Delivery room management of the apparently vigorous meconium-stained neonate: results of the multicenter, international collaborative trial

Meconium aspiration syndrome: from pathophysiology to treatment

Meconium aspiration syndrome (MAS) is a clinical condition characterized by respiratory distress in neonates born through meconium-stained amniotic fluid (MSAF). Despite advances in obstetric practices and perinatal care, MAS remains an important cause of morbidity and mortality in term and post-term newborns. Since the 1960s, there have been significant changes in the perinatal and postnatal management of infants born through MSAF. Routine endotracheal suctioning is no longer recommended in both vigorous and non-vigorous neonates with MSAF. Supportive care along with new treatments such as surfactant, inhaled nitric oxide, and high-frequency ventilation has significantly improved the outcome of MAS patients. However, determining the most appropriate approach for this condition continues to be a topic of debate. This review offers an updated overview of the epidemiology, etiopathogenesis, diagnosis, management, and prognosis of infants with MAS.

Mechanical ventilation in special populations

Optimal respiratory support can only be achieved if the ventilator strategy utilized for each individual patient at any given point in the evolution of their disease process is tailored to the underlying pathophysiology. The critically ill newborn infant requires individualized patient care when it comes to mechanical ventilation. This can only occur if the clinician has a good understanding of the different pathophysiologies of a variety of conditions that can lead to respiratory failure. In this chapter we describe the key pathophysiological features of bronchopulmonary dysplasia, meconium aspiration syndrome and lung hypoplasia syndromes with emphasis on congenital diaphragmatic hernia. We review available evidence to guide management an provide specific recommendations for pathophysiologically-based mechanical ventilation support.

Meconium aspiration syndrome: a comprehensive review

Meconium aspiration syndrome (MAS) is a complex respiratory disease that continues to be associated with significant morbidities and mortality. The pathophysiological mechanisms of MAS include airway obstruction, local and systemic inflammation, surfactant inactivation and persistent pulmonary hypertension of the newborn (PPHN). Supplemental oxygen and non-invasive respiratory support are the main therapies for many patients. The management of the patients requiring invasive mechanical ventilation could be challenging because of the combination of atelectasis and air trapping. While studies have explored various ventilatory modalities, evidence to date does not clearly support any singular modality as superior. Patient's pathophysiology, symptom severity, and clinician/unit expertise should guide the respiratory management. Early identification and concomitant management of PPHN is critically important as it contributes significantly to mortality and morbidities.

Effect of Endotracheal Suctioning on Infants Born through Meconium-Stained Amniotic Fluid: A Meta-analysis

OBJECTIVE

Meconium is a common finding in amniotic fluid and placental specimens, particularly in term and post-term pregnancies. The objective of this paper was to perform a meta-analysis to examine the impact of endotracheal suctioning on the occurrence of meconium aspiration syndrome (MAS), mortality, and complications.

STUDY DESIGN

PubMed, EMBASE, and the Cochrane library were systematically searched for comparative studies. Odds ratios (ORs), weighted mean differences (WMDs), and corresponding 95% confidence intervals (CIs) were used to compare the outcomes.

RESULTS

Twelve studies were included in the meta-analysis. There were no significant impacts of endotracheal suctioning on the occurrence of MAS (OR = 3.05, 95% CI: 0.48-19.56), mortality (OR = 1.25, 95% CI: 0.35-4.44), the need for mechanical ventilation (OR = 4.20, 95% CI: 0.32-54.72), the occurrence of pneumothorax (OR = 0.99, 95% CI: 0.34-2.85), persistent pulmonary hypertension of the newborn (PPHN), (OR = 1.31, 95% CI: 0.58-2.98), hypoxic-ischemic encephalopathy (HIE) (OR = 0.82, 95% CI: 0.52-1.30), and length of stay (WMD = -0.11, 95% CI: -0.99-0.77).

CONCLUSION

Routine endotracheal suctioning at birth is not useful in preventing MAS, mortality, mechanical ventilation, PPHN, HIE, and prolonged length of stay in neonates born through MSAF.

KEY POINTS

· Routine suctioning is not recommended for newborns.. · Endotracheal aspiration is not beneficial for MAS.. · Future research may focus on selected neonates..

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.

Meconium-stained amniotic fluid

Green-stained amniotic fluid, often referred to as meconium-stained amniotic fluid, is present in 5% to 20% of patients in labor and is considered an obstetric hazard. The condition has been attributed to the passage of fetal colonic content (meconium), intraamniotic bleeding with the presence of heme catabolic products, or both. The frequency of green-stained amniotic fluid increases as a function of gestational age, reaching approximately 27% in post-term gestation. Green-stained amniotic fluid during labor has been associated with fetal acidemia (umbilical artery pH <7.00), neonatal respiratory distress, and seizures as well as cerebral palsy. Hypoxia is widely considered a mechanism responsible for fetal defecation and meconium-stained amniotic fluid; however, most fetuses with meconium-stained amniotic fluid do not have fetal acidemia. Intraamniotic infection/inflammation has emerged as an important factor in meconium-stained amniotic fluid in term and preterm gestations, as patients with these conditions have a higher rate of clinical chorioamnionitis and neonatal sepsis. The precise mechanisms linking intraamniotic inflammation to green-stained amniotic fluid have not been determined, but the effects of oxidative stress in heme catabolism have been implicated. Two randomized clinical trials suggest that antibiotic administration decreases the rate of clinical chorioamnionitis in patients with meconium-stained amniotic fluid. A serious complication of meconium-stained amniotic fluid is meconium aspiration syndrome. This condition develops in 5% of cases presenting with meconium-stained amniotic fluid and is a severe complication typical of term newborns. Meconium aspiration syndrome is attributed to the mechanical and chemical effects of aspirated meconium coupled with local and systemic fetal inflammation. Routine naso/oropharyngeal suctioning and tracheal intubation in cases of meconium-stained amniotic fluid have not been shown to be beneficial and are no longer recommended in obstetrical practice. A systematic review of randomized controlled trials suggested that amnioinfusion may decrease the rate of meconium aspiration syndrome. Histologic examination of the fetal membranes for meconium has been invoked in medical legal litigation to time the occurrence of fetal injury. However, inferences have been largely based on the results of in vitro experiments, and extrapolation of such findings to the clinical setting warrants caution. Fetal defecation throughout gestation appears to be a physiologic phenomenon based on ultrasound as well as in observations in animals.

[The evolution of approach in the resuscitation of neonates born with meconium-stained amniotic fluid: a tale of two countries, China and U.S.A., in the past 60 years]

Neonates born through meconium-stained amniotic fluid (MSAF) may develop complications including meconium aspiration syndrome, persistent pulmonary hypertension of newborn and death. The approach to the resuscitation of these neonates has significantly evolved for the past few decades. Initially, under direct visualization technique, neonates with MSAF were commonly suctioned below the vocal cords soon after delivery. Since 2015, Neonatal Resuscitation Program (NRP^®) of the American Academy of Pediatrics has recommended against "routine" endotracheal suctioning of non-vigorous neonates with MSAF but favored immediate resuscitation with positive pressure ventilation via face-mask bagging. However, the China neonatal resuscitation 2021 guidelines continue to recommend routine endotracheal suctioning of non-vigorous neonates born with MSAF at birth. This review article discusses the differences and the rationales in the approach in the resuscitation of neonates with MSAF between Chinese and American NRP^® guidelines over the past 60 years.

Resuscitation with Intact Cord Versus Clamped Cord in Late Preterm and Term Neonates: A Randomized Controlled Trial

OBJECTIVE

To compare the effect of intact cord versus clamped cord resuscitation on the physiologic transition of neonates receiving positive-pressure ventilation (PPV) at birth.

