Periextubation caffeine in preterm neonates: a randomized dose response trial

Association of Caffeine Daily Dose With Respiratory Outcomes in Preterm Neonates: A Retrospective Cohort Study

Apnea and poor respiratory drive increase the risk of extubation failure (EF) and prolonged invasive mechanical ventilation (IMV) in preterm neonates (pre-nates) with respiratory distress. Caffeine citrate (CC) is often prescribed for pre-nates in doses of 5-10 mg/kg in 24 h. This study aimed to evaluate the most effective dosage regimen (5 mg/kg/day vs >5-10 mg/kg/day) to prevent apnea and EF with minimal caffeine-associated potential side effects (CC-APSEs) in pre-nates. This one-year retrospective cohort study included all the eligible neonates admitted to NICU and received CC-therapy till 28 days of life (DOL) or discharge. Based on CC-daily dose formed LD-caffeine-group (5 mg/kg/day) and HD-caffeine-group (>5-10 mg/kg/day). Antenatal, prenatal, and postnatal characteristics, CC-regimen, comorbidities, and CC-APSEs were compared between the groups. Predictors of apnea and EF were analyzed through logistic regression. There were 181 and 72 neonates in the LD and HD-caffeine-groups respectively. In HD-caffeine-group daily CC-dose was 7 to 7.5 mg/kg/day in 93% of neonates and >7.5 to 10 mg/kg/day in only 7%. Significantly fewer neonates experienced apnea and EF in the HD-caffeine-group till 28DOL or discharge. This difference was even greater in the subgroup of ≤28 weeks GA (15.6% vs 40.0%; P < .01). In HD-caffeine-group the incidence of severe/moderate-BPD was significantly lower and the frequency of CC-APSEs was higher. Multivariate analysis showed that; the smaller the GA higher the risk of apnea (AOR = 0.510, 95% CI 0.483-0.999) and EF (AOR = 0.787, 95% CI 0.411-0.997). The HD-caffeine was inversely associated with developing apnea (AOR = 0.244, 95% CI 0.053-0.291) and EF (AOR = 0.103, 95% CI 0.098-2.976). IMV-duration before extubation (AOR = 2.229, 95% CI 1.672-2.498) and severe/moderate-BPD (AOR = 2.410, 95%CI 1.104-2.952) had a high risk of EF. Initiating early HD-caffeine may prevent apnea and extubation failure in preterm neonates. Optimization of caffeine initiation time and dosages can be a safe and feasible approach to decrease the burden of neonatal respiratory morbidities.

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).

Improving rates of successful extubation: Medications

This chapter focuses on the pharmacological management of newborn infants in the peri-extubation period to reduce the risk of re-intubation and prolonged mechanical ventilation. Drugs used to promote respiratory drive, reduce the risk of apnoea, reduce lung inflammation and avoid bronchospasm are critically assessed. When available, Cochrane reviews and randomised trials are used as the primary sources of evidence. Methylxanthines, particularly caffeine, are well studied and there is accumulating evidence to guide clinicians on the timing and dosage that may be used. Efficacy and safety for doxapram, steroids, adrenaline and salbutamol are summarised. Management of term infants, extubation following surgery, accidental and complicated extubation and the use of cuffed endotracheal tubes are presented. Overall, caffeine is the only drug with a substantial evidence base, proven to increase the likelihood of successful extubation in preterm infants; no drugs are needed to facilitate extubation in most term infants. Future studies might further define the role of caffeine in late preterm infants and evaluate medications for post-extubation stridor, bronchospasm or apnoea not responsive to methylxanthines.

What do we know about the sleep effects of caffeine used to treat apnoea of prematurity? A systematic review of the literature

OBJECTIVE

Scientific scrutiny has proved the safety and benefits of caffeine to treat apnoea of prematurity (AOP). However, there is no consensus on the effects of this treatment on sleep, especially considering the key role of adenosine and early brain development for sleep maturation. We systematically reviewed studies with sleep as a primary and/or secondary outcome or any mention of sleep parameters in the context of caffeine treatment for AOP.

METHODS

We performed a systematic search of PubMed, Web of Science and the Virtual Health Library from inception to 7 September 2022 to identify studies investigating the short- and long-term effects of caffeine to treat AOP on sleep parameters. We used the PIC strategy considering preterm infants as the Population, caffeine for apnoea as the Intervention and no or other intervention other than caffeine as the Comparison. We registered the protocol on PROSPERO (CRD42021282536).

RESULTS

Of 4019 studies, we deemed 20, including randomised controlled trials and follow-up and observational studies, to be eligible for our systematic review. The analysed sleep parameters, the evaluation phase and the instruments for sleep assessment varied considerably among the studies. The main findings can be summarised as follows: (i) most of the eligible studies in this systematic review indicate that caffeine used to treat AOP seems to have no effect on key sleep parameters and (ii) the effects on sleep when caffeine is administered earlier, at higher doses or for longer periods than the most common protocol have not been investigated. There is a possible correlation between the caffeine concentration and period of exposure and negative sleep quality, but the sleep assessment protocols used in the included studies did not have high-quality standards and could not provide good evidence.

CONCLUSIONS AND IMPLICATIONS

Sleep quality is an important determinant of health, and better investments in research with adequate sleep assessment tools are necessary to guarantee the ideal management of children who were born preterm.

New World Health Organization recommendations for care of preterm or low birth weight infants: health policy

Approximately 11% of infants are born preterm, and complications of prematurity are the most common cause of death in children aged under five years. Almost one million preterm infants die each year across low, high and middle income countries. In 2021, the World Health Organization (WHO) convened a Guideline Development Group (GDG) to examine evidence and formulate recommendations for care of preterm or low birthweight (LBW) infants according to WHO Guideline Review Committee (GRC) criteria. GRADE methods were used to assess the certainty of evidence and the GDG developed judgements using the DECIDE (Developing and Evaluating Communication strategies to support Informed Decisions and practice based on Evidence) framework. Twenty-five recommendations were made; 11 recommendations were new, and 16 were for preventive and promotive care. Kangaroo Mother Care (KMC) was recommended to start immmediately after birth as routine care for all preterm or LBW newborns (except for critically ill infants who are in shock, unable to breath spontaneously after resuscitation, or require ventilatory support) both in the facility and at home. New recommendations were also made for caffeine to treat apnoea and for extubation; family involvement in routine care for preterm or LBW infants; and for post-discharge home-visit follow-up care. New recommendations were also made to consider use of probiotics, emollient therapy, caffeine for prevention of apnoea, continuous positive airway pressure (CPAP) immediately after birth (with or without respiratory distress) in infants less than 32 weeks gestational age; and for family support to enable the care of preterm or LBW infants. The recommendations confirm the pivotal role of preventive and promotive care for preterm and LBW infants, especially the importance of keeping the baby and mother together, and empowering and supporting families to care for their preterm or LBW infant. WHO is now working to help scale up care for small and sick newborns, including organizational shifts in all 'health system building blocks' such as infrastructure, commodities, workforce and monitoring.

Funding

Nil.

Caffeine dosing regimens in preterm infants with or at risk for apnea of prematurity

BACKGROUND

Very preterm infants often require respiratory support and are therefore exposed to an increased risk of bronchopulmonary dysplasia (chronic lung disease) and later neurodevelopmental disability. Caffeine is widely used to prevent and treat apnea (temporal cessation of breathing) associated with prematurity and facilitate extubation. Though widely recognized dosage regimes have been used for decades, higher doses have been suggested to further improve neonatal outcomes. However, observational studies suggest that higher doses may be associated with harm.

