Outcome of Neonates with Meconium Aspiration Syndrome on High Frequency Oscillatory Ventilation in NICU of Tertiary Care Centre

Background: Meconium Aspiration Syndrome (MAS) is a complex respiratory disease of the term and near-term neonate. Inhalation of meconium causes airway obstruction, atelectasis, epithelial injury, surfactant inhibition and pulmonary hypertension, the chief clinical manifestations of which are hypoxemia and poor lung compliance. Supplemental oxygen is the mainstay of therapy of MAS, with around one-third of infants requiring mechanical ventilation. For those ventilated, high ventilator pressures, as well as relatively long inspiratory time and slow ventilatory rate, may be necessary to achieve adequate oxygenation. High frequency ventilation may offer a benefit in infants with refractory hypoxemia and/or gas trapping. High-frequency oscillatory ventilation (HFOV) is a lung-protective strategy that can be utilized in the full spectrum of patient populations ranging from neonatal to adults with acute lung injury. HFOV uses low tidal volumes and constant mean airway pressures in conjunction with high respiratory rates to provide beneficial effects on oxygenation and ventilation, while eliminating the traumatic “inflate–deflate” cycle imposed by CV. Few studies have shown that, HFOV can effectively improve lung ventilation and oxygenation function, shorten ventilator treatment time and reduce the incidence of air leakage for neonatal MAS, making it a safe and effective treatment method. Objective:To study the Outcome of Neonates with Meconium Aspiration Syndrome on High Frequency Oscillatory Ventilation (HFVO).Material & Methods:It is a Prospective Observational Study of 10 neonates >34 weeks of gestation and birth weight >1500gm with meconium-stained liquor with respiratory distress requiring mechanical ventilation. Study was conducted over a period of 10months from August 2021 to May 2022. These neonates requiring mechanical ventilation were electively first hand put on SensorMedics 3100A High Frequency Oscillatory Ventilator after taking informed written consent from parents and given appropriate Intensive care. Data was analyzed at the end of the study duration and looked for outcome in the form of successful weaning from mechanical ventilation and discharge from NICU, and Death.Results:8 out of 10 (80%) neonates with MAS that were ventilated via HFOV were successfully weaned from mechanical ventilation and discharged, while death was reported in 2 out of 10 (20%) of the neonates included in the study.Conclusion:80% of neonates with MAS that were provided mechanical ventilation in the form of HFOV were effectively weaned off from mechanical ventilation, whereas 20% neonates died. This shows clinical effectiveness of HFOV in MAS making it a safe and effective treatment modality in neonates with MAS.

A STUDY ON FETO-MATERNAL OUTCOME IN A POSTDATED PREGNANCY

BACKGROUND: The objective of the study is to find out the fetal and maternal complications in post dated pregnancy. This is a prospective observational study. METHODS: Patients who have completed 40weeks of gestational age, meeting the inclusion criteria. RESULTS: Of 100 cases 74(74%) cases were under 20 to 25 years, majority cases were primigravida (66%), overall caesarean rate was 36%, Meconium-stained liquor with fetal distress was the most common indication for LSCS 9(25 %). Fetal distress was the most common fetal complications, number of induced labor is 71.4% at 41 weeks 1 day to 42 weeks CONCLUSION: In our study we concluded that prolonged pregnancy was associated with significant risk of perinatal complications like fetal distress, meconium aspiration syndrome and IUGR. There was significantly increased risk of obstetric complications like oligohydramnios, perineal tear, atonic PPH and shoulder dystocia.

