An evaluation of hydrocortisone dosing for neonatal refractory hypotension

Blood pressure values and hypotension management in extremely preterm infants: a multi-center study

OBJECTIVE

To describe high/low daily blood pressures (BP) and variability in BP management with vasoactive infusions (VI) and/or hydrocortisone (HC) in extremely preterm infants.

STUDY DESIGN

Analysis of data from 24-27 weeks' gestation infants in the Preterm Erythropoietin Neuroprotection (PENUT) Trial. Daily high/low BPs, the use of VI and/or HC, and adverse outcomes were compared descriptively and using regression models.

RESULTS

936 infants were included; 64% untreated, 20% VI, 3% HC, and 13% VI + HC. BP ranges are described for the 602 untreated infants. Considerable inter- and intra-center variability was demonstrated in the rate of VI and/or HC use and the lowest BP on the day of VI or HC initiation.

CONCLUSIONS

Despite published expert opinion guidance regarding BP management in extremely preterm infants, our results suggest a continued lack of consensus result in both inter- and intra-center variability in practice. Well-designed studies in the field are urgently needed.

Vital signs as physiomarkers of neonatal sepsis

Neonatal sepsis accounts for significant morbidity and mortality, particularly among premature infants in the Neonatal Intensive Care Unit. Abnormal vital sign patterns serve as physiomarkers of sepsis and provide early warning of illness before overt clinical decompensation. The systemic inflammatory response to pathogens signals the autonomic nervous system, leading to changes in temperature, respiratory rate, heart rate, and blood pressure. In infants with comorbidities of prematurity, vital sign abnormalities often occur in the absence of infection, which confounds sepsis diagnosis. This review will cover the mechanisms of vital sign changes in neonatal sepsis, including the cholinergic anti-inflammatory pathway mediated by the vagus nerve, which is critical to the host response to infectious and inflammatory insults. We will also review the clinical implications of vital sign changes in neonatal sepsis, including their use in early warning scores and systems to direct clinicians to the bedside of infants with physiologic changes that might be due to sepsis. IMPACT: This manuscript summarizes and reviews the relevant literature on the physiological manifestations of neonatal sepsis and how we monitor and analyze these through vital signs and advanced analytics.

Co-bedding of Preterm Newborn Pigs Reduces Necrotizing Enterocolitis Incidence Independent of Vital Functions and Cortisol Levels

Background: Preterm infants are born with immature organs, leading to morbidities such as necrotizing enterocolitis (NEC), a gut inflammatory disease associated with adverse feeding responses but also hemodynamic and respiratory instability. Skin-to-skin contact including "kangaroo care" may improve infant survival and health via improved vital functions (e.g., pulmonary, cardiovascular) and endocrine influences by adrenal glucocorticoids. Clinical effects of skin-to-skin contact for newborn siblings ("co-bedding") are not known. Using NEC-susceptible Preterm pigs as models, we hypothesized that co-bedding and exogenous glucocorticoids improve vital functions and NEC resistance. Methods: In experiment 1, cesarean-delivered, formula-fed Preterm pigs were reared in incubators with (co-bedding, COB, n = 30) or without (single-bedding, SIN, n = 29) a sibling until euthanasia and tissue collection on day four. In experiment 2, single-bedded Preterm pigs were treated postnatally with a tapering dose of hydrocortisone (HC, n = 19, 1-3 mg/kg/d) or saline (CON, n = 19). Results: Co-bedding reduced NEC incidence (38 vs. 65%, p < 0.05) and increased the density of colonic goblet cells (+20%, p < 0.05) but had no effect on pulmonary and cardiovascular functions (respiration, blood pressure, heart rate, blood gases) or cortisol levels. There were limited differences in intestinal villous architecture and digestive enzyme activities. In experiment 2, HC treatment increased NEC lesions in the small intestine without any effects on pulmonary or cardiovascular functions. Conclusion: Co-bedding may improve gut function and NEC resistance independently of cardiorespiratory function and cortisol levels, but pharmacological cortisol treatment predispose to NEC. Preterm pigs may be a useful tool to better understand the physiological effects of co-bedding, neonatal stressors and their possible interactions with morbidities in Preterm neonates.

Late-onset glucocorticoid-responsive circulatory collapse in premature infants

Late-onset glucocorticoid-responsive circulatory collapse (LGCC) in infants is characterized by sudden onset of hypotension and/or oliguria, which is resistant to volume expanders and inotropes but responds rapidly to intravenous glucocorticoids. LGCC occurs after the first week of life mainly in relatively stable very low birth weight (VLBW) infants. In Japan, the incidence of LGCC is reported to be 8%. Relative adrenal insufficiency (AI) is considered the most likely cause of LGCC, but its detailed pathophysiology remains unclear. Intrinsic and extrinsic factors may affect the pathophysiological mechanism. LGCC should be recognized as one of the high-risk complications in VLBW infants and managed promptly and properly, because if it is not, it may cause life-long neurological problems. To diagnose relative AI, an accurate evaluation of adrenal function is necessary; however, the interpretation of basal serum cortisol levels is difficult in preterm infants after 7 days of life. To recognize LGCC, it is recommended that blood pressure and urine volume be carefully monitored, even outside of the transitional period. If no underlying causes are documented or volume expansion and inotropic support fail, intravenous hydrocortisone should be initiated, and an additional dose of hydrocortisone is required when the response is inadequate. There are few reports to verify or characterize LGCC and this phenomenon has not been recognized worldwide to date. This review summarizes the current knowledge about LGCC in premature infants and evaluates the most significant new findings regarding its pathophysiology, treatment, and prognosis.

European Consensus Guidelines on the Management of Respiratory Distress Syndrome - 2019 Update

As management of respiratory distress syndrome (RDS) advances, clinicians must continually revise their current practice. We report the fourth update of "European Guidelines for the Management of RDS" by a European panel of experienced neonatologists and an expert perinatal obstetrician based on available literature up to the end of 2018. Optimising outcome for babies with RDS includes prediction of risk of preterm delivery, need for appropriate maternal transfer to a perinatal centre and timely use of antenatal steroids. Delivery room management has become more evidence-based, and protocols for lung protection including initiation of CPAP and titration of oxygen should be implemented immediately after birth. Surfactant replacement therapy is a crucial part of management of RDS, and newer protocols for its use recommend early administration and avoidance of mechanical ventilation. Methods of maintaining babies on non-invasive respiratory support have been further developed and may cause less distress and 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 using caffeine and, if necessary, postnatal steroids are also important considerations. Protocols for optimising general care of infants with RDS are also essential with good temperature control, careful fluid and nutritional management, maintenance of perfusion and judicious use of antibiotics all being important determinants of best outcome.