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Biomedical subjects

C Guilleminault

Publications and source records attributed to C Guilleminault.

At least 235 records · Page 13Linked to original sources
PubMed1991

Changes in the QT interval during obstructive sleep apnea.

Abnormalities of ventricular repolarization are associated with life-threatening ventricular arrhythmias. The effects of obstructive sleep apnea on the QT interval were evaluated in 12 male patients with obstructive sleep apnea syndrome (OSAS) who had no evidence of underlying cardiac, pulmonary or central nervous system disease. Seventy episodes of OSAS during nonrapid eye movement (NREM) sleep were randomly selected for analysis of RR and QT intervals. Differences in the QT interval, corrected QT interval (QTc) and RR interval just before the onset of apnea, at the end of apnea and during the postapnea hyperventilation period were compared. As expected, the RR interval prolonged considerably during OSAS (1,499 +/- 128 msec) compared to quiet sleep (1,019 +/- 131 msec, p less than 0.002) and decreased during the postapnea hyperventilation period (969 +/- 152 msec, p less than 0.002). The QT interval was prolonged at the onset of apnea (482 +/- 34 msec) compared to the active awake state (421 +/- 10 msec, p less than 0.01). Further prolongation of the QT interval was observed during OSAS (528 +/- 64 msec, p less than 0.002). The QT interval shortened abruptly during the postapnea hyperventilation period (435 +/- 34 msec, p less than 0.002). The QTc was also prolonged during the onset of apnea (482 +/- 34 msec) and shortened significantly during apnea (435 +/- 34 msec, p less than 0.002) and during the postapnea hyperventilation period (423 +/- 39 msec). Significant variations of the RR interval, QT and QTc intervals were not observed during episodes of NREM sleep after initiation of effective therapy in six patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Arousal↗
PubMed1991

Evaluation of the upper airway in patients with obstructive sleep apnea.

Multiple methods have been used to study the structure and physiological behavior of the upper airway (UA) in patients with obstructive sleep apnea (OSA). Valuable information may be obtained from the physiologic measurement of pressure and resistance along the UA, as well as from imaging techniques that include: direct or fiberoptic visualization, cephalometric roentgenograms, fluoroscopy, acoustic reflection, computerized tomography, and magnetic resonance imaging. This review summarizes the information that each of these methods has contributed to our understanding of the UA. The results obtained with these different methodologies have generally been complementary with structural narrowing being identified in the majority of patients with OSA. This narrowing is usually focal and located in the velopharyngeal or retropalatal segment of the UA. This is also the predominant site of initial UA collapse. Although obesity with enlargement of soft tissue structures is considered the predominant mechanism leading to UA narrowing, abnormal craniofacial development on a genetic or developmental basis plays an important contributory role.

Airway Obstruction↗
PubMed1991

Insomnia and use of hypnotics: study of a French population.

A cross-sectional study of insomnia and hypnotic use was performed in a sample of the French population. The quota method was used to select the sample of 1,003 subjects, with less than 3% substitution. Subjects were 15 years old and older and were representative of the French population based on gender, age, marital status and living environment. Subjects were asked questions relevant to the complaint of insomnia and hypnotic use and filled out questionnaires measuring anxiety and depression. The complaint of insomnia is common, even in the 15-24-year-old group. Overall, more women than men were afflicted. The largest group of insomniac subjects, and the group who most often used hypnotics "frequently and chronically", were women 45 years and older. Men presented a sharp increase in hypnotic use after 65 years of age. Ten percent of the entire sample used hypnotics, 8% for more than 6 months and 6.17% on a chronic and frequent basis. Retired and unemployed elderly were also chronic and frequent hypnotic users: aging and social isolation correlate with chronic and frequent hypnotic usage. Higher scores on anxiety and depression scales correlate with more frequent complaints of nocturnal sleep disturbances. Young individuals are a significant complainer group but use hypnotics rarely. A rural environment was associated, overall, with fewer insomnia complaints, but environment had much less impact on complaints and hypnotic use in the elderly than in other age groups. One may question whether, in the French population, hypnotic prescription and intake are not responses to a social rather than a medical problem.

