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Biomedical subjects

J Chastre

Publications and source records attributed to J Chastre.

At least 55 records · Page 3Linked to original sources
PubMed1993

Pilot study of cardiopulmonary risk from pentoxifylline in adult respiratory distress syndrome.

Neutrophils and cytokines are directly involved in the pathophysiology of adult respiratory distress syndrome (ARDS). Pentoxifylline (PTX) has been shown in vitro to protect against the inflammatory effects of neutrophils and cytokines. The same protective effects have been demonstrated on animal models of lung injury. These results suggested that PTX might be useful in patients with ARDS. The cardiopulmonary effects of large doses of PTX were evaluated in a pilot study performed in six patients with severe ARDS. PTX was administered with an initial 1-mg/kg bolus, followed by infusion of 1.5 mg/kg/h over 6 h. No significant change was observed in the gas exchange and hemodynamic parameters, except for a 10 percent increase in the heart rate during the infusion period. Our results demonstrate that large doses of PTX induced only minor hemodynamic changes without worsening in pulmonary gas exchange. Further studies are warranted to evaluate human safety and ultimately the effectiveness of PTX in the treatment of ARDS.

Aged↗
PubMed1992

Procedures for the diagnosis of pneumonia in ICU patients.

The optimal technique for diagnosing nosocomial bacterial pneumonia in critically ill patients cared for in the intensive care unit remains unclear, especially in the subgroup of patients requiring mechanical ventilation. An important advance has been the development of the protected specimen brush technique. Secretions obtained using this technique and evaluated by quantitative cultures are useful in distinguishing patients with and without pneumonia. However, this procedure has important limitations in that results are not available immediately, and in that a few false negative of false positive results may occur. Bronchoalveolar lavage has been suggested to be of value in establishing the diagnosis of pneumonia, because the cells and liquid recovered can be examined microscopically immediately after the procedure and are also suitable for quantitative culture. Microscopic identification of bacteria within cells recovered by lavage may provide a sensitive and specific means for the early and rapid diagnosis of pneumonia in this setting. The lavage technique can also be conveniently incorporated into a protocol along with quantitative culture of samples obtained using the protected specimen brush. This combination will probably improve the overall accuracy of diagnosis while allowing the administration of prompt empiric antimicrobial therapy in most patients with pneumonia.

Bacteriological Techniques↗
PubMed1991

Spontaneous release of granulocyte colony-stimulating factor (G-CSF) by alveolar macrophages in the course of bacterial pneumonia and sarcoidosis: endotoxin-dependent and endotoxin-independent G-CSF release by cells recovered by bronchoalveolar lavage.

Because granulocyte colony-stimulating factor (G-CSF) is known to induce granulopoiesis and activate mature neutrophils, this factor could be important in determining the number and functional activity of neutrophils at sites of lung disease. The purpose of this study was to evaluate the ability of lung immune and inflammatory cells to produce G-CSF, and to seek evidence for the spontaneous production of this factor by cells recovered by lavage from controls and patients with lung diseases in which neutrophils may play a pathogenetic role. Lavage cells from controls produced little G-CSF spontaneously. Alveolar macrophages (AM), but not lymphocytes, produced large amounts following endotoxin stimulation. Lavage cells from patients with respiratory failure associated with bacterial pneumonia, but not those with respiratory failure from noninfectious causes, spontaneously released G-CSF (32 +/- 24 and less than 1 U/10(6) AM, respectively). Lavage cells from five of 15 patients with sarcoidosis and one of five patients with diffuse pulmonary fibrosis also spontaneously released G-CSF, which could not be explained by endotoxin exposure. The release of G-CSF by endotoxin-dependent and -independent mechanisms could play a role in the recruitment and activation of neutrophils in bacterial pneumonia and participate in the pathogenesis of some interstitial lung diseases.

Adult↗
PubMed1991

[Necrotizing fasciitis of the upper limb. 12 cases].

Twelve cases of necrotizing fasciitis or streptococcal cellulitis of the upper limb are reported. Four cases presented with a low grade aggressive for and one case was chronic. Seven fulminating cases resulted in two deaths. These different presentations are in fact different stages of the same disease which is a group A beta-hemolytic streptococcal necrotizing infection of the subcutaneous tissue. It is a medical emergency in which surgery is the main treatment. In cases seen early, surgery helps by making an early diagnosis by showing the typical appearance of the subcutaneous tissue and by isolating organisms in wound culture. In fulminant cases, only extensive surgical debridement can control infection. Delayed or incomplete radical excision may lead to disseminated infection. Infection spreading beyond one upper limb worsens the vital prognosis.

