < .001), nonreassuring or abnormal cardiotocography (CTG) (p < .001), intrapartum maternal fever (p = .002), Apgar scores at the first minute <7 (p < .001) and need of endotracheal intubation at birth (p < .001). Newborns with severe MAS had higher median reactive C protein (86.9 versus 9.65, p = .001) and 73.3% had pulmonary hypertension (p = .027). They required significantly more days of oxygen therapy, mechanical ventilation, nitric oxide, inotropic, and surfactant therapy, as well as longer hospital stay.

CONCLUSIONS

Nonreassuring or abnormal CTG and low Apgar score at the first minute were established as risk factors for MAS and need of surfactant therapy as a predictor of severity.

Early neonatal deaths associated with perinatal asphyxia in infants ≥2500g in Brazil

OBJECTIVE

To assess the annual burden of early neonatal deaths associated with perinatal asphyxia in infants weighing ≥2500g in Brazil from 2005 to 2010.

METHODS

The population study enrolled all live births of infants with birth weight ≥2500g and without malformations who died up to six days after birth with perinatal asphyxia, defined as intrauterine hypoxia, asphyxia at birth, or meconium aspiration syndrome. The cause of death was written in any field of the death certificate, according to International Classification of Diseases, 10th Revision (P20.0, P21.0, and P24.0). An active search was performed in 27 Brazilian federative units. The chi-squared test for trend was applied to analyze early neonatal mortality ratios associated with perinatal asphyxia by study year.

RESULTS

A total of 10,675 infants weighing ≥2500g without malformations died within six days after birth with perinatal asphyxia. Deaths occurred in the first 24h after birth in 71% of the infants. Meconium aspiration syndrome was reported in 4076 (38%) of these deaths. The asphyxia-specific early neonatal mortality ratio decreased from 0.81 in 2005 to 0.65 per 1000 live births in 2010 in Brazil (p<0.001); the meconium aspiration syndrome-specific early neonatal mortality ratio remained between 0.20 and 0.29 per 1000 live births during the study period.

CONCLUSIONS

Despite the decreasing rates in Brazil from 2005 to 2010, early neonatal mortality rates associated with perinatal asphyxia in infants in the better spectrum of birth weight and without congenital malformations are still high, and meconium aspiration syndrome plays a major role.

Placental Lesions in Meconium Aspiration Syndrome

Background

Meconium aspiration syndrome (MAS) is defined by respiratory distress requiring supplemental oxygen in a meconium-stained neonate. MAS is clinically subclassified as mild, moderate, and severe according to the oxygen requirement. The aims of this study were to compare the histological findings in the placentas of MAS neonates with those of meconium-stained but non-MAS neonates and to analyze the correlation between the severity of MAS and the grade of its histological parameters.

Methods

We collected 160 singleton term placentas from neonates with meconium staining at birth from a tertiary medical center, Seoul, Republic of Korea. We reviewed hematoxylin and eosin sections of tissue samples (full-thickness placental disc, chorioamniotic membranes, and umbilical cord).

Results

Funisitis was present more frequently in MAS than in non-MAS (p < .01), of which the stage was correlated with the severity of MAS (p < .001). The histological findings consistent with maternal underperfusion and chronic deciduitis were more frequent in MAS than in non-MAS (p < .05). There was a correlation between the degree of chorionic vascular muscle necrosis and the severity of MAS (p < .05).

Conclusions

Our results suggest that fetal inflammatory response evidenced by funisitis occurs prenatally in MAS and that the stage of funisitis and of chorionic vascular muscle necrosis may be a predictive marker of the severity of MAS.

Respiratory distress in term neonates in low-resource settings

Most neonatal deaths worldwide occur in low- and middle-income countries (LMICs). Respiratory distress is an important cause of neonatal morbidity and mortality. The epidemiology of respiratory distress among term neonates who constitute the vast majority of births is under reported. The scarcely available data from LMICs suggest an incidence of 1.2% to 7.2% among term live births and greater morbidity compared to that in high-income countries. Pneumonia and meconium aspiration syndrome are the predominant causes among outborn neonates, but next only to transient tachypnea among inborn neonates. Community management of neonatal sepsis/pneumonia using simplified antibiotic regimens when referral is not feasible, implementation of non-invasive ventilation, and innovative low-cost technologies to deliver respiratory therapy are important advances that have taken place in these settings. There is an urgent need to generate data on respiratory morbidities among term neonates so that the limited resources in these settings can be allocated judiciously.

