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Fürst G, Riechelmann H, Mann WJ, Amedee RG. Measurement of Pharyngeal Pressure in Patients using Nasal CPAP. ACTA ACUST UNITED AC 2018. [DOI: 10.2500/105065895781808694] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In patients with obstructive sleep apnea syndrome (OSAS), nasal continuous positive airway pressure (nCPAP) prevents pharyngeal collapse by applying positive pressure transnasally. Currently there are not objective criteria to determine whether surgical improvement of nasal resistance is necessary in patients undergoing nCPAP treatment. In 16 patients with documented OSAS, inspiratory and expiratory pressures in the pharynx were measured during nCPAP with pressures ranging from 5 to 20 mbar. Identical studies were performed in 12 patients with severe nasal obstruction without OSAS and in eight normal patients. The results of each group were compared to the nasal resistance as measured by acoustic rhinometry. The pharyngeal pressures under nCPAP were found to be independent of nasal resistance and of the minimal cross-sectional area of the nose. Additionally, nCPAP was effective in individuals with severe nasal obstruction. Nasal obstruction has no influence on nasal pressure when using nCPAP. Perhaps other factors, such as collapsing of the pharynx or tone of the pharyngeal muscles, play a role in determining the nasal pressure of the nCPAP.
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Affiliation(s)
- Gudrun Fürst
- Departments of Otolaryngology, University of Mainz, Mainz, Germany
| | | | - Wolf J. Mann
- Departments of Otolaryngology, University of Mainz, Mainz, Germany
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Abstract
Sleep is an essential function of life and serves a crucial role in the promotion of health and performance. Poor sleep quality and sleep disorders have been a recurrent finding in patients with chronic kidney disease (CKD). Sleep disorders such as obstructive sleep apnea (OSA) can contribute to hypertension, diabetes, cardiovascular disease, and worsen obesity, all of which are implicated in the etiology of CKD, but CKD itself may lead to OSA. Relationships between CKD/end-stage renal disease (ESRD) and OSA have been the subject of numerous investigations, but central sleep apnea (CSA) also is highly prevalent in CKD/ESRD but remains poorly understood, underdiagnosed, and undertreated in these patients. Emerging literature has implicated CSA as another contributor to morbidity and mortality in CKD/ESRD, and several studies have suggested that CSA treatment is beneficial in improving these outcomes. Patients with CKD/ESRD co-existing with congestive heart failure are particularly prone to CSA, and studies focused on managing CSA in congestive heart failure patients have provided important information concerning how best to manage CSA in kidney disease as well. Adaptive servo-ventilation ultimately may represent the treatment of choice in these patients, although a stepped approach using a variety of therapeutic modalities is recommended.
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Affiliation(s)
- Sushma M Dharia
- Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, NM
| | - Mark L Unruh
- Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, NM
| | - Lee K Brown
- Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, NM.
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Cardio-respiratory coordination increases during sleep apnea. PLoS One 2014; 9:e93866. [PMID: 24718564 PMCID: PMC3981754 DOI: 10.1371/journal.pone.0093866] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Accepted: 03/11/2014] [Indexed: 11/19/2022] Open
Abstract
Cardiovascular diseases are the main source of morbidity and mortality in the United States with costs of more than $170 billion. Repetitive respiratory disorders during sleep are assumed to be a major cause of these diseases. Therefore, the understanding of the cardio-respiratory regulation during these events is of high public interest. One of the governing mechanisms is the mutual influence of the cardiac and respiratory oscillations on their respective onsets, the cardio-respiratory coordination (CRC). We analyze this mechanism based on nocturnal measurements of 27 males suffering from obstructive sleep apnea syndrome. Here we find, by using an advanced analysis technique, the coordigram, not only that the occurrence of CRC is significantly more frequent during respiratory sleep disturbances than in normal respiration (p-value<10−51) but also more frequent after these events (p-value<10−15). Especially, the latter finding contradicts the common assumption that spontaneous CRC can only be observed in epochs of relaxed conditions, while our newly discovered epochs of CRC after disturbances are characterized by high autonomic stress. Our findings on the connection between CRC and the appearance of sleep-disordered events require a substantial extension of the current understanding of obstructive sleep apneas and hypopneas.
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Stevens SA, Thakore NJ, Lakin WD, Penar PL, Tranmer BI. A modeling study of idiopathic intracranial hypertension: etiology and diagnosis. Neurol Res 2013; 29:777-86. [PMID: 17553215 DOI: 10.1179/016164107x208112] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVE To investigate the relationship between idiopathic intracranial hypertension (IIH) and transverse sinus stenosis through experiments performed on a validated mathematical model. METHODS A mathematical model of intracranial pressure (ICP) dynamics has been extended to accommodate venous sinus compression through the introduction of a Starling-like resistor between the sagittal and transverse sinuses. RESULTS In the absence of this type of resistor, the sinuses are rigid, and the model has only a unique, stable steady state with normal pressures. With resistance a function of the external pressure on the sinus, a second stable steady state may exist. This state is characterized by elevated ICP concurrent with a compressed transverse sinus. Simulations predict that a temporary perturbation that causes a transient elevation of ICP can induce a permanent transition from the normal to the higher steady state. Comparisons to clinical data from IIH patients provide supporting evidence for the validity of the model's predictions. Simulations suggest a possible clinical diagnostic technique to determine if an individual has a compressible transverse sinus and is at risk for developing IIH. CONCLUSIONS Results of the model experiments suggest that the primary cause of IIH may be a compressible, as opposed to rigid, transverse sinus, and that the observed stenosis is a necessary characteristic of the elevated pressure state.
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Affiliation(s)
- Scott A Stevens
- Division of Information Technology and Sciences, Champlain College, Burlington, VT 05402-0670, USA
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Fiamma MN, O'Connor ET, Roy A, Zuna I, Wilson RJA. The essential role of peripheral respiratory chemoreceptor inputs in maintaining breathing revealed when CO2 stimulation of central chemoreceptors is diminished. J Physiol 2013; 591:1507-21. [PMID: 23359670 DOI: 10.1113/jphysiol.2012.247304] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Central sleep apnoea is a condition characterized by oscillations between apnoea and hyperpnoea during sleep. Studies in sleeping dogs suggest that withdrawal of peripheral chemoreceptor (carotid body) activation following transient ventilatory overshoots plays an essential role in causing apnoea, raising the possibility that sustaining carotid body activity during ventilatory overshoots may prevent apnoea. To test whether sustained peripheral chemoreceptor activation is sufficient to drive breathing, even in the absence of central chemoreceptor stimulation and vagal feedback, we used a vagotomized, decerebrate dual-perfused in situ rat preparation in which the central and peripheral chemoreceptors are independently and artificially perfused with gas-equilibrated medium. At varying levels of carotid body stimulation (CB PO2/PCO2: 40/60, 100/40, 200/15, 500/15 Torr), we decreased the brainstem perfusate PCO2 in 5 Torr steps while recording phrenic nerve activity to determine the central apnoeic thresholds. The central apnoeic thresholds decreased with increased carotid body stimulation. When the carotid bodies were strongly stimulated (CB 40/60), the apnoeic threshold was 3.6 ± 1.4 Torr PCO2 (mean ± SEM, n = 7). Stimulating carotid body afferent activity with either hypercapnia (60 Torr PCO2) or the neuropeptide pituitary adenylate cyclase-activating peptide restored phrenic activity during central apnoea. We conclude that peripheral stimulation shifts the central apnoeic threshold to very hypocapnic levels that would likely increase the CO2 reserve and have a protective effect on breathing. These data demonstrate that peripheral respiratory chemoreceptors are sufficient to stave off central apnoeas when the brainstem is perfused with low to no CO2.