Adult↗
PubMed1990

Bronchoalveolar lavage for rapid diagnosis of the fat embolism syndrome in trauma patients.

OBJECTIVE: To evaluate the usefulness of bronchoalveolar lavage in establishing the diagnosis of the fat embolism syndrome in trauma patients with long-bone fractures. DESIGN: Case series. SETTING: Referral hospital. PATIENTS: Eighteen trauma patients with long-bone fractures, including 5 with definite fat embolism syndrome, 5 in whom the diagnosis had been clinically suspected but was impossible to confirm or exclude before bronchoscopy, and 8 with no clinical evidence of the syndrome. Control groups included 9 patients without previous trauma who developed the adult respiratory distress syndrome for various reasons and 15 normal volunteers. MEASUREMENTS AND MAIN RESULTS: Each patient had fiber-optic bronchoscopy with bronchoalveolar lavage, and the percentage of lavage cells containing intracellular fat droplets stained with oil red 0 were determined. In the five patients with definite fat embolism syndrome, light microscopic study of bronchoalveolar cells stained with oil red 0 showed many large intracellular fat droplets (mean percentage of cells containing fat droplets, 63%; range, 31% to 82%), whereas less than 2% of cells recovered by lavage from trauma patients with no clinical evidence of the syndrome, from patients with the adult respiratory distress syndrome, or from normal volunteers contained such inclusions. Use of the same technique in the five patients with possible fat embolism syndrome permitted the immediate identification of three patients in whom this diagnosis was later confirmed by subsequent autopsy or clinical follow-up. CONCLUSIONS: The identification of fat droplets within cells recovered by bronchoalveolar lavage in trauma patients may be a rapid and specific method for establishing the diagnosis of the fat embolism syndrome.

Adolescent↗
PubMed1990

Abnormal epithelial cells recovered by bronchoalveolar lavage: are they malignant?

The recovery of neoplastic cells by bronchoalveolar lavage is useful in the diagnosis of lung cancer. Abnormal epithelial cells can also be recovered from patients with interstitial lung diseases who do not have cancer, and therefore the usefulness of lavage in the diagnosis of malignancy in this setting is unknown. In this study, we evaluated the diagnostic significance of abnormal lavage cells recovered from patients with diffuse parenchymal abnormalities and compared the usefulness of standard cytologic assessment, correlation with clinical features, and immunocytochemical staining for carcinoembryonic antigen (CEA) in identifying abnormal cells that are truly malignant. Thirty of 2,314 patients had atypical lavage cells, but in only nine was lung cancer demonstrated. Although most patients with clinical suspicion of malignancy had lung carcinoma (six of seven), one such patient did not have cancer, and three were shown to have unsuspected carcinoma. Cytologic criteria identified definitely malignant cells in only four of nine patients with lung cancer, indicating that the approach is not sensitive. Immunostaining of abnormal cells with anti-CEA antibodies proved helpful. All patients with lung malignancy had CEA+ cells (n = 9), and no patient whose abnormal cells were CEA- proved to have cancer (n = 17). Because only nine of 13 patients with CEA+ cells had lung malignancy, the test is not diagnostic, but it appears to limit the need for further evaluation to a smaller group of patients in whom cancer is likely to be present. When used together, cytopathologic findings, detection of CEA by immunocytochemical techniques, and clinical correlates proved useful in diagnosis of lung malignancy, but further improvements are still needed to improve diagnostic accuracy.

Bronchoalveolar Lavage Fluid↗
PubMed1990

Characterization of distal bronchial microflora during acute exacerbation of chronic bronchitis. Use of the protected specimen brush technique in 54 mechanically ventilated patients.