Clinical features of severe meconium aspiration syndrome (MAS) and early predicting factors for severe MAS in neonates with meconium-stained amniotic fluid / 中国当代儿科杂志

OBJECTIVES@#To study the clinical features of severe meconium aspiration syndrome (MAS) and early predicting factors for the development of severe MAS in neonates with meconium-stained amniotic fluid (MSAF).@*METHODS@#A total of 295 neonates who were hospitalized due to Ⅲ° MSAF from January 2018 to December 2019 were enrolled as subjects. The neonates were classified to a non-MAS group (n=199), a mild/moderate MAS group (n=77), and a severe MAS group (n=19). A retrospective analysis was performed for general clinical data, blood gas parameters, infection indicators, and perinatal clinical data of the mother. The respiratory support regimens after birth were compared among the three groups. The receiver operating characteristic (ROC) curve and multivariate logistic regression analysis were used to investigate predicting factors for the development of severe MAS in neonates with MSAF.@*RESULTS@#Among the 295 neonates with MSAF, 32.5% (96/295) experienced MAS, among whom 20% (19/96) had severe MAS. Compared with the mild/moderate MAS group and the non-MAS group, the severe MAS group had a significantly lower 5-minute Apgar score (P<0.05) and a significantly higher blood lactate level in the umbilical artery (P<0.05). Compared with the non-MAS group, the severe MAS group had a significantly higher level of interleukin-6 (IL-6) in peripheral blood at 1 hour after birth (P<0.017). In the severe MAS group, 79% (15/19) of the neonates were born inactive, among whom 13 underwent meconium suctioning, and 100% of the neonates started to receive mechanical ventilation within 24 hours. Peripheral blood IL-6 >39.02 pg/mL and white blood cell count (WBC) >30.345×109/L at 1 hour after birth were early predicting indicators for severe MAS in neonates with MSAF (P<0.05).@*CONCLUSIONS@#Meconium suctioning cannot completely prevent the onset of severe MAS in neonates with MSAF. The neonates with severe MAS may develop severe respiratory distress and require mechanical ventilation early after birth. Close monitoring of blood lactate in the umbilical artery and peripheral blood IL-6 and WBC at 1 hour after birth may help with early prediction of the development and severity of MAS.

Síndrome de aspiración meconial: revisión de la fisiopatología y estrategias de manejo / Meconium aspiration syndrome: review of the pathophysiology and management strategies

El síndrome de aspiración meconial, es una condición clínica caracterizada por insuficiencia respiratoria que ocurre en neonatos nacidos a través de líquido amniótico teñido de meconio, y que puede presentarse como una enfermedad grave con riesgo vital. Su incidencia ha disminuido gracias a mejores prácticas obstétricas y atención perinatal y se ha observado una mejoría en la sobrevida, gracias a mejores prácticas en la UCI neonatal. Sin embargo, el abordaje más adecuado sigue siendo un tema de debate, dado que hasta el momento se basa sólo en medidas de soporte, sin que existan medidas que actúen sobre los mecanismos de daño. Por otro lado, la morbilidad a largo plazo entre los sobrevivientes sigue siendo una preocupación importante. Esta revisión ofrece una visión general actualizada de la epidemiología, la fisiopatología, el diagnóstico, el manejo terapéutico, la prevención y el pronóstico de los pacientes que presentan este cuadro.

Meconium aspiration syndrome is a clinical condition characterized by respiratory failure that occurs in neonates born through meconium-stained amniotic fluid and can present as a serious life-threatening disease. Its incidence has decreased thanks to better obstetric practices and perinatal care, and an improvement in survival has been observed, thanks to better practices in the neonatal ICU. However, the most appropriate approach is still a matter of debate, given that so far it is based only on support measures, without any measures that act on the damage mechanisms. On the other hand, long-term morbidity among survivors remains a major concern. This review offers an updated overview of the epidemiology, pathophysiology, diagnosis, therapeutic management, prevention, and prognosis of patients with this condition.