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Affiliation(s)
- Marie-Noëlle Fiamma
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Faculty of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, Canada T2N 4N1
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Abstract
Breathing disorders during sleep are common in congestive heart failure (CHF). Sleep-disordered breathing (SDB) in CHF can be broadly classified as 2 types: central sleep apnea with Cheyne-Stokes breathing, and obstructive sleep apnea. Prevalence of SDB ranges from 47% to 76% in systolic CHF. Treatment of SDB in CHF may include optimization of CHF treatment, positive airway pressure therapy, and other measures such as theophylline, acetazolamide, and cardiac resynchronization therapy. Periodic limb movements are also common in CHF.
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Aittokallio T, Virkki A, Polo O. Understanding sleep-disordered breathing through mathematical modelling. Sleep Med Rev 2009; 13:333-43. [DOI: 10.1016/j.smrv.2008.09.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2008] [Revised: 09/30/2008] [Accepted: 09/30/2008] [Indexed: 11/17/2022]
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Kim SK, Lee SH, Kang HH, Kang JY, Kim JW, Kim YK, Kim KH, Song JS, Park SH, Moon HS. Relationship between Arousal Indices and Clinical Manifestations in Patients Who Performed Polysomnography. Tuberc Respir Dis (Seoul) 2009. [DOI: 10.4046/trd.2009.67.3.183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Sung Kyoung Kim
- Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Sang Haak Lee
- Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Hyeon Hui Kang
- Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Ji Young Kang
- Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Jin Woo Kim
- Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Young Kyoon Kim
- Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Kwan Hyoung Kim
- Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Jeong Sup Song
- Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Sung Hak Park
- Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Hwa Sik Moon
- Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea
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Stevens SA, Stimpson J, Lakin WD, Thakore NJ, Penar PL. A model for idiopathic intracranial hypertension and associated pathological ICP wave-forms. IEEE Trans Biomed Eng 2008; 55:388-98. [PMID: 18269974 DOI: 10.1109/tbme.2007.900552] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Idiopathic intracranial hypertension (IIH) is a syndrome of unknown cause characterized by elevated intracranial pressure (ICP). While imaging often reveals a stenosis of the transverse sinuses, the role of this feature in IIH has been in dispute. Many patients with chronic daily headache have been found to actually be suffering from a milder form of IIH without papilledema (IIHWOP). These patients often demonstrate hypertensive B-waves and plateau-like waves upon continuous ICP monitoring. Recently, we presented modeling studies which suggest that the sinus stenosis and hypertension of IIH are physiological manifestations of a stable state of elevated pressures that exists when the transverse sinus is sufficiently collapsible. Many of the features of IIH were explained by this model but the prevalence of pathological ICP wave-forms observed in IIHWOP remained unresolved. The model presented here is a modified version of a previous model with a semi-collapsible sinus represented by a refined downstream Starling-like resistor based on experimental data. The qualitative behavior of this model is presented in terms of the collapsibility of the transverse sinus. For a sufficiently rigid sinus, there is a unique stable state of normal pressures. As the degree of collapsibility increases, there is a Hopf bifurcation, the normal state becomes unstable, low-frequency, high-amplitude ICP waves prevail, and small perturbations can lead to hypertensive ICP spikes. As the collapsibility increases further, so does the duration of the waves, until they are replaced by two stable states: one of normal pressures and one of elevated pressures. In this parameter domain, temporary perturbations can now cause permanent transitions between states. The model presented here retains the capability of our previous model to elucidate many features of IIH and additionally provides insight into the prevalence of the low-frequency, high-amplitude waves observed in IIHWOP.
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Affiliation(s)
- Scott A Stevens
- Division of Information Technology and Sciences, Champlain College, Burlington, VT 05402, USA.
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Stephenson R. A theoretical study of the effect of circadian rhythms on sleep-induced periodic breathing and apnoea. Respir Physiol Neurobiol 2004; 139:303-19. [PMID: 15122996 DOI: 10.1016/j.resp.2003.10.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/23/2003] [Indexed: 11/17/2022]
Abstract
This study employed a mathematical model of the respiratory control system to test the plausibility of the hypothesis that circadian rhythms in respiratory control can significantly influence respiratory stability at sleep onset. Computer simulations utilized a standardized "normal" sleep onset effect, superimposed upon systematic changes in chemoreflex parameters that mimicked the peaks and troughs of normal and high amplitude circadian rhythms. The analysis predicted that circadian influences may augment sleep-induced periodic breathing in nocturnal sleep compared with daytime naps. Furthermore, increased circadian amplitude of chemoreflex threshold, or absence of a circadian rhythm in peripheral chemosensitivity, each acted to stabilize respiration during daytime sleep onset and promote periodic breathing during nocturnal sleep onset. High amplitude circadian rhythms in respiratory control were predicted to cause an increasing number and duration of obstructive apnoeas from early to late night. It is suggested that the circadian timing system creates a nocturnal window of respiratory vulnerability and that abnormal circadian rhythms could potentially induce nocturnal sleep apnoea, even in individuals with normal sleep mechanisms.
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Affiliation(s)
- Richard Stephenson
- Department of Zoology, University of Toronto, 25 Harbord Street, Toronto, Ont., Canada M5S 3G5.
