Supplemental Oxygen Treats Periodic Breathing without Effects on Sleep in Late-Preterm Infants.

BACKGROUND: The effect of supplemental oxygen on sleep has not been studied in preterm infants. METHODS: We studied 18 stable late-preterm infants with observed periodic breathing at a median gestational age of 36 weeks. Polysomnography was performed on room air and on 25% oxygen-enriched ambient air. RESULTS: Supplemental oxygen did not affect sleep stage distribution, sleep efficiency, the frequency of sleep stage transitions, the appearance of rapid-eye movement (REM) sleep periods, or the high number of spontaneous arousals. The percentage in periodic breathing out of total sleep time decreased from 10% (interquartile range [IQR] 5-9%) on room air to 1% (IQR 0-3%) (p < 0.001) on supplemental oxygen. Also, the number of central apneas decreased from 48 (IQR 32-68) to 23 (IRQ 15-32) per hour (p < 0.001), and the number of oxygen desaturations of a minimum 3% from 38 (IQR 29-74) to 10 (IQR 5-24) per hour (p < 0.001). On room air in non-REM sleep, the median end-tidal carbon dioxide values were systematically lower during periodic breathing at 5.1 (IQR 4.6-6.4) kPa than during stable breathing at 5.5 (4.9-5.9) kPa (p < 0.0001). CONCLUSIONS: In late-preterm infants, supplemental oxygen effectively reduces periodic breathing and the number of oxygen desaturations while having no significant effect on sleep. The results support the importance of carotid body over-reactivity on the genesis of periodic breathing in preterm infants.

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

BACKGROUND: Caffeine is widely used in preterm infants for apnea control. It has no effect on sleep in the only existing polysomnographic study including ten preterm infants Behavioral and polygraphic studies have conflicting results. METHODS: We studied 21 late-preterm infants at a median gestational age of 36 weeks. Polysomnography was performed twice, at baseline on day 1 and on the day after the onset of caffeine treatment (20 mg/kg loading and 5 mg/kg morning maintenance dose). RESULTS: Caffeine acted short term as a breathing stimulant with reduction of apneas, improved baseline SpO2 (p < 0.001), and decreased 95 percentile of end-tidal carbon dioxide level (p < 0.01). It also increased arousal frequency to SpO2 desaturations of more than 5% (p < 0.001). Caffeine did not affect sleep stage distribution, sleep efficiency, frequency of sleep stage transitions, appearance of REM periods, or the high number of spontaneous arousals. The median spontaneous arousal count was 18 per hour at baseline, and 16 per hour during caffeine treatment (p = 0.88). CONCLUSIONS: In late-preterm infants, caffeine has a clear short-term respiratory stimulant effect, and it increases the arousal frequency to hypoxia. However, caffeine does not appear to act as a central nervous system stimulant, and it has no acute effect on sleep quality. IMPACT: Effects of caffeine on sleep in preterm infants has previously been investigated with only one full polysomnographic study including ten preterm infants. The study showed no effect. The current study shows that caffeine acts short term as a respiratory stimulant and increases arousal frequency to hypoxia. Although a potent central nervous system (CNS) stimulant in adults, caffeine does not seem to have similar acute CNS effect in late-preterm infants. The onset of caffeine treatment has no short-term effect on sleep stage distribution, sleep efficiency, frequency of sleep stage transitions, appearance of REM periods, or the high number of spontaneous arousals.

Pierre Robin sequence causes position-dependent obstructive sleep apnoea in infants.

