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Query: UMLS:C0037315 (sleep apnea)
 8,000 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Periodic breathing (PB) is a pattern of breathing that is frequently recognized in infants being studied for possible sleep apnea. Infants presenting to a sleep laboratory over a 3 1/2-year period who had evidence on their initial study of prolonged (greater than 15% of total sleep time) PB were prospectively studied in an effort to determine the significance of this pattern of breathing. Of the 331 infants studied, 40 demonstrated prolonged PB. Sixteen of these infants, who were of 37 weeks' gestation or greater at birth and did not receive pharmacologic therapy, were studied on at least two occasions (group 1). Of the remaining 24 infants, 11 were treated with methylxanthines by their attending physician (group 2), and 13 did not return for sequential studies (group 3). All infants who were of less than 37 weeks' gestation at birth were separately evaluated (group 4). For group 1, who were studied at a mean age of 15 postnatal weeks, there was a mean of 36.4% periodicity which decreased on the second study to 18.0%. By the fourth study, this had decreased to 9.2%. In group 2, there was a mean of 41.3% periodicity during the first study which decreased to 6.4% on the second study. Infants of group 3 had a mean of 31.4% PB on their initial study and the premature infants, group 4, had 30.1% PB. All infants showed a decrease in PB with sequential studies and no infant was known to have died of sudden infant death syndrome or any other disorder in the first year of life.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Prolonged periodic breathing: significance in sleep studies. 174 Dec 21

The spectrum of breathing events during sleep in patients with obstructive sleep apnoea syndrome (OSAS) after the abolition of obstructive apnoeas has been extensively studied in tracheostomized patients, but has received much less attention in patients submitted to continuous positive airway pressure (CPAP). We analysed the breathing pattern during sleep in forty patients while CPAP was administered. A regular breathing pattern throughout the sleep study was observed in 15 patients. In the remaining 25 subjects, one or more of the following events was observed: central apnoeas, hypopnoeas, periodic breathing, prolonged oxyhaemoglobin desaturations. Central apnoeas during non-rapid eye movement (NREM) sleep appeared almost exclusively after arousals or wakefulness periods; their prevalence did not significantly differ between subjects who showed and who did not show similar events before CPAP. Central apnoeas in rapid eye movement (REM) sleep had a random occurrence. Hypopnoeas were found only in REM sleep, and, like central apnoeas, occurred randomly; in one patient they had a prolonged duration (up to 110 s). Periodic breathing was observed in only two subjects, one of whom had congestive heart failure: it was limited to NREM sleep and was not associated with arousals or shifts in sleep stage. Prolonged oxyhaemoglobin desaturations were found mainly in REM sleep; most subjects with such abnormalities had daytime blood gas alterations. In conclusion, abnormalities of the breathing pattern of patients with OSAS can be observed during CPAP and after tracheostomy, but periodic breathing is less common than is reported after tracheostomy, and is probably caused by different mechanisms.
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PMID:Occurrence of breathing disorders during CPAP administration in obstructive sleep apnoea syndrome. 188 92