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Lanfranco F, Gianotti L, Pivetti S, Navone F, Rossetto R, Tassone F, Gai V, Ghigo E, Maccario M. Obese patients with obstructive sleep apnoea syndrome show a peculiar alteration of the corticotroph but not of the thyrotroph and lactotroph function. Clin Endocrinol (Oxf) 2004; 60:41-8. [PMID: 14678286 DOI: 10.1111/j.1365-2265.2004.01938.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
OBJECTIVE Obstructive sleep apnoea syndrome (OSAS) is strongly associated with obesity (OB) and is characterized by several changes in endocrine functions, e.g. GH/IGF-I axis, adrenal and thyroid activity. It is still unclear whether these alterations simply reflect overweight or include peculiar hypoxia-induced hormonal alterations. Hormonal evaluations have been generally performed in basal conditions but we have recently reported that OSAS is characterized by a more severe reduction of the GH releasable pool in comparison to simple obesity. We aimed to extend our evaluation of anterior pituitary function to corticotroph, thyrotroph and lactotroph secretion under dynamic testing in OSAS in comparison with simply obese and normal subjects. SUBJECTS AND METHODS In 15 male patients with OSAS [age, mean +/- SEM 43.5 +/- 1.6 years; body mass index (BMI) 39.2 +/- 3.1 kg/m2; apnoea/hypopnoea index, (AHI) 53.4 +/- 8.7], 15 male patients with simple obesity (OB, age 39.7 +/- 1.2 years; BMI 41.2 +/- 2.0 kg/m2; AHI 3.1 +/- 1.2 events/h of sleep) and in 15 normal lean male subjects (NS, age 38.2 +/- 1.4 years; BMI 21.2 +/- 0.8 kg/m2; AHI 1.9 +/- 0.8 events/h of sleep) we evaluated: (a) the ACTH and cortisol responses to CRH [2 microg/kg intravenously (i.v.)] and basal 24 h UFC levels; (b) the TSH and PRL responses to TRH (5 microg/kg iv) as well as FT3 and FT4 levels. RESULTS Twenty-four-hour UFC levels in OSAS and OB were similar and within the normal range. Basal ACTH and cortisol levels were similar in all groups. However, the ACTH response to CRH in OSAS (Deltapeak: 30.3 +/- 3.8 pmol/l; DeltaAUC: 682.8 +/- 128.4 pmol*h/l) was markedly higher (P < 0.001) than in OB (Deltapeak: 9.3 +/- 1.4 pmol/l; DeltaAUC 471.5 +/- 97.3 pmol*h/l), which, in turn, was higher (P < 0.05) than in NS (Deltapeak: 3.3 +/- 0.9 pmol/l; DeltaAUC 94.7 +/- 76.7 pmol*h/l). On the other hand, the cortisol response to CRH was not significantly different in the three groups. Basal FT3 and FT4 levels as well as the TSH response to TRH were similar in all groups. Similarly, both basal PRL levels and the PRL response to TRH were similar in the three groups. CONCLUSIONS With respect to patients with simple abdominal obesity, obese patients with OSAS show a more remarkable enhancement of the ACTH response to CRH but a preserved TSH and PRL responsiveness to TRH. These findings indicate the existence of a peculiarly exaggerated ACTH hyper-responsiveness to CRH that would reflect hypoxia- and/or sleep-induced alterations of the neural control of corticotroph function; this further alteration is coupled to the previously described, peculiar reduction of somatotroph function.
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Affiliation(s)
- F Lanfranco
- Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Turin, Turin, Italy
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Stephenson R, Liao KS, Hamrahi H, Horner RL. Circadian rhythms and sleep have additive effects on respiration in the rat. J Physiol 2001; 536:225-35. [PMID: 11579171 PMCID: PMC2278848 DOI: 10.1111/j.1469-7793.2001.00225.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
1. We tested two hypotheses: that respiration and metabolism are subject to circadian modulation in wakefulness, non-rapid-eye-movement (NREM) sleep and rapid-eye-movement (REM) sleep; and that the effects of sleep on breathing vary as a function of time of day. 2. Electroencephalogram (EEG), neck electromyogram (EMG) and abdominal body temperature (T(b)) were measured by telemetry in six male Sprague-Dawley rats. The EEG and EMG were used to identify sleep-wake states. Ventilation (V(I)) and metabolic rate (V(CO2)) were measured by plethysmography. Recordings were made over 24 h (12:12 h light:dark) when rats were in established states of wakefulness, NREM sleep and REM sleep. 3. Statistically significant circadian rhythms were observed in V(I) and V(CO2) in each of the wakefulness, NREM sleep and REM sleep states. Amplitudes and phases of the circadian rhythms were similar across sleep-wake states. 4. The circadian rhythm in V(I) was mediated by a circadian rhythm in respiratory frequency (f(R)). Tidal volume (V(T)) was unaffected by time of day in all three sleep-wake states. 5. The 24 h mean V(I) was significantly greater during wakefulness (363.5 +/- 18.5 ml min(-1)) than during NREM sleep (284.8 +/- 11.1 ml min(-1)) and REM sleep (276.1 +/- 13.9 ml min(-1)). V(CO2) and V(T) each significantly decreased from wakefulness to NREM sleep to REM sleep. f(R) was significantly lower in NREM sleep than in wakefulness and REM sleep. 6. These data confirm that ventilation and metabolism exhibit circadian rhythms during wakefulness, and NREM and REM sleep, and refute the hypothesis that state-related effects on breathing vary as a function of time of day. We conclude that the effects of circadian rhythms and sleep-wake state on respiration and metabolic rate are additive in the rat.
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Affiliation(s)
- R Stephenson
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada M5S 1A1.
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Stephenson R, Mohan RM, Duffin J, Jarsky TM. Circadian rhythms in the chemoreflex control of breathing. Am J Physiol Regul Integr Comp Physiol 2000; 278:R282-6. [PMID: 10644650 DOI: 10.1152/ajpregu.2000.278.1.r282] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mechanisms underlying the circadian rhythm in lung ventilation were investigated. Ten healthy male subjects were studied for 36 h using a constant routine protocol to minimize potentially confounding variables. Laboratory light, humidity, and temperature remained constant, subjects did not sleep, and their meals and activities were held to a strict schedule. Respiratory chemoreflex responses were measured every 3 h using an iso-oxic rebreathing technique incorporating prior hyperventilation. Subjects exhibited circadian rhythms in oral temperature and respiratory chemoreflex responses, but not in metabolic rate. Basal ventilation [i.e., at subthreshold end-tidal carbon dioxide partial pressure (PET(CO(2)))] did not vary with time of day, but the ventilatory response to suprathreshold PET(CO(2)) exhibited a rhythm amplitude of approximately 25%, mediated mainly by circadian variations in the CO(2) threshold for tidal volume. We conclude that the circadian rhythm in lung ventilation is not a simple consequence of circadian variations in arousal state and metabolic rate. By raising the chemoreflex threshold, the circadian timing system may increase the propensity for respiratory instability at night.
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Affiliation(s)
- R Stephenson
- Respiratory Research Group, University of Toronto, Toronto, Ontario, Canada M5S 1A1.
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Baldwin DR, Kolbe J, Troy K, Belcher J, Gibbs H, Frankel A, Eaton T, Christmas T, Veale A. Comparative clinical and physiological features of Maori, Pacific Islanders and Europeans with sleep related breathing disorders. Respirology 1998; 3:253-60. [PMID: 10201052 DOI: 10.1111/j.1440-1843.1998.tb00131.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
UNLABELLED Recent studies have suggested that there is a familial association of sleep apnoea syndrome and that this is not entirely explained by inheritance of known risk factors. Maori (M) and Pacific Islanders (PI) have many of the body habitus features associated with sleep apnoea and therefore might be expected to exhibit more severe disease than Europeans (E). OBJECTIVE To compare the clinical and physiological characteristics of the different ethnic groups and to determine if race was an independent predictor of severity of sleep apnoea. METHODOLOGY A prospective evaluation of patients attending the Sleep Disordered Breathing Clinic which serves the whole of Auckland (population 1.1 million), New Zealand was conducted for the period July 1994 to August 1995. The evaluation included history including a 26 question questionnaire, Epworth sleepiness score, examination, and where indicated, full polysomnography. RESULTS A total of 233 patients (154 E, 48 M and 33 PI), underwent full polysomnography. Forty-one (85%) of the M and 31 (94%) of PI had obstructive or mixed sleep apnoea compared with only 74 (49%) of the E (P < 0.0001; chi 2). There were few racial differences in the responses to the sleep questionnaire. M and PI were shown to have much greater neck and waist circumference and body mass indices. Severity parameters (apnoea-hypopnoea index, wake and minimum oxygen saturation, and apnoea duration) were greater for both M and PI compared with E (P < 0.001; Mann-Whitney U-test). Stepwise regression identified neck size, body mass index and age as independent predictors of severity. CONCLUSION When other factors were controlled for, race was not an important independent predictor of severity of sleep apnoea.