STUDY DESIGN

This open-label, parallel-group, randomized controlled superiority trial was conducted in a tertiary care hospital in India. Neonates born at ≥34 weeks of gestation after a complicated pregnancy or labor were randomized just before birth to receive resuscitation according to the Neonatal Resuscitation Program algorithm with either an intact cord (intact cord resuscitation group) or after early cord clamping (early cord clamping resuscitation group). The allocated study intervention was administered if the neonate needed PPV at birth. The primary outcome was expanded Apgar score at 5 minutes after birth.

RESULTS

Birth weight, gestational age, and the incidence of pregnancy complications were similar in the 2 study groups. The proportion of neonates who received PPV was lower in the intact cord resuscitation group (28.7% vs 36.5%, P = .05; relative risk, 0.79; 95% CI, 0.61-1.01). Among neonates who received PPV, the expanded Apgar score at 5 minutes was significantly higher in the intact cord resuscitation group (median, 15 [IQR, 14-15] vs 14 [IQR, 13-15]; P < .001). The expanded Apgar score at 10 minutes, Apgar scores at 5 and 10 minutes, and oxygen saturation at 1, 5, and 10 minutes were also higher in the intact cord resuscitation group.

CONCLUSION

In late preterm and term neonates, resuscitation with an intact cord results in better postnatal physiologic transition than the standard practice of resuscitation after immediate cord clamping.

TRIAL REGISTRATION

Clinical Trial Registry of India (www.ctri.nic.in); trial registration no. CTRI/2020/02/023379.

Is it feasible to avoid suction before spontaneous breathing is established?

BACKGROUND

Suctioning of the posterior pharynx immediately after birth during neonatal resuscitation can produce a vagal response resulting in bradycardia or apnea. The feasibility of delaying any airway suctioning and avoiding deep suctioning has not been studied.

OBJECTIVES

To test the hypothesis that newborn resuscitation is feasible with the following two guidelines: 1) avoiding any suctioning until the infant establishes spontaneous respiration, and 2) avoiding the use of deep suction with catheters.

STUDY DESIGN

A quality improvement project was implemented using these two guidelines. Infants' mouth was cleaned with a dry cloth. No suction was started until infants establish spontaneous breathing. Then, bulb suction was used to clear secretions from the sides of the mouth and the nose without reaching the back of the pharynx. Deep suction using catheters was not used. Neonatal staff and physicians received biweekly training to support these changes. Resuscitation data before and after the practice change were compared.

RESULTS

A total of 999 sequential cases were compared; of them 501 and 498 infants were resuscitated before and after the implementation of the new practice, respectively. Suction before spontaneous breathing occurred in 12.4% in the first cohort. There were no differences between groups except for less use of oxygen with the new guidelines (12.4% vs 4.4%, P < 0.001).

CONCLUSION

Avoidance of any suction prior to spontaneous breathing and not applying deep suction with catheters are feasible during newborn resuscitation. These practices are associated with decreased exposure to oxygen in the delivery room.

Neonatal Outcomes since the Implementation of No Routine Endotracheal Suctioning of Meconium-Stained Nonvigorous Neonates

OBJECTIVE

 This study aimed to evaluate the effect of the 2015 Neonatal Resuscitation Program recommendations of no routine endotracheal suctioning for nonvigorous neonates on the incidence of meconium aspiration syndrome (MAS) and death. We hypothesized that the revised guidelines have not changed the outcome of MAS/death.

STUDY DESIGN

 This was a single-center retrospective cohort study. We recorded data on nonvigorous neonates born at gestational age > 37 weeks, who were divided into period 1, n = 95 (before the new guidelines, January 1, 2013-December 31, 2015) and prospective period 2, n = 91 (after the implementation of new guidelines, January 1, 2017-December 31, 2020). Primary outcomes included MAS and death. Secondary outcomes included respiratory neonatal intensive care unit (NICU) admission, length of NICU stay, and feeding difficulties.

RESULTS

 No significant differences in the occurrence of MAS (11 vs. 17%) (odds ratio [OR] of 1.46 [95% confidence interval [CI]: 0.59-3.55]) or death (1 vs. 3%) (OR of 2.00 [95% CI: 0.18-21.57]) among the two periods were observed. In period 2, there was an increased NICU respiratory admission (37 vs. 61%), with an OR of 2.31 (95% CI: 1.10-4.84). More neonates in period 2 required subsequent intubation for respiratory failure in the delivery room (12 vs. 28%) with an OR of 2.03 (95% CI: 1.02-4.51); p-value of 0.05.

CONCLUSION

 Our study did not observe a significant difference in the incidence of MAS or death between the two periods since the 2015 guidelines. However, the incidence of NICU respiratory admission increased.

KEY POINTS

· Non-vigorous neonates born through MSAF who did not undergo ET suctioning soon after birth did not have increased incidence of MAS or death, but had increased NICU respiratory admissions.. · A large Multi-center RCT may give more clear verdict on the outcomes of these newborns..

Contemporary management of infants born through meconium stained amniotic fluid

Delivery room management of infants delivered through meconium stained amniotic fluid has evolved over the past four decades. The burden of disease weighs more heavily in low- and middle-resource areas. Current information does not allow for precise prediction of infants that will require resuscitation at delivery versus those that need simple stabilization. Optimal care of newborns requires assessment of risk factors and obstetrical and pediatric team preparation to respond to the needs of the newborn.

Versorgung und Reanimation des reifen Neugeborenen nach der Geburt

Die volle Reanimation eines Neugeborenen mit Beatmungen, Thoraxkompressionen und der Gabe von Medikamenten ist ein äußerst seltenes Ereignis, das selbst neonatologische Teams immer wieder vor Herausforderungen stellt. Gerade in diesen seltenen und häufig dramatischen Situationen ist schnelles und umsichtiges Handeln im Team gefragt. Dabei ist die effektivste und meist einzig notwendige Maßnahme für die erfolgreiche Versorgung eines nicht spontan atmenden Neugeborenen eine suffiziente Maskenbeatmung. Wird diese effektiv durchgeführt, sind beim Neugeborenen in den seltensten Fällen tatsächlich Thoraxkompressionen notwendig. Im März 2021 wurde vom European Resuscitation Council (ERC) die neue Leitlinie zur Reanimation von Neugeborenen publiziert. Auf Basis dieser Leitlinie beschreibt der vorliegende Beitrag detailliert den im Algorithmus der Versorgung und Reanimation von reifen Neugeborenen dargestellten Handlungsablauf. Er richtet sich damit einerseits insbesondere an NichtneonatologInnen, die für die Versorgung v. a. von reifen Neugeborenen nach der Geburt verantwortlich sind. Andererseits soll er auch jenen zur Unterstützung dienen, die medizinisches Personal in der Versorgung von lebensbedrohten Neugeborenen trainieren und den Algorithmus der Neugeborenenreanimation als didaktisches Konzept vermitteln.

Neonatal outcomes of non-vigorous neonates with meconium-stained amniotic fluid before and after change in tracheal suctioning recommendation

OBJECTIVE

To evaluate the short-term outcomes of non-vigorous infants born through meconium-stained amniotic fluid (MSAF) before and after implementation of no-tracheal suctioning guidelines.

STUDY DESIGN

Single-center retrospective study of ≥36-week gestation neonates with MSAF.

RESULTS

During routine-suction era (9/2013-12/2014), 280/2306 neonates (12%) were born through MSAF and 39 (14%) were non-vigorous. Thirty (77%) of non-vigorous infants underwent tracheal suctioning. In the no-suction era (1/2017-12/2018), 282/2918 neonates (9.7%) were born through MSAF and 30 (10.6%) were non-vigorous and one needed intubation. Admissions for meconium aspiration syndrome (15% vs 53%) and respiratory distress (18% vs 57%) were significantly higher among non-vigorous infants in the no-suction era.

