Early Caffeine Administration and Neurodevelopmental Outcomes in Preterm Infants

Cardiovascular and cerebrovascular effects of caffeine maintenance in preterm infants during the transitional period

BACKGROUND AND AIM

Caffeine is routinely used for the prophylaxis of prematurity-related apnoeas. We aimed to evaluate the effect of caffeine maintenance on cardiovascular and cerebrovascular haemodynamics using a non-invasive multimodal monitoring in preterm infants during the transitional period.

METHODS

Infants <32 weeks' gestational age (GA) were enrolled in this observational prospective study. The following parameters were recorded before and after the administration of caffeine citrate 5 mg/kg using near-infrared spectroscopy, pulse oximetry and electrical velocimetry: heart rate, cardiac output, stroke volume, cardiac contractility, systemic vascular resistance (SVR), perfusion index, peripheral and cerebral oxygenation, cerebral fractional oxygen extraction, correlation index between cerebral oxygenation and heart rate (TOHRx, marker of cerebrovascular reactivity). Multilevel mixed-effects linear models were used to assess the impact of caffeine and of relevant clinical covariates on each parameter.

RESULTS

Seventy-seven infants (mean GA 29.3 ± 2.5 weeks, mean birthweight 1148 ± 353 g) were included. Caffeine administration was associated with increased SVR (B = 0.623, p = 0.004) and more negative TOHRx values (B = -0.036, p = 0.022), which suggest improved cerebrovascular reactivity.

CONCLUSIONS

Caffeine administration at maintenance dosage during postnatal transition is associated with increased systemic vascular tone and improved cerebrovascular reactivity. A possible role for caffeine-mediated inhibition of adenosine receptors may be hypothesized.

IMPACT

This study provides a thorough and comprehensive overview of multiple cerebrovascular and cardiovascular parameters, monitored non-invasively by combining near-infrared spectroscopy, electrical velocimetry and pulse oximetry, before and after the administration of caffeine at maintenance dosage in preterm infants during postnatal transition. Caffeine was associated with an improvement in cerebrovascular reactivity and with a slight but significant increase in systemic vascular resistance, with no additional effects on other cardiovascular and cerebrovascular parameters. Our results support the safety of caffeine treatment even during a phase at risk for haemodynamic instability such as postnatal transition and suggest potential beneficial effects on cerebral haemodynamics.

Early versus late caffeine and/or non-steroidal anti-inflammatory drugs (NSAIDS) for prevention of intermittent hypoxia-induced neuroinflammation in the neonatal rat

Preterm infants often experience frequent intermittent hypoxia (IH) episodes which are associated with neuroinflammation. We tested the hypotheses that early caffeine and/or non-steroidal inflammatory drugs (NSAIDs) confer superior therapeutic benefits for protection against IH-induced neuroinflammation than late treatment. Newborn rats were exposed to IH or hyperoxia (50% O2) from birth (P0) to P14. For early treatment, the pups were administered: 1) daily caffeine (Caff) citrate (Cafcit, 20 mg/kg IP loading on P0, followed by 5 mg/kg from P1-P14); 2) ketorolac (Keto) topical ocular solution in both eyes from P0 to P14; 3) ibuprofen (Ibu, Neoprofen, 10 mg/kg loading dose on P0 followed by 5 mg/kg/day on P1 and P2); 4) Caff+Keto co-treatment; 5) Caff+Ibu co-treatment; or 6) equivalent volume saline (Sal). On P14, animals were placed in room air (RA) with no further treatment until P21. For late treatment, pups were exposed from P0 to P14, then placed in RA during which they received similar treatments from P15-P21 (Sal, Caff, and/or Keto), or P15-P17 (Ibu). RA controls were similarly treated. At P21, whole brains were assessed for histopathology, apoptosis, myelination, and biomarkers of inflammation. IH caused significant brain injury and hemorrhage, inflammation, reduced myelination, and apoptosis. Early treatment with Caff alone or in combination with NSAIDs conferred better neuroprotection against IH-induced damage than late treatment. Early postnatal treatment during a critical time of brain development, may be preferable for the prevention of IH-induced brain injury in preterm infants.

Caffeine pharmacokinetics following umbilical vein injection during delayed cord clamping in preterm lambs

BACKGROUND

Spontaneous breathing during and after delayed cord clamping (DCC) stabilizes cardiopulmonary transition at birth. Caffeine stimulates breathing and decreases apnea in premature newborns. We evaluated the pharmacokinetics and physiological effects of early caffeine administration-direct injection into the umbilical vein (UV) during DCC or administered through a UV catheter (UVC) after delivery.

METHODS

Eighteen extremely premature lambs (125-127d, term gestation 145d) were exteriorized and instrumented. Lambs received caffeine-citrate at high (40 mg/kg) or standard-dose (20 mg/kg) via direct UV (DUV) injection during DCC, or via the UVC.

RESULTS

Mean peak plasma caffeine concentrations were lower with high-dose DUV compared to UVC (18 ± 4.3 vs. 46 ± 12 mg/L, p < 0.05). With standard-dose caffeine, mean peak plasma levels were 7.48 ± 2.6 with DUV and 28.73 ± 9.4 mg/L with UVC. The volume of distribution was higher in the DUV group compared to UVC (2.5 ± 1.0 vs. 0.69 ± 0.15 L/kg) with an estimated 39 ± 18% entering the maternal circulation. Maternal peak concentrations were 0.79 ± 0.71 and 1.43 ± 0.74 mg/L with standard and high-dose DUV, respectively.

CONCLUSIONS

Caffeine injected directly into the UV during DCC is feasible but achieves lower concentrations due to high volume of distribution including maternal circulation. Further trials evaluating DUV caffeine injection should use higher caffeine doses.

IMPACT

Respiratory stimulation with early caffeine may reduce the need for intubation in preterm infants. In the preterm lambs, caffeine injection directly into the umbilical vein during delayed cord clamping is feasible. Plasma caffeine concentrations are less than half when administered directly into the umbilical vein during delayed cord clamping compared to administration via an umbilical venous catheter following birth likely attributed to a larger volume of distribution or injection site leak. There were no significant hemodynamic alterations following caffeine injection.

The Babyccino: The Role of Caffeine in the Prevention of Acute Kidney Injury in Neonates-A Literature Review

Acute kidney injury (AKI) in neonates is associated with increased morbidity and mortality. Theophylline (a methylxanthine) has been shown to prevent neonatal AKI but is seldom used due to its unfavorable profile. Caffeine, another methylxanthine, is utilized ubiquitously to treat apnea of prematurity, but there are no randomized trials evaluating its efficacy in preventing neonatal AKI. This literature review aims to summarize the existing research pertaining to the relationship between caffeine and neonatal AKI. The review was conducted using Pubmed, Embase, Google Scholar, and Cochrane. Inclusion criteria incorporated empirical studies, being published in English, and being available electronically. All eight studies identified were included. Seven studies found caffeine-exposed premature neonates had lower rates of AKI than caffeine-unexposed neonates. Four found reduced AKI severity with caffeine exposure. One study included term neonates and did not find a difference in the AKI rate between caffeine-exposed and non-exposed babies. Limitations include exclusively observational studies, short study periods, heterogenous definitions of prematurity, and a lack of assessment of dose-effect relationships. In conclusion, premature neonates exposed to caffeine appear to have lower rates and potentially less severe AKI. Further research is needed before caffeine can be considered for use in the primary prevention of neonatal AKI.

Variables related to bronchopulmonary dysplasia severity: a Six-Year retrospective study

OBJECTIVES

This was a retrospective observational study conducted in a tertiary neonatal intensive care unit, in order to investigate factors which influenced the severity of bronchopulmonary dysplasia under NICHD new classification.

METHODS

Six years of clinical data with different grades of bronchopulmonary dysplasia patients were collected and analyzed, bivariate ordinal logistic regression model and multivariable ordinal logistic regression model were used with sensitivity analyses.