Study of early perinatal outcome in lower segment caesarean section in severe foetal distress at tertiary care centre

Background: For asphyxia, the fetus reacts with a series of responses. First there is redistribution of blood flow to vital centres to limit the deleterious effects of oxygen limitation in the brain, heart and adrenal glands. A further compensatory response is that overall fetal oxygen consumption declines to values as low as 50% of the control.Methods: This was a prospective study. Early perinatal outcome of newborns delivered through Caesarean section due to clinical foetal distress in labour was compared with a group of newborns similarly delivered via Caesarean section without a diagnosis of clinical foetal distress. Data collected and analysed using appropriate standard statistical methods i.e. Chi-square (X2) test and ‘Z’ - test.Results: Most common indication for NICU admission in study group was MAS (Meconium Aspiration Syndrome 14%) followed by MAS with perinatal asphyxia (5.33%), MAS with Hypoxic ischaemic encephalopathy (HIE) - stage III (3.33%) paerintal asphyxia (2.66%), severe PNA with HIE - III (0.66%) and TTN (0.66%) meconium gastritis (0.66%) respectively.Conclusions: Clinical foetal distress (study group) was found to be significantly associated with low 1 min and 5 min. Apgar score. There was no significant difference in immediate NICU admission whether D-D (i.e. detection fetal detection to delivery interval) time interval <30 minutes or >30 minutes. But rate of mortality was high when D-D (i.e. detection fetal detection to delivery interval) was >30 minutes.

Comparative analysis of maternal and fetal outcome in meconium stained amniotic fluid and clear liquor in primigravida

Background: The present study was undertaken to evaluate the significance of MSAF and its fetal outcome in parturients.Methods: A total of 121 pregnant women who had completed more than 37 weeks of gestation with live singleton pregnancy, spontaneous onset of labor and at term with adequate pelvis were included in the study. All (121) low risk primigravida with MSAF were studied to identify maternal and fetal outcome and compared with equal number of cases with clear amniotic fluid. Meconium stained cases were clinically classified into two groups- thin (54 cases) and thick (67 cases). MSAF on spontaneous or artificial rupture of membranes were monitored with fetal heart rate abnormality, 1- and 5-minutes Apgar score, NICU admissions and neonatal complications as outcome variables.Results: Overall incidence of meconium staining of AF during labour was 7.71%. The common fetal heart rate abnormalities i.e. bradycardia was seen in 36% in MSG. Apgar score of less than 7 was observed in MSG at 5 minutes in 5% of cases, in thick group. Major neonatal complication was birth asphyxia in MSG (18.18%) that was more in thick MSG (14.87%). MAS were observed in 6 cases in thick and 4 cases in thin meconium stained cases. NICU care was required in 18% cases in MSG and in control group it was required in 7% cases. Neonatal morbidity was more in newborn with thick meconium group (52%) compared to thin meconium group (20%).Conclusions: The present study confirmed that meconium staining of amniotic fluid adversely influences the fetal outcome.

A study on clinical profile of meconium aspiration syndrome in relation to gestational age and birth weight and their immediate outcome

Background: Aim of the study was to understand the factors causing meconium aspiration syndrome (MAS) in relation to gestational age and birth weight and their immediate outcome.Methods: This study was done on babies admitted in the neonatal intensive care unit (NICU) of Thanjavur medical college hospital, who fulfilled the criteria of MAS. Babies born with meconium stained amniotic fluid (MSAF), were resuscitated as per NRP guidelines. The babies with complications of MAS were admitted to NICU and were observed for their immediate outcome in the hospital.Results: MAS occurred most commonly in babies having fetal distress and in mothers with history of PIH. It is seen more commonly in babies born through caesarean section and in term babies with mean gestational age of 38-40 weeks of gestation and mean birth weight of 2.71 kg. Most babies were depressed at birth and most common cause of mortality was hypoxic ischemic encephalopathy (HIE stage III), significantly contributing 37.5% of cases of MAS. There was significant and strong association between the birth weight and mortality. Thick MSAF was significantly associated with need for mechanical ventilation and subsequently higher mortality. Babies born through caesarean section with MAS also had significantly poor outcome.Conclusions: MAS is an entity which is commonly seen in term and post term babies with birth weight >2.5 kg. There is a significant correlation between the birth weight and outcome in MAS. When thick meconium stained liquor is noted prior to birth, anticipation is necessary and non vigorous babies need aggressive management and possibly early ventilation. Asphyxiated babies should be followed up astutely. Continuous monitoring and early intervention, followed by due resuscitation as per guidelines can reduce the morbidity, complications and the mortality in MAS.