CONCLUSIONS

In this single-center study, non-vigorous infants born through MSAF without routine-tracheal suctioning had a higher incidence of NICU admission for MAS and respiratory distress compared to the routine-suction era. Multicenter randomized trials evaluating tracheal suction in non-vigorous infants with MSAF are warranted.

Appropriate Management of the Nonvigorous Meconium-Stained Newborn Meconium

Before 2015, major changes in Neonatal Resuscitation Program (NRP) recommendations not supporting previously endorsed antepartum, intrapartum and postpartum interventions to prevent meconium aspiration syndrome were based on adequately powered multicenter randomized controlled trials. The 2015 and 2020 American Heart Association guidelines and 7th and 8th edition of NRP suggest not performing routine intubation and tracheal suctioning of nonvigorous meconium-stained newborns. However, this was given as a weak recommendation with low-certainty evidence. The purpose of this review is to summarize the evidence and explore the question of appropriate delivery room management for nonvigorous meconium-stained newborns.

Impact of the Revised NRP Meconium Aspiration Guidelines on Term Infant Outcomes

OBJECTIVES

To evaluate the association of the Neonatal Resuscitation Program, Seventh Edition changes on term infants born with meconium-stained amniotic fluid (MSAF).

STUDY DESIGN

We evaluated the effect of no longer routinely intubating nonvigorous term infants born with MSAF in 14 322 infants seen by the resuscitation team from January 1, 2014 to June 30, 2017 in a large, urban, academic hospital.

RESULTS

Delivery room intubations of term infants with MSAF fell from 19% to 3% after the change in guidelines (P = <.0001). The rate of all other delivery room intubations also decreased by 3%. After the implementation of the Seventh Edition guidelines, 1-minute Apgar scores were significantly more likely to be >3 (P = .009) and significantly less likely to be <7 (P = .011). The need for continued respiratory support after the first day of life also decreased. Admission rates to the NICU, length of stay, and the need for respiratory support on admission were unchanged.

CONCLUSIONS

Implementation of the Neonatal Resuscitation Program, Seventh Edition recommendations against routine suctioning nonvigorous infants born with MSAF was temporally associated with an improvement in 1-minute Apgar scores and decreased the need for respiratory support after the first day of life. There was also a significant decrease in total intubations performed in the delivery room. This has long-term implications on intubation experience among frontline providers.

Tracheal suction at birth in non-vigorous neonates born through meconium-stained amniotic fluid

BACKGROUND

Neonates born through meconium-stained amniotic fluid (MSAF) are at risk of developing meconium aspiration syndrome (MAS). Neonates who are non-vigorous due to intrapartum asphyxia are at higher risk of developing MAS. Clearance of meconium from the airways below the vocal cords by tracheal suction before initiating other steps of resuscitation may reduce the risk of development of MAS. However, conducting tracheal suction may not only be ineffective, it may also delay effective resuscitation, thus prolonging and worsening the hypoxic-ischaemic insult.  OBJECTIVES: To evaluate the efficacy of tracheal suctioning at birth in preventing meconium aspiration syndrome and other complications among non-vigorous neonates born through meconium-stained amniotic fluid.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search Cochrane Central Register of Controlled Trials (CENTRAL 2020, Issue 11) in the Cochrane Library; Ovid MEDLINE(R) and Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Daily and Versions(R) (1946 to 25 November 2020) for randomised controlled trials (RCTs) and quasi-randomised trials. We also searched clinical trials databases and the reference lists of retrieved articles for RCTs and quasi-randomised trials (up to November 2020).

SELECTION CRITERIA

We included studies enrolling non-vigorous neonates born through MSAF, if the intervention being tested included tracheal suction at the time of birth with an intent to clear the trachea of meconium before regular breathing efforts began. Tracheal suction could be performed with an endotracheal tube or a wide-gauge suction catheter. Neonates in the control group should have been resuscitated at birth with no effort made to clear the trachea of meconium.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data, consulting with a third review author about any disagreements. We used standard Cochrane methodological procedures, including assessment of risk of bias for all studies. Our primary outcomes were: MAS; all-cause neonatal mortality; and incidence of hypoxic-ischaemic encephalopathy (HIE). Secondary outcomes included: need for mechanical ventilation; incidence of pulmonary air leaks; culture-positive sepsis; and persistent pulmonary hypertension. We used the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

We included four studies (enrolling 581 neonates) in the review. All four studies were conducted in tertiary care hospitals in India. Three of the four studies included neonates born at and beyond term gestation, whereas one included neonates born at and beyond 34 weeks of gestation. Due to the nature of the intervention, it was not possible to blind the healthcare personnel conducting the intervention. Tracheal suction compared to no suction in non-vigorous neonates born through MSAF In non-vigorous infants, no differences were noted in the risks of MAS (RR 1.00, 95% CI 0.80 to 1.25; RD 0.00, 95% CI -0.07 to 0.08; 4 studies, 581 neonates) or all-cause neonatal mortality (RR 1.24, 95% CI 0.76 to 2.02; RD 0.02, 95% CI -0.03 to 0.07; 4 studies, 575 neonates) with or without tracheal suctioning. No differences were reported in the risk of any severity HIE (RR 1.05, 95% CI 0.68 to 1.63; 1 study, 175 neonates) or moderate to severe HIE (RR 0.68, 95% CI 0.43 to 1.09; 1 study, 152 neonates) among non-vigorous neonates born through MSAF. We are also uncertain as to the effect of tracheal suction on other outcomes such as incidence of mechanical ventilation (RR 0.99, 95% CI 0.68 to 1.44; RD 0.00, 95% CI -0.06 to 0.06; 4 studies, 581 neonates), pulmonary air leaks (RR 1.22, 95% CI 0.38 to 3.93; RD 0.00, 95% CI -0.02 to 0.03; 3 studies, 449 neonates), persistent pulmonary hypertension (RR 1.29, 95% CI 0.60 to 2.77; RD 0.02, 95% CI -0.03 to 0.06; 3 studies, 406 neonates) and culture-positive sepsis (RR 1.32, 95% CI 0.48 to 3.57; RD 0.01, 95% CI -0.03 to 0.05; 3 studies, 406 neonates). All reported outcomes were judged as providing very low certainty evidence.

AUTHORS' CONCLUSIONS

We are uncertain about the effect of tracheal suction on the incidence of MAS and its complications among non-vigorous neonates born through MSAF. One study awaits classification and could not be included in the review. More research from well-conducted large trials is needed to conclusively answer the review question.

European Resuscitation Council Guidelines 2021: Newborn resuscitation and support of transition of infants at birth

The European Resuscitation Council has produced these newborn life support guidelines, which are based on the International Liaison Committee on Resuscitation (ILCOR) 2020 Consensus on Science and Treatment Recommendations (CoSTR) for Neonatal Life Support. The guidelines cover the management of the term and preterm infant. The topics covered include an algorithm to aid a logical approach to resuscitation of the newborn, factors before delivery, training and education, thermal control, management of the umbilical cord after birth, initial assessment and categorisation of the newborn infant, airway and breathing and circulation support, communication with parents, considerations when withholding and discontinuing support.

Neonatal Respiratory Distress Secondary to Meconium Aspiration Syndrome

Infants born through meconium-stained amniotic fluid (MSAF) are 100 times more likely than infants born through clear amniotic fluid to develop respiratory distress in the neonatal period. Meconium aspiration syndrome (MAS) is a common cause of respiratory distress in term and post-mature neonates. MAS is defined as respiratory distress accompanied by a supplemental oxygen requirement in an infant born with MSAF, in the absence of any other identified etiology to explain the symptoms. Therapy for MAS is supportive, and should be tailored to each infant’s specific pathophysiology. In cases of MAS with severe persistent pulmonary hypertension of the newborn (PPHN), patients may remain hypoxic despite aggressive ventilation, and in these cases surfactant, inhaled nitric oxide (iNO) and extracorporeal membrane oxygenation (ECMO) can be life-saving. Long-term prognosis for MAS is more related to severity of initial hypoxemia and possible neurological insult than to the pulmonary pathology.

