SEARCH · PubMed Health

Results for “OSA”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources

PubMed2003

[Cephalometry study of craniofacial and upper airway in boys with OSAS].

OBJECTIVE: The purpose of the study was to find out craniofacial and upper airway characteristics of boys with OSAS. METHODS: Craniofacial and upper airway morphology was studied by computerized cephalometric analysis in 7 mixed dentition boys with OSAS and 29 healthy boys. RESULTS: The main differences of OSAS patients were shown as follows: longer dimension of cranial base with clockwise rotation of palate plane and mandibular plane, increased height of the tongue, inferiorly displaced hyoid bone, decreased sagittal dimension of upper airway in soft palate level and tongue base level. In addition, the tongue and soft palate occupied a larger portion of the oropharyngeal area. CONCLUSION: Patients with OSAS presented multiple abnormalities in craniofacial and upper airway. Cephalometry can be useful in diagnosis and determining the appropriate treatment for OSAS patients.

Cephalometry↗

PubMed2006

[Factors determining the decision to initiate nCPAP therapy in patients with obstructive sleep apnea (OSA)].

UNLABELLED: The aim of the study was to determine the factors which influence the decision to initiate nCPAP therapy in patients with OSA. 184 patients with OSA were enrolled to the study. They were divided into two groups: group "T" ("treated") which consisted of 112 patients who were being treated with nCPAP and group "R" (resigned") which consisted of 68 patients who refused nCPAP therapy. The main causes of their refusal were: the possibility of surgical treatment, nCPAP intolerance and high costs associated with the purchase of a nCPAP device. The mean age of the patients was comparable in both groups (49.2 +/- 8.7 vs 50.5 +/- 10.6 yrs). Patients from group T had a significantly higher body weight and BMI than the patients from group R (106.6 +/- 2.1 kg vs 94.1 +/- 20.9 kg, p < 0.0001 and 35.0 +/- 6.3 kg/m2 vs 31.1 +/- 6.3 kg/m2, p < 0.00005 respectively). The patient evaluation included physical examination, a questionnaire concerning symptoms related with OSA and OSA assessment by poly-MESAM, polysomnography (PSG) before and with nCPAP trial therapy. RESULTS: the following parameters obtained in the poly-MESAM recording differed significantly (p < 0.001) between group T and group R: RDI (54.6 vs 41.7), HRV index (24 vs 11), SaO2 min (67.0 vs 75% and SaO2 mean (84 vs 88%). Analysis of the baseline PSG did not reveal differences in sleep structure in both groups. We found a significantly higher AHI in group T (63.6 vs 44.9, p < 0.00005). PSG confirmed a significantly lower SaO2 min and SaO2 mean in group T (67.0 vs 75.0%, p < 0.001 and 89.0 vs 92%, p < 0.00002 respectively) and also revealed a significantly longer total sleep time with SaO2 < 90% in this group (183.0 vs 55.0 min, p < 0.0005). We did not find any differences between both study groups in the parameters obtained in PSG with nCPAP trial therapy. CONCLUSIONS: OSA patients who decide to be treated with nCPAP are more obese, have a higher BMI and demonstrate a more severe disease assessed by PSG.

Adult↗

PubMed1995

[Effect continuous positive airway pressure (CPAP) on left ventricular diastolic function in patients with obstructive sleep apnea syndrome--OSAS].

22 patients with (OSAS) obstructive sleep apnea syndrome were divided into two groups: patients with OSAS and without arterial hypertension, and OSAS with hypertension. The effect of CPAP (continuous positive airway pressure) on the left ventricular function was evaluated using 2D and Doppler echocardiography. Systolic left ventricular function (ejection fraction) was normal in all patients. The decrease in peak mitral flow velocity during early diastole E (m/sec), the increase of atrio-systolic contraction A (m/sec), the increase in E/A and prolonged isovolumic relaxation time (IVRT) was observed in the both groups at the beginning of the study. After three month treatment with CPAP the increase in the ratio E/A, 1.38 + 0.23 m/sec vs 0.98 + 0.28 (p < 0.05) and a reduction in IVRT, 79 + 6.8 milisec vs 91.3 + 6.3 (p < 0.05) in the group with OSAS and hypertension was observed. In the group with OSAS and without hypertension only a statistically significant reduction in IVRT was observed, 77.8 + 5.4 vs 83.7 + 5.15 milisec p < 0.05.

