PubMed Health⌕ Search

Biomedical subjects

W De Backer

Publications and source records attributed to W De Backer.

At least 37 records · Page 2Linked to original sources
PubMed1998

Non-CPAP treatment of obstructive sleep apnoea.

Obstructive sleep apnoea is a frequently occurring disease that can have important consequences including disabling hypersomnolence and sleepiness as well as cardiovascular diseases like hypertension. Treatment modalities are, however, limited. The efficacy of nasal continuous positive airway pressure (CPAP) stands out, but not all patients can tolerate this treatment or be compliant with it. Efficacious alternative therapies are still remarkably few in number. It is demonstrated and concluded that only patients with mild forms of the disease can currently be considered for non-CPAP treatments. Patients with predominantly breathing pattern abnormalities can be cured with medical therapy. Those with predominantly upper airway collapse and with mildly elevated critical closing pressure can be treated with surgical procedures such as uvulopalatopharyngoplasty (UPPP). The exact indications for electrical stimulation of the hypoglossal nerve are still to be determined, although preliminary results seem to be promising for well-selected patients.

Electric Stimulation Therapy↗
PubMed1997

Assessment of respiratory effort by means of strain gauges and esophageal pressure swings: a comparative study.

We characterized apneas by a quantitative method (esophageal pressure measurements) and by a qualitative method (strain gauges) at the same time in 22 patients with sleep-related breathing disorders. Detection of respiratory effort by strain gauges significantly overestimated the total number of central apneas in each patient. Despite this overestimation, none of the patients was wrongly diagnosed as having pure central sleep apnea syndrome. Strain gauges are sufficiently reliable for the characterization of apneas in most patients. When strain gauges reveal that most apneas are central in origin, verification by esophageal pressure measurements is recommended.

Body Mass Index↗
PubMed1997

Influence of uvulopalatopharyngoplasty on alpha-EEG arousals in nonapnoeic snorers.

Arousals are more numerous in heavy snorers than in nonsnorers and might be a cause of excessive daytime sleepiness (EDS) in these patients. The present study investigated whether treatment of snoring by uvulopalatopharyngoplasty (UPPP) had an influence on sleep microstructure in nonapnoeic snorers. The polysomnographic records of 10 nonapnoeic snorers were reviewed retrospectively and arousals scored according to the American Sleep Disorders Association (ASDA) 3 s definition. Scores for snoring, EDS and polysomnographic data were compared before and after UPPP (mean (+/-SD) time interval 249 +/- 183 days). UPPP resulted in a subjective improvement of snoring and a significant decrease in the arousal index (mean 14.6, 95% confidence interval (95% CI) 8.5-20.8 vs mean 9.1, 95% CI 6.6-11.5) (p = 0.01). EDS and the amount of slow-wave sleep remained unchanged. Uvulopalatopharyngoplasty resulted in an improvement of subjective snoring and a significant decrease of arousals in nonapnoeic snorers. Although these data do not provide any insight into whether the improvement observed can be maintained on a long-term basis, uvulopalatopharyngoplasty can be considered as a useful treatment modality to reduce sleep fragmentation and snoring in nonapnoeic snorers.

Adult↗
PubMed1996

High levels of leukaemia inhibitory factor in ARDS.

Although elevated concentrations of a few cytokines have been shown to be present in the bronchoalveolar lavage (BAL) fluid (BALF) of patients with the acute (adult) respiratory distress syndrome (ARDS), the pathogenesis of ARDS is largely unknown. Leukaemia inhibitory factor (LIF), a growth factor recently recognised as a polyfunctional cytokine integrated in cytokine networks was measured in unconcentrated BALF of patients from different patient groups. LIF was measured in BALF by means of a specific and sensitive ELISA (detection limit 10 pg/ml) in BALF (lavage of 3 x 50 ml in the right middle lobe). LIF was not detected in the BALF of 13 healthy control patients and in only one (34 pg/ml) out of 25 patients at risk for ARDS (after cardiopulmonary bypass surgery) who underwent BAL 4 h after the end of the extracorporeal circulation. High and detectable levels were found in the unconcentrated BALF of 10 out of 12 patients with full-blown ARDS (212 +/- 116, mean +/- SEM, range 10-985 pg/ml). There was a good correlation between the level of LIF in the BALF and a number of markers of inflammation such as neutrophils/ml, albumin and protein levels. The biological role of LIF in these BALFs is not readily explained by its currently known actions and it is unknown whether LIF contributes to or is a response to local tissue damage. Our results indicate that this cytokine is part of the inflammatory cytokine cascade in ARDS.

Adult↗
PubMed1996

Increased prevalence of sleep disturbances and daytime sleepiness in subjects with bronchial asthma: a population study of young adults in three European countries.

