Association between Baseline Cortisol Serum Concentrations and the Effect of Prophylactic Hydrocortisone in Extremely Preterm Infants

Hydrocortisone in very preterm neonates for BPD prevention: meta-analysis and effect size modifiers

OBJECTIVES

To clarify if systemic hydrocortisone, in protocols allowing to start it before the 15th day of life, prevents bronchopulmonary dysplasia (BPD) or other adverse outcomes in very preterm neonates, and to identify any possible effect size modifiers.

STUDY DESIGN

Systematic review and meta-analysis following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Additional analyses included meta-regressions and review of biological plausibility.

RESULTS

Seven trials were included, they were of general good quality and accounted for a total of 2193 infants. Hydrocortisone treatment did not reduce BPD (risk ratio (RR) 0.84 (95% CI 0.64 to 1.04)), but heterogeneity was evident (I2=51.6%). The effect size for BPD is greatest for 10-12 days duration of treatment (β=0.032 (0.01), p=0.007) and tended to be greater in patients with chorioamnionitis (β=-1.5 (0.841), p=0.07). Hydrocortisone treatment may significantly reduce mortality (RR 0.75 (95% CI 0.59 to 0.91)), there is no heterogeneity (I2=0) and the reduction tended to be greater in males (β=-0.06 (0.03), p=0.07). Hydrocortisone may significantly reduce necrotising enterocolitis (NEC; RR 0.72 (95% CI 0.53 to 0.92)); there is neither heterogeneity (I2=0%) nor any effect size modifiers. Hydrocortisone did not affect other adverse outcomes of prematurity.

CONCLUSIONS

Systemic hydrocortisone may be considered, on a case-by-case evaluation, to reduce mortality and NEC, while it does not affect BPD. There are some potential effect size modifiers for mortality and BPD which should be addressed in future explanatory trials.

PROSPERO REGISTRATION NUMBER

CRD42023400520.

Sample entropy correlates with intraventricular hemorrhage and mortality in premature infants early in life

BACKGROUND

Mortality and intraventricular hemorrhage (IVH) are common adverse outcomes in preterm infants and are challenging to predict clinically. Sample entropy (SE), a measure of heart rate variability (HRV), has shown predictive power for sepsis and other morbidities in neonates. We evaluated associations between SE and mortality and IVH in the first week of life.

METHODS

Participants were 389 infants born before 32 weeks of gestation for whom bedside monitor data were available. A total of 29 infants had IVH grade 3 or 4 and 31 infants died within 2 weeks of life. SE was calculated with the PhysioNet open-source benchmark. Logistic regressions assessed associations between SE and IVH and/or mortality with and without common clinical covariates over various hour of life (HOL) censor points.

RESULTS

Lower SE was associated with mortality by 4 HOL, but higher SE was very strongly associated with IVH and mortality at 24-96 HOL. Bootstrap testing confirmed SE significantly improved prediction using clinical variables at 96 HOL.

CONCLUSION

SE is a significant predictor of IVH and mortality in premature infants. Given IVH typically occurs in the first 24-72 HOL, affected infants may initially have low SE followed by a sustained period of high SE.

IMPACT

SE correlates with IVH and mortality in preterm infants early in life. SE combined with clinical factors yielded ROC AUCs well above 0.8 and significantly outperformed the clinical model at 96 h of life. Previous studies had not shown predictive power over clinical models. First study using the PhysioNet Cardiovascular Toolbox benchmark in young infants. Relative to the generally accepted timing of IVH in premature infants, we saw lower SE before or around the time of hemorrhage and a sustained period of higher SE after. Higher SE after acute events has not been reported previously.