RESULTS

We identified seven variables were associated with the severity of BPD via a bivariate ordinal logistic regression model, including the level of referral hospital (OR 0.273；95% CI 0.117, 0.636), method of caffeine administration (OR 00.418；95% CI 0.177, 0.991), more than two occurrences of reintubation (OR 4.925；95% CI 1.878, 12.915), CPAP reapplication (OR 2.255；95% CI 1.059, 4.802), presence of positive sputum cultures (OR 2.574；95% CI 1.200, 5.519), the cumulative duration of invasive ventilation (OR 1.047；95% CI 1.017, 1.078), and postmenstrual age at the discontinuation of oxygen supplementation (OR 1.190；95% CI 1.027, 1.38). These seven variables were further analyzed via all multivariable ordinal logistic regression models, and we found that tertiary hospital birth and early administration of caffeine could reduce the severity of BPD by approximately 70% (OR 0.263；95% CI 0.090, 0.770) and 60% (OR 0.371；95% CI 0.138, 0.995), respectively. In contrast, multiple reintubations were related to higher BPD severity with an OR of 3.358 (95% CI 1.002, 11.252).

CONCLUSION

Improving perinatal care in level II hospitals, standardized caffeine administration, and optimized extubation strategy could potentially decrease the severity of BPD.

Methylxanthine for the prevention and treatment of apnea in preterm infants

BACKGROUND

Very preterm infants often require respiratory support and are therefore exposed to an increased risk of chronic lung disease and later neurodevelopmental disability. Although methylxanthines are widely used to prevent and treat apnea associated with prematurity and to facilitate extubation, there is uncertainty about the benefits and harms of different types of methylxanthines.

OBJECTIVES

To assess the effects of methylxanthines on the incidence of apnea, death, neurodevelopmental disability, and other longer-term outcomes in preterm infants (1) at risk for or with apnea, or (2) undergoing extubation.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, two other databases, and three trial registers (November 2022).

SELECTION CRITERIA

We included randomized trials in preterm infants, in which methylxanthines (aminophylline, caffeine, or theophylline) were compared to placebo or no treatment for any indication (i.e. prevention of apnea, treatment of apnea, or prevention of re-intubation).

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods and GRADE to assess the certainty of evidence.

MAIN RESULTS

We included 18 studies (2705 infants), evaluating the use of methylxanthine in preterm infants for: any indication (one study); prevention of apnea (six studies); treatment of apnea (five studies); and to prevent re-intubation (six studies). Death or major neurodevelopmental disability (DMND) at 18 to 24 months. Only the Caffeine for Apnea of Prematurity (CAP) study (enrolling 2006 infants) reported on this outcome. Overall, caffeine probably reduced the risk of DMND in preterm infants treated with caffeine for any indication (risk ratio (RR) 0.87, 95% confidence interval (CI) 0.78 to 0.97; risk difference (RD) -0.06, 95% CI -0.10 to -0.02; number needed to treat for an additional beneficial outcome (NNTB) 16, 95% CI 10 to 50; 1 study, 1869 infants; moderate-certainty evidence). No other trials reported DMND. Results from the CAP trial regarding DMND at 18 to 24 months are less precise when analyzed based on treatment indication. Caffeine probably results in little or no difference in DMND in infants treated for prevention of apnea (RR 1.00, 95% CI 0.80 to 1.24; RD -0.00, 95% CI -0.10 to 0.09; 1 study, 423 infants; moderate-certainty evidence) and probably results in a slight reduction in DMND in infants treated for apnea of prematurity (RR 0.85, 95% CI 0.71 to 1.01; RD -0.06, 95% CI -0.13 to 0.00; NNTB 16, 95% CI 7 to > 1000; 1 study, 767 infants; moderate-certainty evidence) or to prevent re-intubation (RR 0.85, 95% CI 0.73 to 0.99; RD -0.08, 95% CI -0.15 to -0.00; NNTB 12, 95% CI 6 to >1000; 1 study, 676 infants; moderate-certainty evidence). Death. In the overall analysis of any methylxanthine treatment for any indication, methylxanthine used for any indication probably results in little or no difference in death at hospital discharge (RR 0.99, 95% CI 0.71 to 1.37; I2 = 0%; RD -0.00, 95% CI -0.02 to 0.02; I2 = 5%; 7 studies, 2289 infants; moderate-certainty evidence). Major neurodevelopmental disability at 18 to 24 months. In the CAP trial, caffeine probably reduced the risk of major neurodevelopmental disability at 18 to 24 months (RR 0.85, 95% CI 0.76 to 0.96; RD -0.06, 95% CI -0.10 to -0.02; NNTB 16, 95% CI 10 to 50; 1 study, 1869 infants; moderate-certainty evidence), including a reduction in the risk of cerebral palsy or gross motor disability (RR 0.60, 95% CI 0.41 to 0.88; RD -0.03, 95% CI -0.05 to -0.01; NNTB 33, 95% CI 20 to 100; 1 study, 1810 infants; moderate-certainty evidence) and a marginal reduction in the risk of developmental delay (RR 0.88, 95% CI 0.78 to 1.00; RD -0.05, 95% CI -0.09 to -0.00; NNTB 20, 95% CI 11 to > 1000; 1 study, 1725 infants; moderate-certainty evidence). Any apneic episodes, failed apnea reduction after two to seven days (< 50% reduction in apnea) (for infants treated with apnea), and need for positive-pressure ventilation after institution of treatment. Methylxanthine used for any indication probably reduces the occurrence of any apneic episodes (RR 0.31, 95% CI 0.18 to 0.52; I2 = 47%; RD -0.38, 95% CI -0.51 to -0.25; I2 = 49%; NNTB 3, 95% CI 2 to 4; 4 studies, 167 infants; moderate-certainty evidence), failed apnea reduction after two to seven days (RR 0.48, 95% CI 0.33 to 0.70; I2 = 0%; RD -0.31, 95% CI -0.44 to -0.17; I2 = 53%; NNTB 3, 95% CI 2 to 6; 4 studies, 174 infants; moderate-certainty evidence), and may reduce receipt of positive-pressure ventilation after institution of treatment (RR 0.61, 95% CI 0.39 to 0.96; I2 = 0%; RD -0.06, 95% CI -0.11 to -0.01; I2 = 49%; NNTB 16, 95% CI 9 to 100; 9 studies, 373 infants; low-certainty evidence). Chronic lung disease. Methylxanthine used for any indication reduces chronic lung disease (defined as the use of supplemental oxygen at 36 weeks' postmenstrual age) (RR 0.77, 95% CI 0.69 to 0.85; I2 = 0%; RD -0.10, 95% CI -0.14 to -0.06; I2 = 18%; NNTB 10, 95% CI 7 to 16; 4 studies, 2142 infants; high-certainty evidence). Failure to extubate or the need for re-intubation within one week after initiation of therapy. Methylxanthine used for the prevention of re-intubation probably results in a large reduction in failed extubation compared with no treatment (RR 0.48, 95% CI 0.32 to 0.71; I2 = 0%; RD -0.27, 95% CI -0.39 to -0.15; I2 = 69%; NNTB 4, 95% CI 2 to 6; 6 studies, 197 infants; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

Caffeine probably reduces the risk of death, major neurodevelopmental disability at 18 to 24 months, and the composite outcome DMND at 18 to 24 months. Administration of any methylxanthine to preterm infants for any indication probably leads to a reduction in the risk of any apneic episodes, failed apnea reduction after two to seven days, cerebral palsy, developmental delay, and may reduce receipt of positive-pressure ventilation after institution of treatment. Methylxanthine used for any indication reduces chronic lung disease (defined as the use of supplemental oxygen at 36 weeks' postmenstrual age).

National survey on caffeine use in neonatal units across the United Kingdom

AIM

To understand the variations in practice for caffeine use among neonatal units in the United Kingdom.

METHODS

An online survey was sent to every neonatal unit in the United Kingdom.