The aim of this study was to investigate whether asthma is associated with decreased quality of sleep and increased daytime sleepiness. The study involved a random population of 2,202 subjects supplemented by 459 subjects with suspected asthma, aged 20-45 yrs. The subjects were from Reykjavik (Iceland), Uppsala and Göteborg (Sweden) and Antwerp (Belgium), and participated in the European Community Respiratory Health Survey. The investigation included a structured interview, methacholine challenge, skinprick tests and a questionnaire on sleep disturbances. Participants in Iceland and Sweden also estimated their sleep times and made peak expiratory flow (PEF) recordings during a period of 1 week. Asthma was defined as self-reported physician-diagnosed asthma with current asthma-related symptoms (n = 267). Difficulties inducing sleep (DIS) and early morning awakenings (EMA) were about twice as common, and daytime sleepiness 50% more common, in asthmatics compared with subjects without asthma. After adjusting for possible confounders, a positive association was found between asthma and: DIS (odds ratio (OR) = 1.8); EMA (OR = 2.0); daytime sleepiness (OR = 1.6); snoring (OR = 1.7); and self reported apnoeas (OR = 3.7). Allergic rhinitis, which was reported by 71% of subjects with asthma, was independently related to DIS (OR = 2.0) and daytime sleepiness (OR = 1.3). A significant correlation was found between the number of asthma-related symptoms and sleep disturbances (p < 0.001). Asthma is associated with decreased subjective quality of sleep and increased daytime sleepiness. Concurrent allergic rhinitis may be an important underlying cause of sleep impairment in asthmatic patients.

Adult↗
PubMed1995

Chronic CO2 drive in patients with obstructive sleep apnea and effect of CPAP.

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.

Adult↗
PubMed1995

Daytime sleepiness, snoring and gastro-oesophageal reflux amongst young adults in three European countries.

OBJECTIVES: To study the geographical variation in daytime sleepiness, snoring and disrupted breathing during sleep and to identify and compare risk factors using the same method in four European cities. DESIGN: A cross-sectional, multicentre epidemiological survey. SETTING: Reykjavik in Iceland, Uppsala and Göteborg in Sweden and Antwerp in Belgium. PARTICIPANTS: A random population sample of 2202 subjects who participated in the European Community Respiratory Health Survey. MAIN OUTCOME MEASURES: Sleep disturbances and daytime symptoms. RESULTS: At all the centres, 5% of the men and 2-3% of the women reported snoring every night. Daytime sleepiness (DS) was more often reported in Uppsala [odds ratio (OR) and 95% confidence interval: 1.6 (1.2-2.1)] than in the other centres, whilst daytime tiredness (DT) was most common in Reykjavik [ OR 1.8 (1.4-2.1)]. Snoring was positively correlated with age, male gender and body-mass index in all areas. Symptoms of gastro-oesophageal reflux were associated with DS: OR 2.6 (1.5 4.4) and DT: OR 4.5 (2.7-7.6) and disrupted breathing: OR 3.8 (1.4-10). DS and DT were reported more often by women than by men. CONCLUSION: The prevalence of snoring was about the same in all four areas, whilst there was a geographical variation in daytime sleepiness and tiredness. As complaints of DS and DT and disrupted breathing were more common in subjects who reported symptoms of gastro-oesophageal reflux, we suggest that polysomnographic studies comparing sleep patterns in adult patients with and without reflux should be conducted.

Adult↗
PubMed1995

Obstructive sleep hypopnea syndrome in a patient with Marfan syndrome treated with oxygen therapy.

A patient with Marfan's syndrome and obstructive sleep hypopnea syndrome is reported. She had complained about insomnia, tiredness and hypersomnolence lasting 2 years. A complete nightly polysomnography revealed 94 obstructive hypopneas (the hypopnea index was 12.85) and no obstructive apneas. Presumably an increased laxity of the pharyngeal wall was responsible for the phenomenon. A therapy with CPAP was started, but was not tolerated by the patient. Oxygen therapy on the other hand turned out to be effective and well tolerated.

Adult↗
PubMed1995

Sleep related breathing disorders: the respiratory control system and its instability during sleep.

Respiratory control and instability in the breathing pattern during sleep. Unstable breathing during sleep plays an important role in the development of sleep related breathing disorders (SRBD). Periodic breathing, as a hallmark of this instability, is a common initiator of these disorders. In addition, structure and function of the upper airway are prone to intrinsic and extrinsic, congenital and acquired abnormalities which are as well responsible for the pathogenesis of SRBD.

Body Mass Index↗
PubMed1995

Prevalence of sleep disturbances among young adults in three European countries.

The aim of this investigation was to study the geographic variation in sleep complaints and to identify risk factors for sleep disturbances in three European countries: Iceland (Reykjavik), Sweden (Uppsala and Göteborg) and Belgium (Antwerp). The study involved a random population of 2,202 subjects (age 20-45 years) who participated in the European Community Respiratory Health Survey. The subjects answered a questionnaire on sleep disturbances. Participants in Iceland and Sweden also estimated their sleep habits and sleep times during a period of 1 week in a sleep diary. Habitual (> or = 3/week) difficulties inducing sleep (DIS) were reported by 6-9% and early morning awakenings by 5-6% of the subjects. The estimated number of awakenings and the prevalence of nightmares was significantly lower in Reykjavik. Participants in Reykjavik went to bed at night and woke in the morning approximately 1 hour later than participants at the Swedish centers (p < 0.001). Symptoms of gastroesophageal reflux (GER) were associated with DIS (odds ratio [OR] = 2.7), nightmares (OR = 4.4), longer sleep latency and frequent nocturnal awakenings. Smoking correlated positively to DIS (OR = 1.8) and estimated sleep latency. We conclude that the prevalence of DIS was fairly similar at these four European centers but that there was a variation in the prevalence of nightmares and nocturnal awakenings. The significant correlation between reported GER and subjective quality of sleep should be followed up in studies using objective measurements.