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Affiliation(s)
- D R Baldwin
- Dept of Respiratory Medicine, Nottingham City Hospital, UK
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Hudgel DW, Gordon EA, Thanakitcharu S, Bruce EN. Instability of ventilatory control in patients with obstructive sleep apnea. Am J Respir Crit Care Med 1998; 158:1142-9. [PMID: 9769273 DOI: 10.1164/ajrccm.158.4.9712105] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Because of the oscillatory pattern of upper airway resistance and breathing during sleep in patients with obstructive sleep apnea (OSA), we hypothesized that OSA patients have an underlying instability of ventilatory drive to inspiratory muscles. To assess the stability of ventilatory drive in OSA patients and controls, we used the pseudorandom binary stimulation (PRBS) test and examined the closed- and open-loop responses to hyperoxic hypercapnia. The closed-loop response is produced by interactions of dynamic gain in controller, plant, and ventilatory feedback. The open-loop response reflects controller dynamic gain or frequency-dependent chemosensitivity. As compared with 16 nonapneic, nonobese control subjects, a group of nine obese OSA patients had a higher peak response and a more rapid and irregular recovery phase of the closed-loop CO2 response in the PRBS test. The two groups had similar open-loop responses in the PRBS test, suggesting that central dynamic CO2 chemosensitivity was not abnormal in OSA. We conclude that the differences between OSA patients and controls in the closed-loop response in the PRBS test are not due to differences in dynamic controller gain, but are related to differences in dynamic plant gain and/or negative ventilatory feedback. In addition to OSA, obesity may affect these variables and may have been responsible for our findings.
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Affiliation(s)
- D W Hudgel
- Case Western Reserve University MetroHealth Medical Center, Cleveland, Ohio, USA
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Lai J, Bruce EN. Ventilatory stability to transient CO2 disturbances in hyperoxia and normoxia in awake humans. J Appl Physiol (1985) 1997; 83:466-76. [PMID: 9262442 DOI: 10.1152/jappl.1997.83.2.466] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Modarreszadeh and Bruce (J. Appl. Physiol. 76: 2765-2775, 1994) proposed that continuous random disturbances in arterial PCO2 are more likely to elicit ventilatory oscillation patterns that mimic periodic breathing in normoxia than in hyperoxia. To test this hypothesis experimentally, in nine awake humans we applied pseudorandom binary inspired CO2 fraction stimulation in normoxia and hyperoxia to derive the closed-loop and open-loop ventilatory responses to a brief CO2 disturbance in terms of impulse responses and transfer functions. The closed-loop impulse response has a significantly higher peak value [0.143 +/- 0.071 vs. 0.079 +/- 0.034 (SD) l . min-1 . 0.01 l CO2-1, P = 0.014] and a significantly shorter 50% response duration (42.7 +/- 13.3 vs. 72.3 +/- 27.6 s, P = 0.020) in normoxia than in hyperoxia. Therefore, the ventilatory responses to transient CO2 disturbances are less damped (but generally not oscillatory) in normoxia than in hyperoxia. For the closed-loop transfer function, the gain in normoxia increased significantly (P < 0.0005), while phase delay decreased significantly (P < 0.0005). The gain increased by 108.5, 186.0, and 240.6%, while phase delay decreased by 26.0, 18.1, and 17.3%, at 0. 01, 0.03, and 0.05 Hz, respectively. Changes in the same direction were found for the open-loop system. Generally, an oscillatory ventilatory response to a small transient CO2 disturbance is unlikely during wakefulness. However, changes in parameters that lead to additional increases in chemoreflex loop gain are more likely to initiate oscillations in normoxia than in hyperoxia.
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Affiliation(s)
- J Lai
- Center for Biomedical Engineering, University of Kentucky, Lexington, Kentucky 40506-0070, USA
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Zinkovska S, Kirby DA. Intracerebroventricular propranolol prevented vascular resistance increases on arousal from sleep apnea. J Appl Physiol (1985) 1997; 82:1637-43. [PMID: 9134914 DOI: 10.1152/jappl.1997.82.5.1637] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Despite the increased risk of sudden cardiac death associated with sleep apnea, little is known about mechanisms controlling cardiovascular responses to sleep apnea and arousal. Chronically instrumented pigs were used to investigate the effects of airway obstruction (AO) during rapid-eye-movement (REM) and non-REM (NREM) sleep and arousal on mean arterial pressure (MAP), heart rate (HR), cardiac output (CO), and total peripheral resistance (TPR). A stainless steel cannula was implanted in the lateral cerebral ventricle. During REM sleep, HR was 133 +/- 10 beats/min, MAP was 65 +/- 8 mmHg, CO was 1,435 +/- 69 ml/min, and TPR was 0.046 +/- 0.004 mmHg.ml-1.min. During AO, CO decreased by 90 +/- 17 ml/min (P < 0.05). On arousal from AO, MAP increased by 15 +/- 3 mmHg, HR increased by 10 +/- 3 beats/min, and TPR increased by 0.008 +/- 0.001 mmHg.ml-1.min (all P < 0.05). Changes during NREM were similar but were more modest during AO. After the intracerebroventricular administration of propranolol (50 micrograms/kg; a beta-adrenoreceptor blocking agent), decreases in CO during AO and increases in HR during arousal were intact, but increases in MAP and TPR were no longer significant. These data suggest that vascular responses to AO during sleep may be regulated in part by beta-adrenergic receptors in the central nervous system.
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Affiliation(s)
- S Zinkovska
- Children's Hospital, Harvard Medical School, Boston 02115, USA
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Noda A, Okada T, Katsumata K, Yasuma F, Nakashima N, Yokota M. Suppressed cardiac and electroencephalographic arousal on apnea/hypopnea termination in elderly patients with cerebral infarction. J Clin Neurophysiol 1997; 14:68-72. [PMID: 9013361 DOI: 10.1097/00004691-199701000-00006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The goal of the present investigation is to show the clinical significance of arousal response at termination of apnea/hypopnea in patients with sleep apnea syndrome (SAS) after cerebral infarction. We polygraphically assessed "cardiac arousal," which is defined as an abrupt increase in heart rate at a termination of sleep apnea/hypopnea, and electroencephalographic (EEG) arousal. There were six elderly subjects, bedridden after cerebral infarction, with SAS aged 71-87 years (mean 72.3 years) and 11 age-matched patients with SAS aged 61-78 years (mean 62.3 years) as controls. The following sleep parameters were measured: number of apneas per hour (apnea index [AI]), number of hypopneas per hour (hypopnea index [HI]), summation of the two (apnea/hypopnea index [AHI]), and duration in which nocturnal oxygen saturation was decreased below 90% (duration of SaO2 < 90%). We calculated the ratio of apnea/hypopnea per hour with cardiac arousal to total apnea/hypopneas (XI) (% cardiac arousal [XI/AHI x 100]) and the ratio of that with EEG arousal (YI) (% EEG arousal [YI/AHI x 100]). Between the two groups, we found no significant difference in body mass index, the ratio of central apnea to total apnea/hypopnea, AHI, duration of apnea/hypopnea, lowest SaO2, and duration of SaO2 < 90%. Compared with controls, % cardiac and % EEG arousals were significantly lower in patients with cerebral infarction. In contrast, the ratio of HI to AHI was significantly higher in patients with cerebral infarction than in control subjects. Our findings indicate that cardiac and EEG arousals at termination of apnea/hypopnea are significantly suppressed in elderly patients with SAS after cerebral infarction, which may provide useful information on the pathophysiology of SAS in patients with cerebrovascular disease.