OBJECTIVES

To determine the effects of higher versus standard doses of caffeine on mortality and major neurodevelopmental disability in preterm infants with (or at risk of) apnea, or peri-extubation.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP), and clinicaltrials.gov in May 2022. The reference lists of relevant articles were also checked to identify additional studies.

SELECTION CRITERIA

We included randomized (RCTs), quasi-RCTs and cluster-RCTs, comparing high-dose to standard-dose strategies in preterm infants. High-dose strategies were defined as a high-loading dose (more than 20 mg of caffeine citrate/kg) or a high-maintenance dose (more than 10 mg of caffeine citrate/kg/day). Standard-dose strategies were defined as a standard-loading dose (20 mg or less of caffeine citrate/kg) or a standard-maintenance dose (10 mg or less of caffeine citrate/kg/day). We specified three additional comparisons according to the indication for commencing caffeine: 1) prevention trials, i.e. preterm infants born at less than 34 weeks' gestation, who are at risk for apnea; 2) treatment trials, i.e. preterm infants born at less than 37 weeks' gestation, with signs of apnea; 3) extubation trials: preterm infants born at less than 34 weeks' gestation, prior to planned extubation.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We evaluated treatment effects using a fixed-effect model with risk ratio (RR) for categorical data and mean, standard deviation (SD), and mean difference (MD) for continuous data.  MAIN RESULTS: We included seven trials enrolling 894 very preterm infants (reported in Comparison 1, i.e. any indication). Two studies included infants for apnea prevention (Comparison 2), four studies for apnea treatment (Comparison 3) and two for extubation management (Comparison 4); in one study, indication for caffeine administration was both apnea treatment and extubation management (reported in Comparison 1, Comparison 3 and Comparison 4). In the high-dose groups, loading and maintenance caffeine doses ranged from 30 mg/kg to 80 mg/kg, and 12 mg/kg to 30 mg/kg, respectively; in the standard-dose groups, loading and maintenance caffeine doses ranged from 6 mg/kg to 25 mg/kg, and 3 mg/kg to 10 mg/kg, respectively. Two studies had three study groups: infants were randomized in three different doses (two of them matched our definition of high dose and one matched our definition of standard dose); high-dose caffeine and standard-dose caffeine were compared to theophylline administration (the latter is included in a separate review). Six of the seven included studies compared high-loading and high-maintenance dose to standard-loading and standard-maintenance dose, whereas in one study standard-loading dose and high-maintenance dose was compared to standard-loading dose and standard-maintenance dose. High-dose caffeine strategies (administration for any indication) may have little or no effect on mortality prior to hospital discharge (risk ratio (RR) 0.86, 95% confidence of interval (CI) 0.53 to 1.38; risk difference (RD) -0.01, 95% CI -0.05 to 0.03; I² for RR and RD = 0%; 5 studies, 723 participants; low-certainty evidence). Only one study enrolling 74 infants reported major neurodevelopmental disability in children aged three to five years (RR 0.79, 95% CI 0.51 to 1.24; RD -0.15, 95% CI -0.42 to 0.13; 46 participants; very low-certainty evidence). No studies reported the outcome mortality or major neurodevelopmental disability in children aged 18 to 24 months and 3 to 5 years. Five studies reported bronchopulmonary dysplasia at 36 weeks' postmenstrual age (RR 0.75, 95% CI 0.60 to 0.94; RD -0.08, 95% CI -0.15 to -0.02; number needed to benefit (NNTB) = 13; I² for RR and RD = 0%; 723 participants; moderate-certainty evidence). High-dose caffeine strategies may have little or no effect on side effects (RR 1.66, 95% CI 0.86 to 3.23; RD 0.03, 95% CI -0.01 to 0.07; I² for RR and RD = 0%; 5 studies, 593 participants; low-certainty evidence). The evidence is very uncertain for duration of hospital stay (data reported in three studies could not be pooled in meta-analysis because outcomes were expressed as medians and interquartile ranges) and seizures (RR 1.42, 95% CI 0.79 to 2.53; RD 0.14, 95% CI -0.09 to 0.36; 1 study, 74 participants; very low-certainty evidence). We identified three ongoing trials conducted in China, Egypt, and New Zealand.

AUTHORS' CONCLUSIONS

High-dose caffeine strategies in preterm infants may have little or no effect on reducing mortality prior to hospital discharge or side effects. We are very uncertain whether high-dose caffeine strategies improves major neurodevelopmental disability, duration of hospital stay or seizures. No studies reported the outcome mortality or major neurodevelopmental disability in children aged 18 to 24 months and 3 to 5 years. High-dose caffeine strategies probably reduce the rate of bronchopulmonary dysplasia. Recently completed and future trials should report long-term neurodevelopmental outcome of children exposed to different caffeine dosing strategies in the neonatal period. Data from extremely preterm infants are needed, as this population is exposed to the highest risk for mortality and morbidity. However, caution is required when administering high doses in the first hours of life, when the risk for intracranial bleeding is highest. Observational studies might provide useful information regarding potential harms of the highest doses.

Interventions to Reduce Severe Brain Injury Risk in Preterm Neonates: A Systematic Review and Meta-analysis

Importance

Interventions to reduce severe brain injury risk are the prime focus in neonatal clinical trials.

Objective

To evaluate multiple perinatal interventions across clinical settings for reducing the risk of severe intraventricular hemorrhage (sIVH) and cystic periventricular leukomalacia (cPVL) in preterm neonates.

Data Sources

MEDLINE, Embase, CENTRAL (Cochrane Central Register of Controlled Trials), and CINAHL (Cumulative Index to Nursing and Allied Health Literature) databases were searched from inception until September 8, 2022, using prespecified search terms and no language restrictions.

Study Selection

Randomized clinical trials (RCTs) that evaluated perinatal interventions, chosen a priori, and reported 1 or more outcomes (sIVH, cPVL, and severe brain injury) were included.

Data Extraction and Synthesis

Two co-authors independently extracted the data, assessed the quality of the trials, and evaluated the certainty of the evidence using the Cochrane GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach. Fixed-effects pairwise meta-analysis was used for data synthesis.

Main Outcomes and Measures

The 3 prespecified outcomes were sIVH, cPVL, and severe brain injury.

Results

A total of 221 RCTs that assessed 44 perinatal interventions (6 antenatal, 6 delivery room, and 32 neonatal) were included. Meta-analysis showed with moderate certainty that antenatal corticosteroids were associated with small reduction in sIVH risk (risk ratio [RR], 0.54 [95% CI, 0.35-0.82]; absolute risk difference [ARD], -1% [95% CI, -2% to 0%]; number needed to treat [NNT], 80 [95% CI, 48-232]), whereas indomethacin prophylaxis was associated with moderate reduction in sIVH risk (RR, 0.64 [95% CI, 0.52-0.79]; ARD, -5% [95% CI, -8% to -3%]; NNT, 20 [95% CI, 13-39]). Similarly, the meta-analysis showed with low certainty that volume-targeted ventilation was associated with large reduction in risk of sIVH (RR, 0.51 [95% CI, 0.36-0.72]; ARD, -9% [95% CI, -13% to -5%]; NNT, 11 [95% CI, 7-23]). Additionally, early erythropoiesis-stimulating agents (RR, 0.68 [95% CI, 0.57-0.83]; ARD, -3% [95% CI, -4% to -1%]; NNT, 34 [95% CI, 22-67]) and prophylactic ethamsylate (RR, 0.68 [95% CI, 0.48-0.97]; ARD, -4% [95% CI, -7% to 0%]; NNT, 26 [95% CI, 13-372]) were associated with moderate reduction in sIVH risk (low certainty). The meta-analysis also showed with low certainty that compared with delayed cord clamping, umbilical cord milking was associated with a moderate increase in sIVH risk (RR, 1.82 [95% CI, 1.03-3.21]; ARD, 3% [95% CI, 0%-6%]; NNT, -30 [95% CI, -368 to -16]).

