Caffeine is a respiratory stimulant without effect on sleep in the short-term in late-preterm infants

Medical intelligence using PPG signals and hybrid learning at the edge to detect fatigue in physical activities

The educational environment plays a vital role in the development of students who participate in athletic pursuits both in terms of their physical health and their ability to detect fatigue. As a result of recent advancements in deep learning and biosensors benefitting from edge computing resources, we are now able to monitor the physiological fatigue of students participating in sports in real time. These devices can then be used to analyze the data using contemporary technology. In this paper, we present an innovative deep learning framework for forecasting fatigue in athletic students following physical exercise. It addresses the issue of lack of precision computational models and extensive data analysis in current approaches to monitoring students' physical activity. In our study, we classified fatigue and non-fatigue based on photoplethysmography (PPG) signals. Several deep learning models are compared in the study. Using limited training data, determining the optimal parameters for PPG presents a significant challenge. For datasets containing many data points, several models were trained using PPG signals: a deep residual network convolutional neural network (ResNetCNN) ResNetCNN, an Xception architecture, a bidirectional long short-term memory (BILSTM), and a combination of these models. Training and testing datasets were assigned using a fivefold cross validation approach. Based on the testing dataset, the model demonstrated a proper classification accuracy of 91.8%.

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

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

Effects of caffeine therapy for apnea of prematurity on sleep and neurodevelopment of preterm infants at 6 months of corrected age

STUDY OBJECTIVES

To determine the differences in sleep patterns between preterm infants who received caffeine and those who did not and to evaluate the effects of caffeine therapy on early neurodevelopment. Secondarily, actigraphy and polysomnography were compared to evaluate the sleep of preterm infants.

METHODS

Twenty-eight preterm infants ages 28-34 weeks admitted to a single-center Level III neonatal intensive care unit between May 2020 and May 2021 were included. Sleep was assessed by actigraphy for 72 hours with Respironics Mini-Mitter® Actiwatch-2 and Brief Infant Sleep Questionnaire at 6 months corrected age. On the first day of actigraphy, infants underwent polysomnography between 10:00 am and 3:00 pm. Neurodevelopment was evaluated by the Bayley Scales of Infant and Toddler Development-III, the Ages & Stages Questionnaire, and the Hammersmith Infant Neurological Examination.

RESULTS

There were no significant differences in sleep parameters measured by actigraphy, the Brief Infant Sleep Questionnaire, and polysomnography between infants in the caffeine group (n = 12) and no-caffeine group (n = 16). Sensitivity (91.07%) and agreement rate (77.21%) for the actigraphy against polysomnography were highest at the automatic threshold. No significant differences were observed in the neurodevelopment of infants in the caffeine group compared to the no-caffeine group.

CONCLUSIONS

Sleep parameters and neurodevelopmental outcomes were not different in infants at 6 months of corrected age with regard to caffeine therapy. Actigraphy at the automatic threshold can be used in infants for sleep pattern assessment.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Name: Influence of Caffeine Therapy in Preterm Infants; URL: https://www.clinicaltrials.gov/ct2/show/NCT04376749; Identifier: NCT04376749.

CITATION

Atalah YEY, Barış HE, Akdere SK, et al. Effects of caffeine therapy for apnea of prematurity on sleep and neurodevelopment of preterm infants at 6 months of corrected age. J Clin Sleep Med. 2023;19(12):2075-2085.

Alteration of intracerebral metabolites and subjective sleepiness by acute caffeine administration in adults

Background

Caffeine is the most widely consumed psychostimulant. Despite this, the effects of acute caffeine intake on brain metabolite levels remain largely unknown. We aimed to investigate the effect of acute caffeine intake on brain metabolite concentrations in different caffeine consumption habit groups and to explore the association between metabolite changes and sleepiness.

Methods

Forty-five healthy adults were divided into groups based on their daily caffeine consumption: ≥1 cup/day, <1 cup/day, and no consumption. The exclusion criteria were the presence of neurological disorder, habitual consumption of mind-altering substances, and individuals who were unable to undergo magnetic resonance imaging. Mescher-Garwood point resolved spectroscopy and conventional spectroscopy data were acquired at 3 Tesla from voxels in the thalamus and posterior cingulate cortex (PCC). Subjective sleepiness was measured with the Karolinska Sleepiness Scale.

Results

The results of two-way repeated measures analysis of variance indicated a significant interaction effect between time and group for glutamate, glycerylphosphocholine and phosphocholine (GPC + PCH), myo-inositol, glutamate + glutamine (Glx), and creatine and phosphocreatine (Cr + PCr) of the thalamus (all P<0.01), and glutamate (P<0.0001), GPC + PCH (P=0.016), and Glx (P<0.0001) of the PCC. The change between pre- and post-caffeine intake results with significant reductions in γ-aminobutyric acid-positive macromolecule (GABA+) (thalamus, P=0.011), Glx (thalamus, P=0.002), glutamate (PCC, P<0.0001), and significant increments in GPC + PCH (thalamus, P=0.012 and PCC, P<0.0001), myo-inositol (thalamus, P=0.009), and Glx (PCC, P<0.0001). The change among the groups, with the ≥1 cup/day was significantly higher than the <1 cup/day or no consumption for glutamate (PCC, P=0.028), GPC (thalamus, P=0.001; PCC, P=0.026), and Cr + PCr (PCC, P=0.035); ≥1 cup/day was significantly lower than <1 cup/day and no consumption for glutamate (thalamus, P<0.0001), Cr + PCr (thalamus, P=0.003), Glx (thalamus, P=0.014), and myo-inositol (PCC, P=0.009). Bivariate correlation analysis revealed that GABA+ in the thalamus voxel (r=-0.7676; P<0.0001) was negatively correlated with subjective sleepiness.