Lung ultrasonography to diagnose meconium aspiration syndrome of the newborn

Objective To investigate the diagnostic value of lung ultrasonography for neonatal meconium aspiration syndrome (MAS). Methods This prospective observational study enrolled patients diagnosed with MAS based on medical history, clinical manifestations and chest X-ray and control newborns without MAS. During ultrasonography, each lung was divided into three regions (front, lateral, and back), using anterior and posterior axillary lines as the boundary. While scanning each region of the lungs, the hand piece was perpendicular or parallel to the ribs. Results This study enrolled 117 newborns with MAS and 100 controls. The main lung ultrasonographic findings in patients with MAS were: (i) pulmonary consolidation with air bronchogram was found in all patients; (ii) pleural line anomalies and the disappearance of the A-line was found in all patients; (iii) atelectasis was found in 19 (16.2%) severe cases, who demonstrated severe massive atelectasis and visible lung pulse; (iv) pleural effusion was found in 16 patients (13.7%); and (v) alveolar-interstitial syndrome or B-line in the non-consolidation area was found in all patients with MAS. Conclusion Ultrasonography can be used routinely to diagnose MAS in an accurate, reliable, convenient, and non-invasive manner.

Current Concepts in the Management of Meconium Aspiration Syndrome

In developing countries, meconium aspiration syndrome (MAS) is an important cause of morbidity and mortality among neonates. The concepts of pathophysiology and management of meconium stained amniotic fluid (MSAF) and meconium aspiration syndrome have undergone tremendous change in recent years. Routine intranatal and postnatal endotracheal suctioning of meconium in vigorous infants is no longer recommended. Recent studies have challenged its role even in non-vigorous infants. Supportive therapy like oxygen supplementation, mechanical ventilation and intravenous fluids are the cornerstone in the management of meconium aspiration syndrome. Availability of surfactant, inhaled nitric oxide, high frequency ventilators and extracorporeal membrane oxygenation has made it possible to salvage more infants with meconium aspiration syndrome. In this review the authors have discussed the current concepts in the pathophysiology and management of MAS. Drugs in trials and future therapeutic targets are also discussed briefly.

Predictive Value of Cerebroplacental Ratio in Detection of Perinatal Outcome in High-Risk Pregnancies

OBJECTIVE

To assess the predictive value of cerebroplacental ratio (i.e., S/D ratio of middle cerebral artery to S/D ratio of Umbilical artery) in detection of perinatal outcome in high-risk pregnancies.

MATERIAL AND METHOD

This retrospective study was conducted on 150 patients between 28 and 40 weeks of gestation (25 low risk and 125 high risk) who attended OPD and indoor wards of Teerthanker Mahaveer medical college and research center, Moradabad. All patients had serial color Doppler ultrasounds done after taking informed consent which was repeated at 2 weeks interval, and data were collected with regard to perinatal outcome.

RESULT AND CONCLUSION

Cerebroplacental ratio is having higher sensitivity and negative predictive value in detection of IUGR, Meconium aspiration syndrome, operative interference for fetal distress, and NICU admissions in comparison to its components. So, better prediction of neonatal outcome can be done by C/U ratio.

Endotracheal suction in term non vigorous meconium stained neonates-A pilot study

AIM

To evaluate the effect of 'No endotracheal suction' on occurrence of meconium aspiration syndrome (MAS) and/or all-cause mortality in non-vigorous neonates born through meconium stained amniotic fluid (MSAF).

METHODS

This pilot randomized controlled trial enrolled term non-vigorous neonates (≥37 weeks) born through MSAF. Neonates randomized to 'No Endotracheal suction group' ('No ET' Group; n=88) did not undergo endotracheal suction before the definitive steps of resuscitation. Neonates randomized to 'Endotracheal suction group' ('ET' Group; n=87) underwent tracheal suction as part of the initial steps as per the current NRP recommendations. The primary outcome was occurrence of MAS and/or death. Secondary outcome variables were duration and severity of respiratory distress, need for respiratory support, development of hypoxic ischemic encephalopathy (HIE) and duration of oxygen therapy and hospitalization.

RESULTS

Baseline characters including birth weight and gestational age were similar between the two groups. MAS was present in 23 (26.1%) vs. 28 (32.2%) neonates in 'No ET' and 'ET' groups respectively (OR 0.4 (0.12-1.4); p=0.14) with 4 (4.6%) and 9 (10.34%) deaths amongst these neonates with MAS in respective groups (OR 0.75 (0.62-1.2); p=0.38). Other parameters like severity and duration of respiratory distress, need for respiratory support, incidence of HIE, duration of oxygen therapy and duration of hospitalization were comparable.