INTRODUCTION: Obstructive sleep apnoea (OSA) and feeding difficulties are key problems for Pierre Robin sequence (PRS) infants. OSA management varies between treatment centres. Sleep positioning represents the traditional OSA treatment, although its effectiveness remains insufficiently evaluated. DESIGN: To complete a polysomnographic (PSG) evaluation of effect of sleep position on OSA in PRS infants less than 3 months of age. We analysed a 10-year national reference centre dataset of 76 PRS infants. PSG was performed as daytime recordings for 67 in the supine, side and prone sleeping position when possible. In most cases, recording included one cycle of non-rapid eye movement (NREM) and rapid eye movement (REM) sleep in each position. RESULTS: One-third of infants (9/76, 12%) had severe OSA needing treatment intervention prior to PSG. During PSG, OSA with an obstructive apnoea and hypopnoea index (OAHI) >5 per hour was noted in 82% (55/67) of infants. OSA was most severe in the supine and mildest in the side or in the prone positions. The median OAHI in the supine, side and prone positions were 31, 16 and 19 per hour of sleep (p=0.003). For 68% (52/67) of the infants, either no treatment or positional treatment alone was considered sufficient. CONCLUSIONS: The incidence of OSA was 84% (64/76) including the nine infants with severe OSA diagnosed prior to PSG. For the most infants, the OSA was sleep position dependent. Our study results support the use of PSG in the evaluation of OSA and the use of sleep positioning as a part of OSA treatment.

Spontaneous and apnea arousals from sleep in preterm infants.

BACKGROUND: The significance of arousal in apnea termination in preterm infants is not known. METHODS: We investigated the appearance of arousals from sleep with polysomnography for 21 preterm infants at a median age of 36 gestational weeks. RESULTS: The polysomnographic appearance of sleep was fragmented by frequent arousals. The number of spontaneous arousals unrelated to apneas was 18 per hour in sleep; higher in rapid eye movement (REM) sleep than in non-REM sleep (p < 0.001). Eighty-two percent of arousals were regarded as spontaneous, and 18% were related to apneas. In turn, arousal followed 5% of all apneas; 30% of mixed, 2% of central, and 20% of long apneas defined as apnea of prematurity. Apneas without an arousal led to lower oxygen saturation levels than those followed by an arousal (p < 0.001). Mixed apneas with an arousal had stronger breathing effort and a higher number of breaths compared with apneas without an arousal (p < 0.05). CONCLUSIONS: In preterm infants, frequent spontaneous arousals or arousal-type phenomena make the polysomnographic appearance of sleep fragmented. However, even long apneas or hypoxia commonly fail to elicit arousals or any sign of sleep interruption. Our findings suggest that arousal appears not to be the main mechanism for apnea termination in preterm infants. IMPACT: Polysomnographic appearance of sleep in preterm infants is fragmented by arousals. Contrary to older children and adults, arousal to apnea is uncommon in preterm infants. Even long mixed apneas with desaturation mostly fail to elicit an arousal response. In preterm infants, apnea termination appears not to depend on an arousal. Low arousability is suggested to be caused by a low ventilation response to hypoxia.

Caffeine and supplemental oxygen effectively suppress periodic breathing with only minor effects during long episodes of apnoea in preterm infants.

AIM: We investigated the characteristics and effects of sleep stage, supplemental oxygen and caffeine on periodic breathing (PB) and apnoea of prematurity (AOP) in preterm infants. METHODS: This 2013-2015 study recruited 21 preterm infants on neonatal wards in the Helsinki and Uusimaa Hospital District, Finland, at a median corrected gestational age of 35.7 weeks and performed polysomnography at baseline, during supplemental oxygen and during caffeine treatment. RESULTS: All infants demonstrated PB, during a median of 11% of sleep time and 85% of PB occurred during non-rapid eye movement sleep (NREM). Apnoea episodes were brief during PB, but 66% were associated with oxygen desaturation. Supplemental oxygen substantially reduced PB time by 99% and caffeine by 91%. Oxygen desaturation decreased from 38 per hour at baseline to 8.5 with oxygen and 24 with caffeine (all p < 0.001). AOPs decreased from 1.4 per hour at baseline to 0.4 with oxygen (p = 0.03) and 0.3 with caffeine (p = 0.07). Most (84%) apnoea episodes over 15 seconds were mixed episodes during REM sleep. CONCLUSION: PB occurred predominantly during NREM sleep, caused intermittent hypoxia, and was suppressed by supplemental oxygen and caffeine. In contrast, long apnoea episodes representing AOP were only modestly decreased.