To obtain accurate information on distal bronchial microflora during acute exacerbation in patients with chronic bronchitis, we prospectively studied 54 such patients who had been receiving mechanical ventilation because of hypercapnic respiratory failure. Fiberoptic bronchoscopy using a protected specimen brush (PSB) was performed on each patient within the first 24 h after admission. Cultures of protected brush specimens demonstrated no growth in 27 patients (50%). With the exception of fever (38.2 +/- 0.8 versus 37.7 +/- 0.6 degrees C; p less than 0.05), the initial severity of the episode of exacerbation was similar in patients with and without infection. A total of 44 organisms were isolated in the 27 patients with positive cultures; the predominant pathogens were Hemophilus spp. and Streptococcus spp. (involved in 74% of cases), but other organisms were isolated in 12 of 27 patients. Mortality rates, duration of mechanical ventilation, and duration of hospitalization were not significantly different between patients with bronchial microflora treated with appropriate antimicrobial therapy (n = 27) and patients without bronchial microflora either receiving empirical antibiotic therapy (n = 18) or not (n = 9). These data suggest that distal bronchial infection due to the usual pathogens, as far as shown by protected specimen brush cultures, may not be the sole or even the predominant cause of acute exacerbation of chronic bronchitis in patients requiring mechanical ventilation.

Acute Disease↗
PubMed1990

Incidence and morbidity of cytomegaloviral infection in patients with mediastinitis following cardiac surgery.

To determine the incidence and morbidity of infections with CMV associated with mediastinitis after conventional cardiac surgery, 115 consecutive adult patients with mediastinitis were evaluated with viral cultures of blood and urine. Shedding of CMV was seen in 29 patients (25 percent) within a mean period of 37 +/- 22 days after cardiopulmonary bypass. Viremia was documented in 79 percent (23) of these 29 patients. Acute renal failure and enzymatic abnormalities (AST and LDH) were significantly more common in patients with virologically proven infection with CMV (p less than 0.05). In patients who survived the initial period of bacterial infection, major differences in their clinical course were observed according to their virologic status. After the 15th day of hospitalization following the débridement, the persistence of local infection was more frequent (p less than 0.05) and the mortality was higher (p less than 0.01) in CMV-infected patients. Moreover, the mean duration of hospitalization in the ICU for survivors was 69 +/- 36 days in viral shedders, compared with 48 +/- 27 days in nonshedders (p less than 0.05). Infection with CMV in mediastinitis occurs frequently and is associated with persistence of local infection, prolonged hospitalization, and increased late mortality.

Antibodies, Viral↗
PubMed1990

Fiberoptic bronchoscopy in ventilated patients. Evaluation of cardiopulmonary risk under midazolam sedation.

One hundred seven acutely ill ventilated patients were prospectively studied to ascertain the severity and frequency of alterations in gas exchange and hemodynamic parameters during brief bronchoscopy. Sedation was performed using midazolam (0.1 mg/kg IV) without topical anesthesia. An average decline in PaO2 of 26 percent was observed at the end of the procedure, compared to the baseline value, and this was associated with a mild increase in PaCO2 in spite of the use of a special adapter. Alterations in mean systolic blood pressure appeared to be modest, consisting of a 10 percent decrease from the control level, related to sedation, and a 10 percent rise from baseline during the procedure, associated with a concomitant mild tachycardia. At that time, central hemodynamic measurements performed in a subset of 31 patients showed a significant increase in cardiac output associated with higher pulmonary wedge pressure. Fourteen patients developed hypoxemia of less than 60 mm Hg on FIO2 adjusted to 0.8. Of the ten risk factors univariately associated with hypoxemia, only the presence of ARDS (p less than 0.001) and "fighting" the ventilator during the procedure (p less than 0.05) remained significant after stepwise logistic regression. Attempts to prevent hypoxemia in critically ill patients should focus on inducing complete sedation, with careful attention to hemodynamic status, or providing maximal levels of oxygen to the ventilator (or both).

Adult↗
PubMed1990

[Diagnostic criteria for respiratory infection in intensive care patients].

The optimal technique for diagnosing nosocomial bacterial pneumonia in critically ill patients cared for in an Intensive Care Unit remains unclear. Firstly, fever, purulent secretions and new pulmonary infiltrates can be associated with a variety of other common pathological processes. Secondly, microscopic and culture of tracheal secretions are frequently unrewarding since the upper respiratory tract of most ventilated patients is colonized with potential pulmonary pathogens, wether or not deep pulmonary infection is present. Thus, the results of studies evaluating the clinical diagnosis of nosocomial pneumonia in this setting have been very disappointing. An important advance has been the development of the protected specimen brush technique. We and others have demonstrated that the secretions obtained using this technique and evaluated by quantitative cultures are useful in distinguishing patients with and without pneumonia. However, this procedure has important limitations in that results are not available immediately and in that a few false negative or false positive results may be observed. Recently, the use of bronchoalveolar lavage has been suggested to be of value in establishing the diagnosis of pneumonia since the cells recovered by lavage may provide a sensitive and specific means for early and rapid diagnosis of pneumonia in this setting and that the lavage technique can be conveniently incorporated into a protocol along with the quantitative culture of samples obtained using the protected specimen brush.