Meconium Aspiration Syndrome: A Narrative Review

Meconium aspiration syndrome is a clinical condition characterized by respiratory failure occurring in neonates born through meconium-stained amniotic fluid. Worldwide, the incidence has declined in developed countries thanks to improved obstetric practices and perinatal care while challenges persist in developing countries. Despite the improved survival rate over the last decades, long-term morbidity among survivors remains a major concern. Since the 1960s, relevant changes have occurred in the perinatal and postnatal management of such patients but the most appropriate approach is still a matter of debate. This review offers an updated overview of the epidemiology, etiopathogenesis, diagnosis, management and prognosis of infants with meconium aspiration syndrome.

[Newborn resuscitation and support of transition of infants at birth]

The European Resuscitation Council has produced these newborn life support guidelines, which are based on the International Liaison Committee on Resuscitation (ILCOR) 2020 Consensus on Science and Treatment Recommendations (CoSTR) for Neonatal Life Support. The guidelines cover the management of the term and preterm infant. The topics covered include an algorithm to aid a logical approach to resuscitation of the newborn, factors before delivery, training and education, thermal control, management of the umbilical cord after birth, initial assessment and categorisation of the newborn infant, airway and breathing and circulation support, communication with parents, considerations when withholding and discontinuing support.

Outcomes of endotracheal suctioning in non-vigorous neonates born through meconium-stained amniotic fluid: a systematic review and meta-analysis

OBJECTIVE

We aimed to systematically review and analyse the outcomes of non-endotracheal suctioning (non-ETS) versus ETS in non-vigorous meconium-stained neonates.

DESIGN

We conducted a systematic review of non-ETS and ETS in non-vigorous infants born through meconium-stained amniotic fluid (MSAF). We searched PubMed/Medline, Scopus, Clinical Trials.gov, Cumulative Index to Nursing and Allied Health, and Cochrane Library databases from inception to November 2019, using keywords and related terms. Only non-vigorous infants born through MSAF included in randomised controlled trials, were included. We calculated overall relative risks (RRs) and mean differences with 95% CIs using a random-effects model, to determine the impact of ETS in non-vigorous infants born through MSAF.

MAIN OUTCOME MEASURES

The primary outcome was the incidence of meconium aspiration syndrome (MAS). Secondary outcomes were respiratory outcome measures (pneumothorax, persistent pulmonary hypertension of the newborn, secondary pneumonia, need for respiratory support, duration of mechanical ventilation), initial resuscitation and others including shock, perinatal asphyxia, convulsions, neonatal mortality, blood culture-positive sepsis and duration of hospital stay.

RESULTS

A total of 2085 articles were identified in the initial database search. Four studies, including 581 non-vigorous meconium-stained infants, fulfilled the inclusion criteria, comprising 292 infants in the non-ETS group and 289 in the ETS group. No statistically significant difference was found for MAS (RR 0.98; 95% CI 0.71 to 1.35).

CONCLUSIONS

Initiating ETS soon after birth in non-vigorous meconium-stained infants may not alter their neonatal outcomes.

Extra-Corporeal Membrane Oxygenation for Neonatal Respiratory Support

To review our experience with Extra-Corporeal Membrane Oxygenation (ECMO) for respiratory support in neonates. From 1989 to 2018 2114 patients underwent respiratory ECMO support, with 764 (36%) neonates. Veno-Venous (V-V) cannulation was used in 428 (56%) neonates and Veno-Arterial (V-A) in 336 (44%). Historically V-V ECMO was our preferred modality, but due to lack of suitable cannula in the last 7 years V-A was used in 209/228 (92%) neonates. Mean and inter-quartile range of ECMO duration was 117 hours (inter-quartile range 90 to 164 hours). Overall 724 (95%) neonates survived to ECMO decannulation, with 640 (84%) hospital discharge. Survival varied with underlying diagnosis: meconium aspiration 98% (354/362), persistent pulmonary hypertension 80% (120/151), congenital diaphragmatic hernia 66% (82/124), sepsis 59% (35/59), pneumonia 86% (6/7), other 71% (43/61). Survival was 86% with V-V and 80% with V-A cannulation, better than ELSO Registry with 77% V-V and 63% V-A. Major complications: cerebral infarction/hemorrhage in 4.7% (31.1% survival to discharge), renal replacement therapy in 17.6% (58.1% survival to discharge), new infection in 2.9%, with negative impact on survival (30%). Following a circuit design modification and subsequent reduction in heparin requirement, intracerebral hemorrhage decreased to 9/299 (3.0%) radiologically proven cerebral infarction/hemorrhage. We concluded (1) outcomes from neonatal ECMO in our large case series were excellent, with better survival and lower complication rate than reported in ELSO registry. (2) These results highlight the benefits of ECMO service in high volume units. (3) The similar survival rate seen in neonates with V-A and V-V cannulation differs from the ELSO register; this may reflect the change in cannulation enforced by lack of suitable V-V cannula and all neonates undergoing V-A cannulation.

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.

Impact of meconium consistency on infant resuscitation and respiratory outcomes: a retrospective-cohort study and systematic review

Objective: To compare short-term outcomes of infants born with thick versus thin meconium stained amniotic fluid (MSAF) and to perform a systematic review of the topic.Methods: A retrospective, single center, cohort study of infants' ≥34 weeks' gestation born with MSAF between 1 June 2013 and 30 September 2016. Birth resuscitation and respiratory outcomes were compared between the groups. A systematic review was conducted of similar studies published between 1 January 2000 and 30 June 2019.Results: 1507 infants were eligible; 464 (30.8%) thick, 1,043 (69.2%) thin MSAF. The thick group required more respiratory support at birth and was 5.5-fold (95% CI: 2.51-11.95) more likely to and have meconium aspiration syndrome (MAS) and 2.1-fold more likely (95% CI: 0.89-4.83) to require either noninvasive respiratory support or intubation than the thin group. The thick group also had significantly higher oxygen supplementation >24 h (p < .001) and pneumothorax (p = .002). Across 12 studies included in the systematic review, infants with thick MSAF required more intensive birth resuscitation, ventilation support, with higher incidences of MAS. Study differences prohibited data comparisons and quantitative outcome evaluations.Conclusion: Infants with thick MSAF required more intensive birth resuscitation and ventilation support. Our findings need confirmation in robust, prospective cohort studies.

Change in neonatal resuscitation guidelines and trends in incidence of meconium aspiration syndrome in California

OBJECTIVE

To describe trends in the incidence and severity of meconium aspiration syndrome (MAS) around the release of revised Neonatal Resuscitation Program (NRP) guidelines in 2016.

STUDY DESIGN

The California Perinatal Quality Care Collaborative database was queried for years 2013-2017 to describe the incidence and outcomes of infants with MAS. Results were analyzed based on both individual years and pre- vs. post-guideline epochs (2013-15 vs. 2017).

RESULT

Incidence of MAS decreased significantly from 2013-15 to 2017 (1.02 to 0.78/1000 births, p < 0.001). Among infants with MAS, delivery room intubations decreased from 2013-15 to 2017 (44.3 vs. 35.1%; p = 0.005), but similar proportion of infants required invasive respiratory support (80.1 vs. 80.8%), inhaled nitric oxide (28.8 vs. 28.4%) or extracorporeal membrane oxygenation (0.81 vs. 0.35%).

CONCLUSION

While the study design precludes confirmation of implementation of the recent NRP recommendation, there was no increase in the incidence or severity of MAS following its release.

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.