Steroid Metabolomic Signature in Term and Preterm Infants

Adrenal function is essential for survival and well-being of preterm babies. In addition to glucocorticoids, it has been hypothesized that C19-steroids (DHEA-metabolites) from the fetal zone of the adrenal gland may play a role as endogenous neuroprotective steroids. In 39 term-born (≥37 weeks gestational age), 42 preterm (30-36 weeks) and 51 early preterm (<30 weeks) infants 38 steroid metabolites were quantified by GC-MS in 24-h urinary samples. In each gestational age group, three distinctive cluster were identified by pattern analysis (k-means clustering). Individual steroidal fingerprints and clinical phenotype were analyzed at the 3rd day of life. Overall, the excretion rates of C21-steroids (glucocorticoid precursors, cortisol, and cortisone metabolites) were low (<99 μg/kg body weight/d) whereas the excretion rates of C19-steroids were up to 10 times higher. There was a shift to higher excretion rates of C19-steroids in both preterm groups compared to term infants but only minor differences in the distribution of C21-steroids. Comparable metabolic patterns were found between gestational age groups: Cluster 1 showed mild elevation of C21- and C19-steroids with the highest incidence of neonatal morbidities in term and severe intraventricular hemorrhage in early preterm infants. In cluster 2 lowest excretion in general was noted but no clinically unique phenotype. Cluster 3 showed highest elevation of C21-steroids and C19-steroids but no clinically unique phenotype. Significant differences in steroid metabolism between clusters are only partly reflected by gestational age and disease severity. In early preterm infants, higher excretion rates of glucocorticoids and their precursors were associated with severe cerebral hemorrhage. High excretion rates of C19-steroids in preterm infants may indicate a biological significance.

Risk factors and epidemiology of spontaneous intestinal perforation among infants born at 22-24 weeks' gestational age

OBJECTIVE

To describe the epidemiology, risk factors, and timing of spontaneous intestinal perforation (SIP) among infants born at 22-24 weeks' gestational age (GA).

STUDY DESIGN

Observational cohort study among infants born at 22-24 weeks' GA in 446 neonatal intensive care units.

RESULTS

We identified 9712 infants, of whom 379 (3.9%) developed SIP. SIP incidence increased with decreasing GA (P < 0.001). Antenatal magnesium (odds ratio (OR) 1.42; 95% confidence interval (CI), 1.09-1.85), antenatal indomethacin (OR 1.40; 95% CI, 1.06-1.85), postnatal indomethacin (OR 1.61; 95% CI, 1.23-2.11), and postnatal hydrocortisone exposure (OR 2.02; 95% CI 1.50-2.73) were associated with SIP. Infants who lost 15-20% (OR 1.77; 95% CI, 1.28-2.44) or >20% (OR 2.04; 95% CI, 1.46-2.85) of birth weight had higher odds of SIP than infants with weight loss <10%.

CONCLUSIONS

Antenatal magnesium exposure, antenatal indomethacin exposure, postnatal hydrocortisone exposure, postnatal indomethacin exposure, and weight loss ≥15% were associated with SIP.

Glucocorticoid signature of preterm infants developing bronchopulmonary dysplasia

BACKGROUND

Systemic inflammation plays a key role in the development of bronchopulmonary dysplasia (BPD). Cortisol is known to dampen inflammation. However, adrenal function following preterm birth is characterized by insufficient cortisol levels for the degree of inflammation, and a relative abundancy of cortisol precursors. We investigated whether this pattern could contribute to the development of BPD in preterm infants born <30 weeks of gestation.

METHODS

Cortisol, cortisone, 17-OH progesterone (17-OHP) and 11-deoxycortisol were measured in serum obtained at postnatal days 1, 3, 7, 14 and 28, using liquid-chromatography-tandem-mass-spectrometry. The presence of BPD was ascertained at 36 weeks postmenstrual age.

RESULTS

Sixty-five infants were included for analysis, of whom 32 (49%) developed BPD. Preterm infants developing BPD, as compared to those without BPD, had higher levels of 17-OHP, 11-deoxycortisol and cortisone relative to cortisol in their first week of life, but not at birth or beyond day 7.

CONCLUSION

Preterm infants developing BPD had higher levels of cortisol precursors and cortisone relative to cortisol in their first week of life than infants without BPD. These findings suggest that BPD is preceded by an activated hypothalamus-pituitary-adrenal axis that could not meet the high cortisol demands, which may predispose to inflammation and BPD.