Bronchoalveolar Lavage Fluid↗
PubMed1989

Diagnosis of nosocomial pneumonia in intensive care unit patients.

The optimal technique for diagnosing nosocomial bacterial pneumonia in critically ill patients cared for in the intensive care unit remains unclear, especially in the subgroup of patients requiring mechanical ventilation. An important advance has been the development of the protected specimen brush technique. We and others have demonstrated that secretions obtained using this technique and evaluated by quantitative cultures are useful in distinguishing patients with and without pneumonia. However, this procedure has important limitations in that results are not available immediately and in that a few false negative or false positive results may be observed. Recently, the use of bronchoalveolar lavage has been suggested to be of value in establishing the diagnosis of pneumonia, since the cells and liquid recovered can be examined microscopically immediately after the procedure and are also suitable for quantitative culture. We believe that microscopic identification of bacteria within cells recovered by lavage may provide a sensitive and specific means for early and rapid diagnosis of pneumonia in this setting and that the lavage technique can be conveniently incorporated into a protocol along with the quantitative culture of samples obtained using the protected specimen brush. This combination will probably improve the overall accuracy of diagnosis while allowing the administration of prompt empiric antimicrobial therapy in the majority of patients with pneumonia.

Cross Infection↗
PubMed1989

Nosocomial pneumonia in patients receiving continuous mechanical ventilation. Prospective analysis of 52 episodes with use of a protected specimen brush and quantitative culture techniques.

Epidemiologic studies of nosocomial bacterial pneumonia in patients requiring mechanical ventilation have been limited because of the poor reliability of diagnosis procedures in this setting. To determine prognostic and descriptive factors of ventilator-associated (V-A) pneumonia, we prospectively studied 567 patients who had been receiving mechanical ventilation for more than 3 days in our unit. Fiberoptic bronchoscopy using a protected specimen brush (PSB) was performed on each patient suspected of having pneumonia because of the presence of a new pulmonary infiltrate and purulent tracheal secretions. The diagnosis of V-A pneumonia was retained only if PSB specimens yielded greater than 10(3) cfu/ml of at least one microorganism, unless this result was established to be a false positive result on follow-up. V-A pneumonia developed in 49 patients for a total of 52 episodes (9%). The actuarial risk of V-A pneumonia was 6.5% at 10 days, 19% at 20 days, and 28% at 30 days of ventilation. Patients with pneumonia were significantly older (65 versus 57 yr of age, p less than 0.01) and more frequently had severe underlying illnesses (24 versus 10%, p less than 0.01) than did patients without pneumonia. A total of 84 microorganisms (51 gram-negative and 33 gram-positive) were isolated in significant concentrations from PSB specimens. Pseudomonas aeruginosa and Staphylococcus aureus were involved in 31 and 33% of these pneumonias, respectively. Forty percent of all specimens yielded a polymicrobial flora with more than one potential pathogen.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1988

Diagnosis of nosocomial bacterial pneumonia in intubated patients undergoing ventilation: comparison of the usefulness of bronchoalveolar lavage and the protected specimen brush.