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Affiliation(s)
- A Noda
- Nagoya University, College of Medical Technology, Japan
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19
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Javaheri S, Parker TJ, Wexler L, Liming JD, Lindower P, Roselle GA. Effect of theophylline on sleep-disordered breathing in heart failure. N Engl J Med 1996; 335:562-7. [PMID: 8678934 DOI: 10.1056/nejm199608223350805] [Citation(s) in RCA: 219] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Theophylline has been used to treat central apnea associated with Cheyne-Stokes respiration (periodic breathing). We studied the effect of short-term oral theophylline therapy on periodic breathing associated with stable heart failure due to systolic dysfunction. METHODS Fifteen men with compensated heart failure (left ventricular ejection fraction, 45 percent or less) participated in the study. Their base-line polysomnograms showed periodic breathing, with more than 10 episodes of apnea and hypopnea per hour. In a double-blind crossover study, the patients received theophylline or placebo orally twice daily for five days, with one week of washout between the two periods. RESULTS After five days of treatment, the mean (+/-SD) plasma theophylline concentration was 11 +/- 2 microgram per milliliter. Theophylline therapy resulted in significant decreases in the number of episodes of apnea and hypopnea per hour (18 +/- 17, vs. 37 +/- 23 with placebo and 47 +/- 21 at base line; P<0.001), the number of episodes of central apnea per hour (6 +/- 14, vs. 26 +/- 21 and 26 +/- 20, respectively; P<0.001), and the percentage of total sleep time during which the arterial oxyhemoglobin saturation was less than 90 percent (6 +/- 11 percent, vs., 23 +/- 37 and 14 +/- 14 percent, respectively; P<0.04). There were no significant differences in the characteristics of sleep, the frequency of ventricular arrhythmias, daytime arterial-blood gas values, or the left ventricular ejection fraction during the base-line, placebo, and theophylline phases of the study. CONCLUSIONS In patients with stable heart failure, oral theophylline therapy reduced the number of episodes of apnea and hypopnea and the duration of arterial oxyhemoglobin desaturation during sleep.
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Affiliation(s)
- S Javaheri
- Pulmonary Services, Veterans Affairs Medical Center, Cincinnati, OH 45220, USA
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20
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Pillar G, Peled N, Katz N, Lavie P. Predictive value of specific risk factors, symptoms and signs, in diagnosing obstructive sleep apnoea and its severity. J Sleep Res 1994; 3:241-244. [PMID: 10607131 DOI: 10.1111/j.1365-2869.1994.tb00137.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A positive diagnosis of obstructive sleep apnoea (OSA) is based on a combination of characteristic symptoms and polysomnographic findings. The present study evaluated the specificity and sensitivity of several risk factors, signs and symptoms in predicting an Apnoea Index in 86 patients referred to the sleep laboratory with suspected OSA. All 86 subjects completed a detailed questionnaire, were interviewed, underwent a brief physical examination, and then a whole-night polysomnographic study. Stepwise multiple regression analysis revealed that self reporting on apnoeas, neck circumference index (NCI), age, and a tendency to fall asleep unintentionally, were all significant positive predictors of apnoea index (AI), explaining 41.8% of the variability. The sensitivity of the model for predicting OSA (taking OSA as AI > 10) was 92.2%, specificity was 18.2% and the positive predictive value was 76.6%. Raising the cut-off AI values resulted in decreased sensitivity and increased specificity. Applying the predicting equation of AI to another group of 50 patients referred to the sleep laboratory with suspected OSA revealed similar results. However, running the equation on 105 offspring of OSA patients who did not complain of OSA-associated symptoms resulted in 32% sensitivity and 94% specificity in predicting OSA. It is concluded that questionnaires, interviews and physical examination, can only vaguely predict AI, and cannot replace polysomnographic recordings. However, the low rates of false negative in predicting AI > 10, and the low rates of false positive in predicting AI > 50, can be used for specific purposes.
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Affiliation(s)
- G Pillar
- Sleep Laboratory, Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
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21
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Matsuzawa Y, Kobayashi T, Fujimoto K, Yamaguchi S, Shinozaki S, Kubo K, Sekiguchi M, Hayashi R, Sakai A, Ueda G. Nocturnal periodic breathing and arterial oxygen desaturation in acute mountain sickness. ACTA ACUST UNITED AC 1994. [DOI: 10.1580/0953-9859-5.3.269] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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22
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Leibowitz G, Shapiro MS, Salameh M, Glaser B. Improvement of sleep apnoea due to acromegaly during short-term treatment with octreotide. J Intern Med 1994; 236:231-5. [PMID: 8046324 DOI: 10.1111/j.1365-2796.1994.tb01288.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Two acromegalic patients suffering from severe obstructive sleep apnoea syndrome were treated with the long-acting somatostatin analogue octreotide. Daytime sleepiness and fatigue improved within a few days. Repeat sleep studies performed after octreotide treatment revealed more confluent sleep with a shorter duration of sleep apnoea. Nocturnal hypoxaemia improved in one patient. Octreotide might be an effective noninvasive treatment for sleep apnoea of acromegaly.
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Affiliation(s)
- G Leibowitz
- Department of Endocrinology and Metabolism, Hebrew University Hadassah Medical Centre, Jerusalem, Israel
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23
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Hanly P, Zuberi N, Gray R. Pathogenesis of Cheyne-Stokes respiration in patients with congestive heart failure. Relationship to arterial PCO2. Chest 1993; 104:1079-84. [PMID: 8404170 DOI: 10.1378/chest.104.4.1079] [Citation(s) in RCA: 121] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
In order to determine which patients with congestive heart failure (CHF) develop Cheyne-Stokes respiration (CSR) during sleep, we compared the cardiorespiratory profiles of CHF patients with CSR to those of CHF patients without CSR. Overnight polysomnography and continuous transcutaneous PCO2 (tc PCO2) monitoring, estimation of left ventricular ejection fraction (LVEF), pulmonary function tests, and chest radiograph were performed on 16 consecutive patients with chronic, stable CHF. The tc PCO2 monitor (Kontron 7640) was calibrated so that measurements reflected arterial PCO2 values. A mean value was calculated for wakefulness (W) and total sleep time (TST). Circulation time (CT) from the lung to the carotid body was estimated from the end of an apnea or voluntary breath-hold to the nadir of oxygen desaturation recorded on an ear oximeter. The duration of CSR was expressed as a percent of TST. Nine patients developed CSR during sleep (52.5 +/- 31.6 percent TST) (group 1) and 7 did not (group 2). All patients were male and both groups were a similar age (64 +/- 8 vs 63 +/- 4 years) and weight (body mass index, 28.1 +/- 3.5 vs 25.4 +/- 3.4 kg/m2). There were no significant intergroup differences between LVEF (22 +/- 5.2 vs 24.1 +/- 5.2 percent), CT (19.1 +/- 3.6 vs 15.9 +/- 6.7 s), SaO2 (W) (94 +/- 1.2 vs 92.4 +/- 2.1 percent), and SaO2 (TST) (90.8 +/- 2.7 vs 92.4 +/- 2.1 percent). The tc PCO2 (W) was lower in group 1 (34.4 +/- 3.5 vs 38.1 +/- 1.9 mm Hg), increased during sleep by a similar amount in both groups (1.6 +/- 1.5 vs 2.1 +/- 2.2 mm Hg), and was significantly lower during sleep in group 1 (36.1 +/- 3.4 vs 40.2 +/- 2.2 mm Hg). We conclude that CHF patients with CSR hyperventilate during sleep and wakefulness and that CHF patients with awake hypocapnia are more likely to develop CSR during sleep. These findings indicate that arterial PCO2 is important in determining which CHF patients develop CSR.