IMPACT

Relative adrenal insufficiency is common in the first weeks after preterm birth, resulting in insufficient cortisol production for the degree of inflammation and a relative abundance of cortisol precursors; Whether this pattern contributes to the development of bronchopulmonary dysplasia (BPD) is not fully elucidated, since most studies focused on cortisol levels; Preterm infants developing BPD had higher levels of cortisol precursors and cortisone relative to cortisol in the first week of life, suggestive of a hypothalamus-pituitary-adrenal-axis activation during BPD development which cannot meet the high cortisol demands in tissues; This glucocorticoid pattern is likely to dispose to inflammation and BPD.

Prophylactic indomethacin, antenatal betamethasone, and the risk of intestinal perforation in infants <28 weeks' gestation

OBJECTIVE

To determine if intestinal perforations before 14 days (either spontaneous (SIP) or necrotizing enterocolitis-induced) are increased when infants who received antenatal betamethasone shortly before birth are treated with prophylactic indomethacin (PINDO).

STUDY DESIGN

Observational study of 475 infants <28 week's gestation assigned to either a PINDO-protocol (n = 231) or expectant management protocol (n = 244) during consecutive protocol epochs.

RESULTS

Intestinal perforations before 14 days occurred in 33/475 (7%). In unadjusted and adjusted models, we found no associations between PINDO-protocol and intestinal perforations. PINDO-protocol did not increase intestinal perforations or SIP-alone even when given to infants who received betamethasone <7 or <2 days before delivery. 213/231 (92%) PINDO-protocol infants actually received indomethacin. The results were unchanged when examined just in those who received indomethacin.

CONCLUSION

In our study, early intestinal perforations and SIP-alone were not increased when PINDO was used by protocol in infants who received antenatal betamethasone shortly before birth.

European Consensus Guidelines on the Management of Respiratory Distress Syndrome: 2022 Update

Respiratory distress syndrome (RDS) care pathways evolve slowly as new evidence emerges. We report the sixth version of "European Guidelines for the Management of RDS" by a panel of experienced European neonatologists and an expert perinatal obstetrician based on available literature up to end of 2022. Optimising outcome for babies with RDS includes prediction of risk of preterm delivery, appropriate maternal transfer to a perinatal centre, and appropriate and timely use of antenatal steroids. Evidence-based lung-protective management includes initiation of non-invasive respiratory support from birth, judicious use of oxygen, early surfactant administration, caffeine therapy, and avoidance of intubation and mechanical ventilation where possible. Methods of ongoing non-invasive respiratory support have been further refined and may help reduce chronic lung disease. As technology for delivering mechanical ventilation improves, the risk of causing lung injury should decrease, although minimising time spent on mechanical ventilation by targeted use of postnatal corticosteroids remains essential. The general care of infants with RDS is also reviewed, including emphasis on appropriate cardiovascular support and judicious use of antibiotics as being important determinants of best outcome. We would like to dedicate this guideline to the memory of Professor Henry Halliday who died on November 12, 2022.These updated guidelines contain evidence from recent Cochrane reviews and medical literature since 2019. Strength of evidence supporting recommendations has been evaluated using the GRADE system. There are changes to some of the previous recommendations as well as some changes to the strength of evidence supporting recommendations that have not changed. This guideline has been endorsed by the European Society for Paediatric Research (ESPR) and the Union of European Neonatal and Perinatal Societies (UENPS).

Tolerance of hydrocortisone prophylaxis administration in extreme preterm neonates: Experience of a single UK level III neonatal unit

OBJECTIVE

To assess the safety of the routine use of low-dose prophylactic hydrocortisone to improve survival without bronchopulmonary dysplasia (BPD) in infants born <28 weeks' gestation.

DESIGN

A single-centre retrospective cohort study of infants born <28 weeks, before and after hydrocortisone implementation. Data was collected from electronic patient records and compared between both groups.

MAIN OUTCOME MEASURES

The incidence of serious adverse events associated with hydrocortisone use was measured in each group. The rates of spontaneous intestinal perforation (SIP), late onset sepsis (LOS). Necrotising enterocolitis (NEC) and BPD were compared.