CONCLUSION

This study demonstrates that it is feasible to randomize non-vigorous infants born through meconium stained liquor to receive on not receive endotracheal suction. There is a need for a multi-center trial to address whether the current practices and guidelines can be justified.

High-Frequency Jet Ventilation against Small-Volume Conventional Mechanical Ventilation in the Rabbit Models of Neonatal Acute Lung Injury

Patients with acute lung injury are ventilated by conventional mechanical ventilation (CMV) rather than high-frequency jet ventilation (HFJV). This study estimated the potential usefulness of HFJV in acute lung injury. The issue was addressed by comparing the effects on lung function of CMV and HFJV in two rabbit models of neonatal acute lung injury: repetitive saline lung lavage (LAV) and meconium aspiration syndrome (MAS) induced by intratracheal meconium instillation. The animals were then ventilated with either HFJV or CMV for 4 h. Ventilatory pressures, blood gases, and indexes of gas exchange were assessed. Lung edema formation was expressed as wet-dry lung weight ratio. Both LAV and MAS significantly decreased lung compliance, increased airway resistance, and caused severe hypoxemia, hypercarbia, and acidosis. Although CMV was superior to HFJV at 1 h of ventilation, there were no clinically relevant differences in lung function or edema formation between CMV and LAV in both models of respiratory insufficiency at 4 h of ventilation. We conclude that, HFJV may be used for ventilation in acute non-homogenous lung injury.

Effect of intrapartum oropharyngeal (IP-OP) suction on meconium aspiration syndrome (MAS) in developing country: A RCT

OBJECTIVE

Evidence about IP-OP suction and selective tracheal intubation in meconium stained neonates is from developed countries. Little information is available about their role in developing countries with high incidence of meconium staining and MAS. This randomized trial was planned to evaluate the effectiveness of IP-OP suction in meconium stained term neonates on prevention of MAS and reduction of its severity.

PATIENTS AND METHODS

Out of 540 meconium stained full term, cephalic presentation, singleton neonates without major congenital malformations born from June'08 to January'09, 31 were excluded and 509 randomized. In the intervention group IP-OP suction was done at the time of delivery of head using a 10 Fr suction catheter with a negative pressure of 100 mmHg. No IP-OP suction was performed in control group. All neonates with MSAF were assessed as vigorous or non-vigorous after birth and provided care as per NRP guidelines 2005.

RESULTS

Two hundred and fifty three neonates were randomized to IP-OP suction and 256 to no IP-OP suction. Eighty-two neonates (16%) developed MAS, the primary outcome parameter, with 40 infants in the intervention group (15.8%) and 42 (16.4%) in the non-intervention group (RR 0.86, 95% CI 0.60-1.54). Incidence of severe MAS was comparable (3.55% vs. 2.34%) (P value=0.40). Other variables like requirement of oxygen >48 h (9.8% vs. 10.5%) and mortality (2.7% vs. 1.7%) were also comparable.

CONCLUSIONS

IP-OP suctioning did not reduce the incidence or severity of MAS even in a setting of high incidence of MAS in a developing country. The mortality in two groups was comparable.

Diagnosis and management of persistent pulmonary hypertension of the newborn

Persistent pulmonary hypertension of new born (PPHN) is associated with mortality and morbidity; it may be idiopathic or secondary to a number of conditions. The mainstay of diagnosis and to exclude structural abnormalities is echocardiography. Brain type natriuretic peptide (BNP) levels are elevated in PPHN, but are insufficiently sensitive to contribute to routine diagnosis. Management includes improving oxygenation by optimising lung volume by ventilatory techniques and/or surfactant and administering pulmonary vasodilator agents. Inhaled nitric oxide (iNO), a selective pulmonary vasodilator, reduces the need for extracorporeal membrane oxygenation in term infants; it does not, however, improve mortality or have any long term positive effects in prematurely born infants or infants with congenital diaphragmatic hernia. Other pulmonary vasodilators have been reported in case series to be efficacious alone or in combination with iNO. Randomised trials with long term follow up are required to identify the optimum therapeutic strategies in PPHN.