NICU Admissions for Meconium Aspiration Syndrome before and after a National Resuscitation Program Suctioning Guideline Change

The Textbook of Neonatal Resuscitation, seventh edition, does not suggest routine endotracheal suctioning for non-vigorous infants born through meconium-stained amniotic fluid. We compared 301,150 infants at ≥35 weeks' gestational age inborn at 311 Vermont Oxford Network member centers in the United States (U.S.) and admitted to neonatal intensive care units (NICU) who were born before (2013 to 2015) and after (2017) the guideline change. Logistic regression models adjusting for clustering of infants within centers were used to calculate risk ratios. NICU admissions for infants with a diagnosis of meconium aspiration syndrome (MAS) decreased from 1.8% to 1.5% (risk ratio: 0.82; 95% confidence interval: 0.68, 0.97) and delivery room endotracheal suctioning in this group decreased from 57.0% to 28.9% (0.51; 0.41, 0.62). Treatment with conventional or high frequency ventilation, inhaled nitric oxide, or extracorporeal membrane oxygenation remained unchanged 42.3% vs. 40.3% (0.95; 0.80, 1.13) among infants with MAS and 9.1% vs. 8.2% (0.91; 0.87, 0.95) among infants without MAS. The use of surfactant among infants with MAS increased from 24.6% to 30% (1.22; 1.02, 1.48). Mortality (2.6 to 2.9%, 1.12; 0.74, 1.69) and moderate/severe hypoxic-ischemic encephalopathy (5.4 to 6.8%, 1.24; 0.91, 1.69) increased slightly in 2017. Subgroup analyses of infants with 1 min Apgar scores of ≤3 found similar results. While NICU admissions for MAS and tracheal suctioning decreased after the introduction of the new guideline with no subsequent increase in severe respiratory distress among infants with and without a MAS diagnosis, limitations in our study preclude inferring that the new guideline is safe or effective.

Have the 2015 Neonatal Resuscitation Program Guidelines changed the management and outcome of infants born through meconium-stained amniotic fluid?

BACKGROUND

In 2015, the Neonatal Resuscitation Program (NRP) guidelines were updated to recommend that nonvigorous infants delivered through meconium-stained amniotic fluid (MSAF) do not require routine intubation and tracheal suction.

OBJECTIVE

Explore the implications of 2015 NRP guidelines on delivery room management and outcome of infants born through MSAF.

DESIGN

Retrospective cohort study.

SETTINGS

King Abdul-Aziz University Hospital (KAUH).

PATIENTS AND METHODS

All term ( greater than or equal 37 weeks) infants born in KAUH through MSAF between January 1, 2016, and December 31, 2017, were included. Patients were divided into two groups according to the date of birth: period 1 (January 1, 2016, to December 31, 2016), before the implementation of the new NRP guidelines; period 2 (January 1, 2017, to December 31, 2017), after the implementation.

MAIN OUTCOME MEASURES

Outcomes of infants born through MSAF.

SAMPLE SIZE

420 infants.

RESULTS

A majority of infants (n=261) were born in period 1 and 159 after in period 2. No differences were found in the booking status of mothers, cesarean section rate, and number of deliveries attended by physicians between the 2 cohorts. Infants in both cohorts were of similar gestational age, birth weight, and gender. A nonsignificant lower rate of intubation at birth (2.3% vs 0.6%), admission to neonatal intensive care unit (3.8% vs 3.1%), and meconium aspiration syndrome (1.5% vs 0.6%) were found in period 2 compared with period 1. Only 1 infant died in period 1.

CONCLUSION

After the implementation of 2015 NRP guidelines, fewer infants were intubated at birth for MSAF. No difference was observed in the rate of associated morbidities and mortality.

LIMITATIONS

A single-center retrospective study of misclassification bias because some of the medical staff started practicing the new guidelines before the official implementation.

CONFLICT OF INTEREST

None.

Waived Consent in Perinatal/Neonatal Research-When Is It Appropriate?

Informed consent is a process ensuring that subjects enrolled in research are appropriately informed of the risks and benefits. While this process is well-defined when it is possible and practical to obtain consent prior to the research intervention, it can be less clear in cases of deferred or waived consent. Defining minimal risk, such as when research is attempting to determine which of two currently practiced interventions is safest and/or most effective, is critical to moving forward in establishing appropriate care in newborns. For perinatal/neonatal research the challenge lies between the ethical justification for approaching women in labor or under medication vs. the scientific integrity of excluding a number of subjects that may potentially benefit the most from an intervention. Researchers must work with their IRBs as well as families who have participated in trials to determine the most appropriate method for obtaining informed consent from expectant parents. Clinical researchers and IRBs ultimately need to find a middle ground for the appropriate use of deferred or waived consent.

Delivery Room Management of Meconium-Stained Newborns and Respiratory Support

: media-1vid110.1542/5839992674001PEDS-VA_2018-1485Video Abstract BACKGROUND AND OBJECTIVES: Recently, the Neonatal Resuscitation Program (NRP) recommended against routine endotracheal suctioning of meconium-stained nonvigorous newborns but suggested resuscitation with positive pressure ventilation. Our purpose is to study the effects of this change in management.

METHODS

In this multicenter cohort study, we compare 130 nonvigorous newborns born during the retrospective 1-year period before the implementation of new NRP guidelines (October 1, 2015, to September 30, 2016) to 101 infants born during the 1-year prospective period after implementation (October 1, 2016, to September 30, 2017).

RESULTS

Endotracheal suctioning was performed predominantly in the retrospective group compared with the prospective group (70% vs 2%), indicating the change in practice. A significantly higher proportion of newborns were admitted to the NICU for respiratory issues in the prospective group compared with the retrospective group (40% vs 22%) with an odds ratio (OR) of 2.2 (95% confidence interval [CI]: 1.2-3.9). Similarly, a significantly higher proportion of infants needed oxygen therapy (37% vs 19%) with an OR of 2.5 (95% CI: 1.2-4.5), mechanical ventilation (19% vs 9%) with an OR of 2.6 (95% CI: 1.1-5.8), and surfactant therapy (10% vs 2%) with an OR of 5.8 (95% CI: 1.5-21.8). There were no differences in the incidence of other outcomes, including meconium aspiration syndrome.

CONCLUSIONS

The recent NRP guideline change was not associated with an increased incidence of meconium aspiration syndrome but was associated with an increased incidence of NICU admissions for respiratory issues. Also, the need for mechanical ventilation, oxygen, and surfactant therapy increased.

Yield of meconium in non-vigorous neonates undergoing endotracheal suctioning and profile of all neonates born through meconium-stained amniotic fluid: a prospective observational study

BACKGROUND

Delivery room management of infants born via meconium-stained amniotic fluid (MSAF) is quite controversial. No study has tried to quantify the amount of meconium that can be aspirated from the trachea of a non-vigorous neonate born through MSAF.

AIMS

To study the yield of meconium in non-vigorous neonates born through MSAF undergoing endotracheal (ET) suctioning.

METHODS

This was a prospective observational study conducted from 1 March 2015 to 31 October 2015. A total of 760 neonates born through MSAF were enrolled. All non-vigorous neonates underwent ET suctioning. Meconium aspirated was quantified as nil (no meconium aspirated), insignificant (when only streaks of meconium were present in the ET tube), minimal (when the whole length of ET tube was filled with meconium) and significant (when the whole ET tube was filled with meconium and it poured into the suction tubing or when repeat suctioning was required).

RESULTS

The amount of meconium aspirated from the trachea was nil to insignificant in 46% of the neonates who underwent tracheal suctioning. Only 14.4% of the neonates had significant meconium aspirated from the trachea. Almost 46% of the non-vigorous infants underwent tracheal suctioning without any important amount of meconium being aspirated from the trachea.

