Changing incidence and outcome of infants with respiratory distress syndrome in the 1990s: a population-based survey

Pulmonary Surfactant Replacement Therapy for Respiratory Distress Syndrome in Neonates: a Nationwide Epidemiological Study in Korea

BACKGROUND

Pulmonary surfactant (PS) replacement therapy, as a safe and effective treatment for respiratory distress syndrome (RDS) may have further increased with the extended insurance coverage since 2011 in Korea. Thus, this study aimed to investigate the epidemiologic data of PS replacement therapy for RDS in Korea and to analyze the complications associated with RDS.

METHODS

We included 19,442 infants who were treated with PS and diagnosed with RDS (International Classification of Diseases-10 codes: P22.0) between 2014 and 2018 from the Health Insurance Review and Assessment database. Birth certificate data from Statistics Korea were used to estimate the incidence of RDS.

RESULTS

The average incidence of RDS within the study period was 0.99% among live births. Repeated doses of PS were administered to 1,688 infants (8.7%), ranging from 2 doses in 929 infants (4.8%) to 9 doses in 1 infant (0.01%). The incidence of RDS in term infants markedly increased over 5 years from 0.2% to 0.34%. The incidence was similarly increased among the preterm infants. The RDS mortality rate was 6.3% and showed a decreasing trend according to year. The mortality rate was significantly higher in the lower gestational age group. A decreasing trend was observed in the incidence of the complications, such as patent ductus arteriosus, intraventricular hemorrhage, and bronchopulmonary dysplasia, except for pneumothorax in term infants. The complications were also higher in the lower gestational age group and the lower birth weight group. However, pneumothorax was the most frequent complication in the term infant group and in infants with birth weight ≥ 2,500 g.

CONCLUSION

Advancements in neonatal care and extended insurance coverage have increased the use of PS replacement therapy for RDS. This, in turn, decreased neonatal mortality and the incidence of the associated complications. The appropriate therapeutic strategy for RDS should be decided according to the gestational age and lung pathology.

Increased risk of pulmonary hypertension following premature birth

Background

Pulmonary hypertension (PAH) among children and adults has been linked to premature birth, even after adjustments for known risk factors such as congenital heart disease and chronic lung disease. The aim of this population-based registry study was to assess the risk of PAH following exposure to premature birth and other factors in the decades when modern neonatal care was introduced and survival rates increased.

Methods

Data on pulmonary hypertension and perinatal factors were retrieved from population-based governmental and national quality registers. Cases were adults and children over five years of age with pulmonary hypertension born from 1973 to 2010 and individually matched to six controls by birth year and delivery hospital. Conditional multiple logistic regression was performed to assess the risk of pulmonary hypertension following premature birth and to adjust for known confounding factors for the total study population and for time of birth, grouped into five-year intervals.

Results

In total, 128 cases and 768 controls were included in the study group. Preterm birth was over three times more common among cases (21%) than among controls (6%). The overall adjusted risk of pulmonary hypertension was associated with premature birth, OR = 4.48 (95% CI; 2.10–9.53). Maternal hypertension, several neonatal risk factors and female gender were independently associated with PAH when potential confounders were taken into account. For each five-year period, the risk of PAH following premature birth increased several times for children born in the 2000s and later, OR = 17.08 (95% CI 5.60–52.14).

Conclusions

Preterm birth, along with other factors, significantly contributes to PAH. PAH following premature birth has increased over the last few decades. Our study indicates that new, yet unknown factors may play a role in the risk of preterm-born infants developing PAH later in life.

Risk factors for respiratory distress syndrome in full-term neonates

Background

Respiratory distress syndrome (RDS) is a one of the most common cause of respiratory morbidity and mortality in neonates. This study was conducted to investigate the risk factors for RDS in full-term neonates.

Methods

We conducted this retrospective study using medical records. The study group included 80 full-term neonates diagnosed with RDS and hospitalized in the neonatal intensive care unit between January 2012 and December 2016, at Yeungnam University Hospital. We analyzed sex, gestational age, birth weight, delivery method, maternal age, number of pregnancy, history of abortion, and complication of pregnancy. The control group included 116 full-time neonates who were hospitalized with jaundice during the same period.

Results

The incidence of full-term RDS was more common in males (odds ratio [OR], 3.288; 95% confidence interval [CI], 1.446-7.479), cesarean section (OR, 15.03; 95% CI, 6.381-35.423), multiparity (OR, 4.216; 95% CI, 1.568-11.335). The other factors rendered no significant results.