Adolescent↗
PubMed1991

Radionuclide evaluation of cardiac function during sleep in children with bronchopulmonary dysplasia.

The influence of sleep on cardiac function in severe bronchopulmonary dysplasia was assessed in five children 1.5 to 5 years of age. Left and right ventricular ejection fractions (LVEF and RVEF) were investigated by equilibrium radionuclide ventriculography in five children undergoing polygraphic monitoring during the different states of alertness: wakefulness, nonrapid eye movement sleep, and rapid eye movement sleep. Intraobserver and interobserver LVEF and RVEF measurement reproducibility was high. During quiet, supine wakefulness, LVEF was normal, but RVEF was low. During sleep, a decrease in both LVEF and RVEF, expressed as a percentage of the awake value, was marked in the two children with the most nocturnal desaturation and longest duration of paradoxic rib cage motion during inspiration. It is concluded that radionuclide ventriculography can be easily performed during sleep in children and can provide useful information regarding right ventricular function during sleep in children with severe bronchopulmonary dysplasia.

Bronchopulmonary Dysplasia↗
PubMed1991

Leftward shift of the interventricular septum and pulsus paradoxus in obstructive sleep apnea syndrome.

Echocardiograms were taken from the parasternal long axis view during nocturnal sleep in ten patients diagnosed with OSAS. A table designed to support the echocardiographic probe prevented significant sleep disturbances during monitoring and allowed continuous data collection with and without nasal CPAP administration. In five of ten patients, there was before CPAP treatment a diastolic LSIVS during NREM sleep, inducing a flattening of the left ventricle. Arterial blood pressure recordings showed pulsus paradoxus when LSIVS was occurring. Nasal CPAP led to normal, unobstructed breathing, significant decrease in Pes nadir and disappearance of LSIVS and pulsus paradoxus. Increase in left ventricular afterload and increase in total peripheral resistance could lead to hypertrophy and hypertension in some OSAS patients. The presence of pulsus paradoxus in OSAS indicates a marked increase in Pes nadir, and its disappearance with nasal CPAP may be one of the signs of effective treatment of OSAS.

Adult↗
PubMed1991

Snoring (I). Daytime sleepiness in regular heavy snorers.

Fifteen men, mean (means) age 44 years, were investigated. Their means body mass index was 21.9 kg/m2, and all of them had a respiratory disturbance index below 5 and had good nocturnal oxygen saturation. The subjects were monitored several nights both with and without the following devices: a tight-fitting facial mask, a pneumotachometer, and an esophageal balloon. They were also monitored with and without nasal continuous positive airway pressure. The Multiple Sleep Latency Test was administered after three of the experimental nights (after the baseline nights and after the second nasal CPAP night). Determination of short EEG arousals during nocturnal sleep, which lasted 2 to 10 s, was performed. The relationship between short EEG arousals, the esophageal pressure nadir, and airflow decrease was investigated. We also determined the relationship between clinical reporting of decrease in daytime alertness and MSLT results, and the relationship between MSLT results and the frequency of EEG arousals. The monitoring indicated that heavy snorers may present significant increase in Pes nadir with abrupt decrease in flow leading to EEG arousals. The frequency at which EEG arousals occur has an impact on MSLT scores. Nasal CPAP improves MSLT scores and eliminates these respiration-related EEG arousals. Some heavy snorers without obstructive sleep apnea syndrome may be at risk of having a decrease in daytime alertness.

Adult↗
PubMed1991

Does oximetry contribute to the detection of apneic events? Mathematical processing of the SaO2 signal.