Meconium aspiration syndrome and neonatal outcome: a hospital based study

Background: The incidence of meconium stained amniotic fluid is 8-20% among all deliveries. The Aspiration of meconium into the airway results in various short term and long term morbidities and mortality. Timely management of these neonates with meconium in amniotic fluid may prevent Meconium aspiration syndrome.Methods: This prospective cohort study was conducted at Kempegowda Institute of Medical Sciences, Bangalore. All live Term neonates born between December 2016 and July 2018 with meconium in amniotic fluid were enrolled in the study. Details of the neonate was entered in the pre-designed Proforma. The objective of this study the outcome of MAS neonates and find factors associated with Meconium aspiration syndrome when compared with Meconium stained amniotic fluid neonates as a whole. These associated factors were presented as Odds Ratio (OR) and 95% Confidence Interval. Chi-square test was done where applicable and a p-value <0.05 was taken as significant.Results: Meconium aspiration syndrome was seen in 79 out of the 188 neonates born with meconium stained amniotic fluid.Conclusions: The morbidity and mortality in a neonate with Meconium stained amniotic fluid (MSAF) to develop meconium aspiration syndrome (MAS) can be avoided with timely antenatal care. Meconium-stained babies should be aggressively managed to prevent complications like perinatal asphyxia and respiratory failure which may lead to the mortality. Those neonates with risk for adverse outcome should be managed with special focus on respiratory care with use of assisted ventilation and inhaled nitric oxide and extracorporeal membrane oxygenation, where available.

Study of respiratory complications and outcome in meconium stained deliveries

Background: To study the development of respiratory complications in the form of meconium aspiration syndrome (MAS), persistent pulmonary hypertension of newborn (PPHN), pulmonary hemorrhage and pneumothorax in neonates born through meconium stained liquor.Methods: It was a prospective study conducted during the period of February to October 2018. All live babies associated with meconium stained liquor were included.Results: Total 606 neonates with meconium stained amniotic fluid (MSAF) were enrolled. Chance of meconium passage was more after 37wk of gestation, in birth weight >2.5 kg and in AGA babies. The rate of LSCS was higher in MSAF group. MAS developed in 28% cases, out of which 42.9% expired. PPHN developed in 6.9% cases, out of which 80% expired. 100% mortality was there in babies with pulmonary hemorrhage. Apgar scores <7 is significantly associated with the development of respiratory complications. 22.8% of vigorous babies and all non-vigorous babies developed respiratory complications showing statistical significance with P-value of <0.00001. Mortality in MSAF was 12%. All babies who expired had severe meconium aspiration syndrome. 83.9% of the patients stayed for <7 days in the hospital. All of the expiry except one occurred within 7 days of life due to development of respiratory complications.Conclusions: MSAF is associated with the development of respiratory complications and mortality in neonates. Non-vigorous babies and the babies with Apgar scores <7 at birth are more prone to developing respiratory complications. Most of the MSAF babies were discharged and mortality was more in patients with respiratory complications.

Study on etiological profile of respiratory distress in new borns in a teaching hospital

Background: The aim is to study the various risk factors associated with development of severe respiratory distress in the new born.Methods: This was a prospective study of 200 new-borns with respiratory distress. Clinical details, etiology for the respiratory distress, system-wise factors responsible for the distress, severity and duration of respiratory distress, oxygen therapy, type of treatment, mortality, maternal and antenatal risk factors, radiological findings were noted in all the cases and were analysed.Results: Of the 200 cases with respiratory distress, 118 (59%) had severe respiratory distress. 154 cases with distress were of respiratory system in origin out of which 45% (70 out of 154) were due to Meconium aspiration syndrome, 42% (64 out of 154) were due to Respiratory distress syndrome, 12% (18 out of 154) were due to transient tachypnea of new-born and 2% were due to congenital pneumonia. More number of female patients had severe respiratory distress. Mortality was 2.5%.Conclusions: Meconium aspiration syndrome is the most common cause of respiratory distress in new born. Almost 60% of new borns with respiratory distress developed severe respiratory distress who required intensive monitoring. Risk factors like meconium stained liquor, vaginal delivered new borns, preterm gestation age, and female gender of new born were associated with severe respiratory distress in new borns.

