Methylxanthine for the prevention and treatment of apnea in preterm infants

Methylxanthines for the prevention or treatment of intermittent hypoxemia or respiratory insufficiency in late preterm infants

OBJECTIVES

This is a protocol for a Cochrane Review (intervention). The objectives are as follows: To assess the benefits and harms of methylxanthines in preventing or treating intermittent hypoxemia or respiratory insufficiency in late preterm infants.

Gastroesophageal reflux disease in preterm infants: unmet needs

INTRODUCTION

Many preterm present somatic symptoms including aerodigestive and cardiorespiratory manifestations, in combination with irritability and/or distress, which are often attributed to gastroesophageal reflux (GER), albeit for unclear reasons.

AREAS COVERED

We searched in PubMed, Google Scholar, and MEDLINE for guidelines, reviews, and randomized controlled trials up to March 2024.

EXPERT OPINION

The diagnosis of GER-disease (GERD) in preterm is challenging because manifestations are atypical and diagnostic investigations difficult and not devoid of risk for adverse events. In case of vomiting or regurgitation, GER as a consequence of anatomical or metabolic conditions should be considered. Although many preterm infants are treated with proton pump inhibitors, this is seldom needed. Low-quality evidence for alginates is available, but needs further evaluation. There is a need for an effective and safe prokinetic favoring esophageal clearance, increasing lower esophageal sphincter pressure and stimulating gastric emptying. Non-drug treatment such as feeding adaptations (volume, duration, and composition) and positional changes are insufficiently applied. Thickened formula is not indicated in preterm babies. In case none of the above recommendations did result in sufficient improvement, and if documentation of acid GER is not possible, a 2-4 week trial of a proton pump inhibitor is acceptable.

Strategies for cessation of caffeine administration in preterm infants

BACKGROUND

Apnea and intermittent hypoxemia (IH) are common developmental disorders in infants born earlier than 37 weeks' gestation. Caffeine administration has been shown to lower the incidence of these disorders in preterm infants. Cessation of caffeine treatment is based on different post-menstrual ages (PMA) and resolution of symptoms. There is uncertainty about the best timing for caffeine discontinuation.

OBJECTIVES

To evaluate the effects of early versus late discontinuation of caffeine administration in preterm infants.

SEARCH METHODS

We searched CENTRAL, PubMed, Embase, and three trial registries in August 2023; we applied no date limits. We checked the references of included studies and related systematic reviews.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) in preterm infants born earlier than 37 weeks' gestation, up to a PMA of 44 weeks and 0 days, who received caffeine for any indication for at least seven days. We compared three different strategies for caffeine cessation: 1. at different PMAs, 2. before or after five days without symptoms, and 3. at a predetermined PMA versus at the resolution of symptoms.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Primary outcomes were: restarting caffeine therapy, intubation within one week of treatment discontinuation, and the need for non-invasive respiratory support within one week of treatment discontinuation. Secondary outcomes were: number of episodes of apnea in the seven days after treatment discontinuation, number of infants with at least one episode of apnea in the seven days after treatment discontinuation, number of episodes of intermittent hypoxemia (IH) within seven days of treatment discontinuation, number of infants with at least one episode of IH in the seven days after of treatment discontinuation, all-cause mortality prior to hospital discharge, major neurodevelopmental disability, number of days of respiratory support after treatment discontinuation, duration of hospital stay, and cost of neonatal care. We used GRADE to assess the certainty of evidence for each outcome.