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Affiliation(s)
- P Hanly
- Department of Medicine, Wellesley Hospital, University of Toronto, Canada
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24
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Abstract
The study of ventilatory periodicities is relevant to the problem of obstructive sleep apnea. Apneas occur at the nadirs of periodicities during sleep. Periodicities can be caused by chemical instability, related to unstable action of the closed loop feedback system for the chemical regulation of breathing. Such instability occurs when overall loop gain is greater than or equal to unity and the phase lag around the loop is 180 degrees. Periodic breathing during hypoxia and in patients with congestive heart failure is likely to be explained by this mechanism. Periodic breathing can also be the result of state instability. Here ventilation declines at sleep onset and the resultant changes in blood gases trigger an arousal, i.e., sudden transition to a lighter stage of sleep. With arousal, ventilation increases. Thus, periodic breathing is secondary to these changes in sleep state. These processes, chemical instability and state instability, can interact and produce complex patterns of oscillation in ventilation.
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Affiliation(s)
- A I Pack
- Department of Medicine, University of Pennsylvania Medical Center, Philadelphia
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25
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Langevin B, Fouque D, Léger P, Robert D. Sleep apnea syndrome and end-stage renal disease. Cure after renal transplantation. Chest 1993; 103:1330-5. [PMID: 8486006 DOI: 10.1378/chest.103.5.1330] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
We report two patients undergoing maintenance hemodialysis who presented with sleep apnea syndrome (SAS). The first patient is a 36-year-old man with a terminal Berger's glomerulopathy and associated obstructive sleep apnea syndrome (OSAS) (apnea-hypopnea index [AHI] = 80). He was receiving home hemodialysis and was treated by nasal continuous positive airway pressure (CPAP). After successful renal transplantation, his symptoms completely disappeared, and control polysomnography greatly improved (AHI = 9). The second patient had hypokalemic nephropathy with severe, uncontrolled hypertension and hypertensive myocardiopathy. He was receiving home dialysis and showed a central sleep apnea syndrome with an AHI of 51. He also was successfully treated by nasal CPAP. After renal transplantation, his sleep improved, insomnia disappeared, and polysomnography showed great improvement (AHI = 5). We discuss the role of periodic breathing related to end-stage renal disease associated metabolic abnormalities, as a pathogenetic factor of these SASs. Respiratory correction of chronic metabolic acidosis, "uremic toxins," "middle molecules," and hemodialysis are all evoked as etiologic factors and their own roles are discussed.
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Affiliation(s)
- B Langevin
- Intensive Care Unit, Hôpital Croix-Rousse, Lyon, France
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26
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Cherniack NS. Future Directions in Sleep Research: A Respiratory Physician's Perspective. EAR, NOSE & THROAT JOURNAL 1993. [DOI: 10.1177/014556139307200308] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- Neil S. Cherniack
- School of Medicine, Vice President for Medical Affairs, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106–4915
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27
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Stewart DA, Grunstein RR, Berthon-Jones M, Handelsman DJ, Sullivan CE. Androgen blockade does not affect sleep-disordered breathing or chemosensitivity in men with obstructive sleep apnea. THE AMERICAN REVIEW OF RESPIRATORY DISEASE 1992; 146:1389-93. [PMID: 1456553 DOI: 10.1164/ajrccm/146.6.1389] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
As sleep apnea is more prevalent in men and testosterone has known effects on sleep apnea and chemosensitivity, reduction of androgen activity may influence sleep-disordered breathing and respiratory control. We studied the effect of 1 wk of treatment with flutamide, a nonsteroidal antiandrogen, on sleep, respiration, and ventilatory control in eight men with sleep apnea. Results on flutamide were compared with two baseline studies performed before and after the drug treatment period. Although effective androgen blockade was achieved as evidenced by increased hormone levels, flutamide had no effect on sleep architecture or chemoresponsiveness to hypoxia and hypercapnia. There was a trend towards a reduction in respiratory disturbance index in both NREM and REM sleep (41 +/- 4 baseline versus 34 +/- 3 flutamide, p = 0.09 NREM; 53 +/- 4 baseline versus 48 +/- 3 flutamide, p = 0.16 REM), but this was not significant. Our results indicate that androgen blockade had no clinically significant effect on sleep, sleep-disordered breathing, or chemosensitivity in patients with moderate to severe sleep apnea. More specific blockers such as gonadotrophin-releasing hormone analogs may have more clinical effect or, alternatively, androgen blockade may be more beneficial in patients with milder sleep apnea.
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Affiliation(s)
- D A Stewart
- Sleep Disorders Centre, Royal Prince Alfred Hospital, Camperdown, Australia
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28
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Abstract
Central sleep apnea is not a single disease but represents the final pathway in a large group of heterogeneous disorders. Control of normal breathing during sleep relies upon finely coordinated anatomical and physiological mechanisms and their destabilization leads to central apnea. The causes of central sleep apnea can be classified into 4 groups: neurologic disorders, periodic breathing, upper airway abnormalities, and idiopathic syndromes. Clinical features result from the interaction between the underlying disorder and control of respiration. Two different prototypes emerge: patients who are hypercapnic (central hypoventilation and/or impaired respiratory mechanics) and those who are eucapnic or hypocapnic (periodic breathing and idiopathic hyperventilation). The causes and severity of apnea can be determined by clinical assessment, pulmonary function testing, and overnight polysomnography. Further management involves specific treatment of the underlying condition and reducing the sequelae of recurrent apneas during sleep, namely cardiorespiratory dysfunction and sleep disruption. This review outlines an approach to the management of central sleep apnea based upon an understanding of its pathophysiology.