Meconium-stained amniotic fluid as a risk factor for perinatal asphyxia

Background: The aim of this study was to find out immediate fetal outcome in meconium-stained amniotic fluid in relation to perinatal asphyxia.Methods: This retrospective study includes medical records of all neonates admitted to Neonatal Intensive Care Unit (NICU) between December 2016 and July 2018. The variables reviewed are age, sex, weight, mode of delivery, gestational age, presence of meconium aspiration syndrome (MAS) and perinatal asphyxia.Results: Out of 408 total admissions in NICU, 69.1% were male babies and remaining 30.9% were female babies. In the study out of 36 subjects with Perinatal Asphyxia, 38.9% had MAS and 61.1% had not MAS. Out of 372 subjects without perinatal asphyxia, 93.8% had no MAS and 6.2% had MAS. There was significant association between MAS and perinatal asphyxia. Odds ratio was 9.656. i.e. those with MAS had 9.656 times higher risk for perinatal asphyxia.Conclusions: The management of MAS, which is a perinatal problem, requires a well concerted and coordinated action by the obstetrician and pediatrician. Prompt and efficient delivery room management can minimize the sequelae of aspirated meconium and decrease the chance of perinatal asphyxia in the new born babies.

Role of Intrapartum Transcervical Amnioinfusion in Meconium Stained Liquor

Background: Pregnancy is associated with several risks toboth mother and fetus. Meconium staining of amniotic fluid isone of the important risk factors associated with neonatalmortality. Thus the aim of this study was to assess theeffectiveness of amnioinfusion in treatment of thick meconiumstained amniotic fluid and compare the results with controlgroup.Materials and Methods: It was a prospective case controlstudy conducted from October 2015 to September 2017, in thedepartment of Obstetrics and Gynaecology, at Indira GandhiInstitute of Medical Sciences (IGIMS), Patna. We included 100cases of thick meconium complicated deliveries. The patientswere categorized as study group who received amnioinfusionand control group who received standard treatment. Eachgroup contained 50 patients.Results: We found that the need for caesarean section waslow in study group. The Apgar score also effectively improvedin the study group compared to the control group at 1 minute, 5minute and 10 minutes interval. Amnioinfusion reduced theincidence of meconium below the vocal cord and meconiumaspiration syndrome. There was also reduction in admission ofinfants to NICU in those cases who received amnioinfusioncompared to control groups.Conclusion: We concluded that transcervical amnioinfusion issimple and effective method that aids in improvement ofperinatal outcomes of those cases complicated with thickmeconium.

Meconium aspiration syndrome: clinical profile, risk factors and outcome in central India

Background: Meconium aspiration syndrome (MAS) is a life-threatening respiratory disease affecting some neonates born through meconium-stained amniotic fluid (MSAF). MSAF complicates delivery in approximately 8% to 25% of live births, of which nearly 5% of the neonates born through MSAF develop MAS. The present study was undertaken to find out the prevalence of MSAF and MAS and to study the etiology, risk factors, clinical profile and outcome of MAS.Methods: By purposive sampling technique, all newborns, fulfilling the inclusion criteria during one year of study period were enrolled in this hospital based cross-sectional observational study. Risk factors and clinical profile were compared between those who died and survived.Results: Out of 8765 deliveries in hospital 1220 neonates were born with MSAF of which 94 neonates had MAS. Thereby, incidence of MSAF was 13.9% and incidence of MAS out of MSAF was 7.7 %. Of the 94 neonates who had MAS 13.82% died. Almost 3/4th of the MAS neonates were term and AGA. MAS were more common in primigravida mother (68%) and LSCS deliveries (53.2%). Of the total MAS 54.2% had thick meconium in whom mortality was 92.3%. The mortality in MAS cases was significant in low 5-minute APGAR score and non-vigorous baby.Conclusions: Since MSAF is associated with higher morbidity and mortality, if the knowledge of risk factors is known to health care personnel then timely referral or intervention can help in decreasing MAS and its complications.