Adult↗

PubMed2005

Reorganization of sleep patterns in severe OSAS under prolonged CPAP treatment.

OBJECTIVE: To evaluate the immediate and long-term recovery processes of sleep and daytime vigilance in patients with sleep apnea syndrome (OSAS) after continuous CPAP treatment. METHODS: Five consecutive polysomnographic (PSG) studies were carried out on 10 male patients with severe OSAS. The first recording (baseline) was accomplished without ventilatory support (N0). The other 4 recordings were carried out during the CPAP titration night (N1), during the second night of treatment (N2), during the third night of treatment (N3), and after 30 days of regular CPAP use (N30). Ten age-balanced healthy male subjects were selected from the Parma Sleep Center database as controls. Respiratory variables, conventional PSG variables, arousals, CAP (cyclic alternating pattern) variables, and daytime function (including MSLT) were quantified. ANOVA followed by post-hoc tests explored the differences between controls and OSAS patients in the different recording conditions (N0, N1, N2, N3, N30). The PSG measures that showed significant ANOVA values were correlated with the MSLT scores. RESULTS: Values of control subjects were recovered by REM sleep, REM latency, subtypes A3 and arousal index during N1, by CAP rate and total arousals during N2, by deep sleep (stages 3 + 4) during N3, by light sleep (stages 1 + 2) during N30. The only measures which remained below control values even after 1 month of sustained treatment were the amount of CAP cycles and A1 subtypes. MSLT scores correlated significantly with CAP rate, deep sleep and arousals. CONCLUSIONS: The changes induced by CPAP treatment do not restore immediately a normal sleep structure, which is re-established with different time scales SIGNIFICANCE: The modifications of sleep patterns and the different adjustments of phase A subtypes allow us to monitor the reorganization of sleep in OSAS patients treated with CPAP and the hierarchy of the mechanisms involved in sleep regulation.

Adult↗

PubMed2004

Osa modulates the expression of Apterous target genes in the Drosophila wing.

The establishment of the dorsal-ventral axis of the Drosophila wing depends on the activity of the LIM-homeodomain protein Apterous. Apterous activity depends on the formation of a higher order complex with its cofactor Chip to induce the expression of its target genes. Apterous activity levels are modulated during development by dLMO. Expression of dLMO in the Drosophila wing is regulated by two distinct Chip dependent mechanisms. Early in development, Chip bridges two molecules of Apterous to induce expression of dLMO in the dorsal compartment. Later in development, Chip, independently of Apterous, is required for expression of dLMO in the wing pouch. We have conducted a modular P-element based EP (enhancer/promoter) misexpression screen to look for genes involved in Apterous activity. We have found Osa, a member of the Brahma chromatin-remodeling complex, as a positive modulator of Apterous activity in the Drosophila wing. Osa mediates activation of some Apterous target genes and repression of others, including dLMO. Osa has been shown to bind Chip. We propose that Chip recruits Osa to the Apterous target genes, thus mediating activation or repression of their expression.

Animals↗

PubMed2005

Short-term effects of oral theophylline in addition to CPAP in mild to moderate OSAS.