RESULTS

We received a response from 92 neonatal units (47%) with the proportion of response from special care, Local neonatal units, neonatal intensive care units and neonatal surgical units were 23%, 34%, 23% and 21% respectively. All the units reported the use of caffeine, and 40 units (46%) initiated caffeine within 24 h of birth. Fifty-nine units (64%) reported routine use of caffeine for pre-term infants <32 weeks. Seventy-one units (77%) reported that they continue caffeine for infants needing mechanical ventilation. Thirty-one units (34%) discontinued caffeine at 34 weeks post-menstrual age, irrespective of the respiratory support. Ten units (11%) reported discontinuation of caffeine only after weaning off all respiratory support, and 40% of units had a variable practice of discontinuing caffeine depending on the individual baby. Seventy-nine units (86%) reported they would regularly optimise caffeine dose based on weight checks.

CONCLUSION

Our survey showed some variation in practice with regards to the timing of caffeine initiation, gestational age cut-off for routine caffeine prescription and discontinuation.

Observational cohort study of use of caffeine in preterm infants and association between early caffeine use and neonatal outcomes

OBJECTIVE

To quantify trends in caffeine use in infants born at <32 weeks' gestational age (GA), and to investigate the effects of early vs late caffeine on neonatal outcomes.

STUDY DESIGN

Retrospective propensity score matched cohort study using routinely recorded data from the National Neonatal Research Database of infants born at <32 weeks' GA admitted to neonatal units in England and Wales (2012-2020).

RESULTS

89% (58 913/66 081) of infants received caffeine. In 70%, caffeine was started early (on the day of birth or the day after), increasing from 55% in 2012 to 83% in 2020. Caffeine was given for a median (IQR) of 28 (17-43) days starting on day 2 (1-3) and continued up to 34 (33-34) weeks postmenstrual age.In the propensity score matched cohort of 13 045 pairs of infants, the odds of preterm brain injury (early caffeine, 2306/13 045 (17.7%) vs late caffeine, 2528/13 045 (19.4%), OR=0.89 (95% CI 0.84 to 0.95)) and bronchopulmonary dysplasia (BPD) (early caffeine, 4020/13 045 (32.8%) vs late caffeine, 4694/13 045 (37.7%), OR=0.81 (95% CI 0.76 to 0.85)) were lower in the group that received early caffeine compared with those who received it later.

CONCLUSIONS

Early use of caffeine has increased in England and Wales. This is associated with reduced risks of BPD and preterm brain injury. Randomised trials are needed to find the optimal timing of caffeine use and the groups of infants who will benefit most from early administration of caffeine.

A two-center retrospective study: association of early caffeine administration and oxygen radical diseases in neonatology in Chinese preterm neonates

Introduction

Since December 2012, the prophylactic use of caffeine to treat AOP in preterm infants has been approved in China. This study aimed to investigate the relationship between early caffeine treatment initiation and the incidence of oxygen radical diseases in neonatology (ORDIN) in Chinese preterm infants.

Methods

A retrospective study was conducted at two hospitals in South China, involving 452 preterm infants with gestational ages less than 37 weeks. The infants were divided into early (227 cases, initiating within 48 h after birth) and late (225 cases, initiating over 48 h after birth) caffeine treatment group. Logistic regression analysis and Receiver Operating Characteristic (ROC) curves were used to evaluate the association between early caffeine treatment and the incidence of ORDIN.

Results

The results showed that extremely preterm infants in early treatment group had a lower incidence of PIVH and ROP compared to those in the late treatment group (PIVH, 20.1% versus 47.8%, P = 0.02; ROP, 70.8% versus 89.9%, P = 0.025). Very preterm infants in the early treatment group had a lower incidence of BPD and PIVH compared to those in the late treatment group (BPD, 43.8% versus 63.1%, P = 0.002; PIVH, 9.0% versus 22.3%, P = 0.001). Moreover, VLBW infants who received early caffeine treatment exhibited a decreased incidence of BPD (55.9% versus 80.9%, P = 0.000), PIVH (11.8% versus 33.1%, P = 0.000), and ROP (69.9% versus 79.8%, P = 0.043) compared to those in the late treatment group. Infants in the early caffeine treatment showed a reduced likelihood of PIVH (adjusted odds ratio, 0.407; 95%CI, 0.188-0.846) but did not exhibit a significant association with other terms of ORDIN. ROC analysis revealed that early initiation of caffeine treatment was associated with lower risk of BPD, PIVH, and ROP in preterm infants.

Discussion

In conclusion, this study demonstrates that early initiation of caffeine treatment is associated with a decreased incidence of PIVH in Chinese preterm infants. Further prospective investigations are necessary to verify and elucidate the precise effects of early caffeine treatment on complications in preterm Chinese infants.

Bronchopulmonary Dysplasia in Extremely Premature Infants: A Scoping Review for Identifying Risk Factors

BACKGROUND

Over the years, bronchopulmonary dysplasia (BPD) affects the pulmonary function of infants, resulting in chronic health burdens for infants and their families. The aim of this scoping review was to screen available evidence regarding perinatal risk factors associated with the development and severity of BPD.

METHODS

The eligibility criteria of the studies were year of publication between 2016 and 2021; setting of a developed country; English or Japanese as the study language; and randomized controlled, cohort, or case-control design. The titles and abstracts of the studies were screened by independent reviewers.

RESULTS

Of 8189 eligible studies, 3 were included for severe BPD and 26 were included for moderate BPD. The risk factors for severe BPD were male sex, iatrogenic preterm birth, maternal hypertensive disorders of pregnancy (HDP), low gestational age, small-for-gestational-age (SGA) birth weight, mechanical ventilation on day 1, and need for patent ductus arteriosus (PDA) management. The risk factors for moderate or severe BPD included male sex, premature rupture of membranes, clinical chorioamnionitis, maternal HDP, SGA birth weight, bubbly/cystic appearance on X-ray, and PDA management.

CONCLUSIONS

We identified several risk factors for BPD. We plan to confirm the validity of the new classification using the existing dataset.

Protective Effects of Early Caffeine Administration in Hyperoxia-Induced Neurotoxicity in the Juvenile Rat

High-risk preterm infants are affected by a higher incidence of cognitive developmental deficits due to the unavoidable risk factor of oxygen toxicity. Caffeine is known to have a protective effect in preventing bronchopulmonary dysplasia associated with improved neurologic outcomes, although very early initiation of therapy is controversial. In this study, we used newborn rats in an oxygen injury model to test the hypothesis that near-birth caffeine administration modulates neuronal maturation and differentiation in the hippocampus of the developing brain. For this purpose, newborn Wistar rats were exposed to 21% or 80% oxygen on the day of birth for 3 or 5 days and treated with vehicle or caffeine (10 mg/kg/48 h). Postnatal exposure to 80% oxygen resulted in a drastic reduction of associated neuronal mediators for radial glia, mitotic/postmitotic neurons, and impaired cell-cycle regulation, predominantly persistent even after recovery to room air until postnatal day 15. Systemic caffeine administration significantly counteracted the effects of oxygen insult on neuronal maturation in the hippocampus. Interestingly, under normoxia, caffeine inhibited the transcription of neuronal mediators of maturing and mature neurons. The early administration of caffeine modulated hyperoxia-induced decreased neurogenesis in the hippocampus and showed neuroprotective properties in the neonatal rat oxygen toxicity model.

The association of salivary caffeine levels with serum concentrations in premature infants with apnea of prematurity

The purpose of this paper is to verify whether the concentrations of caffeine in saliva are comparable to serum concentrations in preterm infants who are treated with caffeine for apnea of prematurity. This is a prospective observational study. Eligible participants were newborn infants < 37 weeks of gestational age treated with oral or intravenous caffeine for apnea of prematurity. Two paired samples of saliva and blood were collected per patient. Tube solid-phase microextraction coupled online to capillary liquid chromatography with diode array detection was used for analysis. A total of 47 infants with a median gestational age of 28 [26-30] weeks and a mean of 1.11 ± 0.4 kg of birth weight. Median postmenstrual age, when samples were collected, was 31 [29-33] weeks. Serum caffeine median levels of 19.30 μg/mL [1.9-53.90] and salivary caffeine median levels of 16.36 μg/mL [2.20-56.90] were obtained. There was a strong positive Pearson's correlation between the two variables r = 0.83 (p < 0.001).

