Search PubMed⌕ Search

Biomedical subjects

J C Meurice

Publications and source records attributed to J C Meurice.

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

Influence of correction of flow limitation on continuous positive airway pressure efficiency in sleep apnoea/hypopnoea syndrome.

We evaluated the efficiency of two different treatment procedures with continuous positive airway pressure (CPAP) on sleep, nocturnal breathing characteristics and daytime vigilance in 18 newly diagnosed patients with untreated sleep apnoea/hypopnoea syndrome (SAHS) randomly allocated to two different groups. In group I, the positive pressure (PP) level was set to suppress flow limitation (PFL), while in group II the PP was set at a level that eliminated only apnoea/hypopnoea and snoring (PAHS). At the end of a 3 week period of home CPAP therapy, a follow-up sleep study, vigilance and cognitive tests were made. Overall, PFL was significantly higher than PAHS values (PFL: 10.42.6 cmH2O; PAHS: 8.9+/-2.6 cmH2O; p<0.01, mean+/-SD). We found no difference in sleep quality, nocturnal saturation and apnoea/hypopnoea index, or in daytime vigilance tests between the two groups at the end of the treatment period. However, there was a significantly greater scattering in the changes of sleep latency in group II than in group I. This was associated with a significant difference in the daily duration of nasal CPAP use between the two groups (group I: 7.29+/-0.95 h x day(-1); group II: 6.01+/-0.94 h x day(-1); p=0.01) and with a positive correlation between final maintenance of wakefulness test values and the duration of CPAP use (p<0.05; r=0.55). These results tend to show that correcting flow limitation is associated with a higher observance and a more important efficiency in normalizing daytime vigilance than with conventional nasal continuous positive airway pressure.

Aged↗
PubMed1998

Simultaneous laboratory-based comparison of ResMed Autoset with polysomnography in the diagnosis of sleep apnoea/hypopnoea syndrome.

ResMed Autoset (AS) is a simplified diagnosis system for obstructive sleep apnoea/hypopnoea syndrome (OSAS) based on the respiratory flow/time relationship by pressure variation measured through simple nasal prongs. A multicentre prospective trial was used to compare AS and polysomnography (PSG) for diagnosing 95 patients, with suspected OSAS. Physicians gave a pretest probability of the patient having OSAS. The apnoea/hypopnoea index (AHI) was compared between the two methods of diagnosis for the whole population and for subgroups according to the pretest probability. Twenty-four patients had AHI < 15 events x h(-1) on PSG and 19 AHI 15-30, and 52 patients had AHI > or = 30. Correlation between AHI assessed by AS and PSG was r=0.87 for total sleep time (TST), p<0.0001. A Bland and Altman plot gave an agreement between the two methods of +/-40%. For a threshold of AHI > or = 15 events x h(-1) to diagnose OSAS, AS has a sensitivity of 92%, specificity of 79%, positive predictive value of 93% and negative predictive value of 76%. With a pretest probability > or = 80%, sensitivity and positive predictive value were 98 and 100% respectively. Of six false negative, four had a high pretest probability (> 80%) or Epworth score > or = 10. Using these parameters as a criterion for proceeding to PSG after a negative AS study would mean that two apnoeic patients (AHI 20 and 17 events x h(-1) by PSG) would escape detection. The Autoset is useful for the detection of obstructive sleep apnoea but with high pretest probability and a negative Autoset result polysomnography should be performed.

Adult↗
PubMed1998

Acute Q fever pneumonia: a review of 80 hospitalized patients.

