VA/Q ratios distribution and oral almitrine bismesylate in COPD patients under mechanical ventilation: preliminary results.
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Almitrine↗
Biomedical subjects
Y Castaing
Publications and source records attributed to Y Castaing.
Ultrastructural study of peripheral nerve in Guillain-Barré syndrome presence of mononuclear cells in axons.
As has been shown during the course of experimental allergic neuritis, in the Guillain-Barré syndrome there is an invasion of the myelin sheath in certain fibres by a mononuclear cell, with an intact axon. In a series of 45 cases we have been able to show this feature in 31 cases. In certain cases the cytoplasm prolongation of the invading cell was seen in the myelin sheath, forcing apart two neighbouring layers. In five cases we have furthermore observed the presence of mononuclear cells located either between the myelin and the axon which is deformed, or on the inside of the axon. Such an anomaly was frequent in one recent case and was occasionally found in four other cases.
Axons↗
[Acute adrenal insufficiency due to bilateral adrenal hematoma following severe thrombopenia induced by low-molecular-weight heparin].
BACKGROUND: Bilateral adrenal hematoma is an uncommon cause of acute adrenal insufficiency. An association with thrombopenia induced by low-molecular-weight heparin even more so. Diagnosis is difficult as the clinical manifestations mimic septic shock. CASE REPORT: A 63-year-old woman developed acute adrenal insufficiency due to bilateral adrenal hematoma following severe thrombopenia induced by low-molecular-weight heparin prescribed after an orthopedic operation. Outcome was favorable. CONCLUSION: Acute adrenal insufficiency must be entertained as a possible diagnosis in patients with heparin-induced thrombopenia.
Acute Disease↗
[A multicenter trial of a device for treating obstructive sleep apnea by continuous positive pressure].
The efficacy and tolerance of a nasal CPAP device marketed in France (Pression +, Sefam) for the treatment of obstructive sleep apnoea syndromes have been evaluated in a co-operative trial including 12 patients. This study confirmed the efficacy of nasal CPAP on sleep parameters: total sleep time was increased; light non-REM sleep was diminished; slow-wave sleep and REM sleep were augmented; sleep apnoeas were eliminated completely or almost completely; oxygen saturation was markedly improved. At one month follow-up, most clinical features were improved; daytime blood gases showed little change but the number of red cells was decreased. On the whole, the tolerance was good in this highly motivated group of patients: eleven patients (92%) were willing to continue their home treatment with the same device. Most difficulties were due to the making of a tailored molded nasal mask and its use during sleep.
Adolescent↗
Guillain-Barré syndrome: an ultrastructural study of peripheral nerve in 65 patients.
65 biopsies of peripheral nerve from patients suffering from Guillain-Barré syndrome were studied by electron microscopy. In 48 cases there was macrophagic invasion of the Schwann cells of certain myelinated fibers, and in 32 of these cases some myelin sheaths were stripped away by an elongated macrophagic process. Vesicular disruption of the myelin sheath was observed in only 8 cases and in less than 1% of the myelinated fibers. Uncompacted myelin lamellae were observed in a few myelinated fibers. These ultrastructural lesions are analysed and commented on with a view to selecting patients who are to undergo plasma exchange.
Biopsy↗
Effect of 26% oxygen breathing on ventilation and perfusion distribution in patients with cold.
Fourteen patients suffering from severe but stable chronic airway obstruction were studied while breathing room air and mildly hyperoxic mixture (26%). The data were collected at the end of each 30 min randomized breathing period. The multiple inert gas elimination technique was used to detect alterations in ventilation-perfusion (VA/Q) mismatching. Ventilatory, arterial and mixed venous blood gases, and hemodynamic measurements were made simultaneously. To show a possible effect of O2 on hypoxic pulmonary vasoconstriction (HPV), the fractional part of cardiac output perfusing low VA/Q areas was separated using as upper limit of VA/Q the compartments with PAO2 70, 60 and 50 mmHg while breathing oxygen, compared to the percentage of blood flow in the same areas limited by the same VA/Q unit in air breathing conditions. Only a few changes due to O2 are statistically significant: 1) a rise in PaO2 (+20.2 +/- 8.3 mmHg) and PvO2 (+4.2 +/- 2.18 mmHg) without any change in ventilation, respiratory frequency, pH, PaCO2, haemodynamics and overall criterion of distribution; 2) a moderate increase in inert gas dead space; 3) an increase in the percentage of blood flow under the limit when chosen at 50 mmHg (+3 +/- 2.8%). This change could be related to an inhibition of HPV response while breathing O2 in compartments previously placed above the limit in air. Consequently, their VA/Q decrease and their perfusions are summed with those under the limit in O2. These data suggest that mild hyperoxia has a slight but real deleterious effect on pulmonary gas exchange.
