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Biomedical subjects

R W Light

Publications and source records attributed to R W Light.

232 records · Page 13Linked to original sources

Pleural lavage: a novel diagnostic approach for diagnosing exudative pleural effusion.

Patients with pleural effusions frequently present a diagnostic and therapeutic challenge. The diagnosis is based on the interpretation of the results of thoracentesis or pleural biopsy. When a malignant tumor metastasizes to the pleura, tumor cells can be seeded over the mesothelial surface or in the subserous layer. In the former situation, tumor cells are abundant in pleural fluid, but in the latter, few malignant cells are exfoliated into the pleural cavity, and microscopic deposits may not be visualized at thoracoscopy. Pleural lavage cytologic study at the time of thoracoscopy has not been studied. The purpose of this study was to assess the value of thoracoscopic pleural lavage as an adjuvant in the diagnostic workup of patients with exudative pleural effusions. Fifty patients with exudative pleural effusions were investigated by pleural fluid cytologic findings, Abram's pleural biopsy, thoracoscopy, and pleural lavage cytologic findings. After aspiration of all pleural fluid, 300 mL saline was instilled into the pleural cavity and then recovered for cytologic analysis. The final diagnoses were 32 malignant (64%), 15 tuberculous (30%), and 3 idiopathic (6%) effusions. In the malignant group, thoracoscopic biopsy had the highest yield (94%) followed by lavage cytologic analysis (84%), fluid cytologic analysis (62%), and biopsy with Abram's needle (50%). The sensitivity of combined thoracoscopy and lavage cytologic analysis was 96%. In the patients with tuberculous pleuritis, the yield from the pathologic examination of the biopsy specimen was 93% with thoracoscopy and 60% with the Abrams needle. The diagnostic yield with cytologic analysis on pleural lavage fluid is significantly higher than that on pleural fluid. This is probably because the cells in the lavage fluid are fresher and better preserved than those in the regular pleural fluid, which may have undergone degenerative changes, yielding false-negative results. Pleural lavage cytologic analysis should be performed in patients with suspected malignant pleural effusion who are subjected to diagnostic thoracoscopy, because it may provide additional information to thoracoscopic biopsy.

Adult↗

Penetration of clarithromycin in experimental pleural empyema model fluid.

BACKGROUND: The degree of penetration of clarithromycin into the pleural fluid has not been studied. OBJECTIVE: To determine the degree to which clarithromycin penetrates into empyemic pleural fluid using a new rabbit model of empyema. METHODS: An empyema was created via the intrapleural injection of 1 ml turpentine followed 24 h later by instillation of 5 ml (10(10)) Escherichia coli bacteria (ATCC 35218) into the pleural space of New Zealand white rabbits. After an empyema was verified by thoracentesis and pleural fluid analysis, clarithromycin 30 mg/kg was administered intravenously. Antibiotic levels were determined on samples of pleural fluid and blood samples collected serially over 12 h. Antibiotic levels were estimated using HPLC. RESULTS: The antibiotic penetrated well into the empyemic pleural fluid (AUC(PF)/AUC(serum) ratio of 1.57). The time to equilibration between the pleural fluid and blood antibiotic levels was 8 h. The peak pleural fluid level (Cmax(PF) of 2.88 microg/ml) occurred 1 h (Tmax(PF) of 1 h) after infusion and decreased thereafter. The Cmax(serum) was 3.53 microg/ml at 1 h after administration. CONCLUSION: The levels of clarithromycin in the pleural fluid after intravenous administration are inhibitory for most of the usual pathogens causing empyema. The degree of penetration of clarithromycin should be considered when macrolides are selected for the treatment of patients with empyema.

Animals↗

Pleural fluid parameters identifying complicated parapneumonic effusions.

BACKGROUND: Controversy exists regarding the clinical utility of pleural fluid parameters as prognosticators of complicated parapneumonic effusions that require drainage. OBJECTIVES: The purpose of this prospective study is to further assess the utility of these parameters in the management of a larger series of parapneumonic effusions and to determine appropriate binary decision thresholds. METHODS: We studied 238 consecutive patients with parapneumonic effusions who underwent diagnostic thoracentesis. RESULTS: We found that pleural fluid pH had the highest diagnostic accuracy (area under the curve, AUC: 0.928; 95% confidence interval, CI: 0.894-0.963) compared with pleural fluid glucose (AUC: 0.835; 95% CI: 0.773-0.897), LDH (AUC: 0.824; 95% CI: 0.761-0.887) or pleural fluid volume (AUC: 0.706; 95% CI: 0.634-0.777). The optimal binary decision threshold for pleural fluid pH identifying complicated effusions requiring drainage was 7.15. Binary, multilevel and continuous likelihood ratios (LRs) for pH were calculated to estimate the likelihood of complication of the pleural effusion. Values for the LRs were compared for each of the three strategies, and relative clinical and statistical significances were assessed. Binary LRs provided significantly less information than continuous strategies. CONCLUSION: The pH has the highest diagnostic accuracy for identifying complicated parapneumonic pleural effusions. The binary decision threshold determining the need for chest drainage is 7.15 in our patient series. We recommend continuous LRs to estimate the post-test probability of the complication as they provide the most information compared with binary LRs. Our results do not support the use of pleural fluid LDH as independent predictor of complicated parapneumonic effusions.

Aged↗

The adult respiratory distress syndrome and pancuronium bromide.

The institution and maintenance of artificial ventilation for a patient with the adult respiratory distress syndrome (ARDS) is frequently difficult because the hypoxic patient is often confused, agitated, or combative. Pancuronium bromide, a recently introduced neuromuscular blocking agent, was used to facilitate artificial ventilation in 6 patients with ARDS. As compared with morphine sulfate and diazepam, pancuronium bromide has fewer cardiovascular and central-nervous system effects. It also has fewer cardiovascular effects than does curare, and its prolonged administration does not lead to a desensitization neuromuscular block as is seen with succinylcholine. However, continuous high-quality nursing care is necessary if this drug is used.

Abdominal Injuries↗