CONCLUSION

The measurement of salivary caffeine concentrations after intravenous or oral administration offers an alternative to serum caffeine monitoring in apnea of prematurity. Measurement of salivary concentration minimizes blood draws, improves blood conservation, and subsequently minimizes painful procedures in premature infants.

WHAT IS KNOWN

• Salivary sampling may be useful when is applied to extremely low birth weight infant, in whom blood sampling must be severely restricted.

WHAT IS NEW

• The measurement of caffeine salivary concentrations after intravenous or oral administration offers an alternative to serum caffeine monitoring in apnoea of prematurity. • Salivary sampling may be a valid non-invasive alternative that could be used to individualize and optimize caffeine dose.

A survey of barriers and facilitators to caffeine use for apnoea of prematurity in low- and middle-income countries

BACKGROUND

Despite its associated benefits which include better long-term pulmonary and neurodevelopmental outcome, the use of caffeine for apnoea of prematurity (AoP) has been limited in low- and middle-income countries (LMIC).

AIM

To better understand current caffeine use, the barriers and facilitators to its use and perceptions and practices in LMIC which have a disproportionately high burden of prematurity.

METHODS

An anonymous online global survey was conducted, targeting healthcare providers working and training in paediatrics and/or neonatology in LMIC.

RESULTS

A total of 181 respondents in 16 LMIC were included in the analysis; most were physicians working in publicly-funded urban tertiary hospitals. Most had received training in the use of caffeine for AoP (77%), reported expertise (70%) and confidence (96%) in its use, and had access to caffeine (65%). Caffeine availability was reported to be the greatest barrier (48%) and the greatest facilitator (37%). Other common barriers included cost (31%), access (7%) and policies or guidelines on caffeine use (7%); other common facilitators included policies or guidelines on caffeine use (11%), access (10%), staff/other providers' acceptance of caffeine as an appropriate treatment (9%) and the availability of staff to administer caffeine (8%). Most (79%) noted that access to caffeine was important, 92% agreed that caffeine improves quality of care, and 95% agreed that caffeine improves patient outcome.

CONCLUSION

Improving availability and access to low-cost caffeine will be key to increasing caffeine use in LMIC.

ABBREVIATIONS

AoP: Apnoea of Prematurity; LMIC: low- and middle-Income countries; REDCap: Research Electronic Data Capture.

Caffeine and bronchopulmonary dysplasia: Clinical benefits and the mechanisms involved

Bronchopulmonary dysplasia (BPD) is a chronic respiratory disease that occurs during the neonatal period and is commonly associated with prematurity. This condition results in a severe economic burden on society and the families involved. Caffeine is used not only for the treatment of apnea in prematurity, but also for the prevention of BPD. There are multiple clinical benefits of caffeine treatment, including improved extubation success, a reduced duration of mechanical ventilation, improved lung function, and a reduction of patent ductus arteriosus requiring treatment. These clinical benefits of caffeine for the treatment of BPD are supported by both clinical trials and evidence from animal models. However, the mechanism by which caffeine protects against BPD remains unclear. Here, we review the clinical value of caffeine in the prevention of BPD and its potential mechanisms of action, including anti-inflammatory, antioxidant, antifibrotic, and antiapoptotic properties, the regulation of angiogenesis, and diuretic effects. Our aim is to provide a new theoretical basis for the clinical treatment of BPD.

The Conflicting Role of Caffeine Supplementation on Hyperoxia-Induced Injury on the Cerebellar Granular Cell Neurogenesis of Newborn Rats

Preterm birth disrupts cerebellar development, which may be mediated by systemic oxidative stress that damages neuronal developmental stages. Impaired cerebellar neurogenesis affects several downstream targets important for cognition, emotion, and speech. In this study, we demonstrate that oxidative stress induced with high oxygen (80%) for three or five postnatal days (P3/P5) could significantly damage neurogenesis and proliferative capacity of granular cell precursor and Purkinje cells in rat pups. Reversal of cellular neuronal damage after recovery to room air (P15) was augmented by treatment with caffeine. However, downstream transcripts important for migration and differentiation of postmitotic granular cells were irreversibly reduced by hyperoxia, without rescue by caffeine. Protective effects of caffeine in the cerebellum were limited to neuronal survival but failed to restore important transcript signatures.

Five-year outcomes of premature infants randomized to high or standard loading dose caffeine

OBJECTIVE

To examine 5-year outcomes in children enrolled in a pilot randomized controlled trial of a high loading dose of caffeine after preterm birth.

STUDY DESIGN

Seventy-four very low birth weight neonates were randomized within the first 24 h of life to receive a high (80 mg/kg) or standard (20 mg/kg) loading dose of caffeine citrate. At 5 years of age, we conducted standardized neurodevelopmental tests and collected parent reports of child socioemotional problems.

RESULT

Seventy-four percent of survivors returned for follow up. Children obtained similar scores on neurodevelopmental and socioemotional evaluations. There was no difference in the incidence of any neurodevelopmental delay after controlling for confounding factors.

CONCLUSION

Five-year follow up of a pilot trial of high loading dose caffeine citrate documented no profound impacts on childhood neurodevelopment or socioemotional outcome.

Pharmacological Neuroprotection of the Preterm Brain: Current Evidence and Perspectives

Despite improvements in viability, the long-term neurodevelopmental outcomes of preterm babies remain serious concern as a significant percentage of these infants develop neurological and/or intellectual impairment, and they are also at increased risk of psychiatric illnesses later in life. The current challenge is to develop neuroprotective approaches to improve adverse outcomes in preterm survivors. The purpose of this review was to provide an overview of the current evidence on pharmacological agents targeting the neuroprotection of the preterm brain. Among them, magnesium sulfate, given antenatally to pregnant women with imminent preterm birth before 30 to 34 weeks of gestation, as well as caffeine administered to preterm infants after birth, exhibited neuroprotective effects for human preterm brain. Erythropoietin treatment of preterm infants did not result in neuroprotection at 2 years of age in two out of three published large randomized controlled trials; however, long-term follow-up of these infants is needed to come to definite conclusions. Further studies are also required to assess whether melatonin, neurosteroids, inhaled nitric oxide, allopurinol, or dietary supplements (omega-3 fatty acids, choline, curcumin, etc.) could be implemented as neuroprotectants in clinical practice. Furthermore, other pharmacological agents showing promising signs of neuroprotective efficacy in preclinical studies (growth factors, hyaluronidase inhibitors or treatment, antidiabetic drugs, cannabidiol, histamine-H3 receptor antagonists, etc.), as well as stem cell- or exosomal-based therapies and nanomedicine, may prove useful in the future as potential neuroprotective approaches for human preterm brain. KEY POINTS: · Magnesium and caffeine have neuroprotective effects for the preterm brain.. · Follow-up of infants treated with erythropoietin is needed.. · Neuroprotective efficacy of several drugs in animals needs to be shown in humans..

Recent research on the effect of common treatments given in the perinatal period on neurodevelopment in offspring

The perinatal period is the key period for the development of brain and central nervous system, and different events in this period will have a profound influence on brain development. Glucocorticoids, antibiotics, magnesium sulfate, caffeine, pulmonary surfactant, and mild hypothermia treatment are commonly used drugs or treatment methods in the perinatal period and are closely associated with the prognosis of neonatal neurodevelopment. This article reviews the latest research on the effect of perinatal treatments on neonatal neurodevelopment, so as to provide a reference for clinical decision making.