STUDY OBJECTIVES: To emphasize epidemiologic, clinical, or radiologic characteristics whose detection could lead to an early diagnosis and to enhance therapeutic efficacy. PATIENTS: Eighty hospitalized patients from 1982 to 1996. DESIGN: The diagnosis of Q fever infection was serologically confirmed in all the patients (phase II Coxiella burnetii antibody) using the complement fixation test and/or the indirect immunofluorescence antibody test. RESULTS: Patients from rural and urban areas were noted in the same proportion; however, the usual epidemiologic factors such as contact with cats or farm animals were found in 40% of the patients. Mean age+/-SD was 49+/-20 years, and there was a higher sex ratio of male to female patients (1:3.44). We found a specific seasonal distribution since 80% of the cases occurred between February and May. Delay before referring to hospital was 8.2+/-7.8 days, while 69.3% of the patients received an antibiotic treatment that was mainly penicillin or cephalosporin. The dominant clinical features were dry cough and high fever, as the maximal temperature reached more then 40 degrees C in 58% of the patients. Digestive symptoms were rare. WBC count remained within normal range in 80% of the cases with a low proportion of lymphocytes in half of the patients, and the sedimentation rate was usually elevated (55+/-34 mm). Altered liver function consisted more frequently in an elevated level of alkaline phosphatase (70% of the cases) than transaminases, while hyponatremia was frequently mentioned (28.2% of the patients). We found radiologic evidence of unique lobar or segmental alveolar opacity involving more likely the lower lobes in 55 patients, and multiple or interstitial opacities in the others. Chest radiographs were considered normal in eight patients. The clinical response was favorable in all the patients with a reduction in fever 4.8+/-3.9 days after the start of treatment with the second antibiotic that included mainly erythromycin or quinolones, and chest radiographs returned to normal in 81% of the patients within the first month.

Acute Disease↗
PubMed1998

[Desquamative interstitial pneumopathy: a rare form of diffuse interstitial pneumopathy].

Desquamative interstitial pneumonia (PID) is a rare disorder initially described by Liebow in 1965. It is characterised by the presence of an interstitial pneumonia consisting of minimal lesions of interstitial fibrosis and by the accumulation of a rich intraalveolar cellular material principally composed of macrophages. Numerous aetiologies have been found particularly that due to long term Nitrofurantoin. We report the observation of a 57 year old patient, a cigarette smoker, in whom the diagnosis of PID was made after histological examination of a lung biopsy. Based on this observation the pathogenesis and possible different aetiologies of PID are discussed.

Anti-Infective Agents, Urinary↗
PubMed1997

Long-term evolution of daytime somnolence in patients with sleep apnea/hypopnea syndrome treated by continuous positive airway pressure.

We demonstrated in a previous study that excessive daytime sleepiness (EDS) in patients who have sleep apnea/hypopnea syndrome (SAHS) and are undergoing continuous positive airway pressure (CPAP) treatment improved differently in two groups of patients: in group I, multiple sleep latency tests (MSLT) were normalized after 50 days of treatment (individual value > 10 minutes), whereas they remained low (individual value < 10 minutes) in group II, with a significant difference between groups. To evaluate the long-term evolution of daytime somnolence under nasal CPAP treatment, five patients from group I and seven patients from group II underwent a new polysomnography and MSLT 4 years after the previous study. Clinical, polysomnographic and MSLT results obtained at baseline before treatment (T1), after the initial 50-day period of CPAP treatment (T2), and after 4 years (T3) were compared. The significant difference in mean MSLT value between the two groups previously observed at T1 and T2 disappeared at T3 (group I: 12.4+/-5.9 minutes; group II: 9.7+/-5.9 minutes). We found that this long-term improvement in excessive daytime somnolence was independent of the initial MSLT value, the severity of SAHS, and the initial MSLT changes under nasal CPAP. Long-term MSLT evolution was significantly correlated to CPAP compliance. These results demonstrate that even in the absence of a significant increase in MSLT at the beginning of CPAP treatment, further improvement is still possible several years later, which may encourage the regular, long-term use of nasal CPAP by patients.

Aged↗
PubMed1996

Effects of naloxone on upper airway collapsibility in normal sleeping subjects.

BACKGROUND: To evaluate the possible influence of endorphin release on upper airway collapsibility the effects of naloxone, an opiate receptor antagonist, were measured. METHODS: The effects of naloxone on upper airway collapsibility were studied in five normal sleeping men in a pilot study. During a sleep fragmentation night the subjects received either naloxone or a volume matched saline placebo in a double blind crossover design. Critical pressure (Pcrit) was measured during a morning nap following sleep fragmentation. RESULTS: The plasma levels of endorphins increased during sleep fragmentation nights. Pcrit was significantly greater after placebo than after naloxone infusion. CONCLUSIONS: Naloxone may reduce upper airway collapsibility in normal sleeping subjects following sleep fragmentation.

Adult↗
PubMed1996

Effects of mouth opening on upper airway collapsibility in normal sleeping subjects.