Aged↗
[Problems raised by the technique and supervision of home ventilation of chronic respiratory insufficient patients (author's transl)].
The effectiveness of assisted ventilation at home, especially in the case of tracheostomized patients, has been nearly established at the present time. The experience of various centers in France, having or not the support of an independent structured organization, shows that the setting-up and supervision of such therapy can be effectively carried out. Nevertheless, difficult choices remain. Some indications are still questionable, such as the choice of the respirator if the patient has not been tracheostomized. The type of organization is not univocal and could perhaps depend on the number of patients to be cared for. In any case, in the years to come, the experience of the different teams and the technical progress made will lead to a solution to the problems raised: a decrease in the number of hospitalizations and more comfort for the patients can be hoped for.
Home Nursing↗
[Reversible acute hepatic failure after treatment with association of isoniazide-rifampicin (author's transl)].
One case of severe acute hepatic failure happening after surgical treatment of large tuberculous ureteral stenosis is reported. The etiology was the association of isoniazide-rifampicin; the clinical, biological and histological data of these hepatitis cases are specified; their physiopathology, as well as their treatment is studied; prevention by plasmatic evaluation of isoniazide is especially important.
Acute Disease↗
[Inert gas study of heliox gas exchange in patients with COPD].
Ventilation and perfusion distributions were measured in the patients with COPD breathing room air and normoxic helium-oxygen mixture (heliox) successively, using the multiple inert gas method. The D (A-a) O2 were calculated from ideal alveolar gas (Ai) and with West's gas mean model (A). Measured PaO2 and predicted PaO2 were compared during room air and heliox breathing. There were no change in overall distributions and in D (Ai-a) while D (A-a) O2 increase significantly during heliox breathing and the predicted PaO2 were significantly higher than the measured PaO2. Heliox breathing does not seem to change parallel heterogeneity in COPD. These results suggest an impairment of series heterogeneity and O2 diffusion during heliox breathing.
Helium↗
[Toxoplasma encephalitis in acquired immunodeficiency syndrome].
Several outbreaks of fatal opportunistic infections and tumors have recently been reported among homosexual men in the United States. Almost all patients had evidence of cellular immunodeficiency. We have studied a French homosexual man with fatal central nervous system toxoplasmosis. Morphological features (light and electron microscopy) of toxoplasma encephalitis are described.
Acquired Immunodeficiency Syndrome↗
[Pulmonary edema in pulmonary embolism].
We report a case of severe pulmonary embolism in a 37 years old man admitted to the intensive care unit for severe acute respiratory failure. The presenting signs and symptoms were typical for severe pulmonary oedema. Chest radiograph shortly after admission showed local alveolar shadows. In the absence of sepsis, haemodynamic evidence of left ventricular failure on catheterization of the right heart and because of the history of the recent illness, a tentative diagnosis of pulmonary embolism was made. The diagnosis was confirmed by selective pulmonary angiography. The latter demonstrated that pulmonary oedema had been localized only in areas with patent pulmonary arteries and, in addition, confirmed that left ventricular function was normal. Such a pattern of local pulmonary oedema is uncommon in patients and is reminiscent of that observed in animal experiments with severe pulmonary arterial obstruction and overperfusion of unblocked territories. Possible mechanisms of overperfusion oedema are discussed and the hypothesis that humoral factors may increase the permeability of pulmonary microvasculature in cases of severe pulmonary embolism is put forward.
Adult↗
[Effects of oral almitrine on the distribution of VA/Q ratio in chronic obstructive lung diseases (author's transl)].
A double blind study of effects of a low dose of almitrine has been performed in patients with severe chronic obstructive lung diseases. Besides hemodynamic and ventilation data, ventilation-perfusion ratio distribution was measured by the inert gas method in order to try to explain the improvement in blood gases caused by this drug. At the dose of 1.5 mg/kg almitrine produces : 1) an increase in ventilation and PaO2, 2) no change in pulmonary vascular resistances compared to a rise on placebo, 3) a drop of 4% in the percentage of cardiac output perfusing low VA/Q lung units with a concomitant increase in lung units with VA/Q ratio between 0.1 and 10, and 4) no significant change in the distribution of ventilation. The change in the distribution of blood flow is one of the causes of the rise in PaO2, but its mechanism is at yet not clear. The present results suggest arterial vasoconstriction in units with very low VA/Q accompanied by diversion of blood flow towards lung units with higher VA/Q ratio.
Aged↗
[Acute corrosive esophagitis].
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Acute Disease↗