Empirical Antibiotics in Non-Ventilated Cases of Meconium Aspiration Syndrome

PURPOSE: Meconium aspiration is assumed to be a risk factor for bacterial infection, and patients with meconium aspiration syndrome (MAS) are commonly treated with empiric antibiotics in clinical settings. However, little is known about the effectiveness of the empirical antibiotics treatment. Here, we compared the short-term clinical outcomes associated with empirical antibiotics treatment in non-ventilated cases of MAS. METHODS: A retrospective study was conducted on infants admitted with non-ventilated cases of MAS from March 2008 to September 2016. The infants enrolled in the study were divided into two groups based on the antibiotics treatment, and their clinical outcomes were compared. The incidence of sepsis during the hospitalization period and the incidence of delayed sepsis up to 3 months were evaluated. The effects of empirical antibiotic use on respiratory symptoms were evaluated, and the complications were compared. RESULTS: A total of 109 infants were evaluated, of which 61 (56.0%) received antibiotics and 48 (44.0%) did not receive antibiotics. No differences in clinical characteristics were noted between the two groups. However, the empirical antibiotics group showed a significantly higher mean of respiratory rates, C-reactive protein levels, and positive rates, as well as a significantly longer hospitalization period. In clinical outcomes, there were no differences in sepsis rates or respiratory support duration. Furthermore, there were no differences in complications. CONCLUSION: The empirical use of antibiotics did not affect the clinical outcomes in cases of non-ventilated MAS. The role of empirical antibiotics in these infants may need to be reevaluated.

Lung ultrasonography for the diagnosis and monitoring of neonatal meconium aspiration syndrome / 中国小儿急救医学

Neonatal meconium aspiration syndrome( MAS) is a common critical disease and one of the main risk factors leading to death in newborns. MAS was diagnosed mainly by chest X-ray in the past,but can now easily be diagnosed with lung ultrasound. It can reflect the degree of pathological changes in different parts of the lung through multi-angle scanning,and has many advantages over X-ray including accuracy,relia-bility,low-cost and simplicity,as well as the fact that ultrasound incurs no risk of radiation damage. It is therefore feasible and convenient to perform at the bedside in a neonatal ward. This paper summarized the sonographic characteristics of MAS,and introduced other applications of lung ultrasonography in the clinical treatment of MAS.

Effect of different partial pressure of oxygen on the clinical outcome of pulmonary hypertension induced by meconium aspiration syndrome / 中国小儿急救医学