We investigated the influence of mouth opening on upper airway (UA) collapsibility in six healthy sleeping volunteers. UA collapsibility was measured during continuous negative airway pressure trials that consisted of the progressive decrease in pressure in a nasal mask, with simultaneous recording of esophageal pressure and instantaneous flow. Measurements were made under two experimental conditions: mouth closed (MC), and mouth open (MO). Cephalometric measurements were obtained with subjects awake in the same position for both experimental conditions. UA critical pressure (Pcrit) was derived from the relationship between the breath-by-breath values of the maximal inspiratory airflow and the corresponding mask pressure. Pcrit was significantly less negative during MO than during MC (MO, -12.7 +/- 4.8 cm H2O; MC, -16.4 +/- 6 cm H2O, mean +/- SD; p = 0.03). Mouth opening was associated with a significant increase in the total respiratory resistance (MO, 3.8 +/- 1.6 cm H2O/ml/s; MC, 3.0 +/- 1.6 cm H2O/ml/s-1, p = 0.03). Besides an increase in the distance between the teeth and a reduction in the distance between the hyoid bone and the mandible, no significant changes in cephalometric parameters were found between MO and MC. We conclude that mouth opening increases UA collapsibility during sleep and that mouth opening may contribute to the occurrence of sleep-related breathing abnormalities.

Adult↗
PubMed1996

Efficacy of auto-CPAP in the treatment of obstructive sleep apnea/hypopnea syndrome.

The auto-CPAP (Morphée Plus) is characterized by its ability to modify the positive-pressure level applied during the night for the presence or absence of sleep-induced respiratory disorders. The aim of the study was to compare the efficacy of this new mode of CPAP therapy with that of conventional constant-CPAP in the treatment of sleep apnea/hypopnea syndrome (SAHS). Sixteen patients with SAHS were randomly allocated to two groups that were paired for age, apnea/hypopnea index, and mean sleep latency. In the auto-CPAP group, the pressure level could change within fixed limits in both directions (+2 to -4 cm H2O) of the previously determined effective pressure level (Peff). In the constant-CPAP group, patients used the same apparatus (Morphée Plus) in a constant mode at Peff level. At the beginning of the study, the Peff level was determined during a polysomnographic recording. Day-time vigilance was measured subjectively by a standardized questionnaire and objectively by the maintenance of wakefulness test (MWT); Trailmaking tests (TMT) were used to evaluate cognitive functions. After 3 wk of home CPAP therapy, a control sleep study was done with the CPAP machine used in the protocol, and daytime vigilance and cognitive function tests were obtained. Baseline sleep and nocturnal breathing disorders characteristics did not differ between the two groups, and daytime vigilance and cognitive function abnormalities were similarily altered. In both groups, the apnea/hypopnea index was within normal range at the final CPAP sleep study. In the auto-CPAP group, 49.3 +/- 14.9% (mean +/- SD) of home treatment time was spent at a pressure < or = Peff. Home amount of use estimated by the number of sleeping hours with a positive pressure applied was 6.5 +/- 1.0 h in the auto-CPAP group and 5.1 +/- 1.1 h in the constant-CPAP group (p = 0.02). During the control CPAP sleep study, the positive pressure level was significantly lower during Stage III-IV than during the other sleep stages (p = 0.004). The improvement in the MWT and the TMT observed with CPAP therapy was identical in both groups. We conclude that (1) the amount of use during CPAP treatment is higher with auto-CPAP than with constant-CPAP, and (2) Morphée+auto-CPAP is an efficient as conventional CPAP in correcting nocturnal breathing disorders, daytime sleepiness, and cognitive impairment in SAHS.

Arousal↗
PubMed1995

Habitual snoring as a risk factor for brain infarction.

The association of habitual snoring with cerebral ischaemia was studied, in a case control-study, in 133 patients aged 45-75 years (103 men and 30 women) and 133 controls matched for sex and age. Ischaemic stroke was confirmed by brain computed tomography or magnetic resonance imaging. History of risk factors, especially of snoring and sleeping habits was recorded with structured questionnaire during interview. Prevalence of habitual snoring significantly differs between patients with stroke and controls: 31/133 (23.3%) vs 11/133 (8.3%) (Odds ratio 3.4, 95% confidence interval 1.5 to 7.6, p < 0.001). Even after adjusting for matching variables and confounding risk factors (arterial hypertension, cardiac arrhythmia, and obesity), habitual snoring carries a significant risk factor for stroke (odds ratio: 2.9, 95% confidence interval 1.3 to 6.8 (p = 0.01)). The risk of ischaemic stroke was higher among older male patients with arterial hypertension who always snored. Habitual snoring was not significantly linked with sleep-related stroke nor with the pathophysiology of strokes. Inquiring about habitual snoring should become a routine practice, especially among older male patients with arterial hypertension, and specific preventive measures should be instituted at an earlier stage.