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Affiliation(s)
- P J Hanly
- Division of Respiratory Medicine, Wellesley Hospital, University of Toronto, Ontario, Canada
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29
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Orrego H, Carmichael FJ. Effects of alcohol on liver haemodynamics in the presence and absence of liver disease. J Gastroenterol Hepatol 1992; 7:70-89. [PMID: 1543873 DOI: 10.1111/j.1440-1746.1992.tb00939.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- H Orrego
- Department of Medicine, University of Toronto, Ontario, Canada
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30
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Lieber C, Mohsenin V. Cheyne-Stokes respiration in congestive heart failure. THE YALE JOURNAL OF BIOLOGY AND MEDICINE 1992; 65:39-50. [PMID: 1509783 PMCID: PMC2589377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Cheyne-Stokes respiration is an abnormal breathing pattern which commonly occurs in patients with decompensated congestive heart failure and neurologic diseases, in whom periods of tachypnea and hyperpnea alternate with periods of apnea. In the majority of these patients, the ventilatory patterns may not be recognized, and the clinical features are generally dominated by the underlying disease process. Cheyne-Stokes respiration may, however, have profound effects on the cardiopulmonary system, causing oxygen desaturation, cardiac arrhythmias, and changes in mental status. Treatment of Cheyne-Stokes respiration in congestive heart failure with supplemental oxygen or nasal continuous positive airway pressure, in addition to conventional therapy, may improve the overall cardiac function and perhaps the patient's prognosis.
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Affiliation(s)
- C Lieber
- Department of Internal Medicine, Waterbury Hospital, Connecticut
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31
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Sparks DL, Hunsaker JC. Sudden infant death syndrome: altered aminergic-cholinergic synaptic markers in hypothalamus. J Child Neurol 1991; 6:335-9. [PMID: 1719064 DOI: 10.1177/088307389100600409] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Alterations of sleep are reported to occur in sudden infant death syndrome (SIDS). It is well established that the hypothalamus mediates the onset, maintenance, and timing of sleep, and does so via serotonergic and cholinergic mechanisms. We have investigated serotonergic and cholinergic synaptic markers in the hypothalamus from eight SIDS infants and six age-matched non-SIDS infants between 3 and 7 months of age. By use of established methods, we observed a number of chemical alterations in SIDS hypothalamus: (1) tryptophan content was increased and serotonin content was decreased, (2) serotonin binding was increased and imipramine binding was unchanged, (3) monoamine oxidase-A activity was increased without an effect on monoamine oxidase-B, and (4) choline acetyltransferase activity was decreased and acetylcholinesterase activity was unchanged.
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Affiliation(s)
- D L Sparks
- Department of Pathology, University of Kentucky Medical Center, Lexington 40536-0230
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32
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Grunstein RR, Ellis E, Hillman D, McEvoy RD, Robertson CF, Saunders NA. Treatment of sleep disordered breathing. Med J Aust 1991. [DOI: 10.5694/j.1326-5377.1991.tb112891.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Ronald R Grunstein
- Royal Prince Alfred Hospital Missenden RoadCamperdownNSW 2050
- Sleep Disorders Centre
| | - Elizabeth Ellis
- Royal Prince Alfred Hospital Missenden RoadCamperdownNSW 2050
- Sleep Disorders Centre
- School of Physiotherapy
| | - David Hillman
- Department of Pulmonary Physiology, Sir Charles Galrdner Hospital Verdun Street Nedlands WA 6009
| | - R Douglas McEvoy
- Department of Thoracic Medicine, Royal Adelaide Hospital North Terrace Adelaide SA 5000
| | - Colin F Robertson
- Professorial Department of Thoracic Medicine, Royal Children's Hospital Flemington Road Parkville VIC 3052
| | - Nicholas A Saunders
- Department of Medicine, John Hunter Hospital, University of Newcastle Rankin Drive Shortland NSW 2307
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Silage DA. Spectral and coherence analysis applied to sleep apnea. IEEE ENGINEERING IN MEDICINE AND BIOLOGY MAGAZINE : THE QUARTERLY MAGAZINE OF THE ENGINEERING IN MEDICINE & BIOLOGY SOCIETY 1990; 9:76-8. [PMID: 18238326 DOI: 10.1109/51.62913] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The various mechanisms that have been proposed to explain sleep apnea in the elderly are examined. Spectral analysis of the electroencephalogram (EEG), not only in the frequency domain using autoregressive algorithms and the fast Fourier transform, but also in the time domain with comb filters and period-amplitude (PA) analysis, is discussed. The PA features, in particular, may provide an improved basis for the coherence function between ventilation and the state-dependent input.
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Affiliation(s)
- D A Silage
- Dept. of Electr. Eng., Temple Univ., Philadelphia, PA
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Schoenfeld A, Ovadia Y, Neri A, Freedman S. Obstructive sleep apnea (OSA)-implications in maternal-fetal medicine. A hypothesis. Med Hypotheses 1989; 30:51-4. [PMID: 2796809 DOI: 10.1016/0306-9877(89)90125-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
During the past fifteen years the obstructive sleep apnea syndrome (OSAS) has become widely recognized as a quite common disorder with a wide range of serious clinical complications (1, 2, 3). This syndrome arises as a result of sleep related changes in upper airway muscle function and progressive narrowing of the oropharyngeal lumen. The resulting hypoxia (or asphyxia) leads to an arousal response that terminates the initial obstructive event. The exact incidence and prevalence of OSAS is currently unknown. Lavie (4) concluded its prevalence to be 1.26 percent. Others (5, 6) found that the prevalence of heavy regular snoring (taken as an index of at least a partially obstructed airway) increased with age including 40 percent of women and 50 percent of men over 60 years of age. Polygraphically documented OSAS showed incidence of 0.99 percent in an unselected population. Postmenopausal women have frequent episodes. of OSA in contrast with their premenopausal counterparts, who very rarely have any apnea. Since we could not find in the literature any documented OSAS studies in pregnancy, we would like to base our hypothesis on our previously published clinical observations and our recent findings. In the present paper we would like to suggest that pathophysiologic changes of OSAS prolonged throughout many weeks of pregnancy may have an adverse effect upon the feto-placental unit.
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Affiliation(s)
- A Schoenfeld
- Department of Obstetrics and Gynecology, Beilinson Medical Center Petah Tikva, Israel
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35
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Affiliation(s)
- A Williams
- Medical Service, Wadsworth VA Medical Center, West Los Angeles 90073
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36
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Abstract
Periodic breathing (recurrent central apneas) occurs frequently during sleep. Periodic breathing can arise as a result of unstable behavior of the respiratory control system. A mathematical model of the respiratory control system was used to investigate, systematically, the effect of severity of disturbances to respiration and certain system parameters on periodic breathing occurring during sleep. The model consisted of multi-compartment representation of O2 and CO2 stores, a peripheral controller sensitive to O2 and CO2, and a central controller sensitive to CO2. The effects of hypoxia and hypercapnia on the upper airway muscles were not considered in the model. Episodes of hyperventilation or asphyxia were used to disturb the control system and explore the boundaries of stable breathing. Circulation time and metabolic rate were also varied. Simulations with the model produced the following findings: The number of central apneas associated with periodic breathing were greater as circulation time increased; controller gain increases also made the number of apneas greater, although periodic breathing occurs with lower controller gains as circulation time increases. At each level of circulation time there was a range of controller gain changes which caused little change in the number of apneas. There were more apneas with hypoxia; also the number of apneas increased with sleep-associated reductions in metabolic rate. The more rapidly resting PCO2 rose at sleep onset, the greater the likelihood of recurrent apneas. Finally, the more intense the disturbance, the more apneas there were.
