Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0037315 (sleep apnea)
 8,000 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Acetazolamide (ACTZ) reduces sleep apnea in adults exposed to high altitude and augments the ventilatory response to CO2. In order to determine the effect of ACTZ on the ventilatory response to CO2 and the incidence of apnea in preterm infants, 7 infants (BW, 1070 +/- 191 g; postnatal age, 9 +/- 7 days) were randomized to receive ACTZ (5 mg/kg/dose Q6h for 36 hr) and 7 infants (BW, 1092 +/- 292 g; post-natal age, 5 +/- 2 days) received aminophylline (AMINO; 8 mg/kg bolus then 2.5 mg/kg Q12h for 36 hr). Minute ventilation (VE), end-tidal CO2 (PETCO2), ventilatory response to CO2, number of apneic episodes (> or = 15 sec duration), and arterial blood gases were measured before and 24-36 hr after starting therapy. In the AMINO group there was a significant decrease in apnea frequency from 6 +/- 1 to 2 +/- 2 episodes over an 8 hr epoch (P < 0.05), while no significant change was observed in the ACTZ group. The end-tidal CO2 decreased significantly from 44 +/- 7 to 38 +/- 6 mmHg in the AMINO group and from 47 +/- 5 to 36 +/- 5 mmHg in the ACTZ (P < 0.05), which lead to a shift to the left of the CO2-response curve in both groups. The slope of the CO2 response curve did not change significantly in the AMINO group and decreased in the ACTZ group. There was a significant decrease of pH from 7.43 to 7.26 in the ACTZ group, whereas in the AMINO group pH increased from 7.38 to 7.44.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Comparison of the effects of acetazolamide and aminophylline on apnea incidence and on ventilatory response to CO2 in preterm infants. 805 22

A 63-year-old man with severe non-obstructive sleep apnoea (apnoea index 28; apnoea duration 45-60s; O2 saturation between 72% and 98%), who did not respond to common modes of treatment, was successfully treated with CO2. A tent was perfused with compressed air (6 1/min) and increasing amounts of CO2. A concentration of 3% CO2 (180 ml/min) was sufficient to raise the PaCO2 above apnoea threshold and to suppress apnoeas completely. As a result, O2 saturation remained normal throughout the whole night and the symptoms of sleep apnoea disappeared. We hypothesize that the PCO2 ventilatory drive was intact in our patient and that hypocapnia was the major factor causing the non-obstructive sleep apnoea syndrome. Administration of CO2 with a constant flow system could be a safe and easy alternative for patients with non-obstructive sleep apnoea syndrome who present with hypocapnia and an intact respiratory feedback control system.
 ...
PMID:Beneficial effect of inhaled CO2 in a patient with non-obstructive sleep apnoea. 813 21

The amount of different clinically available lasers is increasing. The ENT surgeon can therefore use the best laser for the planned operation. As the resources of the hospital do not increase with the laser technology, a decision has to be made whether in addition to the universal CO2-laser other types must be acquired and which type is best. This paper presents the characteristics and typical tissue interactions of several lasers for the area of the soft palate. Typical operative examples are shown, e.g. partial resection of the soft palate in patients with bronchopathy and sleep apnoea syndrome, tonsillectomy, tonsillotomy and adenotomy in adults.
 ...
PMID:[Current status of laser surgery in the area of the soft palate and adjoining regions]. 814 48

The diagnosis of sleep apnea syndrome (SAS) requires expensive and complex instrumentation. The purpose of the present study was to determine the value of end-tidal CO2 (EtCO2) in screening for sleep apneas. Thirty-nine patients referred to our sleep laboratory because of suspected SAS and ten normal subjects were studied. The EtCO2 was measured using an infrared spectrometer (POET) designed for simultaneous measurement of CO2 and pulse oximetry. In 29 subjects, expired gas was sampled with a nasobuccal mask (Respiron) with lateral orifices. In the other 20 subjects, sampling was done with nasobuccal prongs (Criticare) comprising a four-channel plastic tube to the mouth and the nostrils. Data from an 8-h night were transferred the following day to a microcomputer (Apple Macintosh) for processing. Apnea was defined as an absence of detection of CO2 for more than 10 s. Conventional polysomnography was performed (Respisomnographe). The number of apneas in 8 h and the apnea index (number of apneas in 1 h) were calculated after visual analysis on the screen of the polysomnograph and also with EtCO2 analysis. For recordings made with a nasobuccal mask, the regression curve between the apnea indices computed with EtCO2 and polysomnography was an order 2 polynomial curve (r = 0.76; p < 0.001), with an inflection point at 39 apneas per hour. For recordings with nasobuccal prongs, the correlation was very significant (r = 0.95; p < 0.0001), and the regression curve was linear. The EtCO2 with nasobuccal prongs appears to be a simple and reliable method for screening for SAS.
 ...
PMID:End-tidal CO2 analysis in sleep apnea syndrome. Conditions for use. 841 66