Effect of different maintenance doses of caffeine citrate on ventilator weaning in very preterm infants with respiratory distress syndrome: a prospective randomized controlled trial

OBJECTIVES

To study the effect of different maintenance doses of caffeine citrate on the success rate of ventilator weaning in very preterm infants (gestational age of ≤32 weeks) with respiratory distress syndrome (RDS).

METHODS

A total of 162 preterm infants with RDS who were admitted to the hospital from January 2016 to December 2018 were enrolled in this prospective trial. These infants had a gestational age of ≤32 weeks and required invasive mechanical ventilation. They were randomly divided into a high-dose caffeine group and a low-dose caffeine group, with 81 infants in each group. Within 6 hours after birth, both groups were given caffeine at a dose of 20 mg/kg. After 24 hours, the high- and low-dose caffeine groups were given caffeine at a maintenance dose of 10 mg/kg and 5 mg/kg, respectively. The two groups were compared in terms of re-intubation rate within 48 hours after ventilator weaning, durations of ventilation and oxygen therapy, enteral feeding, weight gain, and the incidence rates of complications and adverse reactions during hospitalization.

RESULTS

The high-dose caffeine group had a significantly lower re-intubation rate within 48 hours after ventilator weaning than the low-dose caffeine group (P<0.05), with frequent apnea as the main reason for failed ventilator weaning in both groups. The high-dose caffeine group had significantly shorter durations of mechanical ventilation and oxygen therapy than the low-dose caffeine group (P<0.05). There were no significant differences between the two groups in the time to total enteral feeding, average daily weight gain, body weight at discharge, and the incidence rates of complications (bronchopulmonary dysplasia, retinopathy of prematurity, necrotizing enterocolitis, and intracranial hemorrhage) and adverse reactions (tachycardia, hypertension, and feeding intolerance) (P>0.05).

CONCLUSIONS

A high maintenance dose of caffeine can safely and effectively reduce the incidence rate of apnea after ventilator weaning and the failure rate of ventilator weaning in RDS preterm infants with a gestational age of ≤32 weeks, and therefore, it holds promise for clinical application.

Diagnosis and management of bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is the most common chronic lung disease in infants and is associated with increased mortality, respiratory morbidity, neurodevelopmental impairment, and increased healthcare costs. In parallel with advances made in the field of neonatal intensive care, the phenotype of BPD has evolved from a fibrocystic disease affecting late preterm infants to one of impaired parenchymal development and dysregulated vascular growth predominantly affecting infants born before 29 weeks' gestational age. BPD has been shown to have significant lifelong consequences. Adults with BPD have been found to have abnormal lung function tests, reduced exercise tolerance, and may be at increased risk for developing chronic obstructive pulmonary disease. Evidence shows that BPD occurs secondary to genetic-environmental interactions in an immature lung. In this review, we evaluate the various clinical definitions, imaging modalities, and biomarker data that are helpful in making an early diagnosis of BPD. In addition, we evaluate recent evidence about the prevention and treatment of BPD. We discuss the invasive and non-invasive ventilation strategies and pharmacological agents used in the early, evolving, and established phases of BPD.

Analysis of Factors Associated With Body Mass Index at Ages 18 and 36 Months Among Infants Born Extremely Preterm

IMPORTANCE

The development of neonatology has been associated with improved survival among infants born extremely preterm, and understanding their long-term outcomes is becoming increasingly important. However, there is little information on body mass index (BMI) among these children.

OBJECTIVE

To determine factors associated with BMI at ages 18 months and 36 months among infants born extremely preterm.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective, multicenter cohort study was conducted using data from the Neonatal Research Network Japan database for 8838 infants born at gestational ages 23 to 28 weeks with data on BMI at 18 months and 36 months. Data were analyzed from April 2018 through June 2021.

EXPOSURES

BMI and BMI z score at ages 18 months and 36 months were regressed with gestational age, intrauterine growth restriction (IUGR) status, and complications during pregnancy and the neonatal period separately by presence of multiple pregnancy and sex.

MAIN OUTCOMES AND MEASURES

BMI and BMI z score at ages 18 months and 36 months.

RESULTS

Among 16 791 eligible infants born extremely preterm, 8838 infants were included in the analysis. There were 7089 infants born from single pregnancies (mean [SD] gestational age, 26.0 [1.6] weeks; 3769 [53.2%] boys; mean [SD] birth weight, 847 [228] g) and 1749 infants born from multiple pregnancies (mean [SD] gestational age, 26.3 [1.5] weeks; 903 [51.6%] boys; mean [SD] birth weight, 860 [217] g). In single pregnancies, every week of increased gestational age was associated with an increase in BMI of 0.21 (95% CI, 0.17-0.25) among boys and 0.20 (95% CI, 0.15-0.25) among girls at age 18 months and 0.21 (95% CI, 0.18-0.24) among boys and 0.21 (95% CI, 0.18-0.24) among girls at age 36 months. There was an interaction association between gestational age and IUGR among boys at age 36 months, with a decrease in the change associated with gestational age of 0.12 (95% CI, 0.05-0.19). Every week of increased gestational age in single pregnancies was associated with an increase in BMI z score of 0.14 (95% CI, 0.17-0.21) among boys and 0.17 (95% CI, 0.13-0.21) among girls at age 18 months and 0.19 (95% CI, 0.16-0.22) among boys and 0.17 (95% CI, 0.15-0.20) among girls at age 36 months. Among single pregnancies, IUGR was associated with a decrease in BMI among boys (0.59 [95% CI, 0.23-0.95]) and girls (0.75 [95% CI, 0.39-1.11]) and BMI z score among boys 0.85 [95% CI, 0.25-0.95)] and girls (0.67 [95% CI, 0.36-0.97] at age 18 months and BMI among boys (0.44 [95% CI, 0.17-0.18]) and girls (0.84 [95% CI, 0.55-1.12]) and BMI z score among boys (0.46 [95% CI, 0.21-0.71]) and girls (0.77 [95% CI, 0.53-1.01]) at age 36 months. In multiple pregnancies, IUGR was associated with a decrease in BMI z score at age 36 months among boys (0.26 [95% CI, 0.42-0.89]) and girls (0.29 [95% CI, 0.22-0.79]). In single pregnancies intraventricular hemorrhage (IVH) was associated with a decrease in BMI of 0.47 (95% CI, 0.21-0.73) among boys and 0.42 (95% CI, 0.13-0.71) among girls at age 18 months and 0.53 (95% CI, 0.32-0.74) among boys and 0.31 (95% CI, 0.07-0.54) among girls at age 36 months. IVH was associated with a decrease in BMI z score in single pregnancies of 0.63 (95% CI, 0.20-0.41) among boys and 0.35 (95% CI, 0.12-0.60) among girls at age 18 months and 0.53 (95% CI, 0.34-0.71) among boys and 0.30 (95% CI, 0.11-0.50) among girls at age 36 months. Similar associations were seen in multiple pregnancies.

CONCLUSIONS AND RELEVANCE

This study found that gestational age, the presence of IUGR and multiple pregnancy, and IVH complications were associated with infant BMI at ages 18 months and 36 months. These findings suggest that these complicating factors should be considered when setting growth targets and nutrition strategies for infants born extremely preterm.

Caffeine citrate for apnea of prematurity-One dose does not fit all a prospective study

BACKGROUND

Caffeine citrate is the most frequently used medication in preterm neonates for the prevention of apnea of prematurity. There is no accepted consensus regarding the optimal caffeine citrate dosing. In this study, we evaluate clinical responses of premature neonates to standard-dose caffeine citrate treatment.

METHODS

A prospective observational study conducted at the NICU at Sheba Medical Center (3/2016-2/2017). The study population included preterm neonates born at a gestational age (GA) < 33 weeks and treated with caffeine citrate according to the local NICU protocol.

