Respiratory events in preterm infants prior to discharge: with and without clinically concerning apnoea

Outpatient Respiratory Management of Infants, Children, and Adolescents with Post-Prematurity Respiratory Disease: An Official American Thoracic Society Clinical Practice Guideline

Background: Premature birth affects millions of neonates each year, placing them at risk for respiratory disease due to prematurity. Bronchopulmonary dysplasia is the most common chronic lung disease of infancy, but recent data suggest that even premature infants who do not meet the strict definition of bronchopulmonary dysplasia can develop adverse pulmonary outcomes later in life. This post-prematurity respiratory disease (PPRD) manifests as chronic respiratory symptoms, including cough, recurrent wheezing, exercise limitation, and reduced pulmonary function. This document provides an evidence-based clinical practice guideline on the outpatient management of infants, children, and adolescents with PPRD. Methods: A multidisciplinary panel of experts posed questions regarding the outpatient management of PPRD. We conducted a systematic review of the relevant literature. The Grading of Recommendations, Assessment, Development, and Evaluation approach was used to rate the quality of evidence and the strength of the clinical recommendations. Results: The panel members considered the strength of each recommendation and evaluated the benefits and risks of applying the intervention. In formulating the recommendations, the panel considered patient and caregiver values, the cost of care, and feasibility. Recommendations were developed for or against three common medical therapies and four diagnostic evaluations in the context of the outpatient management of PPRD. Conclusions: The panel developed recommendations for the outpatient management of patients with PPRD on the basis of limited evidence and expert opinion. Important areas for future research were identified.

Pre-discharge Cardiorespiratory Monitoring in Preterm Infants. the CORE Study

Objective: Ensuring cardiorespiratory (CR) stability is essential for a safe discharge. The aim of this study was to assess the impact of a new pre-discharge protocol named CORE on the risk of hospital readmission (RHR). Methods: Preterm infants admitted in our NICU between 2015 and 2018 were randomly assigned to CORE (exposed) or to standard (not-exposed) discharge protocol. CORE included 24 h-clinical observation, followed by 24 h-instrumental CR monitoring only for high-risk infants. RHR 12 months after discharge and length of stay represent the primary and secondary outcomes, respectively. Results: Three hundred and twenty three preterm infants were enrolled. Exposed infants had a lower RHR (log-rank p < 0.05). The difference was especially marked 3 months after discharge (9.09 vs. 21.6%; p = 0.004). The hospital length of stay in exposed and not-exposed infants was 39(26-58) and 43(26-68) days, respectively (p = 0.16). Conclusions: The CORE protocol could help neonatologists to define the best timing for discharge reducing RHR without lengthening hospital stay.

Intermittent hypoxia in preterm infants: Measurement using the desaturation index

OBJECTIVE

The aims of this study were to: (i) Determine in preterm infants at neonatal discharge the prevalence of intermittent hypoxia (IH), as measured by the oxygen desaturation index (DSI) recorded by pulse oximetry and (ii) Determine the change in values for very preterm infants at 1-month post discharge.

METHODS

Preterm infants were recruited from the Wellington regional neonatal intensive care unit (NICU) and 24-h pulse oximetry recordings performed immediately before discharge. Infants born <32 weeks gestational age (GA) had repeat oximetry 1-month post discharge. Oxygenation measures included the 3% and 4% desaturation (DSI 3%, DSI 4%) indices.

RESULTS

At discharge from the neonatal unit the median and interquartile range (IQR) for DSI 4% was 51 (31-74) events per hour with normal mean SpO₂ (median of 97.9% [97.2-98.8 IQR]). Episodes of IH 1 month post discharge decreased with improvements of between 42% and 57% seen for the three DSI measures. Infants <32 weeks GA had higher median DSI 3 and 4% values at discharge but differences when compared with late preterm infants were not significant.

CONCLUSIONS

Preterm infants have frequent episodes of IH as measured by the 3% and 4% DSI when deemed otherwise ready for discharge home. Further research in a larger cohort of very preterm infants and also in term infants is needed to determine the significance of this finding.

Preterm infants at discharge: nap polysomnography versus 24-hour oximetry

AIM

This study aimed to determine whether measures of intermittent hypoxia derived from 24-hour oximetry correlate with measures of apnoea derived from modified nap polysomnography undertaken for preterm infants before discharge.