Conclusions and Relevance

Results of this study suggest that a few interventions, including antenatal corticosteroids and indomethacin prophylaxis, were associated with reduction in sIVH risk (moderate certainty), and volume-targeted ventilation, early erythropoiesis-stimulating agents, and prophylactic ethamsylate were associated with reduction in sIVH risk (low certainty) in preterm neonates. However, clinicians should carefully consider all of the critical factors that may affect applicability in these interventions, including certainty of the evidence, before applying them to clinical practice.

Optimizing respiratory management in preterm infants: a review of adjuvant pharmacotherapies

Adjuvant respiratory therapies in preterm neonates aim to reduce long-term morbidities and mortality. Commonly utilized therapies include caffeine, systemic glucocorticosteroids, inhaled steroids, inhaled bronchodilators, and diuretics. This review discusses the available literature that supports some of these practices and points out where clinical practices are not corroborated by evidence. Therapies with no proven clinical benefit must be weighed against potential adverse effects.

Caffeine for the Pharmacological Treatment of Apnea of Prematurity in the NICU: Dose Selection Conundrum, Therapeutic Drug Monitoring and Genetic Factors

Caffeine citrate is the drug of choice for the pharmacological treatment of apnea of prematurity. Factors such as maturity and genetic variation contribute to the interindividual variability in the clinical response to caffeine therapy in preterm infants, making the optimal dose administered controversial. Moreover, the necessity for therapeutic drug monitoring (TDM) of caffeine is still worth discussing due to the need to achieve the desired target concentrations as well as concerns about the safety of higher doses. Therefore, we reviewed the pharmacokinetic profile of caffeine in preterm infants, evidence of the safety and efficacy of different doses of caffeine, therapeutic concentration ranges of caffeine and impact of genetic variability on caffeine therapy. Whereas the safety and efficacy of standard-dose caffeine have been demonstrated, evidence for the safety of higher administered doses is insufficient. Thus, preterm infants who lack clinical response to standard-dose caffeine therapy are of interest for TDM when dose optimization is performed. Polymorphisms in pharmacodynamics-related genes, but not in pharmacokinetics-related genes, have a significant impact on the interindividual variability in clinical response to caffeine therapy. For preterm infants lacking clinical response, how to develop individualized medication regimens for caffeine remains to be explored.

A Randomized Controlled Trial Comparing Two Doses of Caffeine for Apnoea in Prematurity

Caffeine is the most commonly used methyl xanthine for the prevention of apnoea in prematurity, but the ideal dose was uncertain, until now. This study compared two doses of caffeine for the prevention of apnoea in prematurity. A clinical trial was conducted on 78 preterm infants ≤32 weeks in Neonatal Intensive Care Unit. They were randomly allocated to receive the intervention (loading 40 mg/kg/day and maintenance of 20 mg/kg/day) or the control (loading 20 mg/kg/day and maintenance of 10 mg/kg/day) dose of caffeine. The primary outcome of the study was the frequency and total days of apnoea per duration of treatment for both groups. The frequency of apnoea ranged from zero to fourteen in the intervention group and zero to twelve in the control group. There was no statistically significant difference between the groups, with a p-value of 0.839. The number of days of apnoea was also similar between both groups, with a p-value of 0.928. There was also no significant difference in adverse events between both regimens. This study did not support the use of higher doses of caffeine as a prevention for apnoea in prematurity.

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.

Pharmacokinetics, pharmacodynamics and metabolism of caffeine in newborns

The plasma elimination half-life of caffeine in the newborn is approximately 100 h. Caffeine is rapidly absorbed with complete bioavailability following oral dosing. Switching between parenteral and oral administration requires no dose adjustments. Caffeine has wide interindividual pharmacodynamic variability and a wide therapeutic index in preterm newborns. Thresholds of measurable efficacy on respiratory drive have been documented at plasma levels around 2 mg/L. At these low levels, caffeine competitively inhibits adenosine receptors (A1 and A2A). The toxicity threshold is ill-defined and possibly as high as 60 mg/L which can be lethal in adults. High doses of caffeine may produce better control of apnea. However, at high systemic drug concentrations, the pharmacodynamic actions of caffeine become more complex and worrisome. They include inhibition of GABA receptors and cholinergic receptors in addition to adenosine receptor inhibition, intracellular calcium mobilization and actions on adrenergic, dopaminergic and phosphodiesterase systems. The role of pharmacogenomic factors as determinants of neonatal pharmacologic response and clinical effects remains to be explored.

Caffeine for preterm infants: Fixed standard dose, adjustments for age or high dose?

Caffeine is an effective treatment for apnea of prematurity and has several important benefits, including decreasing respiratory morbidity and motor impairment. In this article, we focus on the dose of caffeine. We review the evidence regarding the efficacy and safety of standard caffeine dosing and alternative dosing approaches, including the use of high dose caffeine and routine dose adjustments for age. Current evidence suggests high dose caffeine may provide additional benefit in reducing the risk of bronchopulmonary dysplasia and extubation failure, but may also increase the risk of cerebellar hemorrhage and seizures. Increasing the standard caffeine citrate dose every 1-2 weeks to a goal dose of 8 mg per kilogram every 24 h may help maintain therapeutic effect. We conclude by highlighting the need for additional trials before high dose caffeine is routinely used.

Caffeine citrate maintenance doses effect on extubation and apnea postventilation in preterm infants

BACKGROUND

Caffeine citrate is used to prevent apnea in premature infants and help in extubation of invasive ventilation, but the optimal dose remains undetermined.

METHODS

Neonates born at less than 30 weeks gestation who had received invasive ventilation for at least 48 hours and a loading dose of 20 mg/kg caffeine citrate were randomly assigned into high (10 mg/kg daily) or low (5 mg/kg daily) maintenance dose groups. The drug was discontinued if no apnea occurred for 7 consecutive days.

RESULTS

A total of 111 infants were assigned into the high (54) or low (57) dose groups. Extubation failure (16.7% vs 36.8%), age of extubation (8.2 ± 2.1 vs 10.7 ± 2.3 day), duration of invasive ventilation (7.2 ± 2.1 vs 8.5 ± 2.4 day), duration of ventilation before extubation (8.0 ± 1.8 vs 10.1 ± 1.9 day), and number of days of apnea (1.8 ± 1.3 vs 3.2 ± 1.1 day) were significantly lower in the high dose group than the low dose group. Difference in time until failure (6.7 ± 1.7d vs 7.0 ± 1.9d) and duration of nasal continuous positive airway pressure(7.8 ± 1.8 vs 8.0 ± 2.2 day) were not significant. Furthermore, no significant differences in the incidence of tachycardia (9.3% vs 12.3%), abdominal distension (16.7% vs 12.3%), feeding intolerance (3.7% vs 5.3%), or irritability (7.4% vs 5.3%) were observed between groups.

CONCLUSIONS

A higher maintenance dose of caffeine citrate reduced the incidence of extubation failure and apnea of prematurity without increasing the occurrence of adverse reactions.

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

Stopping caffeine in premature neonates: how long does it take for the level of caffeine to fall below the therapeutic range?