Adult↗
PubMed1994

Functional residual capacity and total respiratory system impedance in wheezing infants.

Airways obstruction has been demonstrated in acutely wheezing infants. The aim of the present study was to assess functional abnormalities as detected by measurement of total respiratory system resistance (Rrs) and functional residual capacity (FRC) in infants with a history of recurrent episodes of wheezing, while not acutely ill. In 30 such infants (mean age, 10 months; range, 4-17) and in 10 healthy infants (mean age, 6 months; range, 0-14) four Rrs measurements, performed with the forced pseudo-random noise (PRN) oscillation technique, and three FRC determinations, using the closed-circuit helium dilution technique, were averaged. A lower than predicted FRC was demonstrated in 20/30 (66%) patients. At 16 Hz, Rrs was significantly above predicted in 3/30 (10%) patients. Specific Rrs (Rrs x FRC) at 16 Hz was increased in 5/30 (17%) patients. In conclusion, the PRN oscillation technique combined with FRC measurement by helium dilution detects lung function abnormalities in a minority of wheezing infants during symptom-free intervals.

Airway Resistance↗
PubMed1994

[The usefulness of an alternative EEG scoring system in obstructive sleep apnea].

Careful analysis of the EEG in obstructive sleep apnea (OSA) patients according to the Rechtschaffen and Kales (R & K) criteria indicates that obstructive apneas (OA) are more frequently observed during stage 1 and 2 sleep than during slow wave sleep. However it is also obvious that OA can be recognised during R & K wakefulness stage (St W). The purpose of the present study was to see whether further partition of R & K St W could define a wakefulness stage during which no apneas occur. Ten patients with predominantly OSA were studied (OA-Index 20 +/- 5). Patients EEG were scored according to classic R & K and to modified criteria which further divided R & K St W. Three additional stages were defined (STW-a, STW-b, STW-c). The partitioning of STW of R & K allowed us to define a W-stage (STW-a) during which no apneas occur, and to identify alpha (STW-b) and drowsiness (STW-c) during which OA occur frequently.

Adult↗
PubMed1993

Interleukin-8 production in patients undergoing cardiopulmonary bypass. The influence of pretreatment with methylprednisolone.

Pulmonary dysfunction caused by pulmonary neutrophil sequestration is a frequent postoperative complication in patients undergoing cardiopulmonary bypass (CPB) surgery. It is yet unclear whether treatment with corticosteroids in vivo in these patients can prevent complement-mediated neutrophil activation and sequestration in the lungs. Therefore, we conducted a prospective study in order to investigate whether methylprednisolone (MP) pretreatment (30 mg/kg) could influence the appearance of IL-8 (a recently discovered cytokine with potent neutrophil-chemotactic activity) in the peripheral circulation. We also studied the effects of MP pretreatment on the inflammatory parameters in the bronchoalveolar lavage (BAL) fluid 4 h postoperatively. Although peripheral neutropenia and the rise in IL-8 serum levels was less pronounced in MP-treated than in non-steroid-treated patients, there was no significant difference in albumin, total protein, concentrations of IL-8 and C3a, and the number of neutrophils in the BAL fluid between the two groups. However, when cultured in vitro, alveolar macrophages from patients treated with MP released significantly lower IL-8, both in basal conditions and after stimulation with lipopolysaccharide. Our results show that MP does not prevent (IL-8-mediated) pulmonary neutrophil infiltration after CPB, although it might affect certain aspects of the microvascular lung injury.

Aged↗
PubMed1992

Interleukin 8 (IL-8) in the bronchoalveolar lavage fluid from patients with the adult respiratory distress syndrome (ARDS) and patients at risk for ARDS.

A sensitive and specific radioimmunoassay was used to measure interleukin 8 (IL-8) in bronchoalveolar lavage fluids from control subjects, patients with the adult respiratory distress syndrome (ARDS) and patients undergoing coronary bypass surgery, a risk factor for developing ARDS. Concentrations of IL-8, albumin, total protein and numbers of neutrophils were higher in both patient groups than in controls. Levels of IL-8 were significantly correlated with the influx of neutrophils, plasma protein extravasation and with the PaO2/FiO2 ratio. These data suggest that IL-8 may mediate the recruitment of neutrophils from the vascular compartment into the alveolar space and may therefore be an important determinant in neutrophil-mediated lung injury. Since increased levels of IL-8 were also found in BAL fluid from patients at risk in whom ARDS did not develop, other factors are likely to be involved and IL-8, as well as other markers of inflammation, are of little prognostic use.

Adult↗