Conclusions

Higher caffeine consumption had a significant impact on brain metabolites. Magnetic resonance spectroscopy was sensitive in measuring brain metabolite fluctuations after caffeine intake, particularly the levels of GABA+ in the thalamus, which was significantly correlated with sleepiness.

The effect of acute respiratory events and respiratory stimulants on EEG-recorded brain activity in neonates: A systematic review

Objective

We conducted a systematic review to investigate electroencephalography (EEG) changes during periods of acute respiratory events such as apnoea and the effect of respiratory stimulants on EEG features in infants.

Methods

Studies examining respiration and EEG-recorded brain activity in human neonates between 28 and 42 weeks postmenstrual age were included. Two reviewers independently screened all records and included studies were assessed using the Joanna Briggs Institute Critical Appraisal Tool. The protocol was registered in PROSPERO (CRD42022339873).

Results

We identified 14 studies with a total of 534 infants. Nine articles assessed EEG changes in relation to apnoea, one assessed hiccups, and four investigated the effect of respiratory stimulants. The relationship between neonatal apnoea and EEG changes was inconsistent; EEG suppression and decreased amplitude and frequency were observed during some, but not all, apnoeas. Respiratory stimulants increased EEG continuity compared with before use.

Conclusions

Current studies in this area are constrained by small sample sizes. Diverse exposure definitions and outcome measures impact inference.

Significance

This review highlights the need for further work; understanding the relationship between respiration and the developing brain is key to mitigating the long-term effects of apnoea.

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.

Unexplained Significant Central Sleep Apnea in Infants: Clinical Presentation and Outcomes

OBJECTIVE

Unexplained significant central sleep apnea in term infants presents as central apneas with associated oxygen desaturations requiring respiratory support and monitoring for prolonged periods. However, there is a paucity of literature describing idiopathic central sleep apnea (ICSA) in term or near-term infants. Our aim was to describe the clinical manifestations, polysomnography data, interventions, and trajectory of ICSA in infants.

DESIGN

This is a retrospective study of infants (gestational age ≥ 35 weeks) who presented with significant central apneas and were subsequently diagnosed with ICSA following polysomnography and clinical investigations between January 2011 and April 2021 at a tertiary care hospital in Canada. Polysomnography data, clinical investigations, and treatments were documented.

RESULTS

Eighteen infants (male, 78%; median gestational age 38 weeks) with ICSA were included. Initial polysomnograms were completed at a median (interquartile range [IQR]) age of 1.2 (0.6-1.6) months (n = 18) and follow-up polysomnograms at 12.4 (10.6-14.0) months (n = 13). Compared to baseline diagnostic polysomnograms, at follow-up there was a significant reduction in the median (IQR) central apnea-hypopnea index (26.1 [18.2-52.9] versus 4.2 [2.6-7.2] events/hour; p = 0.001), desaturation index (30.9 [12.2-57.4] versus 3.9 [3.0-7.9] events/hour; p = 0.002), average transcutaneous carbon dioxide (41.9 [40.1-47.3 versus 39.4 [37.5-42.7] mmHg; p = 0.025), and improved nadir oxygen saturation (79.8 [69.1-83.0] versus 85.5 [83.2-87.8]%; p = 0.033), respectively. Prescribed treatments included supplemental oxygen (14/18, 78%), caffeine (5/18, 28%), and noninvasive ventilation (1/18, 6%).

CONCLUSIONS

Infants with significant unexplained ICSA have a favorable clinical trajectory over time. Further research is needed to understand the etiology of this rare disorder.

Precision caffeine therapy for apnea of prematurity and circadian rhythms: New possibilities open up

Caffeine is the globally consumed psychoactive substance and the drug of choice for the treatment of apnea of prematurity (AOP), but its therapeutic effects are highly variable among preterm infants. Many of the molecular underpinnings of the marked individual response have remained elusive yet. Interestingly, the significant association between Clock gene polymorphisms and the response to caffeine therapy offers an opportunity to advance our understanding of potential mechanistic pathways. In this review, we delineate the functions and mechanisms of human circadian rhythms. An up-to-date advance of the formation and ontogeny of human circadian rhythms during the perinatal period are concisely discussed. Specially, we summarize and discuss the characteristics of circadian rhythms in preterm infants. Second, we discuss the role of caffeine consumption on the circadian rhythms in animal models and human, especially in neonates and preterm infants. Finally, we postulate how circadian-based therapeutic initiatives could open new possibilities to promote precision caffeine therapy for the AOP management in preterm infants.