[Alveolar hypoventilation during sleep and domiciliary assisted ventilation]. / Hypoventilation alvéolaire au cours du sommeil et ventilation assistée à domicile.

INTRODUCTION: An alveolar hypoventilation physiologically occurs during sleep and more specifically during REM sleep. STATE OF THE ART: During obstructive chronic respiratory failures, increases in PaCO2 that are associated with REM sleep can participate to the severity of daytime hypercapnia and in a subgroup of patients lead to an indication of nocturnal non-invasive ventilation (NIV) in association with the long-term oxygen therapy. A REM sleep hypoventilation generally appears during the early course of restrictive chronic respiratory failures. This REM sleep hypoventilation represents one of the most frequent reasons for initiating NIV in restrictive respiratory insufficiencies. Obesity-hypoventilation syndrome (OHS) refers to a hypercapnic chronic respiratory failure in which REM sleep hypoventilation is one of the main determinants. In France, in 2004, OHS is the primary chronic respiratory failure leading to at home NIV. NIV on OHS aims to maintain upper airway patency as sleep apnoea is frequently associated and to allow sufficient alveolar ventilation during REM sleep. PERSPECTIVES: Thus, sleep alveolar hypoventilation should be systematically assessed in obese patients and during the time curse evolution of all the chronic respiratory failures. This can be done relatively easily by using nocturnal oximetry concurrently with a transcutaneous PCO2 measurement. CONCLUSION: The understanding of exact mechanisms underlying abnormal respiratory events occurring during sleep allows optimising adjustments in NIV parameters.

Awake flow limitation with negative expiratory pressure in sleep disordered breathing.

BACKGROUND AND PURPOSE: Although upper airway collapsibility (UAC) is theoretically useful to anticipate severity of sleep-disordered breathing (SDB), inspiratory UAC measurements are poorly correlated with obstructive sleep apnea (OSA) severity. PATIENTS AND METHODS: We investigated in 15 healthy and 35 SDB awake subjects whether negative expiratory pressure (NEP) could be a technique which would allow us to anticipate SDB severity. We characterized in these subjects, both in supine and sitting position, at -5 and -10 cm H(2)O, the flow-volume curves and a new NEP quantitative index (ratio of the 'areas under the curve' of NEP flow-volume loop vs. spontaneous flow-volume loop). RESULTS: Abnormal flow-volume curves were significantly more frequent in patients with SDB than in healthy subjects, for both negative pressures in sitting posture and -10 cm H(2)O in supine position. The quantitative index decreased with the severity of SDB, independently of confounding factors (age, body mass index (BMI) and expiratory reserve volume (ERV)). In the supine position, at -5 and -10 cm H(2)O, thresholds of less than 160 and 180% respectively identified in 96.6% of SDB, whereas thresholds of greater than 160 and 180% were adequately classified in 76.9% of controls. CONCLUSIONS: NEP flow-volume curves and quantitative index during wakefulness are useful methods to detect UAC. These results, however, should be confirmed by a prospective study in the general population.

[Metastasis stimulating a myocardial infarction]. / Métastase simulant un infarctus du myocarde.

A patient with a history of bronchial carcinoma was admitted to the coronary care unit with chest pain suggestive of infarction and an ECG showing changes compatible with acute lateral wall infarction. The coronary arteries were shown to be normal and echocardiography revealed an intracardiac mass which MRI confirmed to be a direct extension of the pulmonary tumour. Echocardiography should be performed systematically in patients with chest pain and ECG changes of ischaemia who also have progressive oncological disease.

[Tools available for the diagnosis of obstructive sleep apnea syndrome. Measurements for the evaluation of therapeutic efficacy]. / Outils disponibles pour le diagnostic du syndrome d'apnées du sommeil. Conséquences pour l'évaluation de l'efficacité thérapeutique.

Obstructive sleep apnea syndrome (OSAS) is characterized by the development of repeated episodes of pharyngeal collapse. Respiratory movements attempt to reopen the closed pharynx leading to resumption of ventilation associated with micro-arousals. Three kinds of measurements are needed to establish the diagnosis of OSAS: airflow (reduction or complete interruption), respiratory effort in response to increased airway resistance, micro-arousals associated with the end of the respiratory event. Classically, polysomnography was used to establish sleep architecture using electroencephalography, electromyography and electro-oculography. Air flow was measured by thermistors, chest and abdominal movements and oximetry were monitored. Other more accessible methods can also be used to establish reliable diagnosis. Measuring pulse transit time using ECG and oximeter sensors provide a semi-quantitative measurement of respiratory effort. Likewise, cardiovascular markers (heart rate, blood pressure, pulse time) can be used instead of electroencephalography to establish the arousal pattern. Cardiovascular markers are as sensitive and probably as specific as EEG for identifying micro-arousals. Measuring nasal pressure provides a much less invasive quantitative assessment of airflow than pneumotachography. The shape of the inspiratory signal is also an indirect marker of respiratory effort. These new tools can be used to characterize the three elementary abnormalities observed in OSAS: variations in airflow, increased respiratory effort, fragmented sleep, using a very simplified setting compared with classical techniques. Therapeutic monitoring of OSAS patients, particularly after surgery, should not be limited to physical examination known to lack sufficient sensitivity. It should also include simplified methods or complete polysomnography to obtain a precise measurement of residual respiratory events and sleep pattern after treatment.