RESULTS

There were 88 infants in the pre-hydrocortisone group and 103 infants in the hydrocortisone group. In comparison to the pre-hydrocortisone group, the incidence of SIP in the hydrocortisone group was 7.7 % (vs 3.4 % p = 0.2), NEC 30 % (vs 25 % p = 0.43) and LOS 34 % (vs 30.6 % p = 0.63) Rates of BPD in the hydrocortisone group were 59 % (vs 52.2 % p = 0.33) mortality 18.4 % (vs 20.4 % p = 0.73) and BPD free survival 26.2 % (vs 27.2 % p = 0.87). Infants who received hydrocortisone had a significantly lower requirement of inotropic support of 32 % vs 48.3 % (p = 0.02). Results remained unchanged after logistic regression analyses for potential confounding factors (ethnicity, chorioamnionitis, multiple pregnancy and antenatal steroids).

CONCLUSION

Prophylactic administration of low-dose hydrocortisone for BPD to infants born below 28 weeks' gestation was not associated with an increase in serious adverse outcomes in our population.

Postnatal Corticosteroids to Prevent or Treat Chronic Lung Disease Following Preterm Birth

The American Academy of Pediatrics continues to provide guidance on the use of postnatal corticosteroids to manage or prevent chronic lung disease following preterm birth (formerly referred to as bronchopulmonary dysplasia). Since the last revision of such guidance in 2010, several prospective randomized trials have been published. This revision provides a review of those studies as well as updated recommendations, which include the use of systemic low-dose corticosteroid in preterm neonates with or at high risk for chronic lung disease. High-dose dexamethasone (≥0.5 mg/kg per day) is not recommended. New evidence suggests that inhaled corticosteroids may confer benefit if provided with surfactant as a vehicle, but safety data are lacking. Evidence remains insufficient to make any recommendations regarding routine use of postnatal corticosteroids in preterm infants. Neonatologists and other hospital care providers must continue to use their clinical judgment in individual patients, balancing the potential adverse effects of corticosteroid treatment with those of chronic lung disease. The decision to use postnatal corticosteroids for this purpose should be made together with the infant's parents, and the care providers should document their discussions with parents in the patient's medical record.

Association of Co-Exposure of Antenatal Steroid and Prophylactic Indomethacin with Spontaneous Intestinal Perforation

OBJECTIVE

To evaluate the association of a combined exposure to antenatal steroids and prophylactic indomethacin with the outcome of spontaneous intestinal perforation (SIP) among neonates born at <26 weeks of gestation or <750 g birth weight.

STUDY DESIGN

We conducted a retrospective study of preterm infants admitted to Canadian Neonatal Network units between 2010 and 2018. Infants were classified into 2 groups based on receipt of antenatal steroids; the latter subgrouped as recent (≤7 days before birth) or latent (>7 days before birth) exposures. The co-exposure was prophylactic indomethacin. The primary outcome was SIP. Multivariable logistic regression analysis was used to calculate aORs.

RESULTS

Among 4720 eligible infants, 4121 (87%) received antenatal steroids and 1045 (22.1%) received prophylactic indomethacin. Among infants exposed to antenatal steroids, those who received prophylactic indomethacin had higher odds of SIP (aOR 1.61, 95% CI 1.14-2.28) compared with no prophylactic indomethacin. Subgroup analyses revealed recent antenatal steroids exposure with prophylactic indomethacin had higher odds of SIP (aOR 1.67, 95% CI 1.15-2.43), but latent antenatal steroids exposure with prophylactic indomethacin did not (aOR 1.24, 95% CI 0.48-3.21), compared with the respective groups with no prophylactic indomethacin. Among those not exposed to antenatal steroids, mortality was lower among those who received prophylactic indomethacin (aOR 0.45, 95% CI 0.28-0.73) compared with no prophylactic indomethacin.

CONCLUSIONS

In preterm neonates of <26 weeks of gestation or birth weight <750 g, co-exposure of antenatal steroids and prophylactic indomethacin was associated with SIP, especially if antenatal steroids was received within 7 days before birth. Among those unexposed to antenatal steroids, prophylactic indomethacin was associated with lower odds of mortality.