Neonatal respiratory distress: a practical approach to its diagnosis and management

Respiratory disorders are the most frequent cause of admission to the special care nursery both in term and preterm infants. Pediatricians and primary care providers may encounter newborn infants with respiratory distress in their office, emergency room, delivery room, or during physical assessment in the newborn nursery. The authors have proposed a practical approach to diagnose and manage such infants with suggestions for consulting a neonatologist at a regional center. Their objective is that practicing pediatricians should be able to assess and stabilize such infants, and transfer to or consult a neonatologist, cardiologist, or pulmonologist after reading this article.

Risk factors differentiating mild/moderate from severe meconium aspiration syndrome in meconium-stained neonates

Objective

The aim of this study was to compare the risk factors associated with mild/moderate meconium aspiration syndrome (MAS) with those associated with severe in meconium-stained term neonates.

Methods

Consecutive singleton term neonates (n=671) with meconium staining at birth from all deliveries (n=14,666) in our institution from January 2006 to December 2012 were included. Both maternal and neonatal variables were examined. Among the study population, for women who underwent the trial of labor (n=644), variables associated with labor were also examined. These variables were compared between the mild/moderate MAS group, the severe MAS group, and the MAS-absent group.

Results

MAS developed in 10.6% (71/671) of neonates with meconium staining at birth. Among the neonates with MAS, 81.7% had mild MAS, 5.6% had moderate MAS, and 12.7% had severe MAS. The presence of minimal variability was significantly increased in both the mild/moderate and the severe MAS groups. The frequencies of nulliparity, fetal tachycardia, and intrapartum fever were significantly increased in the mild/moderate MAS group, but not in the severe MAS group. While a longer duration of the second stage of labor was significantly associated with mild/moderate MAS, severe MAS was associated with a shorter duration of the second stage. Notably, low mean cord pH (7.165 [6.850-7.375]) was significantly associated with mild/moderate MAS, but not with severe MAS (7.220 [7.021-7.407]) compared with the absence of MAS (7.268 [7.265-7.271]).

Conclusion

Our data suggest the development of severe MAS is not simply a linear extension of the same risk factors driving mild/moderate MAS.

[Current state of neonatal extracorporeal membrane oxygenation in Colombia: description of the first cases]

Extracorporeal membrane oxygenation is considered a rescue therapy and complex vital support with benefits in cardiorespiratory diseases during neonatal period that fulfil the characteristics of being reversible in neonates older than 34 weeks. The criteria for patient selection and its prompt use are critical for the final result. Even though new alternatives for management of hypoxemic respiratory failure in full term and almost full term neonates have decreased its use, congenital diaphragmatic hernia continues being a complex disease where it can have some applicability. Even though our experience is beginning, constant training will make of extracorporeal membrane oxygenation an option for complex patients in whom maximum therapy fails. This is a report of the first neonatal cases of hypoxemic respiratory failure managed at Fundación Cardiovascular de Colombia.

Risk factors and mortality among newborns with persistent pulmonary hypertension

Objective: To determine the risk factors for persistent pulmonary hypertension of newborns (PPHN) and their influence on mortality.

Methods: This was an observational study conducted at The Children’s Hospital & the Institute of Child Health, Multan, Pakistan, from July 2011 to June 2012.All admitted babies who had respiratory distress, cyanosis and evidence of hypoxia on ABG,s were diagnosed provided that they were having right- to- left or bidirectional hemodynamic shunting at the ductus arteriosus or at patent foramen ovale along with Tricuspid regurgitation (TR) jet >40 mm of Hg on echocardiography. All the demographic, maternal, antenatal, natal and postnatal data were recorded on a predesigned Performa.

Results: There were 79 patients, including 61 males and 18 females. The most common risk factors observed in our study were male sex (72.1%), cesarean section mode of delivery (54.2%), positive pressure ventilation while resuscitation (44.2%) birth asphyxia (40.4%) and meconium aspiration syndrome (MAS)35.4%. It was found that male sex (88.8%), cesarean-section delivery (77.7%), respiratory distress syndrome (RDS) 44.8% and sepsis (44.4%) were more associated with PPHN in premature infants than with term and post term infants. Out of the total 79 patients, death occurred among 7 preterm and 14 terms and post term infants. As a whole, cesarean section mode of delivery (71.4%), birth asphyxia (57.1%) and female sex (52.4%) were found major risk factors associated with mortality. However, respiratory distress syndrome (Relative Risk RR=5), birth asphyxia (RR=2.5) and male sex (RR=2)were found to be associated with increased risk of mortality in preterm than term and post term infants.

Conclusion: Male gender, cesarean section mode of delivery, MAS and RDS are the major risk factors for PPHN in any age group. RDS, Birth asphyxia and male sex are associated with increased risk of mortality in pre term than term and post term infants.