Adult↗
PubMed1995

Influence of sleep on ventilatory and upper airway response to CO2 in normal subjects and patients with COPD.

In order to investigate the influence of the dynamic changes in upper airway (UA) resistance in the pathophysiology of noctural hypoventilation in COPD, we compared the ventilatory pattern and UA resistance, measured at baseline and during CO2 rebreathing, in nine normal men and 13 patients with COPD. Measurements were made during wakefulness and during non-REM sleep during a morning nap after a sleep deprivation night. Ventilatory parameters (VE, VT, VT/TI) were calculated from flow measurements using a Fleich no. 3 pneumotachograph connected to a fitting nasal mask. Pharyngeal pressure was measured with a low-bias catheter referenced to the mask pressure. Baseline UA resistances (supraglottic resistance: SGR) values were similar in the two groups. They significantly increased in both groups from wakefulness to sleep. Furthermore, VE and VT/TI were higher in patients with COPD than in normal subjects during wakefulness and during sleep. The slope of the VE/PETCO2 relationship was significantly lower in patients with COPD than in normal subjects (p = 0.0001), without any significant decrease between wakefulness and sleep. SGR systematically decreased during CO2 rebreathing in both groups during wakefulness and during sleep. The slope of SGR/PETCO2 relationship was lower in patients with COPD than in control subjects during sleep and during wakefulness (p = 0.005), whereas the decrease in SGR with increased VE and VT/TI was similar in both groups and not influenced by sleep. We conclude that the impediment in UA resistance behavior in response to a hypercapnic stimulus in patients with COPD is related to the decrease in their ventilatory response.

Airway Resistance↗
PubMed1995

[Differences in efficiency of continuous positive pressure respiration on the diurnal somnolence of patients with sleep apnea/hypoapnea syndrome].

Diurnal hypersomnia was studied in sixteen patients suffering from the sleep apnoea/hypopnoea syndrome (SHAS) Group I, and seventeen snorers Group II. The groups were studied in their basal state then after 51 +/- 14 days of continuous positive pressure (CPP) in Group I with the aid of clinical scores and of multiple latency tests of sleeping episodes (TLME). The patients in Group I presented with increased and pathological diurnal somnolence (TLME = 3.9 +/- 2.45 min) associated with disturbances of oxygen saturation during the course of sleep (a significant reduction of the mean SaO2) and of the pattern of sleep (significant reduction in light slow sleep at the expense of deep slow sleep, with a significant increase in the index of brief arousals). We have found a positive correlation between the initial TLME and the mean SaO2 during the course of sleep (p < 0.05; R = 0.51) without any correlation with other polysomnographic parameters. At the time of the final assessment, the improvement in TLME in the patients of Group I was significant (p < 0.001). However, in a sub-group of patients (BR: n = 7) the TLME were returned to normal using CPP (16.4 +/- 2.21 min) while those in patients in the second sub-group (MR: n = 9) the TLME remained below ten minutes on CPP (6.18 +/- 1.88 min). In the BR subgroup which presented with the most elevated mean initial TLME levels the amplitude of the rise of TLME between the two groups was significantly larger. No initial polysomnographic difference existed between the two sub-groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Arousal↗
PubMed1994

Auditory brain-stem responses (ABRs) in sleep respiratory disorders.