A detailed analysis was made of nasal capnograms obtained from sleeping children with differing degrees of sleep-induced respiratory obstruction, the severe form being known as obstructive sleep apnoea. Clinical observations of these children were compared with analyses of nasal capnography data. During periods when the degree of obstruction was consistent throughout the first hour of sleep, the means and coefficients of variation of several parameters, derived from the capnograms were calculated. The coefficients of variation showed a close relationship to the degree of obstruction. In comparison, measures of end-tidal carbon dioxide concentration proved to be a very insensitive index of the degree of obstruction. The conclusion is that the usefulness of nasal capnography in predicting and grading obstruction can easily be extended by the use of statistical measures of dispersion and that this concept warrants further work.
 ...
PMID:Nasal capnography in children: automated analysis provides a measure of obstruction during sleep. 844 97

Diagnosis of a sleep apnoea syndrome in severely snoring patients with diurnal sleepiness is growing in importance in the consulting rooms of general practitioners, internists, ENT specialists and pneumologists. However, time and cost reasons limit the diagnostic procedures conducted by practitioners to outpatient screening. Two different systems are presently available in Germany. The MESAM system (Madaus, Freiburg) records by means of a microphone and various electrodes the oxygen saturation, heart rate, snoring and sleeping position of the patient. The Apnoe-Check System (Medanz, Starnberg) determines the nasal and oral respiratory flow by means of a mask fitted with thermistors. Evaluation is accomplished in the case of MESAM via a conventional personal computer whereas with the Apnoea Check System the apnoeas and their duration can be read off direct from a writer. The cost ratio of these systems is approximately 3:1 (MESAM:Apnoea Check). Wie compared both systems by parallel measurements on 19 female and male patients and controlled the results obtained by measurements with a CO2 infrared absorption spectrometer in our sleep lab. A total of 3201 nocturnal events were recorded via MESAM and 1488 via the Apnoe-Check System. The highest number of apneas was recorded by MESAM in a patient with severe sleep apnea syndrome, namely, 546 apnoeas in one night. The lowest number of apnea events was experienced by a healthy male with 33 apneas in a night. With the Apnoe Check the maximum of nocturnal events was 255, the minimum being 8 events in one patient. In 64.6% of all nocturnal events there was time congruence for both systems.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:[Efficiency of portable sleep apnea screening instruments]. 849 63

We previously demonstrated that central apneas during sleep in patients with idiopathic central sleep apnea (ICSA) are triggered by abrupt hyperventilation. In addition, baseline PCO2 at the time of augmented breaths which triggered central apneas was lower than for augmented breaths which did not trigger apneas. These observations led us to hypothesize that patients with ICSA chronically hyperventilate maintaining their PCO2 close to the threshold for apnea during sleep owing to increased chemical respiratory drive. To test these hypotheses, we recorded transcutaneous PCO2 (PtcCO2) during overnight sleep studies on nine consecutive patients with ICSA and nine sex-, age-, and body-mass-index-matched control subjects. Daytime PaCO2 as well as rebreathing and single breath ventilatory responses to CO2 were also measured. Compared with the control subjects, the patients had significantly lower mean PtcCO2 during sleep (37.8 +/- 1.2 versus 42.7 +/- 10.9 mm Hg, p < 0.01) and lower PaCO2 while awake (35.1 +/- 1.3 versus 38.8 +/- 0.9 mm Hg, p < 0.05). Furthermore, patients with ICSA had significantly higher ventilatory responses to CO2 for both the rebreathing (3.14 +/- 0.34 versus 1.60 +/- 0.32 L/min/mm Hg, p < 0.005) and single breath methods (0.51 +/- 0.10 versus 0.25 +/- 0.04 L/min/mm Hg, p < 0.05). We conclude that: (1) patients with ICSA chronically hyperventilate awake and asleep and (2) chronic hyperventilation is probably related to augmented central and peripheral respiratory drive which predisposes to respiratory control system instability.
 ...
PMID:Hypocapnia and increased ventilatory responsiveness in patients with idiopathic central sleep apnea. 852 Jul 61