PURPOSE: To compare the usefulness of specimens recovered using a protected specimen brush and those recovered by bronchoalveolar lavage in the diagnosis of nosocomial pneumonia occurring in intubated patients undergoing ventilation, we performed both procedures in patients suspected of having pneumonia because of the presence of a new pulmonary infiltrate and purulent tracheal secretions. PATIENTS AND METHODS: Twenty-one patients (16 men and five women) with an average age of 57 +/- 12 years were studied. They had been receiving mechanical ventilation for 8 +/- 6 days before inclusion in the trial. The clinical suspicion for nosocomial bacterial pneumonia was high in these patients. Fiberoptic bronchoscopy was performed in each patient. Bronchoscopy specimens were obtained by a protected specimen brush and by bronchoalveolar lavage, and were then processed for quantitative bacterial and fungal culture using standard methods. Total cell counts were performed on an aliquot of resuspended original lavage fluid. Differential cell counts were made on at least 500 cells. In addition, 300 cells were examined at high-power magnification and the percentage of cells containing intracellular microorganisms and the average number of extracellular organisms per oil-immersion field were determined. RESULTS: Quantitative culture of specimens recovered using the protected specimen brush were positive (more than 10(3) colony-forming units [cfu]/ml) in five of five patients with subsequently confirmed pneumonia, and negative (less than 10(3) cfu/ml) in 13 of 13 patients without bacterial pneumonia, but results were not available until 24 to 48 hours after the procedure. Quantification of intracellular organisms in cells recovered by lavage was also useful in distinguishing patients with pneumonia (more than 25 percent of cells with intracellular organisms in five of five patients) from those without pneumonia (less than 15 percent of cells with intracellular organisms in all cases), and results were available immediately. In contrast, quantitative culture of lavage fluid and differential cell counts were of little value in identifying infected patients. CONCLUSION: The protected specimen brush and microscopic identification of intracellular organisms in cells recovered by lavage yield useful and complementary information, and together permit rapid and specific treatment of most patients with nosocomial pneumonia.

Bacteria↗
PubMed1988

Detection of nosocomial lung infection in ventilated patients. Use of a protected specimen brush and quantitative culture techniques in 147 patients.

To determine the usefulness of samples obtained by bronchoscopy using a protected specimen brush and evaluated by quantitative culture techniques in establishing the diagnosis of nosocomial pneumonia in patients requiring mechanical ventilation, we prospectively studied 147 ventilated patients suspected of having nosocomial pneumonia because of the presence of a new pulmonary infiltrate and purulent tracheal secretions. Positive cultures of protected brush specimens (greater than 10(3) cfu/ml) were found in only 45 patients (31%). Subsequent follow-up confirmed the diagnosis of pneumonia in 34 of 45 patients, and in only 4 of 45 patients was a positive culture firmly established to be a false positive result. No patient with less than 10(3) cfu/ml was subsequently shown to have had pneumonia, and the diagnosis was definitely excluded in 72 of 102 patients by the absence of pneumonia at autopsy or recovery without antibiotic therapy. In contrast, when 16 clinical variables were evaluated by stepwise logistic regression analysis, no combination could be identified that was useful in distinguishing patients with bacterial pneumonia. Furthermore, when the actual costs of evaluation and therapy of our patients were compared with the projected costs entailed in treating all patients suspected of having pneumonia with antibiotics, evaluation using the protected specimen brush and quantitative cultures was less expensive after only 6 days of treatment. These results suggest that the appearance of pulmonary infiltrates and purulent tracheal secretions does not result from bacterial pneumonia in a majority of patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1988

Persistence of circadian rhythms in gastric acid, gastrin, and pancreatic polypeptide secretions despite loss of cortisol and body temperature rhythms in man under stress.

During organic stress, severe dysfunctions of fundamental biological phenomena, such as modification of vagal tone, have been described. These dysfunctions could induce changes in the rhythm of acid secretion and/or its hormonal control. We therefore analyzed the effects of acute respiratory failure on the 24 h variations in intragastric pH, serum gastrin, and pancreatic polypeptide levels, taken as a marker of vagal tone. Body temperature and plasma cortisol circadian rhythms were used as marker rhythms. Twelve patients with chronic obstructive pulmonary disease complicated with acute respiratory failure were studied before and during continuous enteral nutrition; half of the patients received ranitidine, a H2 blocker. During the 3 days of the study, intragastric pH was below 2.5 for only one third of the time. No difference was observed between the placebo and the ranitidine groups. Plasma pancreatic polypeptide was within normal ranges despite increased cortisol levels. Gastrin levels reflected changes in intragastric pH over the 24 h time frame and were noted to increase during ranitidine and enteral nutrition. Despite the loss of cortisol and body temperature circadian rhythmicity all throughout the study, circadian rhythms were maintained or restored during the different therapeutic regimens for intragastric pH, serum gastrin, and pancreatic polypeptide levels. Moreover, an ultradian rhythm for gastrin before any treatment, a circadian rhythm for intragastric pH on enteral nutrition, a circadian rhythm for intragastric pH, plasma gastrin and plasma pancreatic polypeptide on ranitidine regimen were observed. Thus during acute respiratory failure, certain physiological circadian rhythms persisted despite the disappearance of "marker" rhythms. Furthermore, these rhythms for digestive secretions could be pharmacologically restored.

Acute Disease↗