Background: Caffeine is routinely used in preterm infants for apnea of prematurity. Preterm infants are usually monitored for 5 days after discontinuation of caffeine to assess for possible recurrence of apnea. Our objective was to determine if the serum concentration of caffeine decreases to a subtherapeutic level 5 days after its discontinuation.Methods: This is a retrospective analysis of caffeine levels after the drug was discontinued in preterm neonates (birth weight ≤1500 g) born between January 2010 and June 2017. The primary outcome was the proportion of infants with therapeutic levels of caffeine 5 days after the drug was stopped.Results: Caffeine levels were measured in 353 samples from 280 infants (birth weight 1246 ± 390 g and gestational age 29.2 ± 2.4 weeks) after discontinuation of the drug. Five and more days after discontinuation of caffeine, 29.3% (82/280) of the infants had caffeine levels ≥5 mg/L. Approximately 41% (75/181) of the caffeine levels measured between 5 and 7 days and 18% (17/95) between 8 and 10 days were ≥5 mg/L. A caffeine dose of >5 mg/kg/day when discontinued was associated with the caffeine level of ≥5 mg/L (OR 2.3, 95% CI 1.28-4.13, p = .005).Conclusions: Preterm infants treated with caffeine frequently had therapeutic levels of caffeine 5-10 days after discontinuation of the drug. The infants receiving higher doses were more likely to have a therapeutic level of caffeine 5 days after stopping the medication. Preterm infants should be monitored for recurrence of apnea for more than 5 days after stopping caffeine or levels should be monitored prior to discharge.

Early high-dose caffeine citrate for extremely preterm infants: Neonatal and neurodevelopmental outcomes

AIM

To examine neonatal morbidities, including the incidence of cerebellar haemorrhage (CBH), and neurodevelopmental outcomes following the administration of high loading dose caffeine citrate compared to standard loading dose caffeine citrate.

METHODS

This was a retrospective study of 218 preterm infants <28 weeks' gestation who received a loading dose of caffeine citrate within the first 36 h of life at the Mater Mothers' Hospital over a 3-year period (2011-2013). Two groups were compared, with 158 neonates in the high-dose cohort receiving a median dose of caffeine citrate of 80 mg/kg and 60 neonates in the standard dose cohort receiving a median dose of 20 mg/kg. Routine cranial ultrasound, including mastoid views, was performed during the neonatal period. At 2 years of age, infants presented for follow-up and were assessed with the Neurosensory Motor Developmental Assessment (NSMDA) and the Bayley Scales of Infant and Toddler Development-III (Bayley-III).

RESULTS

There was no difference in the incidence of neonatal morbidities, including CBH, between the two groups. The incidence of CBH in the high-dose group was 2.5% compared to 1.7% in the standard-dose group. There was no difference in the neurodevelopmental follow-up scores as evaluated with the NSMDA and the Bayley-III.

CONCLUSIONS

The use of early high loading dose caffeine citrate in extremely preterm infants was not shown to be associated with CBH or abnormal long-term neurodevelopmental outcomes. The overall incidence of CBH, however, was much lower than in studies using magnetic resonance imaging techniques. It is suggested that a large randomised clinical trial is needed to determine the optimal dose of caffeine citrate when given early to very preterm infants.

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.

Impact of High-Dose Caffeine on the Preterm Ovine Cerebrum and Cerebellum

Caffeine is one of the few treatments available for infants with apnea of prematurity. As the recommended dosing regimen is not always sufficient to prevent apnea, higher doses may be prescribed. However, little is currently known about the impact of high-dose caffeine on the developing brain; thus, our aim was to investigate the consequences of a high-dose regimen on the immature ovine brain. High-dose caffeine (25 mg/kg caffeine base loading dose; 20 mg/kg daily maintenance dose; n = 9) or saline (n = 8) was administered to pregnant sheep from 105 to 118 days of gestation (DG; term = 147 days); this is broadly equivalent to 28-33 weeks of human gestation. At 119DG, the cerebral cortex, striatum, and cerebellum were assessed histologically and by immunohistochemistry. Compared with controls, caffeine-exposed fetuses showed (i) an increase in the density of Ctip2-positive layers V-VI projection neurons (p = 0.02), Tbr1-positive layers V-VI projection neurons (p < 0.0001), astrocytes (p = 0.03), and oligodendrocytes (p = 0.02) in the cerebral cortex, (ii) a decrease in the density of Cux1-positive layers II-IV projection neurons (p = 0.01) in the cerebral cortex, and (iii) a reduction in the area of Purkinje cell bodies in the cerebellum (p = 0.03). Comparing high-dose caffeine-exposed fetuses with controls, there was no difference (p > 0.05) in: (i) the volume of the cerebral cortex or striatum, (ii) the density of neurons (total and output projection neurons) in the striatum, (iii) dendritic spine density of layer V pyramidal cells, (iv) the density of cortical GABAergic interneurons, microglia, mature oligodendrocytes or proliferating cells, (v) total cerebellar area or dimensions of cerebellar layers, or (vi) the density of cerebellar white matter microglia, astrocytes, oligodendrocytes, or myelin. Daily exposure of the developing brain to high-dose caffeine affects some aspects of neuronal and glial development in the cerebral cortex and cerebellum in the short-term; the long-term structural and functional consequences of these alterations need to be investigated.

High-versus low-dose caffeine in preterm infants: a systematic review and meta-analysis

AIM

Though caffeine is a consolidated treatment in preterm infants, the efficacy and safety of a higher dose have not been systematically appraised.

METHODS

A systematic review was conducted to compare high (loading dose >20 mg/kg and maintenance >10 mg/kg/day) versus low dose of caffeine. MEDLINE, EMBASE, Central and conference proceedings for randomised controlled trials (RCTs) and quasi-RCTs were searched. Two authors independently screened the records, extracted the data and assessed the risk of bias.

RESULTS

As only six RCTs enrolling a total of 816 preterm infants were included, the required information size was not reached. The loading and maintenance doses varied between 20 and 80 mg/kg/day and 3 and 20 mg/kg/day, respectively. The use of high dose had no impact on mortality (RR: 0.85; 95% CI: 0.53-1.38; RCTs = 4). However, it resulted in fewer cases of extubation failure, apnoeas and bronchopulmonary dysplasia (RR: 0.76; 95% CI: 0.60-0.96; studies = 4) and shorter duration of mechanical ventilation. The quality of the evidence was low due to imprecision of the estimates.

CONCLUSION

Due to imprecision, it is not possible to determine whether high-dose caffeine is more effective and safe than a low dose. High dose might improve short-term respiratory function and reduce bronchopulmonary dysplasia.

High versus standard dose caffeine for apnoea: a systematic review

BACKGROUND

Placebo-controlled trials have shown that caffeine is highly effective in treating apnoea of prematurity and reduces the risk of bronchopulmonary dysplasia (BPD) and neurodevelopmental impairment (NDI).

OBJECTIVE

To identify, appraise and summarise studies investigating the modulating effect of different caffeine dosages.

METHODS

A systematic review identified all randomised controlled trials (RCTs) comparing a high versus a standard caffeine treatment regimen in infants with a gestational age <32 weeks, by searching the main electronic databases and abstracts of the Pediatric Academic Societies. Studies comparing caffeine to placebo or theophylline only were excluded. Primary outcomes were BPD and mortality at 36 weeks postmenstrual age. Secondary key-outcome was neurodevelopmental outcome at 12 and 24 months corrected age. Meta-analysis was performed using RevMan 5.3.

RESULTS

Six RCTs including 620 infants were identified. Meta-analysis showed a significant decrease in BPD, the combined outcome BPD or mortality, and failure to extubate in infants allocated to a higher caffeine dose. No differences were found in mortality alone and NDI. The quality of the outcome measures were deemed low to very low according to the Grading of Recommendations Assessment, Development and Evaluation guidelines.