Obstructive sleep apnea (OSA) can be associated with depressed hypercapnic ventilatory response (HCVR) (White D.P., N.J. Douglas, C.K. Pickett, C.W. Willich and J.V. Weil, Am. Rev. Respir. Dis 128:984-986, 1983), which might be responsible for aggravating the sleep-related breathing disorder (SRBD). The present study evaluated whether in patients with various types of sleep apnea a significant decrease in the HCVR could be found (COMPARATIVE STUDY). In a second part of the study chronic CPAP therapy (Continuous Positive Airway Pressure) was evaluated in relation to control of breathing (CPAP STUDY). In the comparative study a significant increase of the slope in the normocapnic OSA and overlap group could be seen. A depressed HCVR could only be observed in chronic hypercapnic OSA. In the CPAP-study it was shown that changes in the AHI after CPAP do not parallel the HCVR. We conclude that in eucapnic OSA patients CPAP therapy does not change CO2 drive. We believe that increased chemical CO2 drive can contribute to its pathogenesis.
 ...
PMID:Chronic CO2 drive in patients with obstructive sleep apnea and effect of CPAP. 860

The dynamics of cerebral blood flow velocity (CBFV) during sleep were investigated in the right middle cerebral artery of 10 patients with sleep apnea syndrome (SAS) (mean age, 37 years) and 10 healthy control subjects (mean age, 32 years) throughout the entire sleep period. A computer-assisted pulsed (2 MHz) transcranial Doppler ultrasonography system was modified for continuous long-term and on-line recording of cerebral hemodynamics. Concurrently, simultaneous polysomnography, continuous BP recordings, and measurement of the end-expiratory carbon dioxide were undertaken. CBFV showed comparable nocturnal profiles in both groups with decreases during non-rapid eye movement (NREM) sleep and increases during rapid eye movement (REM) sleep, indicating that the general pattern of brain perfusion during normal sleep is maintained in SAS. Sleep stage changes were not regularly accompanied by corresponding changes in CBFV. This reflected a quantitative uncoupling between cerebral electrical activity and cerebral perfusion during sleep and indicated a dissociation in the activity of central regulatory mechanisms. Sleep stage-related analysis showed slightly reduced CBFV in patients with SAS compared with healthy control subjects during wakefulness and the first NREM sleep period, suggesting depressed brain activity in the patient group. The higher CBFV values observed in patients with SAS compared with control subjects during REM sleep and sleep stage 2, both preceding and following REM sleep, underline the influence of dynamically changing sleep patterns on cerebral perfusion in these patients. Reproducible rapid decreases in CBFV were related to EEG arousals. Since apneas are terminated by arousals, these results showed that direct neuronal influences on brain perfusion during apnea are evident.
 ...
PMID:Sleep apnea syndrome and cerebral hemodynamics. 879 10

The clinical course and changes in hypercapnic ventilatory drive over time were serially assessed before and after tracheostomy placement in a 14 year old, morbidly obese female patient with Prader-Willi syndrome, severe obstructive sleep apnoea, and obesity-hypoventilation syndrome. A tracheostomy became necessary after supplemental oxygen and continuous positive airway pressure (CPAP) had failed to improve the severity of nocturnal hypoventilation. Continued improvement in the slope to rebreathing hyperoxic hypercapnia occurred from 2-10 weeks after tracheotomy in conjunction with night-time bilevel pressure ventilation, and remained unchanged thereafter. In contrast, increases in mean resting minute ventilation at an end-tidal carbon dioxide tension (PET,CO2) of 8 kPa (60 mmHg) were documented even after 30 weeks. This case study illustrates the time-frame of dynamic ventilatory changes occurring after removal of upper airway resistance and normalization of nocturnal alveolar ventilation.
 ...
PMID:Longitudinal assessment of hypercapnic ventilatory drive after tracheotomy in a patient with the Prader-Willi syndrome. 883 75


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>