RESULTS

The study cohort included 66 preterm neonates of GA < 33 weeks. Thirty infants were defined as responders and 36 as nonresponders to 7.5 mg/kg caffeine citrate treatment, and they required a further dose increase to 10 mg/kg. Infants in the nonresponders group were born at earlier GA than responders (29 vs. 31 weeks, respectively, P = 0.004). The nonresponders required a significantly longer hospital stay (56 vs. 46 days, P = 0.014), and longer supplemental oxygen support (18 vs 2 days, P = 0.008).

CONCLUSIONS

Caffeine citrate initiation at higher doses is safe and does not require routine serum levels monitoring. It might be more effective for controlling apnea of prematurity in preterm neonates born ≤29 weeks of gestation.

From Neonatal Intensive Care to Neurocritical Care: Is It Still a Mirage? The Sicilian Multicenter Project

Background

Neonatal brain injury (NBI) can lead to a significant neurological disability or even death. After decades of intense efforts to improve neonatal intensive care and survival of critically ill newborns, the focus today is an improved long-term neurological outcome through brain-focused care. The goal of neuroprotection in the neonatal intensive care unit (NICU) is the prevention of new or worsening NBI in premature and term newborns. As a result, the neonatal neurocritical care unit (NNCU) has been emerging as a model of care to decrease NBI and improve the long-term neurodevelopment in critically ill neonates.

Purpose

Neurocritical care (NCC) Sicilian project includes three academic sites with NICU in Sicily (Catania, Messina, and Palermo), and its primary goal is to develop neurocritical neonatal care unit (NNCU).

Methods

In 2018, the three NICUs created a dedicated space for neonates with primary neurological diagnosis or at risk for neurological injuries—NNCU. Admission criteria for eligible patients and treatment protocols were created. Contact with parents, environmental protection, basic monitoring, brain monitoring, pharmacological therapy, and organization of the staff were protocolized.

Results

Evaluation of the efforts to establish NNCU within existing NICU, current protocols, and encountered problems are shown. Implications for Practice. Our outcome confirmed the need for dedicated NNCU for neuroprotection of critically ill neonates at risk for a neurological injury. Although the literature on neonatal neurocritical care is still scarce, we see the value of such targeted approach to newborn brain protection and therefore we will continue developing our NNCU, even though there have been problems encountered. The project of building NNCU will continue to be closely monitored.

Conclusions

The development of our neonatal neurocritical model of care is far from being completed. Although it is currently limited to the Sicilian area only, the goal of this paper is to share the development of this multicenter interdisciplinary project focused on a newborn brain protection. After evaluating our outcome, we strongly believe that a combined expertise in neonatal neurology and neonatal critical care can lead to an improved neurodevelopmental outcome for critically ill neonates, from the extremely preterm to those with brain injuries.

Neurodevelopmental outcomes in mild and moderate isolated ventriculomegaly originating in utero

OBJECTIVE

To determine the differences in outcomes between mild and moderate isolated ventriculomegaly (IVM).

METHODS

We conducted a prospective cohort study on 94 fetuses with IVM and evaluated the neurodevelopmental outcomes at 12 months of age using the ASQ-3 and BSID-I neurodevelopmental assessment tools. Progression of VM was defined as an increase in the width of the ventricular by at least 3 mm during sequential ultrasound monitoring. The population was divided into two groups according to ventricular width: mild (10-12 mm) and moderate (12.1-15 mm), which were further evaluated for VM progression in utero separately.

RESULTS

Neurodevelopmental assessments at 12 months were the main form of evaluations. Neurodevelopmental impairment (NDI) was defined as a mental development index (MDI) or psychomotor development index (PDI) < 85. There were no significant differences in NDI values between the mild and moderate groups (p = .155). Compared with the non-in utero progression group (7.6%), the rate of NDI was significantly higher (p = .004) in the group with progression (33.3%). Using linear regression and correlation, no negative correlation was found between the maximum value of atrial diameter (AD) in utero and the PDI (r = -0.021, p = .914) or MDI (r = -0.073, p = .703) score. However, the maximum change in the AD in utero was negatively correlated with both PDI (r = -0.460, p = .011) and MDI (r=-0.422, p = .020) scores.

CONCLUSION

There were likely no differences in neurodevelopmental outcomes between mild and moderate IVM. In fetuses with mild to moderate VM, intrauterine progression may be a poor prognostic factor for neurodevelopmental outcomes.

Evidence for the Management of Bronchopulmonary Dysplasia in Very Preterm Infants

Background: Very preterm birth often results in the development of bronchopulmonary dysplasia (BPD) with an inverse correlation of gestational age and birthweight. This very preterm population is especially exposed to interventions, which affect the development of BPD. Objective: The goal of our review is to summarize the evidence on these daily procedures and provide evidence-based recommendations for the management of BPD. Methods: We conducted a systematic literature research using MEDLINE/PubMed on antenatal corticosteroids, surfactant-replacement therapy, caffeine, ventilation strategies, postnatal corticosteroids, inhaled nitric oxide, inhaled bronchodilators, macrolides, patent ductus arteriosus, fluid management, vitamin A, treatment of pulmonary hypertension and stem cell therapy. Results: Evidence provided by meta-analyses, systematic reviews, randomized controlled trials (RCTs) and large observational studies are summarized as a narrative review. Discussion: There is strong evidence for the use of antenatal corticosteroids, surfactant-replacement therapy, especially in combination with noninvasive ventilation strategies, caffeine and lung-protective ventilation strategies. A more differentiated approach has to be applied to corticosteroid treatment, the management of patent ductus arteriosus (PDA), fluid-intake and vitamin A supplementation, as well as the treatment of BPD-associated pulmonary hypertension. There is no evidence for the routine use of inhaled bronchodilators and prophylactic inhaled nitric oxide. Stem cell therapy is promising, but should be used in RCTs only.

Therapy for Apnoea of Prematurity: A Retrospective Study on Effects of Standard Dose and Genetic Variability on Clinical Response to Caffeine Citrate in Chinese Preterm Infants

INTRODUCTION

Apnoea of prematurity (AOP) is among the most common diagnoses in the neonatal intensive care unit. Caffeine treatment is a preferred treatment choice. However, neonatal caffeine therapy results in significant intersubject variability. This study aimed to determine the effects of plasma caffeine levels based on standard dose and genetic variability on clinical response to caffeine citrate in Chinese preterm infants.

METHODS

This single-center and retrospective study examined data from 112 preterm infants (< 35 weeks gestational age) between July 2017 and July 2018. Subjects were divided into apnoea-free (n = 48) and apnoeic (n = 64) groups, and their clinical outcomes were summarized. Liquid chromatography-tandem mass spectrometry was used to measure levels of caffeine and its primary metabolites. Eighty-eight single-nucleotide polymorphisms were chosen for genotyping by a MassARRAY system.

RESULTS

Preterm infants in the apnoea-free group were associated with a reduction in the incidence of bronchopulmonary dysplasia and a reduced requirement for patent ductus arteriosus ligation. No significant association was observed between plasma-trough-concentration-to-dose (C₀/D) ratio and birth weight, gestational age, or postnatal age in either group. Polymorphisms in CYP1A2 and aryl hydrocarbon receptor (AHR) genes did not affect plasma caffeine levels. Polymorphisms in adenosine receptor genes ADORA1 (rs10920568 and rs12744240), ADORA2A (rs34923252 and rs5996696), and ADORA3 (rs10776727 and rs2298191), especially in AHR (rs4410790) and adenosine deaminase (rs521704), play critical roles in the interindividual response to caffeine therapy.

CONCLUSIONS

Genetic polymorphisms in caffeine's target receptors, but not the exposure levels based on the standard dosing, were associated with variable responses to caffeine therapy in preterm neonates. Future studies are needed to uncover how these genetic variants affect responses to caffeine therapy in this patient population.