The purpose of this study was to assess the ability of continuous nocturnal oximetry to detect sleep apnea syndrome (SAS) and to recognize nonapneic oxyhemoglobin desaturations. Oxygen saturation oscillations, related to successive apneas in SAS or to apneic episodes in COPD or restrictive patients, were quantified using a new index: delta = 1/n sigma 1 n magnitude of delta(SaO2)/delta(t)(12-s intervals) Twenty-six patients (15 SAS, 8 COPD, and 3 restrictive patients) were included in a prospective study comparing nocturnal oximetry and polysomnography over 34 nights. In apneic patients, we found a strong correlation (r2 = 0.73, p less than 0.01) between time spent in apnea and the delta index. In COPD, the number of apneas was also correlated to the delta index (r2 = 0.92, p less than 0.01). A lower threshold for delta of 1.5 is accurate enough to detect apneas if initial SaO2 is greater than 93 percent. If initial SaO2 is greater than 93 percent, the delta threshold should be 0.8 (sensitivity 95 percent). Such a method could contribute to the accurate selection of patients for polysomnography.

Blood Gas Monitoring, Transcutaneous↗
PubMed1991

Dopamine D2 mechanisms in canine narcolepsy.

Narcolepsy is a sleep disorder characterized by abnormal manifestations of rapid-eye-movement (REM) sleep and excessive daytime sleepiness. Using a canine model of the disease, we found that central D2 antagonists suppressed cataplexy, a form of REM-sleep atonia occurring in narcolepsy, whereas this symptom was aggravated by D2 agonists. The effect on cataplexy was stereospecific for the S(-) enantiomer of sulpiride (a D2 antagonist) and the R(+) enantiomer of 3-PPP (a D2 agonist). There was also a significant correlation between the in vivo pharmacological potency and in vitro drug affinity for D2 receptors (but not for D1 and alpha 2 receptors) among the seven central D2 antagonists tested. Selective D1 compounds were also tested; however, the results were inconsistent because both antagonists and agonists generally suppressed cataplexy. Our current results demonstrate that central D2-type receptors are critically involved in the control of cataplexy and REM sleep. Furthermore, the finding that small doses of D2 antagonists suppressed cataplexy and induced behavioral excitation, while small doses of D2 agonists aggravated cataplexy and induced sedation, suggests that this effect is mediated presynaptically. However, considering the fact that selective dopamine reuptake inhibitors did not modify cataplexy and that our previous pharmacological results demonstrated a preferential involvement of the noradrenergic system in the control of cataplexy, we believe that the effect of D2 compounds on cataplexy is mediated secondarily via the noradrenergic systems.

Animals↗
PubMed1991

Changes in left ventricular ejection fraction during REM sleep and exercise in chronic obstructive pulmonary disease and sleep apnoea syndrome.

Nine patients, 4 with chronic obstructive pulmonary disease (COPD) and 5 with obstructive sleep apnoea syndrome (OSAS) were monitored during sleep, rest and exercise. Left ventricular ejection fraction (LVEF) was investigated using gated equilibrium 99mtechnetium ventricular scintigraphy during rapid eye movement (REM) sleep, during exercise, and during wakeful rest. Control wakeful rest periods used for comparison with a study state (either REM sleep or exercise) were always selected during the same circadian segment as that state. Myocardial stress thallium-201 scintigraphy was performed during, and 4 h after, exercise, and results were compared to a daytime rest period. Several patients had myocardial hypoperfusion despite a normal electrocardiographic (ECG) treadmill test. During REM sleep, all patients exhibited a significant change in LVEF (greater than 5%) compared to wakefulness. During exercise, 5 subjects increased their LVEF normally (greater than 5%) and 4 (1 COPD, 3 OSAS) decreased it. All patients had a similar change (increase or decrease) during REM and at maximal exercise. Our results suggest that REM sleep in COPD and in OSAS can produce a myocardial stress as great as that produced by exercise. We conclude that REM sleep, like exercise, is a state in which morbidity may become higher and that it may account for mortality in COPD and OSAS patients with compromised myocardial circulation.

Adult↗
PubMed1990

Benzodiazepines, breathing, and sleep.