CONCLUSIONS

Although this review suggests that administering a higher dose of caffeine might enhance its beneficial effect on death or BPD, firm recommendations on the optimal caffeine dose cannot be given due to the low level of evidence. A large RCT is urgently needed to confirm or refute these findings and determine the optimal dose of caffeine.

Caffeine: an evidence-based success story in VLBW pharmacotherapy

Apnea of prematurity (AOP) is a common and pervasive problem in very low birth weight infants. Methylxanthines were reported >40 years ago to be an effective therapy and, by the early 2000s, caffeine had become the preferred methylxanthine because of its wide therapeutic index, excellent bioavailability, and longer half-life. A clinical trial to address unresolved questions and toxicity concerns, completed in 2004, confirmed significant benefits of caffeine therapy, including shorter duration of intubation and respiratory support, reduced incidence of chronic lung disease, decreased need for treatment of patent ductus arteriosus, reduced severity of retinopathy of prematurity, and improved motor and visual function. Cohort studies have now further delineated the benefits of initiation of therapy before 3 days postnatal age, and of higher maintenance doses to achieve incremental beneficial effects. This review summarizes the pivotal and in particular the most recent studies that have established the safety and efficacy of caffeine therapy for AOP and other respiratory and neurodevelopmental outcomes. Caffeine has a very favorable benefit-to-risk ratio, and has become one of the most prescribed and cost-effective pharmacotherapies in the NICU.

Haemodynamic effects of prenatal caffeine on the cardiovascular transition in ventilated preterm lambs

Background

Caffeine is routinely given to preterm infants hours after birth to treat apnea of prematurity. In view of it’s success, earlier administration in the delivery room is being considered, but little is known about how caffeine may effect the cardiovascular changes during the fetal to neonatal transition. Our aim was to determine the effect of prenatal caffeine administration on haemodynamic parameters in ventilated preterm lambs immediately after birth.

Methods

Catheters (carotid artery and jugular vein) and ultrasonic flow probes (pulmonary artery and carotid artery) were implanted in preterm lambs (~126 ±2 days of gestation; term is 147 days), immediately before delivery by caesarean section. Before the cord was clamped, lambs were intubated and a caffeine (10mg/kg caffeine-base; n = 9) or saline (n = 5) infusion was given intravenously to the ewe and lamb over a 15-minute period. Two minutes after clamping the cord, ventilation commenced with a sustained inflation (35 cm H2O for 30 seconds) followed by ventilation for 30 minutes (target tidal volume of 6-8ml/kg).

Results

Blood gas parameters and rectal body temperature were not different between the two groups. Changes in pulmonary blood flow (PBF) and carotid blood flow (CBF) did not differ significantly between groups. PBF increased significantly after ventilation onset in both groups (caffeine p = 0.022, saline p <0.001) and remained elevated thereafter. CBF did not increase but decreased after SI in the caffeine group. Blood pressure, heart rate, and peripheral oxygen saturation did not differ between groups at any stage of the study.

Conclusion

Prenatal caffeine infusion had no significant effect on acute haemodynamic parameters in ventilated preterm lambs during the cardiorespiratory transition.

Optimizing Caffeine Use and Risk of Bronchopulmonary Dysplasia in Preterm Infants: A Systematic Review, Meta-analysis, and Application of Grading of Recommendations Assessment, Development, and Evaluation Methodology

Caffeine reduces the risk of bronchopulmonary dysplasia (BPD). Optimizing caffeine use could increase therapeutic benefit. We performed a systematic-review and random-effects meta-analysis of studies comparing different timing of initiation and dose of caffeine on the risk of BPD. Earlier initiation, compared to later, was associated with a decreased risk of BPD (5 observational studies; n = 63,049, adjusted OR 0.69; 95% CI 0.64-0.75, GRADE: low quality). High-dose caffeine, compared to standard-dose, was associated with a decreased risk of BPD (3 randomized trials, n = 432, OR 0.65; 95% CI 0.43-0.97; GRADE: low quality). Higher quality evidence is needed to guide optimal caffeine use.

Evaluation of Timing and Dosing of Caffeine Citrate in Preterm Neonates for the Prevention of Bronchopulmonary Dysplasia

OBJECTIVE

The aim of this study was to evaluate the timing and dosing of caffeine therapy in relation to the development of bronchopulmonary dysplasia (BPD).

METHODS

This was a single-center, retrospective cohort study comparing early (days of life 0-2) to late (day of life 3 or greater) caffeine initiation in extremely low birth weight neonates, with a secondary analysis of large (10 mg/kg/day) to small dose (5 mg/kg/day) caffeine.

RESULTS

There were 138 patients in the primary timing analysis. The early caffeine group had a lower incidence and reduced odds of the composite outcome of BPD or all-cause mortality, compared with the late caffeine group (64% vs. 88%, respectively; adjusted p < 0.05; adjusted OR 0.36 [95% CI 0.13-0.98]). No statistically significant difference was found between dosing groups (p = 0.29) in the primary outcome; however, there was a lower rate of patent ductus arteriosus requiring treatment (p = 0.05) and decreased likelihood of discharging home on oxygen (p = 0.02) in the large-dose group compared with the small-dose group.

CONCLUSIONS

Early caffeine initiation significantly decreased the incidence of BPD or all-cause mortality in extremely low birth weight neonates. Patients receiving large-dose caffeine had improved secondary outcomes, although no difference in BPD was noted. Further studies are needed to determine the optimal dosing of caffeine.

Caffeine decreases intermittent hypoxia in preterm infants nearing term-equivalent age

OBJECTIVE

To determine whether intermittent hypoxia (IH) persisting after 36 weeks postmenstrual age (PMA) can be attenuated using caffeine doses sufficient to maintain caffeine concentrations >20 μg ml^-1.

STUDY DESIGN

Twenty-seven infants born <32 weeks were started on caffeine citrate at 10 mg kg^-1 day^-1 when clinical caffeine was discontinued. At 36 weeks PMA, the dose was increased to 14 or 20 mg kg^-1 day^-1 divided twice a day (BID) to compensate for progressively increasing caffeine metabolism. Caffeine concentrations were measured weekly. The extent of IH derived from continuous pulse oximetry was compared to data from 53 control infants.

RESULT

The mean (s.d.) gestational age of enrolled infants was 27.9±2 weeks. Median caffeine levels were >20 μg ml^-1 on study caffeine doses. IH was significantly attenuated through 38 weeks PMA compared with the control group.

CONCLUSION

Caffeine doses of 14 to 20 mg kg^-1 day^-1 were sufficient to maintain caffeine concentrations >20 μg ml^-1 and reduce IH in preterm infants at 36 to 38 weeks PMA.

Caffeine use in the neonatal intensive care unit

Caffeine is the most frequently used medication in the neonatal intensive care unit. It is used for the prevention and treatment of apnea, although this has been associated with lower incidence of bronchopulmonary dysplasia (BPD) and patent ductus arteriosus as well as intact survival at 18-21 months of life. Although neurodevelopmental advantage was no longer statistically significant at age 5 years, caffeine was associated with sustained improvement in co-ordination and less gross motor impairment than placebo. The mechanism of action of caffeine on prevention of apnea and activation of breathing seems to be through central inhibition of adenosine receptors. However, its impact on BPD and neurodevelopmental outcomes might be induced through its effects as anti-inflammatory mediator, protection of white matter, and induction of surfactant protein B. Whereas long-term studies have documented the safety of caffeine as used in current practice, further studies are clearly needed to identify optimum dosing, and time of starting and discontinuing caffeine.

Caffeine citrate - Is it a silver bullet in neonatology?