Theophylline is effective in the treatment of central apneas and periodic breathing. In obstructive sleep apnea syndrome (OSAS), results of pharmacological monotherapy with theophylline are inconsistent. The present study investigates whether additional theophylline in patients with OSAS and continuous positive airway pressure (CPAP) therapy might improve ventilation, lower effective CPAP pressure levels or affect sleep architecture. Patients with mild to moderate OSAS (mean apnea index [AI] 12.8+/-11.7) and CPAP therapy (Autoset system; n=16, all male) received either 900 mg of oral sustained-release theophylline (T) or placebo (P) on two separate nights, 3 days apart, using a randomized double-blind crossover study design. There was no change in AI (T: 0.7+/-1.4 vs. P: 0.7+/-0.6/h; P=0.3) or apnea-hypopnea index (AHI; T: 4.3+/-3.3 vs. P: 4.5+/-3.7/h; P=0.84) when theophylline was added to CPAP therapy. We observed no difference in mean CPAP pressure (T: 6.9+/-2.1 vs. P: 6.7+/-1.9 cm H2O; P=0.7) or 95% pressure percentiles (T: 9.7+/-2.7 vs. P: 9.3+/-2.1cm H2O; P=0.3) when nights with theophylline were compared to placebo nights. Theophylline reduced significantly total sleep time (T: 290.6+/-58.9 vs. P: 338.0+/-40.1 min; P=0.02) and thus sleep efficiency (SE; T: 70.5+/-14.9%, P: 82.0+/-70.5%; P=0.005). Rapid eye movement and slow wave sleep were not affected. Oral theophylline did not show any additional effects on ventilation parameters or pressures in patients with mild to moderate OSAS once CPAP therapy has been successfully installed. SE was reduced with theophylline with unchanged sleep architecture. The role of oral theophylline may be in patients with predominately central apneas not eligible for ventilation therapy or severe cases.

Administration, Oral↗

PubMed2004

Lactate production and catecholamine profile during aerobic exercise in normotensive OSAS patients.

BACKGROUND AND PURPOSE: The aim of the study was to evaluate the catecholaminergic activity and lactate concentration during exercise in normotensive patients with obstructive sleep apnoea syndrome (OSAS). PATIENTS AND METHODS: Thirteen normotensive patients affected by OSAS (mean age+/-standard error (SE), 52.6+/-2.8 yrs; mean apnoea-hypopnea index, 35.7+/-20.3) were enrolled in the study. Night-polysomnography and multiple sleep latency test in the sleep laboratory were performed for every patient. Patients also underwent an incremental workload exercise on a cycloergometer. We evaluated plasma epinephrine and norepinephrine levels in aerobic exercise conditions, relating them to lactate levels. RESULTS: Analysis of the venous lactate curve showed that exercise lactate levels were significantly higher (peak normalised levels, 782 vs. 270%; P<0.001 ), and an earlier lactate threshold was detected, in the patients compared to normal controls. While plasma catecholamine levels were abnormally high in almost all patients at rest, exercise values were not significantly different from controls. Lactate/norepinephrine and lactate/epinephrine area ratios were significantly higher in OSAS subjects than in controls (2.25 vs. 1.21 and 2.37 vs. 1.03, respectively). CONCLUSIONS: The results indicate that abnormal production of lactate during exercise occurs in OSAS, possibly due to some muscular metabolic modification. While catecholaminergic activity is abnormally increased at rest, this activity does not seem to play a significant role in lactate concentration during exercise in these patients.

Blood Pressure↗

PubMed2002

Comparison between anatomy and resistance of upper airway in normal subjects, snorers and OSAS patients.

Upper airway (UA) anatomical abnormalities are frequently observed in obstructive sleep apnea syndrome (OSAS). The correspondence between UA anatomical modifications and UA resistance (UAR) had not been studied. We aimed to determine if cephalometric characteristics could be related to segmental UAR. In twenty-five patients (21 males) (15 OSAS patients, 10 snorers) and 10 control subjects (8 males), segmental UAR were measured in supine position and cephalometry was performed. Inspiratory and expiratory UAR were calculated at peak flow. Length of the soft palate (LP), posterior airway space (PAS), distance from hyoid bone to mandibular plane and to posterior pharyngeal wall were different between the groups (P<0.01). Inspiratory and expiratory, total and segmental, UAR were higher in OSAS (P<0.001). Segmental UAR were correlated with PAS and distance from hyoid bone to mandibular plane and to pharyngeal posterior wall (P<0.05). In conclusion, OSAS patients had higher UAR depending on anatomical variables, especially the place of the hyoid bone.