Conclusion

The risk factors for RDS in full-tern neonates were identified as male sex, cesarean section, and multiparity. Further studies involving more institutions are needed to clarify the risk factors for RDS in full-term infants.

Respiratory distress syndrome in moderately late and late preterm infants and risk of cerebral palsy: a population-based cohort study

OBJECTIVES

Infant respiratory distress syndrome (IRDS) is a known risk factor for intracerebral haemorrhage/intraventricular haemorrhage (ICH/IVH) and periventricular leucomalacia. These lesions are known to increase the risk of cerebral palsy (CP). Thus, we wanted to examine the long-term risk of CP following IRDS in moderately late and late preterm infants.

DESIGN

Population-based cohort study.

SETTING

All hospitals in Denmark.

PARTICIPANTS

We used nationwide medical registries to identify a cohort of all moderately and late preterm infants (defined as birth during 32-36 full gestational weeks) born in Denmark in 1997-2007 with and without hospital diagnosed IRDS.

MAIN OUTCOMES MEASURES

We followed study participants from birth until first diagnosis of CP, emigration, death or end of follow-up in 2014. We computed the cumulative incidence of CP before age 8 years and used Cox's regression analysis to compute HRs of IRDS, comparing children with IRDS to those without IRDS. HRs were adjusted for multiple covariates.

RESULTS

We identified 39 420 moderately late and late preterm infants, of whom 2255 (5.7%) had IRDS. The cumulative incidence of CP was 1.9% in infants with IRDS and 0.5% in the comparison cohort. The adjusted HR of CP was 2.0 (95% CI 1.4 to 2.9). The adjusted HR of CP was 12 (95% CI 4.5 to 34) in children with IRDS accompanied by a diagnosis of ICH/IVH. After restriction to children without diagnoses of perinatal breathing disorders other than IRDS, congenital heart disease and viral or bacterial infections occurring within 4 days of birth, the overall adjusted HR was 2.1 (95% CI 1.4 to 3.1).

CONCLUSIONS

The risk of CP was increased in moderately late and late preterm infants with IRDS compared with infants without IRDS born during the same gestational weeks.

The Role of Lung Ultrasound in Diagnosis of Respiratory Distress Syndrome in Newborn Infants

BACKGROUND

Respiratory distress syndrome (RDS) is one of the most common causes of neonatal respiratory failure and mortality. The risk of developing RDS decreases with both increasing gestational age and birth weight.

OBJECTIVES

The aim of this study was to evaluate the value of lung ultrasound in the diagnosis of respiratory distress syndrome (RDS) in newborn infants.

MATERIALS AND METHODS

From March 2012 to May 2013, 100 newborn infants were divided into two groups: RDS group (50 cases) and control group (50 cases). According to the findings of chest x-ray, there were 10 cases of grade II RDS, 15 grade III cases, and 25 grade IV cases in RDS group. Lung ultrasound was performed at bedside by a single expert. The ultrasound indexes observed in this study included pleural line, A-line, B-line, lung consolidation, air bronchograms, bilateral white lung, interstitial syndrome, lung sliding, lung pulse etc.

RESULTS

In all of the infants with RDS, lung ultrasound consistently showed generalized consolidation with air bronchograms, bilateral white lung or alveolar-interstitial syndrome, pleural line abnormalities, A-line disappearance, pleural effusion, lung pulse, etc. The simultaneous demonstration of lung consolidation, pleural line abnormalities and bilateral white lung, or lung consolidation, pleural line abnormalities and A-line disappearance co-exists with a sensitivity and specificity of 100%. Besides, the sensitivity was 80% and specificity 100% of lung pulse for the diagnosis of neonatal RDS.

CONCLUSIONS

This study indicates that using an ultrasound to diagnose neonatal RDS is accurate and reliable too. A lung ultrasound has many advantages over other techniques. Ultrasound is non-ionizing, low-cost, easy to operate, and can be performed at bedside, making this technique ideal for use in NICU.

High-risk Factors of Respiratory Distress Syndrome in Term Neonates: A Retrospective Case-control Study

BACKGROUND

Respiratory distress syndrome (RDS) is a common critical disease in term neonates, but reasons for the occurrence of RDS remains unclear.

AIMS

This study aimed to investigate the cause of RDS in full-term neonates by a retrospective case-control study.

STUDY DESIGN

Case-control study.