Caffeine citrate is one of the most prescribed drug in the present day NICU for apnea. Its efficacy, tolerability, wide therapeutic index and safety margin has made it the drug of choice among the methylxanthines. Its therapeutic uses in apnea of prematurity, mechanical ventilation, bronchopulmonary dysplasia has made it a "silver bullet" in neonatology. However, there are still controversies surrounding this drug. This review is aimed to update the reader about the basic pharmacology, current therapeutic uses, adverse effects, controversies as well as present and future research of caffeine.

The Role of Caffeine in Noninvasive Respiratory Support

Caffeine is one of the most commonly prescribed medications in preterm neonates and is widely used to treat or prevent apnea of prematurity. Caffeine therapy is safe, effectively decreases apnea, and improves short- and long-term outcomes in preterm infants. In this review, the authors summarize the role of caffeine therapy for preterm infants receiving noninvasive respiratory support. As caffeine is already widely used, recent data are summarized that may guide clinicians in optimizing the use of caffeine therapy, with a review of the timing of initiation, dose, and duration of therapy.

Caffeine for apnea of prematurity: Effects on the developing brain

Caffeine is a methylxanthine that is widely used to treat apnea of prematurity (AOP). In preterm infants, caffeine reduces the duration of respiratory support, improves survival rates and lowers the incidence of cerebral palsy and cognitive delay. There is, however, little evidence relating to the immediate and long-term effects of caffeine on brain development, especially at the cellular and molecular levels. Experimental data are conflicting, with studies showing that caffeine can have either adverse or benefical effects in the developing brain. The aim of this article is to review current understanding of how caffeine ameliorates AOP, the cellular and molecular mechanisms by which caffeine exerts its effects and the effects of caffeine on brain development. A better knowledge of the effects of caffeine on the developing brain at the cellular and/or molecular level is essential in order to understand the basis for the impact of caffeine on postnatal outcome. The studies reviewed here suggest that while caffeine has respiratory benefits for preterm infants, it may have adverse molecular and cellular effects on the developing brain; indeed a majority of experimental studies suggest that regardless of dose or duration of administration, caffeine leads to detrimental changes within the developing brain. Thus there is an urgent need to assess the impact of caffeine, at a range of doses, on the structure and function of the developing brain in preclinical studies, particularly using clinically relevant animal models. Future studies should focus on determining the maximal dose of caffeine that is safe for the preterm brain.

Caffeine for the Treatment of Apnea in Bronchiolitis: A Randomized Trial

OBJECTIVE

To evaluate the efficacy and safety of caffeine citrate in the treatment of apnea in bronchiolitis.

STUDY DESIGN

Eligible infants aged ≤4 months presenting to the main pediatric emergency service with apnea associated bronchiolitis were stratified by gestational age (<34 weeks or longer) and randomized to receive a single dose of intravenous 25 mg/kg caffeine citrate or saline placebo. The primary efficacy outcome was a 24-hour apnea-free period beginning after completion of the blinded study drug infusion. Secondary outcomes were frequency of apnea by 24, 48, and 72 hours after study medication, need for noninvasive/invasive ventilation, and length of stay in the hospital's pediatric intensive care/step-down unit.

RESULTS

A total of 90 infants diagnosed with viral bronchiolitis associated with apnea (median age, 38 days) were enrolled. The rate of respiratory virus panel positivity was similar in the 2 groups (78% for the placebo group vs 84% for the caffeine group). The geometric mean duration to a 24-hour apnea-free period was 28.1 hours (95% CI, 25.6-32.3 hours) for the caffeine group and 29.1 hours (95% CI, 25.7-32.9 hours) for the placebo group (P = .88; OR, 0.99; 95% CI, 0.83-1.17). The frequency of apnea at 24 hours, 24-48 hours, and 48-72 hours after enrollment and the need for noninvasive and invasive ventilation were similar in the 2 groups. No safety issues were reported.

CONCLUSIONS

A single dose of caffeine citrate did not significantly reduce apnea episodes associated with bronchiolitis.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT01435486.

Incorporating pharmacodynamic considerations into caffeine therapeutic drug monitoring in preterm neonates

Background

This study sought to assess the pharmacokinetic and pharmacodynamic relationships of caffeine citrate therapy in preterm neonates who had therapeutic drug monitoring (TDM) in the post-extubation period.

Methods

A retrospective observational study was conducted in preterm neonates who received caffeine citrate therapy for apnea of prematurity and had TDM done in the post-extubation period between January 2006 and October 2011. The relationships between pharmacodynamic effects (heart rate, respiratory rate, episodes of apnea, adverse events) and caffeine serum concentrations were explored.

Results

A total of 177 blood samples were obtained from 115 preterm neonates with a median (range) gestational age of 29 (24 – 33) weeks and birth weight of 1230 (607 – 2304) kg. Caffeine citrate therapy was initiated at a median (interquartile range) postnatal age of 1 (1 – 3) day and TDM was performed at a postnatal age of 15 (10 – 24) days. No direct correlations were found between respiratory rate or apneic episodes and caffeine serum concentrations; however, heart rate and caffeine serum concentrations were significantly correlated (p < 0.05). Dosing regimen of 40/5 mg/kg q12h (loading dose/maintenance dose, time interval) led to similar endotracheal re-intubation rate but increased percentage of patients experiencing tachycardia compared to the standard regimen of 20/5 mg/kg q24h (44.7 % vs 10.2 %, p < 0.001).

Conclusion

Based on this retrospective study, no correlation between episodes of apnea and caffeine serum concentrations was found in neonates who had TDM of caffeine citrate therapy in the post-extubation period, whereas a significant association between tachycardia and concentrations existed. Notwithstanding the absence of severe adverse reactions, TDM should be considered in critically ill neonates with unexplained adverse effects, such as tachycardia.

Electronic supplementary material

The online version of this article (doi:10.1186/s40360-016-0065-x) contains supplementary material, which is available to authorized users.

Salivary caffeine concentrations are comparable to plasma concentrations in preterm infants receiving extended caffeine therapy

AIMS

Caffeine concentrations in preterm infants are usually measured in the blood. However, salivary assays may provide a valid and practical alternative. The present study explored the validity and clinical utility of salivary caffeine concentrations as an alternative to blood concentrations and developed a novel plasma/salivary caffeine distribution model.

METHODS

Paired salivary and plasma samples were obtained in 29 infants. Salivary samples were obtained using a commercially available salivary collection system. Caffeine concentrations in the saliva and plasma were determined using high-performance liquid chromatography. A population pharmacokinetic (PK) model was developed using NONMEM 7.3.

RESULTS

The mean (± standard deviation) gestational age (GA) at birth and birth weight were 27.9 ± 2.1 weeks and 1171.6 ± 384.9 g, respectively. Paired samples were obtained at a mean postmenstrual age (PMA) of 35.5 ± 1.1 weeks. The range of plasma caffeine concentrations was 9.5-54.1 μg ml(-1) , with a mean difference (95% confidence interval) between plasma and salivary concentrations of -0.18 μg ml(-1) (-1.90, 1.54). Salivary and plasma caffeine concentrations were strongly correlated (Pearson's correlation coefficient = 0.87, P < 0.001). Caffeine PK in plasma and saliva was simultaneously described by a three-compartment recirculation model. Current body weight, birth weight, GA, PMA and postnatal age were not significantly correlated with any PK parameter.

CONCLUSIONS

Salivary sampling provides an easy, non-invasive method for measuring caffeine concentrations. Salivary concentrations correlate highly with plasma concentrations. Caffeine PK in saliva and plasma are well described by a three-compartment recirculation model.

