Biomedical subjects
Publications and source records attributed to J C Chevrolet.
We report a patient who presented with an association between propylthiouracil treatment and recurrent episodes of an adult respiratory distress-like syndrome (ARDS). The bouts of ARDS were associated with a generalized reaction suggestive of systemic lupus erythematosus (SLE), responsive to corticosteroid therapy.
The relationship between the organism's oxygen consumption (VO2) and its transport to the cells (DO2), termed the DO2/VO2 relationship, has been the subject of many publications during the past decade. The pathological changes occurring in this relationship in intensive care patients has been much studied, and certain conclusions drawn with regard to monitoring and therapeutic goals. After a brief review of the pathophysiological mechanisms involved we examine the practical implications of the DO2/VO2 concept, focusing on the many methodological and interpretation problems raised.
Methylxanthines are at present widely prescribed for obstructive airway-diseases. However, the exact therapeutic role of these drugs is not clear in 1990. In this short review, we discuss what we think to be a rational use of xanthines in asthma and in COPD patients: shortly speaking, we propose that the drugs are not first-line therapeutic tools and should be only prescribed in selected situations.
Epileptic seizures may be rapidly followed by neurologic pulmonary edema (NPE). While the outcome of respiratory failure may be spontaneously favourable, in some cases death may occur due to respiratory and/or neurologic dysfunction. Two patients with NPE are described, one of whom survived without treatment and is in good health. In the other the outcome was rapidly fatal despite prompt and vigorous medical treatment.
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Difficult weaning is fortunately a rare occurrence in mechanically ventilated patients in ICU. When faced with this problem, a vast number of factors must be carefully considered simultaneously: physiological adjustment, technical problems (tubing, circuit resistances, . . .) [13]. The most promising approach to difficult weaning to date centers on the respiratory muscle function which represents the most common factor allowing weaning success or failure.
A patient with hypertrophic cardiomyopathy developed unilateral right sided pulmonary oedema. Pulmonary angiography showed a proximal severe narrowing of the left pulmonary artery.
Tetanus is now rare in industrialized countries, occurring mainly in elderly patients. To assess whether aggressive therapy of these patients in the intensive care unit is justified, we retrospectively studied all patients with tetanus hospitalized in our institution between 1968 and 1989. Patients over the age of 70 years fared as well as those under 70 years and recovered without sequelae. These results favor aggressive treatment of elderly patients with tetanus in the intensive care unit.
The differential diagnosis of lung cavitations is very broad. We report a case of Pneumocystis carinii pneumonia (PCP) with lung cavitations on the chest X-ray in a patient with the acquired immunodeficiency syndrome (AIDS). We discuss the differential diagnosis of such an X-ray pattern and emphasize that multiple cavitations can be a roentgenographic presentation of PCP.
We report the clinical and pathological findings in a young female patient who was a chronic drug addict for over eight years. In 1984, she presented with tricuspid endocarditis and three years later, was found to have irreversible pulmonary hypertension. Post-mortem examination revealed not only persistent tricuspid endocarditis and evidence of repeated pulmonary thromboembolism explaining her pulmonary hypertension but also a diffuse eosinophilic myocarditis, with myocardial fibre degeneration. The combined pulmonary and myocardial lesions have rarely been documented in the same drug addict. The relationship of these various pathological findings are discussed in the light of the existing literature.
Ventilatory failure, often complicated by pulmonary infection, is a common cause of death in neuromuscular disorders. When severe enough, only intubation and mechanical ventilation can avoid a fatal outcome. In acute, reversible neuromuscular problems, mechanical ventilation is simple and safe, even if long lasting. Pulmonary function tests, particularly repeated vital capacity measurements, are very useful to predict respiratory failure and conduct weaning trials from the respirator. In chronic, progressive and debilitating neuromuscular disorders, to intubate or not remains an ethical dilemma. In an hospital admitting such patients, a clear and explicit consensus about the general policy for the treatment of chronic neuromuscular patients should have been previously discussed to avoid erratic therapeutic options.
The clinical usefulness of scintigraphies with 111Indium radiolabeled antimyosin antibodies (Myoscint) and 99mTc isonitriles (Cardiolite) for the detection and topographic location of acute myocardial infarction (AMI) has been evaluated in 29 patients admitted for suspected AMI. The scintigraphic results were compared to ECG and enzymatic data and, in 22 patients, to coronaro-angiography. The CK enzymes (from 258 to 4986 IU/l, mean 1429) were elevated in all, while the ECG showed diagnostic Q waves in only 21 patients. 2 patients died in cardiogenic shock, one after massive extension of AMI. Myoscint and Cardiolite images were positive in all 29 patients. Both techniques showed concordant results in 27/28 comparable patients, and localized the AMI in 8 patients without diagnostic ECG. Regional comparison in 140 segments of 28 patients was concordant in 91% of the segments, totally discordant in 3 segments and partially discordant in 9 segments. In conclusion, this preliminary study in selected patients shows the clinical usefulness of 111In radiolabeled antimyosin antibodies and 99mTc isonitriles for detection of AMI in all 29 patients and for topographic localization in more than 90% of the cases. Imaging with 111In radiolabeled antimyosin antibodies seems particularly useful in patients with non diagnostic ECG and previous MI and for the detection of right ventricular infarct extension.