Fetal outcome in meconium stained deliveries

OBJECTIVE

To evaluate the foetal outcome in Meconium Stained Amniotic Fluid (MSAF).

MATERIAL AND METHODS

This prospective observational study was carried out in the Department of Obstetrics and Gynaecology, North Eastern Indira Gandhi Regional Institute of Health And Medical Sciences, Shillong, India, over a period of eighteen months, from January 2010 to June 2011. A total of 355 pregnant women who had completed more than 37 weeks of gestation, with singleton pregnancies and cephalic presentations were included in this study. One hundred and sixty five cases with MSAF, were thus selected and they were compared with 190 randomly selected controls.

RESULTS

Among 165 cases, 27.88 % of the cases had regular visits to the Institute at least 3 times previously, 72.12% cases had no previous visit at all. Primigravidas accounted for a majority of cases and approximately 50% cases had gestational ages of more than 40 weeks Pregnancies complicated with pregnancy induced hypertension had statistically significant higher rates of meconium staining among cases (16.97%), as compared to those among controls (7.89%). 21.81% cases had foetal heart rate abnormalities, as were detected by electronic foetal monitoring and presence of foetal bradycardia was statistically higher in cases compared to that in controls. Casearean section rates were nearly double in cases (49.09%). Neonatal outcome was poor in terms of low Apgar score at birth, birth asphyxia, Meconium Aspiration Syndrome (MAS) and increased neonatal admission among cases as compared to that among controls.

CONCLUSION

Meconium stained amniotic fluid is really worrisome from both, obstetrician's and paediatrician's points of view, as it increases the caesarean rates, causes birth asphyxia, MAS and increases neonatal intensive care unit admissions.

Varying patterns of home oxygen use in infants at 23-43 weeks' gestation discharged from United States neonatal intensive care units

OBJECTIVES

To compare proportions of infants at different gestational ages discharged from the neonatal intensive care unit (NICU) on home oxygen, to determine how many were classified with chronic lung disease based on timing of discharge on home oxygen, and to determine the percentage discharged on home oxygen who received mechanical ventilation.

STUDY DESIGN

We evaluated a retrospective cohort of infants of 23-43 weeks' gestational age discharged from 228 NICUs in 2009, using the Pediatrix Clinical Data Warehouse. Multilevel logistic regression analysis identified predictors of home oxygen use among extremely preterm, early-moderate preterm, late preterm, and term infants. Duration of mechanical ventilation and median length of stay were calculated for infants discharged on home oxygen.

RESULTS

For the 48877 infants studied, the rate of home oxygen use ranged from 28% (722 of 2621) in extremely preterm infants to 0.7% (246 of 34 934) in late preterm and term infants. Extremely preterm infants composed 56% (722 of 1286) of the infants discharged on home oxygen; late preterm and term infants, 19% (246 of 1286). After gestational age, mechanical ventilation was the main predictor of home oxygen use; however, 61% of the late preterm and term infants discharged on home oxygen did not receive ventilation. The median length of hospital stay was 95 days (IQR, 76-114 days) for extremely preterm infants discharged on home oxygen, but only 15 days (IQR, 10-22 days) for late preterm and term ventilated infants discharged on home oxygen.

CONCLUSION

Although home oxygen use is uncommon in later-gestation infants, the greater overall numbers of later-gestation infants contribute significantly to the increased need for home oxygen for infants at NICU discharge. Neither respiratory failure nor lengthy hospitalization is a prerequisite for home oxygen use at later gestational age.

Wheezy baby syndrome-A possible sequelae of neonatal meconium aspiration syndrome

Forty children aged 5 months to 3 years and suffering from wheezy baby syndrome (WBS) were evaluated to find out the prevalence of neonatal meconium aspiration syndrome (MAS) from the birth records. Twelve (30%) babies with WBS were detected to have a history of MAS at birth, significant enough to require a neonatal ICU admission. In contrast, only 2% of the 50 control non wheezy babies aged 6 months-3 years had a history of neonatal meconium aspiration syndrome (p<0.001). There was no significant difference in mean number of wheezing spells over six months in the neonatal MAS positive and MAS negative groups (3.4 vs 3.2, p>0.05). Family history of atopy was present in 64.3% of wheezing subjects with normal birth records, while none had such history in babies with neonatal MAS. The results of the present study suggested an association between neonatal MAS and subsequent wheezing.