Caffeine therapy in preterm infants

Caffeine is the most commonly used medication for treatment of apnea of prematurity. Its effect has been well established in reducing the frequency of apnea, intermittent hypoxemia, and extubation failure in mechanically ventilated preterm infants. Evidence for additional short-term benefits on reducing the incidence of bronchopulmonary dysplasia and patent ductus arteriosus has also been suggested. Controversies exist among various neonatal intensive care units in terms of drug efficacy compared to other methylxanthines, dosage regimen, time of initiation, duration of therapy, drug safety and value of therapeutic drug monitoring. In the current review, we will summarize the available evidence for the best practice in using caffeine therapy in preterm infants.

High versus low-dose caffeine for apnea of prematurity: a randomized controlled trial

The optimum caffeine dose in preterm infants has not been well investigated. We aimed to compare the efficacy and safety of high versus low-dose caffeine citrate on apnea of prematurity (AOP) and successful extubation of preterm infants from mechanical ventilation. We compared high-dose (loading 40 mg/kg/day and maintenance of 20 mg/kg/day) versus low-dose (loading 20 mg/kg/day and maintenance of 10 mg/kg/day) caffeine citrate in preterm infants <32 weeks gestation, presented with AOP within the first 10 days of life. A total of 120 neonates (60 in each group) were enrolled. High-dose caffeine was associated with a significant reduction in extubation failure in mechanically ventilated preterm infants (p<0.05), the frequency of apnea (p<0.001), and days of documented apnea (p<0.001). High-dose caffeine was associated with significant increase in episodes of tachycardia (p<0.05) without a significant impact on physician decision to withhold caffeine.

CONCLUSION

The use of higher, than current standard, dose of caffeine may decrease the chance of extubation failure in mechanically ventilated preterm infants and frequency of AOP without significant side effects.

WHAT IS KNOWN

• Caffeine therapy for treatment of apnea of prematurity has been well established over the past few years. The optimal loading and maintenance dose of caffeine in preterm infants is not well-studied. What is New: • This double blind randomized controlled trial demonstrated that using a higher, than current standard, loading and maintenance doses of caffeine for treatment of apnea in preterm infants is well tolerated and significantly decrease the frequency of apnea.

Acute Neonatal Respiratory Failure

Acute respiratory failure requiring assisted ventilation is one of the most common reasons for admission to the neonatal intensive care unit. Respiratory failure is the inability to maintain either normal delivery of oxygen to the tissues or normal removal of carbon dioxide from the tissues. It occurs when there is an imbalance between the respiratory workload and ventilatory strength and endurance. Definitions are somewhat arbitrary but suggested laboratory criteria for respiratory failure include two or more of the following: PaCO₂ > 60 mmHg, PaO₂ < 50 mmHg or O₂ saturation <80 % with an FiO₂ of 1.0 and pH < 7.25 (Wen et al. 2004).

NICU bedside caregivers sustain process improvement and decrease incidence of bronchopulmonary dysplasia in infants < 30 weeks gestation

BACKGROUND

The objective of this study was to investigate whether a respiratory care bundle, implemented through participation in the Vermont Oxford Network-sponsored Neonatal Intensive Care Quality Improvement Collaborative (NIC/Q 2005) and primarily dependent on bedside caregivers, resulted in sustained decrease in the incidence of bronchopulmonary dysplasia (BPD) in infants < 30 wk gestation.

METHODS

A retrospective cohort study was conducted. Infants inborn between 23 wk and 29 wk + 6 d of gestation were included. Patients with congenital heart disease, significant congenital or lung anomalies, or death before intubation were excluded. Four time periods (T1-T4) were identified: T1: September 1, 2002 to August 31, 2004; T2: September 1, 2004 to August 31, 2006; T3: September 1, 2006 to August 31, 2008; T4: September 1, 2008 to August 31, 2010.

RESULTS

A total of 1,050 infants were included in the study. BPD decreased significantly in T3 post-implementation of the respiratory bundle compared with T1 (29.9% vs 51.2%, respectively; adjusted odds ratio [aOR] = 0.06 [95% CI 0.03-0.13], P = < .001). The decrease was not sustained into T4. There was a significant increase in the rate of BPD-free survival to discharge in T3 compared with T1 (53.1% vs 47%; aOR = 1.68 [95% CI 1.11-2.56], P = .01) that was also not sustained. The rate of infants requiring O2 at 28 d of life decreased significantly in T3 versus T1 (40.3% vs 69.9%, respectively; aOR = 0.12 [95% CI 0.07-0.20], P = < .001). Increases in the rate of surfactant administration by 1 h of life and rate of caffeine use were observed in T4 versus T1, respectively. There was a significant decrease in median ventilator days and a significant increase in the median number of noninvasive CPAP days throughout the study period.

CONCLUSIONS

In this study, implementation of a respiratory bundle managed primarily by nurses and respiratory therapists was successful in increasing the use of less invasive respiratory support in a consistent manner among very low birthweight infants at a single institution. However, this study and others have failed to show sustained improvement in the incidence of BPD despite sustained process change.

Impact of daily high-dose caffeine exposure on developing white matter of the immature ovine brain

BACKGROUND

Caffeine is widely used to treat apnea of prematurity, but the standard dosing regimen is not always sufficient to prevent apnea. Before higher doses of caffeine can be used, their effects on the immature brain need to be carefully evaluated. Our aim was to determine the impact of daily high-dose caffeine administration on the developing white matter of the immature ovine brain.

METHODS

High-dose caffeine (25 mg/kg caffeine base loading dose; 20 mg/kg daily maintenance dose; n = 9) or saline (n = 8) were administered to pregnant sheep from 0.7 to 0.8 of term, equivalent to approximately 27-34 wk in humans. At 0.8 of term, the white and gray matter were assessed histologically and immunohistochemically.

RESULTS

Daily caffeine administration led to peak caffeine concentration of 32 mg/l in fetal plasma at 1 h, followed by a gradual decline, with no effects on mean arterial pressure and heart rate. Initial caffeine exposure led to transient, mild alkalosis in the fetus but did not alter oxygenation. At necropsy, there was no effect of daily high-dose caffeine on brain weight, oligodendrocyte density, myelination, axonal integrity, microgliosis, astrogliosis, apoptosis, or neuronal density.

CONCLUSION

Daily high-dose caffeine administration does not appear to adversely affect the developing white matter at the microstructural level.

Drug studies in newborns: a therapeutic imperative

Although some drugs have been developed for the neonate, drug development for the least mature and most vulnerable pediatric patients is lacking. Most of the drugs are off-label or off-patent and are empirically administered to newborns once efficacy has been demonstrated in adults and usefulness is suspected or demonstrated in the older pediatric population. Few drugs are approved by the Food and Drug Administration for use in this population. The factors that prevent the demonstration of efficacy and safety in the newborn are discussed and a change in the current approach for neonatal drug studies is suggested.

Caffeine citrate for very preterm infants: Effects on development, temperament and behaviour

AIM

To compare two dosing regimens for caffeine citrate for neonates born less than 30 weeks gestation in terms of development, temperament and behaviour.

METHODS

A multi-centre, randomised, controlled trial design was undertaken. A total of 287 infants with apnoea of prematurity or in the peri-extubation period were randomised to receive one of two dosage regimens (20 vs. 5 mg/kg/day). The main outcome measure was cognitive development at 1 year of age on the Griffiths Mental Development Scales. Secondary outcome measures included neonatal morbidity, death and disability, temperament at 1 year and behaviour at 2 years of age.