Adult↗

PubMed1998

Sleep fragmentation and daytime vigilance in patients with OSA treated by surgical maxillomandibular advancement compared to CPAP therapy.

Impaired vigilance is a frequent daytime complaint of patients with obstructive sleep apnoea (OSA). To date, continuous positive airway pressure (CPAP) is a well established therapy for OSA. Nevertheless, in patients with certain craniofacial characteristics, maxillomandibular advancement osteotomy (MMO) is a promising surgical treatment. Twenty-four male patients with OSA (pretreatment respiratory disturbance index (RDI) 59.3 SD +/- 24.1 events/h) participated in this investigation. The mean age was 42.7 +/- 10.7 years and the mean body mass index was 26.7 +/- 2.9 kg/m2. According to cephalometric evaluation, all patients had a narrow posterior airway space, more or less due to severe maxillary and mandibular retrognathia. All patients except two were treated first with CPAP for at least 3 months and afterwards by MMO. Two patients only tolerated a CPAP trial for 2 nights. Polysomnographic investigation and daytime vigilance were assessed before therapy, with CPAP therapy and 3 months after surgical treatment. Patients' reports of impaired daytime performance were confirmed by a pretreatment vigilance test using a 90-min, four-choice reaction-time test. The test was repeated with effective CPAP therapy and postoperatively. Daytime vigilance was increased with CPAP and after surgical treatment in a similar manner. Respiratory and polysomnographic patterns clearly improved, both with CPAP and after surgery, and showed significant changes compared to the pretreatment investigation. The RDI decreased significantly, both with CPAP (5.3 +/- 6.0) and postoperatively (5.6 +/- 9.6 events/h). The percentages of non-rapid eye movement Stage 1 (NREM 1) sleep showed a marked decrease (with CPAP 8.2 +/- 3.6% and after MMO 8.2 +/- 4.4% vs. 13.3 +/- 7.4% before treatment), whereas percentages of slow wave sleep increased significantly from 8.0 +/- 6.1% before therapy to 18.2 +/- 12.8 with CPAP and 14.4 +/- 7.3% after MMO. The number of awakenings per hour time in bed (TIB) was significantly reduced after surgery (2.8 +/- 1.3), compared to both preoperative investigation (baseline 4.2 +/- 2.0 and CPAP 3.4 +/- 1.5). Brief arousals per hour TIB were reduced to half with CPAP (19.3 +/- 20.0) and after MMO (19.7 +/- 13.6), compared to baseline (54.3 +/- 20.0). We conclude that the treatment of OSA by MMO in carefully selected cases has positive effects on sleep, respiration and daytime vigilance, which are comparable to CPAP therapy.

Adult↗

PubMed1992

Preoperative discrimination between ovarian carcinoma, non-ovarian gynecological malignancy and benign adnexal masses using serum levels of CA125 and the polymorphic epithelial mucin antigens CASA, OSA and MSA.

