The effects of antenatal corticosteroids and surfactant replacement on neonatal respiratory distress syndrome

Efficacy and safety of surfactant administration by MIST and INSURE techniques in Neonates with Respiratory Distress Syndrome: A randomized controlled trial

Objective

To measure the efficacy and safety of surfactant administered by MIST and INSURE to neonates with respiratory distress syndrome.

Methods

A randomized controlled trial was conducted from June 2021 to August 2022 at the NICU of the University of Child Health Sciences, Lahore. Neonates meeting inclusion criteria i.e with RDS who worsened on nasal Continuous positive airway pressure (nCPAP) (fiO2 30%, pressure 6cmH2O) were enrolled in the study in both interventional arms (MIST, n=36 and INSURE, n=36) using simple random sampling. Data was analysed using SPSS 25.

Results

The mean age of neonates in MIST was 1.27±0.40 days and 1.23±0.48 days in INSURE cohort. Neonates with MIST (n=8) required statistically significant reduced need for IMV than INSURE (n=17) technique (P-Value 0.047). This study could not achieve significant difference in duration of mechanical ventilation (1±1.67; 1.52±1.40 days, P=0.152) and duration of nCPAP (3.27±1.65;3.67±1.64 hrs, P=0.312) in MIST versus INSURE. The second dose of surfactant was administered in fewer cases in MIST (n=2) than INSURE (n=7) (P=0.075). Risk estimation, although not significant, determined less likelihood for the pulmonary haemorrhage (0.908 than 1.095), intraventricular hemorrhage (0.657 than 1.353), administration of the second dose of surfactant (0.412 than 1.690) and greater likelihood of discharge (1.082 than 0.270) at 95% confidence interval with MIST technique.

Conclusion

Surfactant therapy through MIST is effective and there is significantly reduced need of IMV than in INSURE. Safety profile though could not achieve statistical significance yet determines less risk of complications associated with MIST than INSURE.RCT Registration Number: TCTR20210627001.

A case-control study on the effects of incomplete, one, and more than one dexamethasone course on acute respiratory problems in preterm neonates born between 280 and 366 weeks of gestation

OBJECTIVE

To compare the effects of an incomplete course and more than 1 course of dexamethasone, relative to a control of a single complete course, on foetal respiratory problems and other adverse outcomes of preterm birth.

METHODS

This was a retrospective chart review of 1800 women with preterm delivery. Data were collected on newborns whose mothers administered 1 full course of dexamethasone (916/1800; 50.9%), a partial course (716/1800; 39.8%) and more than 1 course (168/1800; 9.3%). Demographic data and adverse maternal and neonatal outcomes were recorded.

RESULTS

Preterm singleton newborns whose mothers received several steroid hormone courses were significantly more likely to have adverse outcomes than newborns of mothers given 1 course. The negative outcomes were the need for positive pressure ventilation ([aOR] 1.831; 95% CI, (1.185,2.829); P = 0.019), ventilator support ([aOR] 1.843; 95% CI, (1.187,2.861); P = 0.011), and phototherapy ([aOR] 1.997; 95% CI, (1.378,2.895); P <  0.001), transient tachypnoea of the newborn ([aOR] 1.801; 95% CI, (1.261,2.571); P = 0.002), intraventricular haemorrhage ([aOR] 2.215; 95% CI, (1.159, 4.233); P = 0.027), sepsis ([aOR] 1.737; 95% CI, (1.086, 2.777); P = 0.007), and admission to neonatal intensive care ([aOR] 1.822; 95% CI, (1.275,2.604); P = 0.001). In the group of very preterm infants, newborns of mothers administered an incomplete course had developed respiratory distress syndrome (RDS) ([aOR] 3.177; 95% CI, (1.485, 6.795); P = 0.006) and used ventilatory support ([aOR] 3.565; 95% CI, (1.912, 6.650); P <  0.001) more than those of mothers receiving a single course.

CONCLUSIONS

Preterm singleton newborns whose mothers were given multiple courses of dexamethasone had an increased incidence of RDS and other adverse outcomes than those of mothers receiving a full course. However, very preterm newborns whose mothers were administered 1 full dexamethasone course had a significantly lower incidence of RDS than those whose mothers were given partial courses.

Y It Matters—Sex Differences in Fetal Lung Development

Within this review, sex-specific differences in alveolar epithelial functions are discussed with special focus on preterm infants and the respiratory disorders associated with premature birth. First, a short overview about fetal lung development, the challenges the lung faces during perinatal lung transition to air breathing and respiratory distress in preterm infants is given. Next, clinical observations concerning sex-specific differences in pulmonary morbidity of human preterm infants are noted. The second part discusses potential sex-specific causes of pulmonary complications, including pulmonary steroid receptors and local lung steroid metabolism. With regard to pulmonary steroid metabolism, it is important to highlight which steroidogenic enzymes are expressed at which stage during fetal lung development. Thereafter, we review the knowledge concerning sex-specific aspects of lung growth and maturation. Special focus is given to alveolar epithelial Na+ transport as a driver of perinatal lung transition and the sex differences that were noted in this process.