Neurophysiological repercussions of sleep respiratory disorders (SRDs) are still unclear. It has been shown that SRDs induce disturbance on auditory event-related potentials with a delayed latency of the cognitive P300 potentials. Since the Auditory Brainstem Responses (ABRs) explore the auditory brainstem structures and are independent on cognition, we evaluated the neurological impact of SDRs on central nervous system by ABRs in these patients. Four groups of patients were studied: snorers (S, 17 subjects), sleep apnoea syndrome (SAS, 48 subjects), apnoeic patients with respiratory insufficiency (SAI, 17 patients) and patients with respiratory insufficiency alone (RI, 12 subjects). A standard polysomnographic study was done in each patient with further quantitative analysis of sleep, respiratory events, and oxygen arterial saturation. ABRs were recorded before the study night and interpeak latencies (IPLs) between waves I, III and V were measured. Results were expressed as the mean of each group for all the different parameters. ABR IPL latencies (IPLI-III, IPLIII-V, IPLI-V) of the four groups were within the normal range. However, comparing groups between themselves, there were significant differences (ANOVA) between groups. Longer IPLIII-V and IPLI-V (which explored the central conduction time) were observed in group SAI compared to group SAS. No evidence on the origin of this elongation was found; the level of hypoxia, in particular, was not related to IPL values. These results show that SAS alone do not affect lower brainstem auditory function, in contrast to the association of SAS and RI.

Adult↗
PubMed1994

Predictive factors of long-term compliance with nasal continuous positive airway pressure treatment in sleep apnea syndrome.

The long-term acceptability of treatment with nasal continuous positive airway pressure (CPAP) was studied prospectively in 44 patients with obstructive sleep apnea syndrome. At 14 months on the average after starting treatment with CPAP, 30 patients (68 percent) were found to be compliant (characterized by use of the apparatus every night throughout the night, for more than 5 h per night). The daily use of nasal CPAP was significantly correlated to the initial apnea/hypopnea index (p = 0.013; r = 0.37), as well as to the percentage of light sleep (p = 0.045; r = 0.30) and slow-wave sleep (p = 0.037; r = -0.31) during the initial polygraphic recording. We found a strong correlation between the daily use of nasal CPAP and the difference in the apnea/hypopnea index (p = 0.025; r = -0.34), the difference in mean oxygen saturation during sleep (p = 0.013; r = 0.38), and the difference in hypersomnia scores (p = 0.006; r = -0.40) obtained before and after treatment by nasal CPAP. Thus, patients used CPAP much more if they had an initial significant clinical handicap and if they were aware of the beneficial effects of CPAP. Under these conditions, patients tended to use the apparatus for the optimal length of time, regardless of the side effects linked to the treatment. This ensured efficacy and the maintenance of good compliance. This study confirms the importance of supervision of the time counter, as well as regular encouragement of patients to use the treatment as long as possible each night, in order to extract a maximum benefit from treatment by nasal CPAP.

Adult↗
PubMed1994

Three-dimensional planar and vector analysis of brainstem auditory evoked potentials as a function of intensity in guinea pig.

Brainstem auditory evoked potentials (BAEPs) have been studied in guinea pigs as a function of intensity by means of the Three-channel Lissajous' trajectory (3-CLT) method. Data were quantified in terms of duration, orientation of planar segments and orientation of equivalent dipoles. The auditory stimulus was a click varying from 48 dB pSPL to 108 dB pSPL by steps of 10 dB pSPL. A semi-automated procedure was used to identify planar segments, by calculating the curvature (apex) and magnitude curves. Dipole analysis was made at the corresponding magnitude peaks and apices. Taking into account a symmetrical orientation of planar segments and equivalent dipoles, similar results were obtained after right and left stimulation. Six planar segments, A, B, C, D, E, F were analysed as were six equivalent dipoles corresponding roughly to P1, N1, P3, N3, P4 and N4 on a vertical lead. There was a parallel latency shift of the first and last point of planar segments as a function of intensity, accounting for the stable duration of a planar segment. Planar segment D (roughly corresponding to N3 on a vertical lead) disappeared as the intensity decreased. Only planar segments C and F and dipole N3 showed a significant change in their orientation. The stable duration of planar segments suggests that intensity coding in the auditory brainstem, in terms of a global function of a system, involved the same number of synapses in a serial circuit while the activated neurons increase in the in parallel circuitry, as the intensity increases. Similar changes in orientation of planar segments C (including P3 of guinea pig BAEPs) and F (including N4 of guinea pig BAEPs) suggest a possible common source with a depolarization followed by a repolarization.

Acoustic Stimulation↗
PubMed1994

[Sacral tuberculous osteitis].

The authors report a case of a 5 year old child suffering from isolated sacral tuberculosis which presented as sudden and total loss of function of the left leg. The rarity of this bony site, and the recurrence at nine months of a presacral abscess after 9 months of anti-tuberculous treatment in an HIV negative child, vaccinated with BCG, justify the presentation of this observation.

Child, Preschool↗