Serum levels of the tumor associated antigens CA125, CASA, OSA and MSA were determined preoperatively in a non-consecutive series of patients with: invasive epithelial ovarian cancer (OC, n = 87), ovarian tumors of low malignant potential (LMP, n = 9), benign adnexal masses (BAM, n = 48) and other peritoneal and pelvic malignancies (n = 48). In addition, serum levels of CASA, OSA, and MSA were determined in 3477 asymptomatic well women. Ninety-eight percent of the asymptomatic women had CASA levels < 6.0 U ml-1, OSA levels < 5.5 U ml-1 and MSA levels < 80.0 U ml-1. Serum CA125 levels were> 35 U ml-1 in 89% of OC, in 44% of LMP, and in 23% of BAM. Serum CASA levels were> 6.0 U ml-1 in 58% of OC, in 0% of LMP, and in 0% of BAM. Serum OSA levels were> 5.5 U ml-1 in 61% of OC in 0% of LMP and in 4% of BAM. Serum MSA levels were> 80.0 U ml-1 in 56% of OC, in 11% of LMP, and in 10% of BAM. When cut-off levels were set to exclude all patients with BAM, the best discrimination from OC using a single assay was achieved using CASA (58%). However, a combination of CASA and CA125 gave positive levels in 69% of OC at levels which precluded BAM. All markers were also elevated in some colon cancers, cervical cancers, uterine cancers and other peritoneal malignancies. A combination of CA125 and CASA levels, obtained preoperatively may assist the general gynecologist in avoiding potentially difficult oncologic surgery.

Journal Article↗

PubMed2001

Prevalence of daytime hypercapnia or hypoxia in patients with OSAS and normal lung function.

The purpose of this study was to determine factors increasing daytime PaCO2 or PaO2 in obstructive sleep apnoea syndrome patients (OSAS) with normal pulmonary function tests. Anthropometric, pulmonary function tests, arterial blood gases and sleep polygraphic data were analysed retrospectively in 218 OSAS patients (apnoea-hypopnoea index > 15 h(-1); 18 females, 55 +/- 11 years): 125 patients had abnormal pulmonary function tests, i.e. one or more flow or volume under 80% or above 120% of predictive value (group I) and 93 had normal pulmonary function tests (group II). Hypercapnia was defined as PaCO2 > or = 6.0 kPa and hypoxia as PaO2 < 9.3 kPa. Patients with abnormal pulmonary function tests were more hypoxic and hypercapnic, more obese, and had a higher apnoea-hypopnoea index (P<0.05). Seventeen patients of group I and four of group II were hypercapnic (13.6% and 4.3%, respectively). Thirty-one patients in group I (24.8%) had a PaO2 < 9.3 kPa and six (6.5%) in group II. Stepwise multiple regression analysis showed that in group II, only two factors were correlated with PaCO2: mean apnoea duration and FRC (respectively: c=0.228, P<0.001; c=0.006, P=0.108); and only two with PaO2: mean apnoea duration: (c=-0.218, P=0.029) and BMI (c=-3.72, P<0.0001). Daytime hypercapnia is present in 4.3% and daytime hypoxia in 6.5% of patients with occlusive sleep apnoea syndrome and normal pulmonary function tests. These alterations in blood gases in OSAS with normal pulmonary function tests should be considered as OSAS severity criteria.

Adult↗

PubMed1997

[Therapy with nasal CPAP (continuous positive airway pressure) in patients with obstructive sleep apnea syndrome (OSAS). II: Side-effects of nCPAP therapy. Effect on long-term acceptance].

BACKGROUND: nCPAP is a well established method for the management of OSAS. The aim of this study was to evaluate long-term side effects and complications of nCPAP therapy and their influence on the patients compliance with treatment. PATIENTS AND METHODS: Forty-one patients with OSAS were interviewed by questionnaire to elucidate the problems and adverse effects of their nCPAP therapy. The patients were divided into responders and non-responders. Non-responding OSAS patients were using their nCPAP devices less then 5 hours each night by definition. RESULTS: The number of side effects and type of complication during nCPAP therapy were the same in both the responding and non-responding groups. The most frequently reported problems were a tender region on the bridge of the nose and discomfort associated with a dry nasal mucosa. Although nCPAP treatment was initially accepted by most patients, adverse effects and other difficulties decreased patient compliance, with time, in many cases. CONCLUSIONS: Despite there being no difference between responders and non-responders with respect to the number and severity of complications, it should not be presumed that these side effects do not influence long-term patient compliance with nCPAP therapy. Patients who suffer from symptoms of OSAS tend to accept these adverse effects, while those who do not feel limited by their disease are less persistent in their use of this treatment modality. Identification and elimination of the problems associated with the use of nCPAP equipment may increase longterm patient compliance. Close monitoring in the outpatient department combined with intermittent inpatient assessment in the sleep laboratory will also help to improve acceptance of nCPAP therapy.