RESULTS

Data on the primary outcome were available for 190 survivors at 12 months corrected for prematurity. A significantly greater mean general quotient was found in the high-dose group (mean (standard deviation), 98.0 (13.8) vs. 93.6 (16.5), P = 0.048). On omission of two infants for whom cognitive assessment was not possible because of disability while the mean general quotient remained higher for infants in the high-dose group, this was no longer statistically significant (P= 0.075). There was a non-significant trend for benefit in the high-dose caffeine group for death or major disability, 15.4% versus 24.2%; relative risk 0.75 (95% confidence interval 0.49-1.14). No differences in the mean values between the two groups were shown for temperament and behaviour.

CONCLUSIONS

Caffeine citrate with a dosage regimen of 20 mg/kg/day did not result in adverse outcomes for development, temperament and behaviour. The borderline benefit in cognition with high-dose caffeine needs further investigation.

Apnea of prematurity: from cause to treatment

Apnea of prematurity (AOP) is a common problem affecting premature infants, likely secondary to a "physiologic" immaturity of respiratory control that may be exacerbated by neonatal disease. These include altered ventilatory responses to hypoxia, hypercapnia, and altered sleep states, while the roles of gastroesophageal reflux and anemia remain controversial. Standard clinical management of the obstructive subtype of AOP includes prone positioning and continuous positive or nasal intermittent positive pressure ventilation to prevent pharyngeal collapse and alveolar atelectasis, while methylxanthine therapy is a mainstay of treatment of central apnea by stimulating the central nervous system and respiratory muscle function. Other therapies, including kangaroo care, red blood cell transfusions, and CO(2) inhalation, require further study. The physiology and pathophysiology behind AOP are discussed, including the laryngeal chemoreflex and sensitivity to inhibitory neurotransmitters, as are the mechanisms by which different therapies may work and the potential long-term neurodevelopmental consequences of AOP and its treatment.

Prophylactic methylxanthines for endotracheal extubation in preterm infants

BACKGROUND

Weaning and extubating preterm infants on intermittent positive pressure ventilation (IPPV) for respiratory failure may be difficult. A significant contributing factor is thought to be the relatively poor respiratory drive and tendency to develop hypercarbia and apnoea, particularly in very preterm infants. Methylxanthine treatment started before extubation might stimulate breathing and increase the chances of successful weaning from IPPV.

OBJECTIVES

To determine the effects of prophylactic methylxanthine treatment on the use of intubation and IPPV and other clinically important side effects in preterm infants being weaned from IPPV and in whom endotracheal extubation is planned.

SEARCH STRATEGY

The standard search strategy of the Cochrane Neonatal Review Group was used. This included searches of The Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 2, 2010), the Oxford Database of Perinatal Trials, MEDLINE (1966 to July 2010), CINAHL (1982 to July 2010) and EMBASE (1988 to July 2010).

SELECTION CRITERIA

All published trials utilising random or quasi-random patient allocation in which treatment with methylxanthines (theophylline or caffeine) was compared with placebo or no treatment to improve the chances of successful extubation of preterm or low birth weight infants were included.

DATA COLLECTION AND ANALYSIS

The standard methods of the Cochrane Collaboration and its Neonatal Review Group were used.

MAIN RESULTS

Seven studies were identified for inclusion. Methylxanthine treatment results in a reduction in failure of extubation within one week (summary RR 0.48, 95%CI 0.32 to 0.71; summary RD -0.27, 95%CI -0.39 to -0.15; NNT 4, 95%CI 3 to 7; six trials, 172 infants). There is significant heterogeneity in the RD meta-analysis perhaps related to the large variation in baseline rate in the control groups (range 20 to 100%).The CAP trial enrolled the largest number of infants, but did not report extubation rates. In the caffeine group, there were lower rates of bronchopulmonary dysplasia, PDA ligation, cerebral palsy and death or major disability at 18 to 21 months. Infants receiving caffeine had reduced postmenstrual ages at time of discontinuing oxygen therapy, positive pressure ventilation and endotracheal intubation.

AUTHORS' CONCLUSIONS

Methylxanthines increase the chances of successful extubation of preterm infants within one week of age. Important neurodevelopmental outcomes are improved by methylxanthine therapy. In any future trials, there is a need to stratify infants by gestational age (a better indicator of immaturity than birth weight). Caffeine, with its wider therapeutic margin, would be the better treatment to evaluate against placebo.

Caffeine versus theophylline for apnea of prematurity: a randomised controlled trial

AIM

To compare standard doses of theophylline and caffeine for apnea of prematurity in terms of apnea frequency and assess the need for therapeutic drug monitoring.

METHODS

Seventy neonates less than 33 weeks gestation, breathing spontaneously, were randomly assigned (open-label) to receive either theophylline or caffeine for treatment or prevention of apnea. The primary outcome measure was the difference in apnea frequency between theophylline and caffeine patient groups. Methylxanthine serum levels were measured on the 1st, 3rd and 7th days of therapy and every 7 days thereafter.

RESULTS

Thirty-seven neonates received theophylline (T) and 33 caffeine (C) for treatment (8 T/10 C) or prevention of apnea (29 T/23 C). Treatment with either methylxanthine significantly decreased apnea events (T, P= 0.012; C, P= 0.005) while only C prophylaxis appeared to control apnea in infants at risk. Analysis of combined (treatment plus prophylaxis) data showed a significant decrease in apnea frequency only in those infants receiving caffeine (P= 0.001). However, there was no sustained benefit of C over T beyond the first week of therapy. T and C concentrations (2.2-13.9 mg/L; 5.5-23.7 mg/L, respectively) in the majority of cases fell within the recommended therapeutic ranges and were not significantly associated with apnea events.

CONCLUSIONS

This study shows an advantage of C over T for premature infants <33 weeks gestation during the first week of therapy. Standard regimens of both methylxanthines do not seem to require routine concentration monitoring in the first 3 weeks of treatment unless indicated by clinical effect.

Caffeine citrate treatment for extremely premature infants with apnea: population pharmacokinetics, absolute bioavailability, and implications for therapeutic drug monitoring

The objective of this study was to develop a population model of the pharmacokinetics (PK) of caffeine after orogastric or intravenous administration to extremely premature neonates with apnea of prematurity who were to undergo extubation from ventilation. Infants of gestational age <30 weeks were randomly allocated to receive maintenance caffeine citrate dosing of either 5 or 20 mg/kg/d. Four blood samples were drawn at prerandomized times from each infant during caffeine treatment. Serum caffeine was assayed by enzyme-multiplied immunoassay technique. Concentration data (431 samples, median: 4 per subject) were obtained from 110 (52 male) infants of mean birth weight of 1009 g, current mean weight (WT) of 992 g, mean gestational age of 27.6 weeks, and mean postnatal age (PNA) of 12 days. Of 1022 doses given, 145 were orogastric, permitting estimation of absolute bioavailability. A 1-compartment model with first-order absorption was fitted to the data in NONMEM. Patient characteristics were screened (P < 0.01) in nested models for pharmacokinetic influence. Model stability was assessed by nonparametric bootstrapping. Clearance (CL) increased nonlinearly with increasing PNA, whereas volume of distribution (Vd) increased linearly with WT, according to the following allometric models: CL (L/h) = 0.167 (WT/70) (PNA/12); Vd (L) = 58.7 (WT/70). The mean elimination half-life was 101. Interindividual variability (IIV) of CL and Vd was 18.8 % and 22.3 %, respectively. Interoccasion variability (IOV) of CL and Vd was 35.1% and 11.1%, respectively. This study established that the elimination of caffeine was severely depressed in extremely premature infants but increased nonlinearly after birth up to age 6 weeks. Caffeine was completely absorbed, which has favorable implications for switching between intravenous and orogastric routes. The interoccasion variability about CL was twice the interindividual variability, which, among other factors, indicates that routine serum concentration monitoring of caffeine in these patients is not warranted.