MAIN RESULTS

We included three RCTs (392 preterm infants). Discontinuation of caffeine at PMA less than 35 weeks' gestation versus PMA equal to or longer than 35 weeks' gestation This comparison included one single completed RCT with 98 premature infants with a gestational age between 25 + 0 and 32 + 0 weeks at birth. All infants had discontinued caffeine treatment for five days at randomization. The infants received either an oral loading dose of caffeine citrate (20 mg/kg) at randomization followed by oral maintenance dosage (6 mg/kg/day) until 40 weeks PMA, or usual care (controls), during which caffeine was stopped before 37 weeks PMA. Early cessation of caffeine administration in preterm infants at PMA less than 35 weeks' gestation may result in an increase in the number of IH episodes in the seven days after discontinuation of treatment, compared to prolonged caffeine treatment beyond 35 weeks' gestation (mean difference [MD] 4.80, 95% confidence interval [CI] 2.21 to 7.39; 1 RCT, 98 infants; low-certainty evidence). Early cessation may result in little to no difference in all-cause mortality prior to hospital discharge compared to late discontinuation after 35 weeks PMA (risk ratio [RR] not estimable; 98 infants; low-certainty evidence). No data were available for the following outcomes: restarting caffeine therapy, intubation within one week of treatment discontinuation, need for non-invasive respiratory support within one week of treatment discontinuation, number of episodes of apnea, number of infants with at least one episode of apnea in the seven days after discontinuation of treatment, or number of infants with at least one episode of IH in the seven days after discontinuation of treatment. Discontinuation based on PMA versus resolution of symptoms This comparison included two RCTs with a total of 294 preterm infants. Discontinuing caffeine at the resolution of symptoms compared to discontinuing treatment at a predetermined PMA may result in little to no difference in all-cause mortality prior to hospital discharge (RR 1.00, 95% CI 0.14 to 7.03; 2 studies, 294 participants; low-certainty evidence), or in the number of infants with at least one episode of apnea within the seven days after discontinuing treatment (RR 0.60, 95% CI 0.31 to 1.18; 2 studies; 294 infants; low-certainty evidence). Discontinuing caffeine based on the resolution of symptoms probably results in more infants with IH in the seven days after discontinuation of treatment (RR 0.38, 95% CI 0.20 to 0.75; 1 study; 174 participants; moderate-certainty evidence). No data were available for the following outcomes: restarting caffeine therapy, intubation within one week of treatment discontinuation, need for non-invasive respiratory support within one week of treatment discontinuation, or number of episodes of IH in the seven days after treatment discontinuation. Adverse effects In the Rhein 2014 study, five of the infants randomized to caffeine had the caffeine treatment discontinued at the discretion of the clinical team, because of tachycardia. The Pradhap 2023 study reported adverse events, including recurrence of apnea of prematurity (15% in the short and 13% in the regular course caffeine therapy group), varying severities of bronchopulmonary dysplasia, hyperglycemia, extrauterine growth restriction, retinopathy of prematurity requiring laser treatment, feeding intolerance, osteopenia, and tachycardia, with no significant differences between the groups. The Prakash 2021 study reported that adverse effects of caffeine therapy for apnea of prematurity included tachycardia, feeding intolerance, and potential neurodevelopmental impacts, though most were mild and transient. We identified three ongoing studies.

AUTHORS' CONCLUSIONS

There may be little or no difference in the incidence of all-cause mortality and apnea in infants who were randomized to later discontinuation of caffeine treatment. However, the number of infants with at least one episode of IH was probably reduced with later cessation. No data were found to evaluate the benefits and harms of later caffeine discontinuation for: restarting caffeine therapy, intubation within one week of treatment discontinuation, or need for non-invasive respiratory support within one week of treatment discontinuation. Further studies are needed to evaluate the short-term and long-term effects of different caffeine cessation strategies in premature infants.

Optimal Strategies of Mechanical Ventilation: Can We Avoid or Reduce Lung Injury?

BACKGROUND

Despite the increasing use of non-invasive support modalities, many preterm infants still need invasive mechanical ventilation. Mechanical ventilation can lead to so-called ventilator-induced lung injury, which is considered an important risk factor in the development of bronchopulmonary dysplasia. Understanding the concepts of lung protective ventilation strategies is imperative to reduce the risk of BPD.