CONCLUSION

The study further supports the recommendation put forth by the International Liaison Committee on Resuscitation (ILCOR) 2015 that selective intubation and tracheal suctioning of non-vigorous MSAF neonates might be of limited benefit.

ABBREVIATIONS

ET: endotracheal; ILCOR: International Liaison Committee on Resuscitation; HIE: hypoxic ischaemic encephalopathy; LMIC: low- and middle-income countries; MAS: meconium aspiration syndrome; MSAF: meconium-stained amniotic fluid; NRP: neonatal resuscitation programme; PPHN: persistent pulmonary hypertension of the newborn; RCT: randomised controlled trial.

Management of Meconium-Stained Newborns in the Delivery Room

The approach to the management of meconium-stained newborns in the delivery room has been changing for over 40 years. The goal is to prevent meconium aspiration syndrome (MAS) and complications related to MAS. For decades, airway obstruction was believed to be a major component of MAS and, consequently, suction maneuvers to remove meconium from the airways were recommended to decrease the frequency and severity of MAS. Initial recommendations were based on observational studies. However, the incidence of MAS and mortality related to MAS has declined since the 1970s, mostly because of a decrease in the number of postterm deliveries. Recently updated guidelines by the American Heart Association and the Neonatal Resuscitation Program have reflected the strength of evidence supporting tracheal intubation and suctioning for nonvigorous, meconium-stained newborns. This article examines practice change since the 1970s in the delivery room management of meconium-stained newborns and evaluates evidence behind the changes.

Evolution of Delivery Room Management for Meconium-Stained Infants: Recent Updates

BACKGROUND

The approach to intrapartum and postnatal management of an infant born through meconium-stained amniotic fluid (MSAF) in the delivery room (DR) has changed several times over the last few decades, leading to confusion and anxiety among health care providers (nurses, nurse practitioners, respiratory therapists, midwives, and physicians). This article provides state-of-the-art insight into the evidence or lack thereof for the changes in guidelines.

PURPOSE

To discuss the evidence for evolution of DR management of vigorous and nonvigorous infants born through any type of MSAF.

METHODS

Review of guidelines from the Neonatal Resuscitation Program of the American Academy of Pediatrics and the American College of Obstetricians and Gynecologists, the International Liaison Committee on Resuscitation, Consensus on Science and Treatment Recommendations, and textbooks of neonatal resuscitation and research using MEDLINE via PubMed.

FINDINGS

In pregnancies complicated by MSAF, intrapartum suctioning of the oro- and nasopharynx and postnatal intubation with tracheal suctioning of infants have been traditionally used to clear the airway and decrease meconium aspiration syndrome. The recommendations for these perinatal practices have changed several times due to some evidence that the procedures are not beneficial and may even be harmful.

IMPLICATIONS FOR PRACTICE

Intrapartum suctioning and postnatal tracheal suctioning of infants (vigorous or nonvigorous) born through MSAF are not recommended. This is a "high-risk" delivery requiring 2 team members to be present at birth-one with full resuscitation skills including tracheal intubation.

IMPLICATIONS FOR RESEARCH

Need to evaluate effects of discontinuing the practice of tracheal suctioning in nonvigorous infants on the incidence of meconium aspiration syndrome and neonatal mortality.

Effect of Nasal Continuous Positive Airway Pressure on Infants With Meconium Aspiration Syndrome: A Randomized Clinical Trial

IMPORTANCE

Nasal continuous positive airway pressure (NCPAP) as a primary respiratory therapy in meconium aspiration syndrome (MAS) has not been studied extensively. Nasal continuous positive airway pressure, when applied in newborns with MAS, may resolve atelectasis by sufficiently expanding partially obstructed small airways and stabilizing the collapsing terminal airways to enhance oxygen exchange.

OBJECTIVE

To compare NCPAP vs standard care in neonates with moderate to severe respiratory failure due to MAS in reducing the need for invasive ventilation.

DESIGN, SETTINGS, AND PARTICIPANTS

This multicenter open-label, parallel-group (1:1 ratio) randomized clinical trial was conducted from August 5, 2014, to May 26, 2016. Data were collected from 3 tertiary care neonatal intensive care units. All infants admitted with respiratory distress, defined as Downe score greater than 4 and peripheral capillary oxygen saturation less than 90%, were assessed for study eligibility if the chest radiograph was suggestive of MAS and they met the other inclusion criteria: gestation longer than 35 weeks, a birth weight greater than 2000 g, and born through meconium-stained amniotic fluid.

INTERVENTIONS

Infants were randomly assigned to either NCPAP or standard care (5-10 L/min hood oxygen).

MAIN OUTCOMES AND MEASURES

The primary outcome was the need for mechanical ventilation in the first 7 days of life.

RESULTS

After excluding 14 infants, 67 infants were randomized to bubble NCPAP and 68 infants to standard care. Baseline characteristics were similar between the 2 groups. Infants randomized to the bubble NCPAP group needed mechanical ventilation less frequently in the first 7 days of life compared with standard care (2 [3.0%] vs 17 [25.0%]); odds ratio, 0.09; 95% CI, 0.02-0.43; P = .002). The need for surfactant (3 [4.5%] vs 11 [16.2%]; odds ratio, 0.24; 95% CI, 0.05-0.87) and culture-positive sepsis (4 [6.0%] vs 13 [19.0%]; odds ratio, 0.28; 95% CI, 0.09-0.93) were higher in the standard care group. There was an increased duration of oxygen therapy (median [interquartile range], 45.5 [28.0-78.3] vs 26 [20.0-48.0] hours; P = .001) in the standard care group. In the NCPAP group vs standard care group, incidence of persistent pulmonary hypertension (9 [13%] vs 19 [28%]; odds ratio, 0.42; 95% CI, 0.17-1.01) and duration of hospital stay (median [interquartile range], 5.0 [4.0-8.8] vs 4.0 [4.0-6.0] days; P = .14) were similar.

CONCLUSIONS AND RELEVANCE

Bubble NCPAP in comparison with standard care for infants with MAS reduces the need for mechanical ventilation in the first 7 days of life.

TRIAL REGISTRATION

Clinical Trial Registry, India Identifier: CTRI/2015/03/005631.

Activation of Toll-like receptors in meconium aspiration syndrome

OBJECTIVE

Meconium aspiration syndrome (MAS) is a common cause of neonatal morbidity and mortality. Incomplete understanding of the pathogenesis of MAS has hindered the development of specific therapies. We hypothesized that activation of Toll-like receptors (TLRs) might play a role in the pathogenesis of MAS. The present study evaluated the expression of TLR 1, 4, 7, 8 and 9 in neonates with MAS.

STUDY DESIGN

The study included 39 neonates with MAS and 17 healthy gestational age-matched neonates as controls. Neonates with maternal chorioamnionitis, perinatal asphyxia, sepsis and congenital malformations were excluded. Good-quality total RNA from umbilical cord blood was reverse transcribed to prepare cDNA using Bio-Rad reverse transcription kit. This cDNA was used to study the expression status of TLR 1, 4, 7, 8 and 9 by real-time quantitative polymerase chain reaction.

RESULTS

Compared with controls, TLR1 and TLR4 were highly expressed, TLR9 was moderately expressed, TLR7 was weakly expressed and TLR8 expression was neutral in neonates with MAS. Within the MAS group, no difference in TLR expression was observed with respect to consistency of meconium, severity of the disease, oxygenation index and outcome.

CONCLUSION

There is activation of TLRs in neonates with MAS. We speculate that these TLRs probably act as endogenous ligands for various components of meconium that initiate the inflammatory cascade of MAS and contribute to its pathogenesis.

Clinico-radiological Observations in Meconium Aspiration Syndrome

INTRODUCTION

To understand and report the prevalence of meconium aspiration syndrome and the clinico-radiological features in a tertiary care hospital of western Nepal.