Adult↗

PubMed1999

Failures in snoring and OSAS surgery.

Significant reduction of snoring noise and valid prevention of neurological and/or cardiovascular complications of OSAS are the basic goals of all modern snoring and OSAS surgical procedures. Any kind of operation, single or multiple, included into a one-step or multistep programs, is said to fail if snoring is not reduced to a significant extent for the patient or if clinical and/or instrumental data after the operation show that Upper Airways Resistance Syndrome (UARS) or OSAS continues to be probably dangerous for the patient to some extent. The real figure of failures in different situations of sleep-disordered syndromes surgery is discussed, along with the possible explanations. A group of patients operated on for snoring and OSAS in our clinic is analyzed retrospectively from the subjective point of view and by means of sleep studies to get a precise quantitative and qualitative idea of the failed cases. The final goal would be to understand how it is possible to reduce to a minimal level the number of true failures.

Adult↗

PubMedDate not supplied

Early online detection of upper airway obstructions in obstructive sleep apnoea syndrome (OSAS) patients.

The obstructive sleep apnoea syndrome (OSAS) is a diagnosis related to snoring and caused by a collapse in the upper airway. OSAS patients suffer from desaturated oxygen levels during sleep as well as daytime sleepiness. In this paper, we propose a system able to identify and detect respiratory disorders online based on monitoring the airflow amplitude from a sleeping OSAS patient. By the use of chi(2)-analysis and a Haar wavelet transform on signals performed offline, reference templates indicating the specific apnoea pattern for four different patients are constructed and used for similarity matching against online signals. Detection is performed in the early stages of an upcoming airway dysfunction, thus providing an opportunity to alert the patient at sleep. The system-testing results indicate robust performance and flexibility for the patient. Our proposed solution can in turn operate as an alternative to today's OSAS treatment of choice, the continuous positive airway pressure (CPAP).

Airway Obstruction↗

PubMed1992

Relations between sleep stage, posture and effective nasal CPAP levels in OSA.

A retrospective analysis of positional data from 100 male patients with obstructive sleep apnea (OSA) was conducted to determine whether or not 1) the degree of positional dependency was similar in rapid eye movement (REM) compared to non-REM (NREM) sleep, 2) positional dependency correlated with effective levels of nasal continuous positive airway pressure (CPAP) and 3) patients with positional OSA preferentially avoided sleeping in the supine position. The apnea-hypopnea index (AHI) was scored separately for sleep state (NREM and REM) and for posture [off back (AHI-O) and on back (AHI-B)]. The ratio of AHI-O/AHI-B was used to define positional OSA as AHI-O/AHI-B less than or equal to 0.50 (P group) and nonpositional OSA as 0.50 less than AHI-O/AHI-B (NP group). A group of 31 patients who had sufficient sleep time in NREM and REM sleep in both sleep postures was selected. In this group 9 out of 22 subjects who showed positional dependency during NREM sleep became nonpositional during REM sleep (0.05 less than p less than 0.10). The mean effective nasal CPAP level was slightly, but significantly, lower in the P group than in the NP group (8.0 versus 9.1 cm H2O; p less than 0.05). In addition, a correlation between AHI and effective nasal CPAP levels was found (r = 0.491; p = 0.0001). The P group had less supine sleep time (SST) than the NP group (32% versus 45% of total sleep; p less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Airway Resistance↗

PubMed1996

Critical analysis of the results of surgery in the treatment of snoring, upper airway resistance syndrome (UARS), and obstructive sleep apnea (OSA).