Encephalopathy in Preterm Infants: Advances in Neuroprotection With Caffeine

With the improvement in neonatal rescue technology, the survival rate of critically ill preterm infants has substantially increased; however, the incidence of brain injury and sequelae in surviving preterm infants has concomitantly increased. Although the etiology and pathogenesis of preterm brain injury, and its prevention and treatment have been investigated in recent years, powerful and effective neuroprotective strategies are lacking. Caffeine is an emerging neuroprotective drug, and its benefits have been widely recognized; however, its effects depend on the dose of caffeine administered, the neurodevelopmental stage at the time of administration, and the duration of exposure. The main mechanisms of caffeine involve adenosine receptor antagonism, phosphodiesterase inhibition, calcium ion activation, and γ-aminobutyric acid receptor antagonism. Studies have shown that there are both direct and indirect beneficial effects of caffeine on the immature brain. Accordingly, this article briefly reviews the pharmacological characteristics of caffeine, its mechanism of action in the context of encephalopathy in premature infants, and its use in the neuroprotection of encephalopathy in this patient population.

Neurodevelopmental outcomes after neonatal caffeine therapy

Improving the adverse neurodevelopmental outcomes associated with prematurity is a priority. In the large international Caffeine for Apnea of Prematurity trial, caffeine improved survival without neurodevelopmental disability at 18 months and demonstrated long term safety up to 11 years. Caffeine is an adenosine receptor antagonist with effects on the brain, lung and other systems. The benefits of caffeine may be primary neuroprotection or reduction of risk factors for impairment, especially bronchopulmonary dysplasia. The effects of caffeine vary with age and dose. Animal data show risks of loss of neuronal protection from hypoxia. Treatment with earlier and higher dose caffeine may be beneficial but concerns remain.

When to start and stop caffeine and why respiratory status matters

Caffeine as tested in the CAP trial is safe and effective for preterm infants with birthweights less than 1250 g. Evidence for its use beyond the indications and timing used in this trial is of low quality and conflicting. Some studies suggest that earlier use of caffeine increases the risk of mortality while others suggest it has important benefits. It appears that infants with apnea of prematurity and those receiving assisted ventilation are the most likely to benefit from caffeine. Based on currently available evidence, routine early prescription of caffeine does not appear to be indicated. Infants continue to have potentially damaging episodes of hypoxia secondary to apnea beyond 34 weeks' postmenstrual age. It is unclear whether prolonged use of caffeine improves outcomes in these infants. Randomized trials to resolve these uncertainties are required. They need to be large, at least the size of the CAP trial, and include neurodevelopmental outcomes.

Caffeine versus aminophylline in combination with oxygen therapy for apnea of prematurity: A retrospective cohort study

The present study was conducted to investigate the clinical significance of caffeine and aminophylline in the treatment of premature infants with apnea under varying conditions of oxygen (O₂) delivery. The clinical data of 120 premature infants with apnea treated with oxygen therapy and either caffeine citrate (20 mg/kg/day; n=77) or aminophylline (10 mg/kg/day; n=43) were retrospectively examined. The therapeutic performance of the drugs after the completion of the treatment was evaluated primarily according to the risk of recurrent episodes of apnea, the changes in the duration and concentration of inhaled O₂ and the incidence of complications. In contrast to aminophylline, caffeine treatment significantly reduced the duration of O₂ inhalation and the inhaled O₂ concentration in the infants treated with mechanical ventilation or O₂ delivery devices (P<0.05). Treatment with caffeine also decreased the incidence of recurrent apnea events and complications in the investigated population (P<0.05 or P<0.01). Caffeine performs better than aminophylline in the treatment of premature infants with apnea under different conditions of O₂ delivery. The therapeutic performance of caffeine is achieved primarily via improving the efficacy of supplemental O₂ and reducing the incidence of complications.

Respiratory Support of the Preterm Neonate: Lessons About Ventilation-Induced Brain Injury From Large Animal Models

Many preterm neonates require mechanical ventilation which increases the risk of cerebral inflammation and white matter injury in the immature brain. In this review, we discuss the links between ventilation and brain injury with a focus on the immediate period after birth, incorporating respiratory support in the delivery room and subsequent mechanical ventilation in the neonatal intensive care unit. This review collates insight from large animal models in which acute injurious ventilation and prolonged periods of ventilation have been used to create clinically relevant brain injury patterns. These models are valuable resources in investigating the pathophysiology of ventilation-induced brain injury and have important translational implications. We discuss the challenges of reconciling lung and brain maturation in commonly used large animal models. A comprehensive understanding of ventilation-induced brain injury is necessary to guide the way we care for preterm neonates, with the goal to improve their neurodevelopmental outcomes.

Confounding biases in studies on early- versus late-caffeine in preterm infants: a systematic review

BACKGROUND

Caffeine is indicated for the management of apnoea of prematurity and extubation in preterm infants. Early initiation of caffeine administration has increased in the past decades with the purpose of reducing respiratory morbidity. However, there might be harms associated with this approach. This systematic review aims to assess whether early administration of caffeine reduces morbidity and mortality in preterm infants.

METHODS

The methods were published in a preregistered protocol. The literature search was performed in February 2019 with no restrictions for language or publication date. Randomised controlled trials (RCTs) and cohort studies comparing early versus late caffeine administration to infants born before week 34 were included.

RESULTS

Two RCTs and 14 cohort studies were included. All studies but one had a serious/critical overall risk of bias. Few studies reported on long-term or patient-relevant outcomes. No meta-analysis could be performed.

CONCLUSION

Based on the available evidence, no conclusions about the optimal timing of caffeine administration can be drawn. There are inherent methodological problems in the cohort studies. RCTs are needed to answer the question of optimal timing for caffeine administration in neonatal care. Future trials should focus on outcomes relevant to patients and their families and include long-term outcomes.

Caffeine Therapy in Preterm Infants: The Dose (and Timing) Make the Medicine

Caffeine is one of the most commonly utilized medications in the NICU. In preterm infants, short-term and long-term pulmonary and neurodevelopmental benefits of therapy are well documented in the literature. While robust evidence supports the use of standard doses of caffeine for apnea of prematurity or to facilitate successful extubation, much remains unknown regarding the boundaries of efficacy and safety for this common therapeutic agent. Escalating dosing regimens seem to provide additional benefit in select infants, but grave toxicity has also been documented with early utilization of high-dose caffeine. Conflicting data exist surrounding the ideal timing of initiation of therapy. Even the widely adhered to discontinuation point has been challenged by data supporting continued use. Until robust data definitively support change, practice should align with current evidence defining clear, safe, and efficacious dosing and timing of caffeine therapy.

Caffeine in preterm infants: where are we in 2020?

The incidence of preterm birth is increasing, leading to a growing population with potential long-term pulmonary complications. Apnoea of prematurity (AOP) is one of the major challenges when treating preterm infants; it can lead to respiratory failure and the need for mechanical ventilation. Ventilating preterm infants can be associated with severe negative pulmonary and extrapulmonary outcomes, such as bronchopulmonary dysplasia (BPD), severe neurological impairment and death. Therefore, international guidelines favour non-invasive respiratory support. Strategies to improve the success rate of non-invasive ventilation in preterm infants include pharmacological treatment of AOP. Among the different pharmacological options, caffeine citrate is the current drug of choice. Caffeine is effective in reducing AOP and mechanical ventilation and enhances extubation success; it decreases the risk of BPD; and is associated with improved cognitive outcome at 2 years of age, and pulmonary function up to 11 years of age. The commonly prescribed dose (20 mg·kg⁻¹ loading dose, 5–10 mg·kg⁻¹ per day maintenance dose) is considered safe and effective. However, to date there is no commonly agreed standardised protocol on the optimal dosing and timing of caffeine therapy. Furthermore, despite the wide pharmacological safety profile of caffeine, the role of therapeutic drug monitoring in caffeine-treated preterm infants is still debated. This state-of-the-art review summarises the current knowledge of caff­eine therapy in preterm infants and highlights some of the unresolved questions of AOP. We speculate that with increased understanding of caffeine and its metabolism, a more refined respiratory management of preterm infants is feasible, leading to an overall improvement in patient outcome.