METHODS

An observational study carried out for a year in 2014-15 in all babies with MAS. Clinical and radiological profiles of MAS in relation to gender, gestational age, mode of delivery, birth weight, Apgar score, thickness of meconium, age at admission and the immediate outcome were studied.

RESULTS

Out of 584 admitted newborns (male=389; female=186) during the study period, 78 (13.4%) had meconium aspiration syndrome with male: female ratio of 1.2:1. Majority of babies admitted to NICU had thick meconium [n=52 (66.7%)]. There was no statistical significant difference in various parameters such as Apgar score at 1 and 5 minutes, respiratory distress, birth asphyxia, duration of oxygen use, MAS severity and chest x-ray in those with thick MAS compared to thin. Among all newborns with MAS, 59% (n=46) had abnormal radiological findings with over two-folds in those with thick MAS (71.7%)] compared to thin (28%). Hyperinflation (47.8%), diffuse patchy infiltration (37%), consolidation (21.7%) collapse (8.7%), right lung fissure (6.5%) and pneumothorax (8.7%) were the abnormal radiological findings seen in MAS babies. The odds of having APGAR score at 1 minute at least 7 or more was twice unlikely in those having thick meconium compared to thin (P=0.02) Conclusions: Thick meconium is relatively common with more significant abnormal radiological findings and low Apgar score.

Meconium "aspiration" (or respiratory distress associated with meconium-stained amniotic fluid?)

The designation meconium aspiration syndrome (MAS) reflects a spectrum of disorders in infants born with meconium-stained amniotic fluid, ranging from mild tachypnea to severe respiratory distress and significant mortality. The frequency of MAS is highest among infants with post-term gestation, thick meconium, and birth asphyxia. Pulmonary hypertension is an important component in severe cases. Prenatal hypopharyngeal suctioning and postnatal endotracheal intubation and suctioning of vigorous infants are not effective. Intubation and suctioning of non-breathing infants is controversial and needs more investigation. Oxygen, mechanical ventilation, and inhaled nitric oxide are the mainstays of treatment. Surfactant is often used in infants with severe parenchymal involvement. High-frequency ventilation and extracorporeal membrane oxygenation are usually considered rescue therapies.

Ethics of Informed Consent for Pragmatic Trials with New Interventions

OBJECTIVES

Pragmatic trials evaluate the comparative benefits, risks, and burdens of health care interventions in real-world conditions. Such studies are now recognized as valuable to the perimarketing stage of drug development and evaluation, with early pragmatic trials (EPTs) being explored as a means to generate real-world evidence at the time of regulatory market approval. In this article, we present an analysis of the ethical issues involved in informed consent for EPTs, in light of the generally recognized concern that traditional ethical rules governing randomized clinical trials, such as lengthy informed consent procedures, could threaten the "real world" nature of such trials. Specifically, we examine to what extent modifications (waivers or alterations) to regulatory consent for EPTs would be ethical.

METHODS

We first identify broadly accepted necessary conditions for modifications of informed consent (namely, the research involves no more than minimal risk of harm, the research is impracticable with regulatory consent, and the alternative to regulatory consent does not violate legitimate patient expectations) and then apply those criteria to the premarket and early postmarket contexts.

RESULTS AND CONCLUSIONS

The analysis shows that neither waivers nor alterations of regulatory consent for premarket EPTs will be ethically permissible. For postmarket EPTs with newly approved interventions, waivers of consent will be ethically problematic, but some studies might be conducted in an ethical manner with alterations to regulatory consent.

Antibiotics for neonates born through meconium-stained amniotic fluid

BACKGROUND

Approximately 1 in 10 pregnancies is affected by meconium passage at delivery, which can result in meconium aspiration syndrome (MAS). MAS can cause respiratory complications and, very rarely, death. Antibiotics have been prescribed for neonates exposed to meconium in amniotic fluid, with the intention of preventing infection due to potential bacterial contaminants.

OBJECTIVES

We conducted this review to assess the efficacy and safety of antibiotics for:1. prevention of infection, morbidity, and mortality among infants born through meconium-stained amniotic fluid (MSAF) who are asymptomatic at birth; and2. prevention of infection, morbidity, and mortality among infants born through MSAF who have signs and symptoms compatible with meconium aspiration syndrome (MAS).

SEARCH METHODS

We performed a literature search using the following databases: MEDLINE (1966 to July 2016); Embase (1980 to July 2016); the Cumulative Index to Nursing and Allied Health Literature (CINAHL; 1982 to July 2016); and the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 7) in the Cochrane Library. We also searched clinical trials databases, conference proceedings, and reference lists of retrieved articles.

SELECTION CRITERIA

We included randomised and quasi-randomised controlled trials that compared antibiotics administered via any route versus placebo or no treatment for prevention of infection among neonates exposed to MSAF, or who developed MAS. We excluded cohort, case control, and any other non-randomised studies and applied no language restrictions. We included studies of term and preterm infants, and we included studies examining use of any antibacterial antibiotics. We included studies that reported on any outcomes of interest.

DATA COLLECTION AND ANALYSIS

We assessed the methodological quality of included trials by reviewing information provided in study reports and obtained by personal communication with study authors. We extracted data on relevant outcomes, estimated effect size, and reported values as risk ratios (RRs), risk differences (RDs), and mean differences (MDs), as appropriate. We conducted subgroup analyses for treatment of MAS and for prophylaxis (asymptomatic neonates exposed to meconium).

MAIN RESULTS

Four randomised controlled studies including a total of 695 participants were eligible for inclusion. Three studies evaluated neonates with MAS, and one study assessed asymptomatic neonates exposed to meconium in amniotic fluid. These studies exhibited varying degrees of methodological rigour: Two studies were at low risk of bias, and two were at unclear risk. We graded evidence derived from these studies as low quality. We downgraded overall evidence owing to the large number of participants lost to follow-up in one trial, the small sample sizes of all trials, and unclear methodological details provided for two trials.The primary outcome was risk of early- and late-onset neonatal sepsis. Antibiotics did not decrease the risk of sepsis in neonates with a diagnosis of MAS (RR 1.54, 95% confidence interval (CI) 0.27 to 8.96; RD 0.00, 95% CI -0.02 to 0.03; 445 participants, three studies; I² = 0%) nor in asymptomatic neonates exposed to meconium in amniotic fluid (RR 0.76, 95% CI 0.25 to 2.34; RD -0.01, 95% CI -0.07 to 0.04; 250 participants, one study; I² = 0%). Results show no significant differences in mortality or duration of stay in hospital between groups given antibiotics and control groups of symptomatic and asymptomatic neonates. One study in asymptomatic neonates reported a significant reduction in duration of mechanical ventilation for the control group compared with the antibiotic group (MD 0.26, 95% CI 0.15 to 0.37; 250 participants, one study; I² = 0%).

AUTHORS' CONCLUSIONS

Upon review of available evidence, we found no differences in infection rates following antibiotic treatment among neonates born through meconium-stained fluid and those with meconium aspiration syndrome. The overall quality of evidence is low owing to the small number of included studies. Well-controlled studies of adequate power are needed.

To Drain or Not to Drain Infraperitoneal Anastomosis After Rectal Excision for Cancer: The GRECCAR 5 Randomized Trial

OBJECTIVE

To assess the effect of pelvic drainage after rectal surgery for cancer.

BACKGROUND

Pelvic sepsis is one of the major complications after rectal excision for rectal cancer. Although many studies have confirmed infectiveness of drainage after colectomy, there is still a controversy after rectal surgery.

METHODS

This multicenter randomized trial with 2 parallel arms (drain vs no drain) was performed between 2011 and 2014. Primary endpoint was postoperative pelvic sepsis within 30 postoperative days, including anastomotic leakage, pelvic abscess, and peritonitis. Secondary endpoints were overall morbidity and mortality, rate of reoperation, length of hospital stay, and rate of stoma closure at 6 months.