Although arterial blood gas analysis remains the "gold standard" for oxygen (O2) and carbon dioxide (CO2) measurements during critical illness, several new techniques are now available for clinicians in this field, i.e. pulse oximetry, transcutaneous (PtcO2) and transconjunctival (PcjO2) O2 monitoring, CO2 continuous measurements in expired gases (capnography) and transcutaneous PCO2 (PtcCO2). While it seems too early to assign a definite role to all these techniques in the management of critically ill patients, several points can be emphasized: 1. pulse oximetry is a cheap, versatile device for monitoring of nonhypoxemic patients; 2. PtcO2 is a good index of poor skin oxygenation and is related to PaO2, but this index should be interpreted with caution in unsteady patients; perhaps its main value is as an early warning that "something is wrong with the patient". PcjO2 may be promising, but more data are needed; 3. PtcCO2 and capnography seem more suitable for research purposes or for patient monitoring in the operating theatre. Finally, it should be emphasized that invasive arterial blood gas measurements using an indwelliing arterial catheter are safe and provide with the best possible acid-base and hemodynamic monitoring. Noncontinuous monitoring of blood gases and, perhaps, the delay between arterial puncture and completion of the analysis seem to be the only drawbacks of this technique.
Nocturnal mechanical ventilation (NMV) is a promising technique increasing survival and improving the quality of life of myopathic and kyphoscoliotic patients. The indications for NMV must be careful and the patients strictly selected. NMV is rarely useful in patients with pulmonary diseases, like COPD or restrictive disorders. When a professional medical and paramedical support is locally available, NMV can be undertaken at home. Negative and positive pressure ventilation can be used for NMV. Actually, tracheostomy can be replaced very often by a new type of positive pressure ventilation via a nasal face mask. We present here our series of 11 patients submitted to NMV and describe carefully the problems and the results of a 5-years experience with NMV in Geneva.
The tracheal and bronchial lesions observed are described in seven patients, presenting with respiratory distress syndrome and receiving both conventional and high frequency jet ventilation for various periods. The histological findings are related to the duration of the exposure as well as the number of pulsations administered to the tracheobronchial tree. Severe damage to the mucosa leading to acute tracheobronchitis, hyperplasia and hypersecretion of the mucosal glands may explain some of the clinical symptoms observed, especially the upper respiratory obstruction. Care should be taken to limit these changes which may lead to various degrees of stenosis in survivors receiving this mode of therapy.
MacLeod's syndrome (Swyer-James' syndrome in the child) is a radiologic entity: hyperlucency of one or several lobes, or even of one lung, scarce hilar shadow on the same side as the abnormal transradiency, and barely visible arterial network on the abnormal side of the thorax. Distal bronchiectases (bronchography) and abnormal distal bronchi (necropsy) suggest that this disease may be due to bronchiolitis in childhood. An obstructive pulmonary disorder, assessed by pulmonary function tests, has been described in this syndrome. However, neither the prevalence nor the severity or evolution of the obstructive defect are known. We have studied two such patients for 5 and 12 years respectively: during this long follow-up period the obstructive disorder, albeit severe, remained stable. We have also analysed the 75 cases in the literature in which pulmonary function tests are available and comparable. We have been able to show that (1) an obstructive disorder is frequent in MacLeod's syndrome, (2) the severity of this disorder differs markedly between patients, and (3) this airflow limitation is probably stable on a long-term basis. These findings are compatible with the pathogenetic hypothesis at present accepted, ie bronchiolitis during childhood, and suggest that the inflammatory bronchial disease may have been generalized in many such patients.
Malnutrition is often observed in patients with chronic respiratory failure, particularly during acute episodes. In this short review, we discuss the nutritional status of patients suffering from chronic obstructive pulmonary disease (COPD) in the stable and acute phases, and the consequences of malnutrition for some components of the respiratory system (respiratory muscles, pulmonary tissue and ventilation control). Finally we propose a realimentation protocol, although at present time there is no proof that renutrition influences short or long term prognosis in such patients.
We analyzed the outcome of 39 consecutive acute exacerbations of chronic obstructive pulmonary disease (COPD) in 35 patients requiring mechanical ventilation, in order to identify the features related to survival. Patients were divided into those surviving less (group A; n = 14) and more (group B; n = 24) than six months. Pulmonary function tests, arterial blood gas levels either on admission or while in a steady state, and nutritional parameters were similar in both groups. Only the duration of mechanical ventilation was longer in group A when compared to group B. In patients dying while being ventilated or surviving less than ten days after extubation, only the forced vital capacity (FVC) was different when compared to the rest of group A. The duration of mechanical ventilation was not related to age or the forced expiratory volume in one second (FEV1). Only a multivariate analysis accounting simultaneously for eight parameters could separate with 78 percent accuracy the different groups of patients; however, following this analysis, 23 percent of the patients in group B could have been falsely classified as nonsurvivors and perhaps rejected for mechanical ventilation. We conclude that the six-month survival of patients with COPD who required mechanical ventilation for an acute exacerbation of their disease cannot be predicted from simple data generally available to the physician in charge at the time of intubation.