Evaluation of the Mortality and Morbidity of Premature Infants During a Five-Year Period in the Neonatal Intensive Care Unit

Background Premature birth is the most important cause of perinatal mortality and morbidity. This study aimed to evaluate mortality and morbidity in premature infants over a five-year period at a university hospital providing tertiary intensive care health services. Methodology All premature infants born alive at ≤37 gestational weeks and hospitalized in neonatal intensive care units were included in the study. Data such as maternal and perinatal characteristics, characteristics of the newborn, respiratory and related problems, neonatal morbidities, and causes of death were retrieved retrospectively from file records. Results A total of 1,780 patients (53.7% male and 46.3% female) were included in the study. High-risk pregnancy was present in 55% of women. Respiratory distress syndrome (RDS) developed in 50.4% of the patients, intracranial hemorrhage in 8.4%, and necrotizing enterocolitis in 5.6%. Mortality was observed in 20.9% of the patients. The most frequent cause of death was RDS and related complications (11.8%), and 66.4% of mortality occurred during the early neonatal period, that is, the first 24 hours of life. Conclusions High-risk pregnancies were significantly associated with neonatal morbidity and mortality. Therefore, the management of maternal health factors should be the priority for controlling neonatal mortality.

Oxidative stress markers in neonatal respiratory distress syndrome: advanced oxidation protein products and 8-hydroxy-2-deoxyguanosine in relation to disease severity

OBJECTIVE

We assessed oxidant-antioxidant status and evaluated the role of lipid peroxidation, oxidative DNA damage, and protein oxidation in the development and severity of neonatal respiratory distress syndrome (RDS).

METHODS

Forty preterm neonates with RDS were compared with another 40 preterm neonates without RDS enrolled as controls. Total antioxidant capacity (TAC), malondialdehyde (MDA), advanced oxidation protein products (AOPPs), 8-hydroxy-2-deoxyguanosine (8-OHdG), and trace elements (copper and zinc) were measured in cord blood (day 0) for all neonates and repeated on day 3 for the RDS group.

RESULTS

Day 0 serum levels of MDA, AOPPs, and 8-OHdG were significantly higher in neonates with RDS than controls with a further increase on day 3. Days 0 and 3 levels of TAC, copper, and zinc were significantly lower in the RDS group compared with controls. Elevated serum levels of 8-OHdG and AOPPs were associated with severe RDS, invasive mechanical ventilation, and high mortality rate. 8-OHdG and AOPPs were positively correlated with MDA, oxygenation index, duration of ventilation, and duration of hospitalization.

CONCLUSIONS

Increased lipid, protein, and DNA oxidation is accompanied by alterations in the antioxidant defense status, which may play a role in the pathogenesis and severity of RDS.

Sex differences and sex steroids in lung health and disease

Sex differences in the biology of different organ systems and the influence of sex hormones in modulating health and disease are increasingly relevant in clinical and research areas. Although work has focused on sex differences and sex hormones in cardiovascular, musculoskeletal, and neuronal systems, there is now increasing clinical evidence for sex differences in incidence, morbidity, and mortality of lung diseases including allergic diseases (such as asthma), chronic obstructive pulmonary disease, pulmonary fibrosis, lung cancer, as well as pulmonary hypertension. Whether such differences are inherent and/or whether sex steroids play a role in modulating these differences is currently under investigation. The purpose of this review is to define sex differences in lung structure/function under normal and specific disease states, with exploration of whether and how sex hormone signaling mechanisms may explain these clinical observations. Focusing on adult age groups, the review addresses the following: 1) inherent sex differences in lung anatomy and physiology; 2) the importance of certain time points in life such as puberty, pregnancy, menopause, and aging; 3) expression and signaling of sex steroid receptors under normal vs. disease states; 4) potential interplay between different sex steroids; 5) the question of whether sex steroids are beneficial or detrimental to the lung; and 6) the potential use of sex steroid signaling as biomarkers and therapeutic avenues in lung diseases. The importance of focusing on sex differences and sex steroids in the lung lies in the increasing incidence of lung diseases in women and the need to address lung diseases across the life span.

Intra-amniotic administration of exogenous pulmonary surfactant for improving in lung maturity of fetal rabbits with intrauterine infection caused by premature rupture of membranes

This study was to investigate the effect of intra-amniotic administration of pulmonary surfactant (PS) on lung maturation in conditions of experimentally induced premature rupture of membranes (PROM) and intrauterine infection of rabbits. To establish animal (rabbit) models of intrauterine infection caused by PROM, E. coli was intrauterinely injected in 24-and 26-day pregnant animals. Twenty healthy pregnancy adult Japanese white rabbits were divided into three groups: the infection group (8 rabbits), infection group with intra-amniotic PS administration (8 rabbits) and healthy controls (4 rabbits). Ultrastructure changes in the lung were observed under an electron microscope 19.5 hours after intervention. The results showed that the lung infection levels of fetal rabbits in the infection group and the infection group with PS had no significant difference. Bacillus bodies and infiltrated inflammatory cells can be occasionally seen in the alveoli, bronchial lumen, and cytoplasm.The type II alveolar epithelial cells (AT-II) were decreased in the infection group than that in control group. Lamellar bodies showed vacuolation changes and different levels of apoptosis. In the infection group with PS, the count of AT-II did not show an obvious decrease. Lamellar bodies increased, and different secretion forms appeared. Also, there was little apoptosis and no obvious collagen fiber hyperplasia in antenatal administration of PS group. We believe that once PROM has happened, intrauterine infection and inflammation stimulated a cascade reaction on the fetal lung, leading to abnormal changes in the alveolar ultrastructure. Intra-amniotic administration of PS can improve the fetal lung ultrastructure and its maturity.