RESULTS

A total of 494 patients were randomized, 25 did not meet the criteria and 469 were analyzed: 236 with drain and 233 without. The anastomotic height was 3.5 ± 1.9 cm from the anal verge. The rate of pelvic sepsis was 17.1% (80/469) and was similar between drain and no drain: 16.1% versus 18.0% (P = 0.58). There was no difference of surgical morbidity (18.7% vs 25.3%; P = 0.83), rate of reoperation (16.6% vs 21.0%; P = 0.22), length of hospital stay (12.2 vs 12.2; P = 0.99) and rate of stoma closure (80.1% vs 77.3%; P = 0.53) between groups. Absence of colonic pouch was the only independent factor of pelvic sepsis (odds ratio = 1.757; 95% confidence interval 1.078-2.864; P = 0.024).

CONCLUSIONS

This randomized trial suggests that the use of a pelvic drain after rectal excision for rectal cancer did not confer any benefit to the patient.

Routine oro/nasopharyngeal suction versus no suction at birth

BACKGROUND

Oro/nasopharyngeal suction is a method used to clear secretions from the oropharynx and nasopharynx through the application of negative pressure via a suction catheter or bulb syringe. Traditionally, airway oro/nasopharyngeal suction at birth has been used routinely to remove fluid rapidly from the oropharynx and nasopharynx in vigorous and non-vigorous infants at birth. Concerns relating to the reported adverse effects of oro/nasopharyngeal suctioning led to a practice review and routine oro/nasopharyngeal suctioning is no longer recommended for vigorous infants. However, it is important to know whether there is any clear benefit or harm for infants whose oro/nasopharyngeal airway is suctioned compared to infants who are not suctioned.

OBJECTIVES

To evaluate the effect of routine oropharyngeal/nasopharyngeal suction compared to no suction on mortality and morbidity in newly born infants.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review group to search the Cochrane Central Register of Controlled Trials (CENTRAL 2016, Issue 3), MEDLINE via PubMed (1966 to April 18, 2016), Embase (1980 to April 18, 2016), and CINAHL (1982 to April 18, 2016). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

Randomised, quasi-randomised controlled trials and cluster randomised trials that evaluated the effect of routine oropharyngeal/nasopharyngeal suction compared to no suction on mortality and morbidity in newly born infants with and without meconium-stained amniotic fluid.

DATA COLLECTION AND ANALYSIS

The review authors extracted from the reports of the clinical trials, data regarding clinical outcomes including mortality, need for resuscitation, admission to neonatal intensive care, five minute Apgar score, episodes of apnoea and length of hospital stay.

MAIN RESULTS

Eight randomised controlled trials met the inclusion criteria and only included term infants (n = 4011). Five studies included infants with no fetal distress and clear amniotic fluid, one large study included vigorous infants with clear or meconium-stained amniotic fluid, and two large studies included infants with thin or thick meconium-stained amniotic fluid. Overall, there was no statistical difference between oro/nasopharyngeal suction and no oro/nasopharyngeal suction for all reported outcomes: mortality (typical RR 2.29, 95% CI 0.94 to 5.53; typical RD 0.01, 95% CI -0.00 to 0.01; I² = 0%, studies = 2, participants = 3023), need for resuscitation (typical RR 0.85, 95% CI 0.69 to 1.06; typical RD -0.01, 95% CI -0.03 to 0.00; I² = 0%, studies = 5, participants = 3791), admission to NICU (typical RR 0.82, 95% CI 0.62 to 1.08; typical RD -0.03, 95% CI -0.08 to 0.01; I² = 27%, studies = 2, participants = 997) and Apgar scores at five minutes (MD -0.03, 95% CI -0.08 to 0.02; I² not estimated, studies = 3, participants = 330).

AUTHORS' CONCLUSIONS

The currently available evidence does not support or refute the benefits or harms of routine oro/nasopharyngeal suction over no suction. Further high-quality studies are required in preterm infants or term newborn infants with thick meconium amniotic fluid. Studies should investigate long-term effects such as neurodevelopmental outcomes.

Genetic Testing for Obesity: Implications and Challenges

PURPOSE OF REVIEW

This review summarizes the experimental literature on behavioral outcomes and psychological effects of genetic testing for obesity. Such tests, although of dubious value, are increasingly marketed to the public, and there has been concern that while results may encourage some consumers to increase the healthfulness of their lifestyles, others may interpret feedback in maladaptive ways.

RECENT FINDINGS

Hypothetical vignettes have been used in artificial settings; few studies have investigated outcomes of actual test results. At present, the effects of genetic testing for obesity seem limited to improving consumers' weight control intentions and motivation rather than actual dietary behavior. Evidence for negative psychological consequences is scarce and seems of greater concern for normal weight persons than for those who are overweight. Better research designs carried out in the field rather than the laboratory with more diverse samples are needed.

Chronic Constipation in Overweight Children

BACKGROUND

Obesity and functional constipation seem to share a common biopsychosocial model of causation. Though chronic constipation can significantly affect the quality of life of an overweight child, this association has not been highlighted in the literature. The purpose of this study was to compare the proportion of overweight children among children with chronic constipation with a control group of children with normal bowel habits.

METHODS

Retrospective chart review with a control population. One hundred one consecutive children 5-18 years of age referred to the Subspecialty Clinic for functional constipation were the study group. The control group consisted of 100 consecutive children from the general pediatric practice seen for physicals and minor illnesses. Children with a body mass index (BMI) of >85 percentile from the National Institutes of Health (NIH) 2000 chart were classified as overweight.

RESULTS

The control and study groups were statistically comparable in mean age (10.97 +/- 3.83 years and 8.07 +/- 2.56 years, respectively) and gender ratio (58 males in each group). Thirty children in the control group and 44 in the study population were overweight (p < .05). Among children with chronic constipation, the group of overweight children was male predominant (70.45% vs 47.36%, p < .05), had increased incidence of psychological/behavioral problems (45.45% vs 22.8%, p < .05), and was more likely to fail treatment (40.9% vs 21.05%, p < .05). There was no significant difference in the clinical profile of constipation, such as mean duration of constipation before presentation, sex ratio, incidence of painful defecation, and soiling and frequency of defecation between these 2 groups.

CONCLUSIONS

There appears to be an association between chronic severe constipation and being overweight. Children with constipation are more likely to be overweight when compared with controls. Among children with chronic constipation, overweight individuals seem to constitute a distinct clinical group. This group is male predominant, has increased incidence of psychological/behavioral disorders, and is more likely to fail treatment.

Waiver of Consent in a Trial Intervention Occurring at Birth-How Do Parents Feel?

BACKGROUND

We have previously demonstrated that it is difficult to obtain a representative subject sample when conducting a randomized controlled trial (RCT) at or near the time of birth and obtaining antenatal consent. Waiver of consent has been used in neonatal trials, but parents' reactions to being enrolled in these trials have never been reported.

METHODS

The parents enrolled in a RCT involving a waiver of consent with a post-delivery discussion were asked to take part in a brief survey. The survey questions included the timing of when parents were informed about the study, and how they felt about their infants being included in the study.

RESULTS

Forty-nine parents completed the online survey. Sixty-nine percent (n = 34) remembered a physician discussing their premature baby with them prior to delivery. Thirty-four percent (17) indicated the physician had discussed participation in the study prior to delivery. Sixty-nine percent (34) indicated that they had a positive or strongly positive feeling about the studies impact on their baby's health.

CONCLUSION

Our study demonstrates that the majority of responding parents of infants who have actually participated in a RCT with a waiver of consent process had a positive response, a minority had a neutral response, and none had a slightly negative or highly negative response to participation in the study.

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.