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37
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Overholt JL, Mitra J, van Lunteren E, Prabhakar NR, Cherniack NS. Naloxone enhances the response to hypercapnia of spinal and cranial respiratory nerves. RESPIRATION PHYSIOLOGY 1988; 74:299-309. [PMID: 3222562 DOI: 10.1016/0034-5687(88)90038-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
To assess the effects of endogenous opiates on respiratory muscle responses to CO2, naloxone was administered intravenously to paralyzed, vagotomized and artificially ventilated cats anesthetized with alpha-chloralose. Neural activity was recorded from the phrenic, hypoglossal (HG), glossopharyngeal (GP) and recurrent laryngeal (RL) nerves. Before naloxone, phasic activity began first in the phrenic at a PETCO2 of 30.0 +/- 1.8 Torr, followed by the RL at a PETCO2 of 33.5 +/- 1.7 Torr, the HG at a PETCO2 of 39.9 +/- 2.1 Torr and the GP at a PETCO2 of 42.5 +/- 2.2 Torr during CO2 rebreathing. Naloxone had no significant effect on the apneic threshold of any of the nerves studied. Naloxone did, however, increase respiratory frequency (P less than 0.01) mainly by causing a significant (P less than 0.01) shortening of TE as it had no significant effect on TI. Naloxone also significantly increased the rate at which peak nerve activity increased with CO2 in the HG (P less than 0.01) and the GP (P less than 0.01) nerves, but not in the phrenic and RL nerves. Instead, the maximum activity produced by hypercapnia and the PETCO2 level at which maximum activity occurred in the phrenic, but not the RL, increased after naloxone. The result of these effects was that naloxone extended the range over which the HG and GP behaved proportionally with the phrenic, but it did not change the curvilinear nature of these relationships.
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Affiliation(s)
- J L Overholt
- Department of Medicine, Case Western Reserve University, Cleveland, Ohio 44106
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Leech JA, Onal E, Dulberg C, Lopata MA. A comparison of men and women with occlusive sleep apnea syndrome. Chest 1988; 94:983-8. [PMID: 3180902 DOI: 10.1378/chest.94.5.983] [Citation(s) in RCA: 66] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Among 118 patients with occlusive sleep apnea syndrome (OSA), defined as daytime hypersomnolence and an apnea hypopnea index (AHI) greater than ten events/h, 41 women were compared with 77 men. Body mass index, spirometric study, PaO2, PaCO2, and results from nocturnal polysomnography were examined in a two-way analysis of variance (ANOVA) for the effects of sex, age group, and a sex-age group interaction. The age groups examined were above and below 42 years, the breakpoint for menopause in the women. Younger persons tended to be more obese and to have a higher AHI. Both sexes had similar pulmonary function, AHI, and nocturnal desaturation, but women experienced significantly fewer completely occluded breathing events and had apneas of shorter mean and maximum duration than men of similar ages. No effect of menopausal status per se was observed. In OSA patients, differences in upper airway occlusion and apnea duration suggest differences between the sexes in upper airway physiology or respiratory control.
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Affiliation(s)
- J A Leech
- Department of Medicine, University of Illinois College of Medicine, Chicago
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Affiliation(s)
- K Prowse
- Department of Respiratory Medicine, City General Hospital, Stoke-on-Trent, Staffs
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elHefnawy A, Saidel GM, Bruce EN. CO2 control of the respiratory system: plant dynamics and stability analysis. Ann Biomed Eng 1988; 16:445-61. [PMID: 3142313 DOI: 10.1007/bf02368009] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A stability analysis of respiratory chemical control is developed using a mathematical model of CO2 mass transport dynamics. Starting with a 3-compartment model of CO2 stores that distinguishes alveolar, muscle, and other tissue, model reduction techniques are applied to obtain a first-order representation of the respiratory plant. This model contains an effective tissue volume for CO2, whose derived value is much smaller than previously predicted. To investigate oscillatory instabilities, a controller which incorporates only peripheral chemoreceptor responses was added to the first-order plant model. An explicit stability index (SI) is obtained analytically from a linearized version of this model. SI varies directly with the controller gain and circulation delay time and inversely with the effective tissue volume and inspired CO2 concentration. Numerical simulations using the first-order nonlinear model show that SI is a good predictor of system stability. According to the linearized model, the system is stable for SI less than 1; from the nonlinear model, the system is stable for SI less than 1.1. For typical normal adults, the SI value is well within the stable region.
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Affiliation(s)
- A elHefnawy
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106
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Abstract
Sudden infant death syndrome (SIDS) affects infants between 1 month and 1 yr of age, has no known cause, and is diagnosed by exclusion of all other causes of death. The primary mechanism of death in SIDS is considered to be irreversible respiratory cessation during sleep. In a small sampling at necropsy we have observed a statistically significant (P less than .005; determined morphometrically) reduction in the anatomic size of the pineal gland in SIDS infants, as compared to age-matched controls. Whether correspondingly altered pineal glandular function is present in SIDS is as yet unanswered.
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Affiliation(s)
- D L Sparks
- Department of Neurology, University of Kentucky, Medical Center, Lexington 40536-0230
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Wortsman J, Eagleton LE, Rosner W, Dufau ML. Mechanism for the Hypotestosteronemia of the Sleep Apnea Syndrome. Am J Med Sci 1987. [DOI: 10.1097/00000441-198704000-00004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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43
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Israel Y, Orrego H. Hypermetabolic state, hepatocyte expansion, and liver blood flow: an interaction triad in alcoholic liver injury. Ann N Y Acad Sci 1987; 492:303-23. [PMID: 3300465 DOI: 10.1111/j.1749-6632.1987.tb48683.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Sindrome de apnea durante el sueño. Arch Bronconeumol 1987. [DOI: 10.1016/s0300-2896(15)31982-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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45
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46
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Ballard RD, Martin RJ. Sleep apnea--diagnosis and treatment. West J Med 1986; 145:248-50. [PMID: 3765609 PMCID: PMC1306904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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47
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Blakley BW, Maisel RH, Mahowald M, Ettinger M. Sleep parameters after surgery for obstructive sleep apnea. Otolaryngol Head Neck Surg 1986; 95:23-8. [PMID: 3106889 DOI: 10.1177/019459988609500106] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Obstructive sleep apnea (OSA) is a disorder that is frequently treated surgically. Few reports in the literature give objective reports of the effect of such treatment on polysomnographic parameters before and after treatment, although symptomatic improvement is common. This article reviews total sleep time (TST) spent in apnea, number of apneic episodes per hour or sleep apnea index (SAI), and oxygen desaturations in such patients treated with tracheostomy, uvulopalatopharyngoplasty (UPP), and combinations of these. Although improvement is noted in these parameters after UPP, this is not as impressive as some reports in the literature indicate. Our suggested indications for this type of surgery are discussed.
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Chanson P, Timsit J, Benoit O, Augendre B, Moulonguet M, Guillausseau PG, Warnet A, Lubetzki J. Rapid improvement in sleep apnoea of acromegaly after short-term treatment with somatostatin analogue SMS 201-995. Lancet 1986; 1:1270-1. [PMID: 2872408 DOI: 10.1016/s0140-6736(86)91405-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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