Objective To study the role of partial pressure of oxygen in the treatment of pulmonary hypertension induced by meconium aspiration syndrome. Methods Retrospective analysis was performed on 58 patients with meconium aspirate and pulmonary hypertension from January 1,2007 to December 31,2016, 28 patients in the death group,and 30 patients in the survival group. Blood gas analysis about two groups of children with mechanical ventilation were collected at four different time points:before mechanical ventilation ( 0 h) ,12 hours after mechanical ventilation,24 hours after mechanical ventilation and 72 hours after mechan-ical ventilation. The 80 mmHg(1 mmHg=0. 133 kPa) in blood gas analysis of the partial pressure of oxygen was used as the boundary point to study the effects about different blood oxygen partial pressures on the length of mechanical ventilation time in the survival group. Results Blood gas analysis showed that there were no significant differences in pH,partial pressure of oxygen,HCO3-,and lactic acid before mechanical ventilation in the two groups,but the pH values were significantly higher in the survival group after 12 h, 24 h,and 72 h of mechanical ventilation(t values:-2. 07,-3. 48,-7. 11;P <0. 05). Partial pressure of oxygen were higher in the surviving group at 12 h,24 h,and 72 h than those in the death group(t values-2. 87,-4. 88,-11. 29; P<0. 05). The HCO3-values of the survival group at 12 h,24 h and 72 h were higher than the death group, and the differences were statistically significant ( t values: -3. 90, -5. 60,-5. 76,P<0. 001). The lactic acid of survival group was significantly lower than the death group at 72 h after ventilation (t=5. 12,P<0. 001). Compared with the death group,partial pressure of carbon dioxide in 24 h,72 h decreased significantly in the surviving group(t values:5. 67,7. 60;P<0. 05). In the surviving group,the partial pressure of oxygen was maintained above 80 mmHg in 18 patients and the mechanical venti-lation time was (7. 17 ± 1. 95) d. The partial pressure of oxygen was below 80 mmHg in 12 patients of the surviving group and the mechanical ventilation time was (8. 67 ± 2. 50)d. The difference was statistically sig-nificant(t =12. 02,P <0. 001). Conclusion In the treatment of newborn with pulmonary hypertension caused by meconium aspiration,maintaining a higher pH value and a partial pressure of oxygen higher than 80 mmHg may be beneficial to the recovery of children with pulmonary hypertension.

Early neonatal deaths associated with perinatal asphyxia in infants ≥2500g in Brazil / Óbitos neonatais precoces associados à asfixia perinatal em neonatos ≥2500g no Brasil

Abstract Objective: To assess the annual burden of early neonatal deaths associated with perinatal asphyxia in infants weighing ≥2500 g in Brazil from 2005 to 2010. Methods: The population study enrolled all live births of infants with birth weight ≥2500 g 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 ≥2500 g without malformations died within six days after birth with perinatal asphyxia. Deaths occurred in the first 24 h 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.

Resumo Objetivo: Avaliar a taxa anual de óbitos neonatais precoces associados à asfixia perinatal em neonatos de peso ≥ 2.500 g no Brasil de 2005 a 2010. Métodos: A população do estudo envolveu todos os nascidos vivos de neonatos com peso ao nascer ≥ 2.500 g e sem malformações que morreram até seis dias após o nascimento por asfixia perinatal, definida como hipóxia intrauterina, asfixia no nascimento ou síndrome de aspiração de mecônio. A causa do óbito foi escrita em qualquer linha do atestado de óbito, de acordo com a Classificação Internacional de Doenças, 10a Revisão (P20.0, P21.0 e P24.0). Foi feita uma pesquisa ativa em 27 unidades federativas brasileiras. O teste qui-quadrado de tendência foi aplicado para analisar os índices de mortalidade neonatal associados a asfixia perinatal até o ano do estudo. Resultados: Morreram 10.675 neonatos com peso ≥ 2.500 g sem malformações até 0-6 dias após o nascimento por asfixia perinatal. Os óbitos ocorreram nas primeiras 24 horas após o nascimento em 71% dos neonatos. A síndrome de aspiração de mecônio foi relatada em 4.076 (38%) dos óbitos. O índice de mortalidade neonatal precoce relacionada à asfixia caiu de 0,81 em 2005 para 0,65 por 1.000 nascidos vivos em 2010 no Brasil (p < 0,001); o índice de mortalidade neonatal precoce relacionada a síndrome de aspiração de mecônio permaneceu entre 0,20-0,29 por 1.000 nascidos vivos durante o período do estudo. Conclusões: Apesar da redução nas taxas no Brasil de 2005 a 2010, as taxas de mortalidade neonatal precoce associadas à asfixia perinatal em neonatos no melhor espectro de peso ao nascer e sem malformações congênitas ainda são altas e a síndrome de aspiração de mecônio desempenha um importante papel.