The benzodiazepines are sedative hypnotic drugs, i.e., central nervous system depressant drugs, that may adversely affect the control of ventilation during sleep. Prescription of these drugs may worsen sleep-related breathing disorders, especially in patients with chronic obstructive pulmonary disease or cardiac failure. The most frequent users of sedative hypnotics are the polymorbid elderly with a secondary complaint of insomnia. Although the benzodiazepines may reduce sleep fragmentation, their long-term use may also cause health problems, such as complete obstructive sleep apnea in heavy snorers or short repetitive central sleep apnea in patients with recent myocardial infarction. Since drugs of this class vary in their effects, it is crucial to note the action of a given benzodiazepine on the control of vital functions during sleep.

Aged↗
PubMed1990

Chronic snoring and obstructive sleep apnea syndrome in children.

Increased upper airway resistance during sleep may lead to heavy snoring and/or obstructive sleep apnea in infants and children. Clinical symptoms will be seen with increased upper airway resistance during sleep, even without obstructive sleep apnea or significant oxygen saturation drop. It may be responsible for apparent life threatening events (ALTE). Mild cranio-facial morphometric changes are often associated with increased upper airway resistance during sleep, and there is a continuous interaction between airway patency during sleep and maxillo-mandibular growth. Nasal CPAP can be as much a diagnostic tool as a treatment procedure. Orthodontic and surgical approaches may also be combined in the treatment of this significant health problem.

Airway Obstruction↗
PubMed1990

Maxillary, mandibular, and hyoid advancement for treatment of obstructive sleep apnea: a review of 40 patients.

Forty patients with documented obstructive sleep apnea syndrome (OSAS) were evaluated following maxillary and mandibular osteotomies (MMO). All patients were evaluated before and after surgery by a physical examination, fiberoptic pharyngoscopy, cephalometric analysis, and polysomnography. Ninety-seven percent of the patients responded to the surgical treatment, based on the polysomnogram. The present indications for MMO are severe OSAS, morbid obesity, and severe mandibular deficiency.

Adolescent↗
PubMed1990

Obstructive sleep apnea syndrome or abnormal upper airway resistance during sleep?

Obstructive sleep apnea syndrome is well known by now, but, at both extremes of age, increased upper airway resistance may lead to clinical symptoms without complete apnea. Abnormal craniofacial features appear to be responsible for the very early appearance during childhood of increased upper airway resistance. In adults, snoring, often related to partial upper airway obstruction located in the pharynx, may be associated with changes in respiratory timing and intermittent arousal. Many treatments are currently available to deal with obstructive sleep apnea syndrome. It is important to recognize the location(s) of the upper airway obstruction before considering treatment and to evaluate the associated risk factors. Early recognition of factors involved in increased upper airway resistance may allow prevention, a more efficacious approach than treatment of an already developed syndrome.

Airway Resistance↗
PubMed1990

Esophageal reflux in symptomatic and asymptomatic infants: postprandial and circadian variations.

Twenty-two full-term infants, nine asymptomatic and 13 symptomatic for chronic digestive problems, had long-term (mean = 21 h) esophageal pH monitoring. All children were observed in strictly standardized conditions including meals and body position. Symptomatic infants presented significantly more esophageal refluxes, spent a greater percentage of time with a pH below 4, had a longer reflux duration (longer clearing time) and presented more refluxes lasting more than 5 min. We performed a determination of the circadian variations of parameters associated with esophageal reflux. Asymptomatic and symptomatic infants presented significant circadian variations of the percentage of time below pH 4 and of the longest duration of reflux. However, symptomatic infants had significantly higher mean values and increased amplitudes of circadian rhythms. Moderate phase lag existed for certain variables between symptomatic and asymptomatic infants. These findings can be helpful when interpreting the results of long-term esophageal pH monitoring.

Analysis of Variance↗
PubMed1990

Cardiac and respiratory responses to esophageal dilatation during REM sleep in human infants.