Respiratory pauses (3-10 sec in duration), apnea (less than 10 sex in duration), and periodic respiration observed in thoracic respirograms were measured in 226 polysomnograms obtained on 17 normal infants during the first year of life. All subjects had one or more respiratory pauses in a majority of recordings; 35% had respiratory pauses in all recordings; 75% of respiratory pauses were associated with body movement. There is marked intersubject and even intrasubject variability in respiratory pause rates. The range of mean respiratory pause rates among subjects was 2.0 - 14.4/h, and for single recordings was 0.0 - 43.6/h. Their occurrence was directly related to the occurrence of periodic respiration. Rates were higher during REM and indeterminate sleep than during slow wave sleep. There was no significant trend toward increase or decrease in respiratory pause rate during the first year post term. Apnea occurred in only one of the 226 recordings (0.4%). Periodic respiration occurred in 8 of 17 subjects (47%), and in 25 of 226 recordings (11%). Its occurrence was unrelated to sleep stage. The following conclusions are considered valid on the basis of the data presented and reports in the literature: (1) Rates of respiratory interruption are higher before than after 40 weeks conceptional age. (2) There is considerable intersubject variability in rates of respiratory interruptions. (3) Respiratory pauses are common during sleep in normal human infants. (4) Respiratory pauses occur more frequently with movements than in their absence. (5) Respiratory pause rates are higher during REM sleep than during slow wave sleep. (6) Apneas of greater than 10-15 sec duration do occur in normal infants, but are rare. From the clinical viewpoint, respiratory pauses (less than 15 sec) of the central type, regardless of abundance, and periodic respiration cannot by themselves be used as evidence that a baby is at risk of anything. The occurrence of apneas (greater than 15 sec duration), especially if any are of the obstructive or mixed types (and perhaps respiratory pauses of the obstructive and mixed types), and/or if associated with bradycardia or decrease in oxygen saturation, indicate sleep apnea syndrome and suggest risk of sudden infant death.
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PMID:Respiratory pauses and apnea during daytime sleep in normal infants during the first year of life: longitudinal observations. 617

A model of the chemoreceptor mediated control of breathing is analysed. Hypoxia is simulated as low equilibrium arterial oxygen both at altitude and at sea level. Conditions for stable and unstable equilibria are examined. Transition to instability leads to periodic breathing and the model predicts that this can cause arterial oxygen to oscillate asymmetrically about the equilibrium in some cases, causing the average to rise. Periodic forcing functions have been applied to cerebral blood flow with the same effect on arterial oxygen. Such asymmetric oscillations leading to enhanced oxygenation have been observed in pulse oxymeter recordings from elderly postoperative patients. This may be important in interpreting studies of unstable breathing patterns and their possible relation to morbidity or mortality in infants (e.g. SIDS) and in the elderly (e.g. sleep apnoea, postoperative hypoxia). Periodic breathing could act as a protective adaptation to counteract pre-existing hypoxia.
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PMID:Can periodic breathing have advantages for oxygenation? 771 5

Periodic breathing with central apneas during sleep is typically triggered by hypocapnia resulting from hyperventilation. We therefore hypothesized that hypocapnia would be an important determinant of Cheyne-Stokes respiration with central sleep apnea (CSR-CSA) in patients with congestive heart failure (CHF). To test this hypothesis, 24 male patients with CHF underwent overnight polysomnography during which transcutaneous PCO2 (PtcCO2) was measured. Lung to ear circulation time (LECT), derived from an ear oximeter as an estimate of circulatory delay, and CSR-CSA cycle length were determined. Patients were divided into a CSR-CSA group (n = 12, mean +/- SEM of 49.2 +/- 6.3 central apneas and hypopneas per h sleep) and a control group without CSR-CSA (n = 12, 4.9 +/- 0.8 central apneas and hypopneas per h sleep). There were no significant differences in left ventricular ejection fraction, awake PaO2, mean nocturnal SaO2, or LECT between the two groups. In contrast, the awake PaCO2 and mean sleep PtcCO2 were significantly lower in the CSR-CSA group than in the control group (33.0 +/- 1.2 versus 37.5 +/- 1.0 mm Hg, p < 0.01, and 33.2 +/- 1.2 versus 42.5 +/- 1.2 mm Hg, p < 0.0001, respectively). Neither group had significant awake or sleep-related hypoxemia. In addition, CSR-CSA cycle length correlated with LECT (r = 0.939, p < 0.001). We conclude that (1) hypocapnia is an important determinant of CSR-CSA in CHF and (2) circulatory delay plays an important role in determining CSR-CSA cycle length.
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PMID:Role of hyperventilation in the pathogenesis of central sleep apneas in patients with congestive heart failure. 814 43