[Surgery and obstructive sleep apnea syndrome: indications and precautions]. / Chirurgie et syndrome d'apnées obstructives du sommeil: indications et précautions.

Surgery has long been a therapeutic option for obstructive sleep apnea syndrome (OSAS). The first procedures targeted the soft palate but results of isolated uvulo-palatopharyngoplasty (UPPP) were inconstant. A better understanding of the mechanisms involved in pharyngeal collapse incited interest in the role of the tongue and the retropharyngeal space. Surgical procedures were then developed for this level of the upper airways. There are a large number of possibilities. Excepting tracheostomy which court-circuits the collapsed zone, all the other procedures are designed to widen more or less one or more of the upper airway levels. The target can be the nose, the soft palate or the tongue, alone or in combinations. In all cases, the surgical alternative should be balanced against a non-invasive option: continuous positive pressure ventilation. The objective is to minimize the operative risks and sequelae while assuring success equivalent to positive pressure ventilation. It is important to note that sufficiently effective and permanent results have not been proven for any surgical technique, excepting tracheostomy and to a lesser degree bimaxillary advancement osteotomy, due to the lack of objective long-term rigorous evaluation. A considerable effort must be made in this domain.

Thoracic lymphangiectasis presenting with chyloptysis and bronchial cast expectoration.

A 70-year-old man with recurrent undiagnosed episodes of bronchial cast expectoration and pulmonary infiltrates on chest radiography for 15 years is described. The diagnosis of chyloptysis was established by chemical analysis of the bronchial aspiration. We emphasize the radiological findings of this rare observation. The CT-associated lymphangiography showed mediastinal lymphangiectasis with retrograde opacification of mediastinal and hilar lymph nodes as well as submucosal lymphatic vessels protruding into the lumen of the tracheo-bronchial tree without evidence of thoracic duct obstruction as well as a "crazy-paving appearance." Congenital incompetence of the valves of the lymphatic vessels originating from the thoracic duct is held to be the cause. Chyloptysis and pulmonary lymphatic disorder should be sought in cases of bronchial cast expectoration.

Sleep apnoea and Turner's syndrome.

A 32-yr-old female with Turner's syndrome and anatomical craniofacial abnormalities, presented with obstructive sleep apnoea syndrome. This was initially treated by nasal continuous positive airway pressure and secondarily cured by maxillomandibullar advancement osteotomy. Anatomical upper airway abnormalities and hormonal factors, which predispose Turner patients to develop obstructive sleep apnoea syndrome, are discussed. A systematic assessment and treatment of sleep-disordered breathing is probably of interest in these patients.

[Thoracic empyema in very old patients: two types of clinical presentation]. / Empyème pleural chez le sujet âgé: deux types de présentation clinique.

INTRODUCTION: Primitive thoracic empyema or empyema secondary to pneumonia represents a significant medical problem necessitating prolonged hospitalizations and increasing the rates of morbidity and mortality. Average patient age is 55 years and remains rare in very old patients (> 85). We report here two observations in very old patients, pointing out the diversity of the clinical presentation. EXEGESIS: Empyema thoracis is classically associated with underlying diseases. It is often polymicrobial but Gram-positive bacteria and anaerobes are more frequent than Gram-negative bacteria. The clinical presentation may be aspecific without any parameters in favor of infectious disease: the rapidity of pleural drainage and antibiotic therapy are the main prognostic factors. CONCLUSION: Because of the diversity of clinical presentation in the elderly population, and because of the efficiency of rapid treatment, geriatric physicians should perform an examination of pleural fluid when pleural effusion is unknown.

Hunter's syndrome and associated sleep apnoea cured by CPAP and surgery.

A 42-yr-old male with Hunter's syndrome presented with severe obstructive sleep apnoea syndrome (OSAS) and daytime respiratory failure. Continuous positive airway pressure (CPAP) therapy was initially ineffective and produced acute respiratory distress. Extensive Hunter's disease infiltration of the upper airway with a myxoma was confirmed. Following surgery to remove the myxoma at the level of the vocal cords, CPAP therapy was highly effective and well tolerated. This report demonstrates the necessity of evaluating fully the upper airway in patients with unusual variants of OSAS, particularly where the disease is not adequately controlled by CPAP.

[Acute eosinophilic pneumonia due to hypersensitivity to carbamazepine]. / Poumon éosinophile aigu révélateur d'un syndrome d'hypersensibilité à la carbamazépine.

The authors report a case of hypersensitivity to carbamazepine presenting as an acute eosinophilic pneumonia and a probable hypersensitivity myopericarditis in a 54-year-old patient treated with carbamazepine for three weeks. Treatment consisted of stopping the carbamazepine and in prolonged corticosteroid therapy. The features of the hypersensitivity syndrome to carbamazepine are mentioned as well as the different pulmonary disorders attributable to carbamazepine.