Forty-one preterm and fullterm infants (26.5-40.5 weeks gestational age and 31.5-50 weeks postconceptional age) free from neurologic and cardiopulmonary disease at the time of testing underwent a standardized esophageal dilatation test (EDT) during polygraphically controlled REM sleep. RR interval and total duration of the respiratory cycle (TTOT) were measured (1) during the 60 s preceding the EDT, i.e. mean control RR and mean control TTOT; (2) during EDT. Percent RR (%RR) was defined as the longest RR interval in milliseconds during EDT divided by mean control RR in milliseconds multiplied by 100, and percent TTOT (%TTOT) as the longest TTOT in seconds during EDT divided by mean control TTOT in seconds multiplied by 100. EDT provoked prolongation of both RR interval and TTOT. %RR decreased significantly with advancing gestational age (p less than 0.003), and %TTOT with advancing postconceptional age (p less than 0.003), indicating that both cardiac and respiratory responses to an EDT challenge are blunted with maturation.

Electrocardiography↗
PubMed1990

Daytime sleepiness and vascular morbidity at seven-year follow-up in obstructive sleep apnea patients.

To evaluate the morbidity associated with obstructve sleep apnea syndrome (OSAS), we undertook a seven-year follow-up study of 198 OSAS patients seen between 1972 and 1980. The patients had been submitted to tracheostomy (71 patients) or had received a weight-loss recommendation (127 patients). Despite a lower mean apnea index (AI) (43 vs 69) and a lower mean body mass index (BMI) (31 vs 34 kg/m2) at entry, excessive daytime sleepiness (EDS) and vascular morbidity were significantly higher in the conservatively treated group. The relative risk (odds ratio) of finding EDS in the conservatively treated group, after adjustment for BMI at seven-year follow-up, was 3.7 (95 percent confidence interval [CI] = 2.6-5.3). The relative risk of developing new vascular problems in the same population, estimated by Cox models, was 2.3 (95 percent CI = 1.5-3.6). The effect of tracheostomy, independent of age, BMI, and AI at entry, was highly significant. At entry, 56 percent of the population already had a vascular problem, particularly hypertension, thus emphasizing the need for earlier treatment of the sleep-related abnormal breathing.

Adolescent↗
PubMed1990

Maxillofacial surgery and nasal CPAP. A comparison of treatment for obstructive sleep apnea syndrome.

Nasal continuous positive airway pressure (CPAP) is the primary therapy for obstructive sleep apnea syndrome (OSAS). Recent reports have indicated, however, that there is a small but significant number of failures related to patient compliance. Primary surgical treatment, which has been uvulopalatopharyngoplasty (UPPP), has declined because of poor results. A reviewed of UPPP failures has shown that while UPPP eliminated palatal obstruction, it failed to eliminate base of tongue obstruction. Maxillofacial surgery has been reported as treatment of OSAS by correcting base of tongue obstruction. Thirty patients with severe OSAS were evaluated to compare nasal CPAP and maxillofacial surgery. The goal was to determine if our surgical protocol was as effective as nasal CPAP. All patients initially underwent baseline diagnostic polysomnography to document OSAS. A nasal CPAP study was performed to determine the appropriate positive end-expiratory pressure. The patients in this study were using nasal CPAP, but they found it unacceptable as long-term treatment and elected surgery. Maxillofacial surgery consisted of maxillary, mandibular, and hyoid advancement. Polysomnography was performed six months following surgery and compared with the night 2 CPAP results. The parameters included in the investigation were the respiratory disturbance index (RDI), lowest SaO2, number of SaO2 falls below 90 percent, total sleep time (TST), REM sleep percent, stage 3-4 sleep percent, and wake after sleep onset. The mean RDI before treatment was 72.0 (SD 25.7). After completing therapy, the RDI from surgery and CPAP was 8.8 (SD 6.0) and 8.6 (SD 4.1), respectively. The mean low SaO2 prior to treatment was 61.0 (SD 13.5), and the CPAP results and postsurgical results were 86.2 (SD 5.5) and 86.1 (SD 4.2), respectively. An analysis of variance was used to examine the results, and there was no statistical difference between nasal CPAP and surgery for all respiratory variables.

Adult↗