METHODS

Infants born ≤32 weeks of gestation were recruited from the neonatal intensive care unit and had a modified polysomnography to assess their respiratory stability once they were ≥35 weeks of postmenstrual age. Infants were defined as unstable if they had more than 10 obstructive events per hour or any apnoea of >20 seconds in length. Infants also had a 24-hour oximetry performed during this period. The results of the 24-oximetry desaturation index (DSI) were compared to nap polysomnography results for central and obstructive apnoea indices and correlations tested.

RESULTS

Twenty-four infants completed the study. There were 15 (63%) infants defined as unstable by the modified polysomnography. The 3% DSI and 4% DSI from the 24-hour oximetry were significantly higher in the unstable infants, and values for all infants correlated with the obstructive index and the central apnoea index from the modified polysomnography.

CONCLUSION

The 3% DSI and 4% DSI values from a 24-hour oximetry study may provide noninvasive measures of respiratory stability in preterm infants ready for discharge.

The Longitudinal Effects of Persistent Apnea on Cerebral Oxygenation in Infants Born Preterm

OBJECTIVE

To assess the incidence and impact of persistent apnea on heart rate (HR), oxygen saturation (SpO₂), and brain tissue oxygenation index (TOI) over the first 6 months after term equivalent age in ex-preterm infants.

STUDY DESIGN

Twenty-four preterm infants born between 27 and 36 weeks of gestational age were studied with daytime polysomnography at 2-4 weeks, 2-3 months, and 5-6 months post-term corrected age. Apneas lasting ≥3 seconds were included and maximal percentage changes (nadir) in HR, SpO_2, and tissue oxygenation index (TOI, NIRO-200 Hamamatsu) from baseline were analyzed.

RESULTS

A total of 253 apneas were recorded at 2-4 weeks, 203 at 2-3 months, and 148 at 5-6 months. There was no effect of gestational age at birth, sleep state, or sleep position on apnea duration, nadir HR, SpO₂, or TOI. At 2-4 weeks, the nadirs in HR (-11.1 ± 1.2 bpm) and TOI (-4.4 ± 1.0%) were significantly less than at 2-3 months (HR: -13.5 ± 1.2 bpm, P < .05; TOI: -7.5 ± 1.1 %, P < .05) and at 5-6 months (HR: -13.2 ± 1.3 bpm, P < .01; TOI: -9.3 ± 1.2%, P < .01).

CONCLUSIONS

In ex-preterm infants, apneas were frequent and associated with decreases in heart rate and cerebral oxygenation, which were more marked at 2-3 months and 5-6 months than at 2-4 weeks. Although events were short, they may contribute to the adverse neurocognitive outcomes that are common in ex-preterm children.

Polysomnographic findings in Rett syndrome: a case-control study

PURPOSE

Rett syndrome is a severe neurodevelopmental disorder mainly affecting females and usually linked to mutations in the methyl-CpG-binding protein 2 gene, with an estimated prevalence of 1 in 10,000 live female births. Clinical features which usually become more apparent over time include breathing dysfunction, seizures, spasticity, peripheral vasomotor disturbance, scoliosis, growth retardation, and hypotrophic feet, with a great variety of presentations. The clear immaturity in brainstem mechanisms is expressed by the presence of early sleep disorders such as nocturnal awakenings, bruxism, and difficulty falling asleep, and no conclusive findings were derived from the few polysomnographic studies about the sleep macrostructural aspects. The aim of this study is to analyze the sleep macrostructural parameters, the nocturnal respiratory characteristic, and the presence of periodic limb movements in a sample of children affected by Rett syndrome.

MATERIALS

Thirteen Rett subjects underwent a polysomnographic study, and the findings were compared with those obtained by a group of 40 healthy children.

RESULTS

The Rett group shows a great impairment in sleep macrostructural and respiratory parameters, with a higher percentage of pathological periodic limb movements than the controls.

CONCLUSIONS

This study may be considered a report about the ventilatory impairment during sleep in Rett syndrome and the first approach to the macrostructural aspects of sleep supported by the PSG data that could be considered mandatory for a better comprehension of this very complex syndrome.