Surgery is widely considered to be the first-line therapy for "simple" snoring and moderate sleep apnea syndrome. Surgical treatment of severe obstructive sleep apnea (OSA) is currently generally considered to be second-line therapy after continuous positive airway pressure (CPAP) treatment. Many patients, however, find difficulty in complying with the continued long-term demands of CPAP treatment and seek a more definitive one-off solution to their sleep-related problem. Surgical therapy has been found useful for snoring, at least on subjective grounds; this has incited patient demand and led surgeons to expand its use for upper airway resistance syndrome (UARS) and possibly OSA. In this paper the surgical procedures of uvulopalatopharyngoplasty (UPPP), nasal surgery, and maxillofacial surgery are discussed and analyzed as they relate to the resolution of snoring, UARS, and OSA. There are many methodological problems in the published literature that make this analysis difficult. We feel that surgical therapy should be comparable to CPAP therapy, fulfilling the same analytical criteria in regard to measurement of severity and improvement of the disorder, as well as an equally sustained effect. Operative risk and side effects need to be clearly stated. Guidelines for future data collection and clinical trials of surgical procedures are proposed, and we recommend randomized prospective multicenter protocols and a registry of patients undergoing surgery for OSA so that long-term follow-up can be achieved.

Airway Obstruction↗

PubMed1995

EEG arousal pattern in habitual snorers with and without obstructive sleep apnoea (OSA).

This study evaluated the arousal pattern and sleep fragmentation in the sleep microstructure of heavy snorers and obstructive sleep apnoea (OSA) patients. Fifteen snorers [Group A, (A + H I) </= 10], 15 mild OSA (Group B, A + H I > 10 </= 30] and 15 moderate to severe OSA (Group C, A + H I > 30) were studied retrospectively analysing the number, duration and type of arousals according to scoring rules concerning definition (including delta bursts) and length (from 2 to 60 s) of phasic arousal events. The number of arousals per hour of sleep related to respiratory events was higher in Groups B and C, whilst in Group A there was a number of arousals not related to apnoea or hypopnoea. Daytime sleepiness, present in all three groups and measured by a subjective evaluation, correlated with both the number and EEG type of arousal, but not with the duration. Statistical analysis indicated that arousal index related to apnoea or hypopnoea was the best variable for determining the sleepiness risk in OSA and snorers. Sleep microstructure analysis seems a good scoring method for the detection of sleep fragmentation and arousals in relation to abnormal respiratory events.

Journal Article↗

PubMed2006

Effect of simulated altitude during sleep on moderate-severity OSA.

OBJECTIVE: These studies were conducted to test the hypothesis that isobaric hypoxia would switch OSA to central sleep apnoea (CSA). METHODS: Five adult men (mean age 54.2 +/- 5.5 years, mean BMI 29.9 +/- 6.7 kg/m(2)) with moderate OSA underwent overnight polysomnography at three altitudes. The highest altitude was simulated in a normobaric hypoxic chamber. RESULTS: The obstructive respiratory disturbance index fell from 25.5 +/- 14.4/h at 60 m to 17.3 +/- 9.2/h at 610 m and 0.5 +/- 0.7/h at 2750 m (P = 0.004 compared with 60 m). The central respiratory disturbance index rose from 0.4 +/- 0.5/h at 60 m to 8.1 +/- 5.8/h at 610 m and 78.8 +/- 29.7/h at 2750 m (P < 0.001 compared with 60 m). Mean sleep SaO(2) fell from 94 +/- 1% at 60 m to 93 +/- 1% at 610 m to 85 +/- 4% at 2750 m (P < 0.001 compared with 60 m). CONCLUSION: Moderate severity OSA at sea level (60 m) was completely replaced by severe CSA at a simulated altitude of 2750 m. The authors believe that the OSA resolved because of an increased respiratory drive [corrected] and an increase in upper airway tone, whereas CSA developed because of hypocapnia in non-rapid eye movement sleep.

Analysis of Variance↗