SUMMARY

Overdistension, atelectasis, and oxygen toxicity are the most important risk factors for VILI. A lung protective ventilation strategy should therefore optimize lung volume (resolve atelectasis), limit tidal volumes, and reduce oxygen exposure. Executing such a lung protective ventilation strategy requires basic knowledge on neonatal lung physiology. Studies have shown that volume-targeted ventilation (VTV) stabilizes tidal volume delivery, reduces VILI, and reduces BPD in preterm infants with respiratory distress syndrome. High-frequency ventilation (HFV) also reduces BPD although the effect is modest and inconsistent. It is unclear if these benefits also apply to infants with more heterogeneous lung disease.

KEY MESSAGES

Understanding basic physiology and the concept of ventilator-induced lung injury is essential in neonatal mechanical ventilation. Current evidence suggests that the principles of lung protective ventilation are best captured by VTV and HFV.

Caffeine for apnea and prevention of neurodevelopmental impairment in preterm infants: systematic review and meta-analysis

This systematic review and meta-analysis evaluated the evidence for dose and effectiveness of caffeine in preterm infants. MEDLINE, EMBASE, CINHAL Plus, CENTRAL, and trial databases were searched to July 2022 for trials randomizing preterm infants to caffeine vs. placebo/no treatment, or low (≤10 mg·kg-1) vs. high dose (>10 mg·kg-1 caffeine citrate equivalent). Two researchers extracted data and assessed risk of bias using RoB; GRADE evaluation was completed by all authors. Meta-analysis of 15 studies (3530 infants) was performed in REVMAN across four epochs: neonatal/infant (birth-1 year), early childhood (1-5 years), middle childhood (6-11 years) and adolescence (12-19 years). Caffeine reduced apnea (RR 0.59; 95%CI 0.46,0.75; very low certainty) and bronchopulmonary dysplasia (0.77; 0.69,0.86; moderate certainty), with higher doses more effective. Caffeine had no effect on neurocognitive impairment in early childhood but possible benefit on motor function in middle childhood (0.72; 0.57,0.91; moderate certainty). The optimal dose remains unknown; further long-term studies, are needed.

Coffee to Make LISA-a-go

In August of 1963, Patrick Bouvier Kennedy, the fourth child of Jackie Onassis Kennedy and John F. Kennedy, died less than 48 hours after his birth from respiratory distress syndrome (RDS) of the newborn. His tragic death inspired research into the physiology of RDS, one product of which was the development of surfactant replacement therapies which have saved millions of neonates from a similar fate. Shortly after the demonstration of its efficacy in 1980, exogenous surfactant replacement therapy became the mainstay intervention for RDS.1 Exogenous surfactant was originally administered via an endotracheal tube in mechanically ventilated neonates, a practice which may lead to ventilator-induced injury to the immature lung.

Caffeine versus other methylxanthines for the prevention and treatment of apnea in preterm infants

BACKGROUND

Methylxanthines, including caffeine, theophylline, and aminophylline, work as stimulants of the respiratory drive, and decrease apnea of prematurity, a developmental disorder common in preterm infants. In particular, caffeine has been reported to improve important clinical outcomes, including bronchopulmonary dysplasia (BPD) and neurodevelopmental disability. However, there is uncertainty regarding the efficacy of caffeine compared to other methylxanthines.

OBJECTIVES

To assess the effects of caffeine compared to aminophylline or theophylline in preterm infants at risk of apnea, with apnea, or in the peri-extubation phase.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, Epistemonikos, the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP), and clinicaltrials.gov in February 2023. We also checked the reference lists of relevant articles to identify additional studies.

SELECTION CRITERIA

Studies: randomized controlled trials (RCTs) and quasi-RCTs Participants: infants born before 34 weeks of gestation for prevention and extubation trials, and infants born before 37 weeks of gestation for treatment trials Intervention and comparison: caffeine versus theophylline or caffeine versus aminophylline. We included all doses and duration of treatment.

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), risk difference (RD), and 95% confidence intervals (CI) for categorical data, and mean, standard deviation, and mean difference for continuous data. We used the GRADE approach to evaluate the certainty of evidence.