The purpose of this study was to elucidate the effects of acute hypobaric hypoxia on nocturnal sleep architecture and respiratory responses in a hypobaric simulator. Five healthy young males (19-23 years old) were recruited to sleep for 8 h at sea level and at simulated altitudes of 1,500, 3,000, and 4,000 m in the simulator (61.2 m3, 20 degrees C, and 60% RH). Each experimental run was separated by at least 3 d. Standard polysomnograph, respiration, and arterial oxygen saturation (SaO2) during sleep were observed. 1) SaO2 decreased significantly with increasing altitude. At 4,000 m, SaO2 showed its lowest value during 1 to 3 h after sleep onset. 2) Sleep architecture below 3,000 m showed almost the same pattern. However, reduction in REM sleep and increased wakefulness were observed at 4,000 m, though such sleep disturbance was not observed in the first one-third of the night spent in bed. 3) Periodic breathing (PB) with apnea and/or hypopnea developed in all subjects above 3,000 m. PB tended to appear in light sleep, though sleep was not always disturbed by PB. It might be concluded that there was no sleep disturbance up to 3,000 m altitude. Nocturnal sleep at 4,000 m, however, was disturbed after a few hours from sleep onset by severe hypoxemia induced by multiplicative effects of hypoxia and hypoventilation during deep sleep. At high altitude, PB seems to not induce arousals consistently, which was different from sleep apnea syndrome at sea level.
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PMID:Sleep and respiration under acute hypobaric hypoxia. 835 17

1. Periodic breathing is known to be associated with cyclic fluctuations in heart rate. The purpose of this study was to evaluate the capability of spectral analysis of heart rate variability to identify episodes with periodic breathing in patients suspected of having sleep apnoea syndrome. 2. Forty-eight subjects complaining of chronic day-time sleepiness were studied using polysomnography and additional monitoring of Holter-ECG and synchronized pulse oximetry. The recordings were divided into 20 min episodes which were identified as recordings registered during normal breathing, periodic breathing, and periods of both normal and abnormal breathing. Power spectral analysis was performed on episodes which met the criteria of stationary of data (313 episodes with normal breathing, 264 episodes with continuous periodic breathing, 80 episodes with both normal and periodic breathing patterns). 3. The ability of parameters, derived from analysis of heart rate variability, to discriminate between episodes with normal and periodic breathing was assessed by receiver-operating characteristic analysis. 4. The spectral power component in the frequency range 0.01-0.07 Hz revealed the greatest accuracy for discriminating between normal and periodic breathing (area under the receiver-operating characteristic curve = 0.929; standard error = 0.009). The analysis of the episodes classified as false-positive at a given test sensitivity of 90% and a corresponding specificity of 77% revealed that half of these episodes had been recorded during transient central nervous arousal reactions related to periodic leg movements or heavy snoring. 5. We concluded that power spectral analysis of heart rate variability offers a possible means of identifying episodes of sleep-related breathing disorders or periodic leg movements. Therefore, analysis of heart rate variability may be a valuable additional diagnostic tool in patients undergoing Holter-ECG recording.
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PMID:Heart rate variability in patients with daytime sleepiness suspected of having sleep apnoea syndrome: a receiver-operating characteristic analysis. 917 31

Ventilation during sleep is under tight metabolic control, and can be destabilized by upper airway obstruction leading to snoring or obstructive apneas, inadequate respiratory pump muscle activity leading to hypoventilation, and central control instability leading to changes in metabolic feedback and loop gain. These three physiologic disturbances can lead to obstructive sleep apnea hypopnea syndrome (OSAHS), hypoventilation syndromes, and periodic breathing. OSAHS places a strain on the cardiac output by virtue of hypoxemia, large negative intrathoracic pressures, and high swings in systemic blood pressure. Periodic breathing, also known as central sleep apnea with Cheyne-Stokes pattern of respiration, is likely to be a product of advanced heart failure.
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PMID:Common sleep problems in ICU: heart failure and sleep-disordered breathing syndromes. 1853 1