Caffeine is the current drug of choice to prevent and treat apnoea of prematurity. There is no agreed protocol on the optimal timing and dosage of caffeine therapy for preterm babies. Data on caffeine metabolism may optimise individualised therapy.http://bit.ly/2LMuJPY

Variations in preterm stabilisation practices and caffeine therapy between two European tertiary level neonatal units

AIM

To investigate interinstitutional differences in preterm infant stabilisation between two European tertiary neonatal centres with particular focus on intubation timing, surfactant administration, caffeine therapy and neonatal morbidity and mortality.

METHODS

Retrospective (2012-2014) study of very low birth weight (VLBW) preterm infants admitted to John Radcliffe Hospital (UK centre) and Charité Medical Centre (German centre). Timing of intubation, surfactant and caffeine administration and respiratory outcomes were examined.

RESULTS

Gestational age, birth weight and five-minute Apgar scores of VLBW infants from the UK centre (n = 86) were comparable to those from the German centre (n = 96). Significant differences in antenatal steroid therapy, intubation timing and surfactant therapy were noted. Timing of caffeine initiation differed significantly between centres (median 0 [0-2.5] UK vs. 2 [1.5-4] days German centre); however, caffeine was discontinued at a similar corrected gestational age of 34.7 weeks. Mechanical ventilation was significantly longer at the UK centre, but there was no difference in bronchopulmonary dysplasia (BPD) (44% UK vs. 36% German centre) or mortality (15% UK vs. 13% German centre).

CONCLUSION

Timing of primary intubation and caffeine therapy differed significantly between centres. However, earlier intubation and caffeine administration in the UK centre were not associated with a changed incidence of BPD.

Current evidence and outcomes for retinopathy of prematurity prevention: insight into novel maternal and placental contributions

Retinopathy of prematurity (ROP) is a blinding morbidity of preterm infants, which represents a significant clinical problem, accounting for up to 40% of all childhood blindness. ROP displays a range of severity, though even mild disease may result in life-long visual impairment. This is complicated by the fact that our current treatments have significant ocular and potentially systemic effects. Therefore, disease prevention is desperately needed to mitigate the life-long deleterious effects of ROP for preterm infants. Although ROP demonstrates a delayed onset of retinal disease following preterm birth, representing a potential window for prevention, we have been unable to sufficiently alter the natural disease course and meaningfully prevent ROP. Prevention therapeutics requires knowledge of early ROP molecular changes and risk, occurring prior to clinical retinal disease. While we still have an incomplete understanding of these disease mechanisms, emerging data integrating contributions of maternal/placental pathobiology with ROP are poised to inform novel approaches to prevention. Herein, we review the molecular basis for current prevention strategies and the clinical outcomes of these interventions. We also discuss how insights into early ROP pathophysiology may be gained by a better understanding of maternal and placental factors playing a role in preterm birth.

Wide variation in caffeine discontinuation timing in premature infants

OBJECTIVE

To assess site variability and concomitant respiratory support related to the timing of caffeine discontinuation, and compare clinical characteristics of infants who discontinued caffeine before vs. within the last week of hospitalization.

STUDY DESIGN

Cohort study of 81,110 infants <35 weeks gestational age and <1500 g birth weight discharged from 304 neonatal intensive care units from 2001-2016.

RESULTS

The mean postmenstrual age at caffeine discontinuation ranged from 32 to 37 weeks among sites. Respiratory support at the time of discontinuation was common, but variable, with 0-57% of infants receiving positive airway pressure at caffeine discontinuation by site. Infants who discontinued caffeine within the last week of hospitalization had longer total duration of caffeine, but were discharged from the hospital at an earlier postmenstrual age.

CONCLUSION

There was substantial variability among sites in the timing of caffeine discontinuation before discharge and respiratory support at the time of caffeine discontinuation.

Predicting Lung Health Trajectories for Survivors of Preterm Birth

Rates of preterm birth (<37 weeks of gestation) are increasing worldwide. Improved perinatal care has markedly increased survival of very (<32 weeks gestation) and extremely (<28 weeks gestation) preterm infants, however, long term respiratory sequalae are common among survivors. Importantly, individual's lung function trajectories are determined early in life and tend to track over the life course. Preterm infants are impacted by antenatal, postnatal and early life perturbations to normal lung growth and development, potentially resulting in significant shifts from the "normal" lung function trajectory. This review summarizes what is currently known about the long-term lung function trajectories in survivors of preterm birth. Further, this review highlights how antenatal, perinatal and early life factors are likely to contribute to individual lung health trajectories across the life course.

Caffeine and Clinical Outcomes in Premature Neonates

Caffeine is the most widely used drug by both adults and children worldwide due to its ability to promote alertness and elevate moods. It is effective in the management of apnea of prematurity in premature infants. Caffeine for apnea of prematurity reduces the incidence of bronchopulmonary dysplasia in very-low-birth-weight infants and improves survival without neurodevelopmental disability at 18-21 months. Follow-up studies of the infants in the Caffeine for Apnea of Prematurity trial highlight the long-term safety of caffeine in these infants, especially relating to motor, behavioral, and intelligence skills. However, in animal models, exposure to caffeine during pregnancy and lactation adversely affects neuronal development and adult behavior of their offspring. Prenatal caffeine predisposes to intrauterine growth restriction and small growth for gestational age at birth. However, in-utero exposure to caffeine is also associated with excess growth, obesity, and cardio-metabolic changes in children. Caffeine therapy is a significant advance in newborn care, conferring immediate benefits in preterm neonates. Studies should help define the appropriate therapeutic window for caffeine treatment along with with the mechanisms relating to its beneficial effects on the brain and the lung. The long-term consequences of caffeine in adults born preterm are being studied and may depend on the ability of caffeine to modulate both the expression and the maturation of adenosine receptors in infants treated with caffeine.

Antioxidative effects of caffeine in a hyperoxia-based rat model of bronchopulmonary dysplasia

Background

While additional oxygen supply is often required for the survival of very premature infants in intensive care, this also brings an increasing risk of progressive lung diseases and poor long-term lung outcomes. Caffeine is administered to neonates in neonatal intensive care for the prevention and treatment of apneas and has been shown to reduce BPD incidence and the need for mechanical ventilation, although it is still unclear whether this is due to a direct pulmonary action via antagonism of adenosine receptors and/or an indirect action. This experimental study aims to investigate the action of caffeine on the oxidative stress response in pulmonary tissue in a hyperoxia-based model of bronchopulmonary dysplasia in newborn rats.

Methods

Newborn Wistar rats were exposed to 21% or 80% oxygen for 3 (P3) or 5 (P5) postnatal days with or without recovery on room air until postnatal day 15 (P15) and treated with vehicle or caffeine (10 mg/kg) every 48 h beginning on the day of birth. The lung tissue of the rat pups was examined for oxidative stress response at P3 and P5 immediately after oxygen exposure or after recovery in ambient air (P15) by immunohistological staining and analysis of lung homogenates by ELISA and qPCR.

Results

Lungs of newborn rats, corresponding to the saccular stage of lung development and to the human lung developmental stage of preterms, showed increased rates of total glutathione and hydrogen peroxide, oxidative damage to DNA and lipids, and induction of second-phase mediators of antioxidative stress response (superoxide dismutase, heme oxygenase-1, and the Nrf2/Keap1 system) in response to hyperoxia. Caffeine reduced oxidative DNA damage and had a protective interference with the oxidative stress response.

Conclusion

In addition to the pharmacological antagonism of adenosine receptors, caffeine appears to be a potent antioxidant and modulates the hyperoxia-induced pulmonary oxidative stress response and thus protective properties in the BPD-associated animal model. Free-radical-induced damage caused by oxidative stress seems to be a biological mechanism progress of newborn diseases. New aspects of antioxidative therapeutic strategies to passivate oxidative stress-related injury should be in focus of further investigations.

Electronic supplementary material

The online version of this article (10.1186/s12931-019-1063-5) contains supplementary material, which is available to authorized users.

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.