MAIN RESULTS

We included 22 trials enrolling 1776 preterm infants. The indication for treatment was prevention of apnea in three studies, treatment of apnea in 13 studies, and extubation management in three studies. In three studies, there were multiple indications for treatment, and in one study, the indication for treatment was unclear. In 19 included studies, the infants had a mean gestational age between 28 and 32 weeks and a mean birth weight between 1000 g and 1500 g. One study's participants had a mean gestational age of more than 32 weeks, and two studies had participants with a mean birth weight of 1500 g or more. Caffeine administrated for any indication may result in little to no difference in all-cause mortality prior to hospital discharge compared to other methylxanthines (RR 1.12, 95% CI 0.68 to 1.84; RD 0.02, 95% CI -0.05 to 0.08; 2 studies, 396 infants; low-certainty evidence). Only one study enrolling 79 infants reported components of the outcome moderate to severe neurodevelopmental disability at 18 to 26 months. The evidence is very uncertain about the effect of caffeine on cognitive developmental delay compared to other methylxanthines (RR 0.17, 95% CI 0.02 to 1.37; RD -0.12, 95% CI -0.24 to 0.01; 1 study, 79 infants; very low-certainty evidence). The evidence is very uncertain about the effect of caffeine on language developmental delay compared to other methylxanthines (RR 0.76, 95% CI 0.37 to 1.58; RD -0.07, 95% CI -0.27 to 0.12; 1 study, 79 infants; very low-certainty evidence). The evidence is very uncertain about the effect of caffeine on motor developmental delay compared to other methylxanthines (RR 0.50, 95% CI 0.13 to 1.96; RD -0.07, 95% CI -0.21 to 0.07; 1 study, 79 infants; very low-certainty evidence). The evidence is very uncertain about the effect of caffeine on visual and hearing impairment compared to other methylxanthines. At 24 months of age, visual impairment was seen in 8 out of 11 infants and 10 out of 11 infants in the caffeine and other methylxanthines groups, respectively. Hearing impairment was seen in 2 out of 5 infants and 1 out of 1 infant in the caffeine and other methylxanthines groups, respectively. No studies reported the outcomes cerebral palsy, gross motor disability, and mental development. Compared to other methylxanthines, caffeine may result in little to no difference in BPD/chronic lung disease, defined as 28 days of oxygen exposure at 36 weeks' postmenstrual age (RR 1.40, 95% CI 0.92 to 2.11; RD 0.04, 95% CI -0.01 to 0.09; 3 studies, 481 infants; low-certainty evidence). The evidence is very uncertain about the effect of caffeine on side effects (tachycardia, agitation, or feed intolerance) leading to a reduction in dose or withholding of methylxanthines compared to other methylxanthines (RR 0.17, 95% CI 0.02 to 1.32; RD -0.29, 95% CI -0.57 to -0.02; 1 study, 30 infants; very low-certainty evidence). Caffeine may result in little to no difference in duration of hospital stay compared to other methylxanthines (median (interquartile range): caffeine 43 days (27.5 to 61.5); other methylxanthines 39 days (28 to 55)). No studies reported the outcome seizures.

AUTHORS' CONCLUSIONS

Although caffeine has been shown to improve important clinical outcomes, in the few studies that compared caffeine to other methylxanthines, there might be little to no difference in mortality, bronchopulmonary dysplasia, and duration of hospital stay. The evidence is very uncertain about the effect of caffeine compared to other methylxanthines on long-term development and side effects. Although caffeine or other methylxanthines are widely used in preterm infants, there is little direct evidence to support the choice of which methylxanthine to use. More research is needed, especially on extremely preterm infants born before 28 weeks of gestation. Data from four ongoing studies might provide more evidence on the effects of caffeine or other methylxanthines.

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.

Caffeine versus other methylxanthines for the prevention and treatment of apnea in preterm infants

This is a protocol for a Cochrane Review (intervention). The objectives are as follows:

To assess the effects of caffeine compared to aminophylline or theophylline in preterm infants at risk of apnea, with apnea, or in the peri‐extubation phase.