Significance of meconium-stained amniotic fluid in term cesarean sections indicated by suspected fetal distress / 中华围产医学杂志

Objectives To investigate the clinical significance of degree Ⅲ meconium-stained amniotic fluid in term pregnancy.Methods Data of 857 full-term gravidas underwent cesarean section for suspected fetal distress in Peking University First Hospital from October 1,2012 to September 30,2014 were retrospectively analyzed.All patients were divided into three groups according to the diagnosis of suspected fetal distress:meconium-stained amniotic fluid group (Group 1,n=172),fetal heart abnormality group (Group 2,n=623) and meconium-stained amniotic fluid in combination with fetal heart abnormality group (Group 3,n=62).General information and fetal prognosis of the three groups were analyzed.Factors that might affect the prognosis of newborns were analyzed between the infants with or without acidosis,asphyxia or aspiration pneumonia.Analysis of variance,independent-samples t test,Chi-square test and rank-sum test were used as statistical methods.Results There were no significant differences in maternal age,gestational age at delivery,parity,nuchal cord loop(s),pH value of umbilical arterial blood and gender of newborns among the three groups (all P＞0.05).The neonatal Apgar score,neonatal asphyxia rate and rate of admitting into pediatric ward within 24 hours after birth in Group 1 were similar to those of Group 2 and 3 [1 min Apgar score:9.9±0.7 vs 9.8±0.7 and 9.8±0.7,F=0.322;5 min Apgar score:10.0±0.3 vs 10.0±0.2 and 10.0±0.0,F=0.517;neonatal asphyxia rate:1.7％ (3/172) vs 2.1％ (13/623) and 1.6％ (1/62),x2=0.129;rate of admitting into pediatric ward:16.3％ (28/172) vs 14.3％ (89/623) and 11.3％ (7/62),x2-0.978] (all P＞0.05).The incidence of neonatal aspiration pneumonia in Group 1 was higher than that of Group 2 and 3 [4.7％ (8/172) vs 3.2％ (2/62) and 1.0％ (6/623)],but the differences had no statistical significance (F=10.680,P=0.050).Conclusions Both degree Ⅲ meconium-stained amniotic fluid and abnormal fetal heart rate have the same indicating significance and should be treated actively to lower the risk of poor prognosis of the newborns.

Application of noninvasive high frequency oscillatory ventilation in neonates with meconium aspiration syn-drome with pulmonary hypertension after extubation / 实用医学杂志

Objective To investigate the clinical value of nasal noninvasive high frequency oscillatory ven-tilation(NHFOV)as a respiratory support after exbutation by comparing it with nasal continuous positive airway pressure(NCPAP)in neonates with meconium aspiration syndrome(MAS)and persistent pulmonary hypertension (PPHN).Methods Infants of MAS with PPHN after exbutation from intensive care unit were randomly divided in-to NHFOV and NCPAP groups. The value of blood oxygen Pressure(PaO2),carbon dioxide partial pressure(Pa-CO2)and PaO2/FiO2at 1 h,12 h,24 h after exbutation were monitored.Results The NHFOV group showed low-er PaCO2than the NCPAP group at 1 h,12 h and 24 h after noninvasive respiratory support[1 h:(41.1 ± 7.2)vs. (45.4 ± 6.7),P=0.000;12 h:(38.9 ± 3.1)vs.(44.6 ± 5.2),P=0.000;24 h:(35.1 ± 8.2)vs.(43.2 ± 7.1),P=0.000].There were no statistically significant difference of both PaO2and PaO2/FiO2at 1 h,12 h,24 h between the two groups(P>0.05).11.43% infants were failed to be extubated in NHFOV group,but 35.29% in NCPAP group, and there was significant difference between the two groups(P=0.021). Conclusion Compared with NCPAP, NHFOV can better reduce carbon dioxide retention in the sequential therapy for neonates after extubation,and it can also decrease the rate of extubation failure.

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.