METHODS

Among the patients admitted to Bayi Children's Hospital between January 2008 and December 2010, a total of 205 full-term neonates with RDS were assigned to the study group, and 410 full-term neonates without RDS were assigned to the control group. Clinical information, including the presence or absence of premature rupture of membranes (PROM), gender of the neonates, mode of delivery, birth weight, and any conditions suffered by the neonates were recorded.

RESULTS

THE RESULTS OF LOGISTIC REGRESSION ANALYSIS SHOWED THAT THE FOLLOWING CAUSES WERE CLOSELY CORRELATED WITH TERM NEONATAL RDS: selective cesarean section (OR: 8.737; 95% CI: 5.232-14.588), severe birth asphyxia (OR: 6.988; 95% CI: 2.990-16.333), small gestational age (OR: 6.222; 95% CI: 2.001-8.993), maternal-fetal infection (OR: 5.337; 95% CI: 1.999-8.233), PROM (OR: 3.380; 95% CI: 1.986-5.754), male sex (OR: 2.641; 95% CI: 1.721-4.053), gestational glucose intolerance or diabetes (OR: 2.415; 95% CI:1.721-4.053), and low birth weight (OR: 2.323; 95% CI: 1.329-4.060).

CONCLUSION

Several high-risk factors, such as selective cesarean section, severe birth asphyxia, maternal-fetal infection, PROM, and male sex are closely correlated with full-term neonatal RDS. These could provide a significant reference for the diagnosis and treatment of term neonatal RDS.

Positive predictive value of the infant respiratory distress syndrome diagnosis in the Danish National Patient Registry

Background

Infant respiratory distress syndrome (IRDS) is the most common respiratory disease in preterm infants, and is associated with considerable morbidity and mortality. Valid data on IRDS are important in clinical epidemiological research.

Objectives

The objective of this study was to estimate the positive predictive value (PPV) of the IRDS diagnosis registered in the population-based Danish National Patient Registry according to the International Classification of Diseases, 8th and 10th revisions.

Methods

Between January 1, 1977 and December 31, 2008, we randomly selected three patients per year, 96 in total, who were registered with an IRDS diagnosis in the Danish National Patient Registry and living in the northern part of Denmark. Data on the infants included information on the presence of predefined clinical symptoms. We defined IRDS as the presence of at least two of four clinical symptoms (tachypnea, retractions or nasal flaring, grunting, and central cyanosis), which had to be present for more than 30 minutes. Using medical record review as the reference standard, we computed the positive predictive value of the registered IRDS diagnosis including 95% confidence intervals (CIs).

Results

We located the medical record for 90 of the 96 patients (94%), and found an overall PPV of the IRDS diagnosis of 81% (95% CI 72%–88%). This did not vary substantially between primary and secondary diagnoses. The PPV was higher, at 89% (95% CI 80%–95%), for preterm infants born before 37 weeks of gestation.

Conclusion

The PPV of the IRDS diagnosis in the Danish National Patient Registry is reasonable when compared with symptoms described in the corresponding medical records. The Danish National Patient Registry is a useful data source for studies of IRDS, particularly if restricted to preterm infants. Nonetheless, the potential impact of misclassification of the IRDS diagnosis must be considered.

Blood glucose level in preterm infants after antenatal exposure to glucocorticoid

AIM

To determine the impact of antenatal glucocorticoid on neonatal glucose homeostasis.

METHODS

This is a retrospective gestationally paired survey followed by a randomized study. On the basis of the interval between last antenatal dexamethasone and birth, 228 preterm infants born before 34 weeks were divided into Short (< 24 h), Intermediate (1-6 days), and Long (> or = 7 days) exposure groups and compared their gestationally paired controls. After a single course of betamethasone, the parturients remaining undelivered for one week were randomized to receive either one dose of betamethasone (n = 52) or placebo (n = 53). Glucose values were recorded at 11 time points in the first 3 days of life. Hypoglycaemic and hyperglycaemic values were counted.

RESULTS

There were no overall differences in mean glucose levels between the antenatal glucocorticoid and the control groups. However, the long exposure time to antenatal glucocorticoid was associated with increased risk of hyperglycaemia (OR 4.1; 2.2-7.6).

CONCLUSION

Antenatal glucocorticoid administration was associated with subtle disturbances of glucose homeostasis in preterm infants. These differences were dependent on the length of drug-delivery interval so that long exposition time seemed to increase the incidence of hyperglycaemia during the first days of life.