The glucose-pH relationship in parapneumonic effusions.

Both a low pleural fluid glucose concentration and pleural fluid acidosis are markers of severe pleural inflammation, but the relationship between these phenomena has not been defined clearly. Therefore, we measured simultaneous pleural fluid glucose concentrations and pH in 25 consecutive parapneumonic pleural fluids. Seventeen effusions had a glucose concentration greater than 60 mg/dl (group 1, 126 +/- 7 mg/dl, mean +/- SEM), while eight had a pleural fluid glucose less than 60 mg/dl (group 2, 15 +/- 3 mg/dl, P less than .01). Pleural fluid pH was 7.35 +/- 0.03 in group 1 compared with 6.83 +/- 0.09 in group 2 (P less than .01). A significant correlation between pleural fluid glucose and pH was found (r = .81, P less than .01). Low-glucose, low-pH effusions were complicated (either loculated or empyemas). Uncomplicated effusions had glucose concentrations greater than 60 mg/dl and a pleural fluid pH greater than 7.30. The concomitant occurrence of low pleural fluid glucose and pH suggests that the mechanisms leading to these phenomena are interrelated.

Pleural mesotheliomas--an analysis of 18 cases and review of the literature.

Eighteen cases of mesothelioma, 7 benign and 11 malignant, were analyzed retrospectively. There were 5 females with benign tumors and 10 males with the malignant variety. The mean age was 59 years in the benign group and 55 years in those with malignant tumors. Exposure to asbestos was documented in one benign and five malignant mesotheliomas. Three patients with benign lesions were asymptomatic on presentation while all 11 with malignant tumors had symptoms, chest pain and dyspnea being the most frequent. Abnormal physical findings were rarely noted in the benign group while all the malignant tumors had abnormal findings on presentation. Signs of a pleural effusion were the most common abnormal physical findings, occurring in 8 of 11 patients. Pleural effusion was the most common roentgenologic finding in malignant mesotheliomas, while a mass lesion was the presenting finding in six of seven of the benign group. Pleural effusion was a usual accompaniment of malignant tumors and was an exudate, usually hemorrhagic with leukocyte counts up to 20,000/mm3. Thoracotomy established the diagnosis in each of the five benign and seven malignant cases in which it was attempted. Pleural biopsy was diagnostic in three of six with malignant and one of two with benign tumors. Pleural fluid cytology did not yield a diagnosis in the seven instances in which it was studied. Excisional surgery was performed in five of the benign cases and all have survived one to six years. No treatment was curative of malignant mesotheliomas. Ten of the 11 with malignant tumors died from 3 to 24 months after onset of symptoms (mean 9.9 months). The clinical features of 82 benign and 160 malignant mesotheliomas from selected series in the literature are reviewed and compared with the present series. The roentgenographic features of 51 benign and 87 malignant tumors are also presented. The clinical and diagnostic features which help differentiate mesotheliomas from bronchogenic carcinomas are discussed. A careful approach to the diagnosis of malignant mesotheliomas may help avoid an unnecessary thoracotomy.

Pleural fluid analysis in malignant mesothelioma. Prognostic implications.

Pleural fluid characteristics of 26 patients diagnosed with malignant mesothelioma over an 18-year period were reviewed and compared with those of patients with effusions due to other malignancies. Survival from time of initial thoracentesis was directly correlated with pleural pH and decreased pleural fluid/serum glucose ratios but was not related to protein or LDH concentration. Decreased pleural fluid pH was statistically related to a decreased pleural fluid/serum glucose ratio. Patients with low pH (less than 7.30) pleural effusions had statistically decreased mean survival and decreased mean pleural fluid/serum glucose ratios compared with patients with normal pH (greater than or equal to 7.30). Patients with malignant mesothelioma pleural effusions had statistically decreased mean pleural fluid pH compared with patients with other malignant pleural effusions. Decreased levels of pleural fluid pH and pleural fluid/serum glucose ratios have negative prognostic significance and probably correlate with the degree of tumor bulk affecting the pleural surface.

The diagnostic value of pleural fluid pH.

One hundred eighty-three patients had simultaneous blood and pleural fluid pH determinations. Thirty-six effusions were transudates, and 147 were exudates. In 46 effusions, the pleural fluid pH was less than 7.30; all 46 were exudates. A pleural fluid pH less than 7.30 was associated with the following six diagnoses: (1) empyema; (2) malignancy; (3) collagen vascular disease; (4) tuberculosis; (5) esophageal rupture; and (6) hemothorax. The results of pleural fluid pH determination are immediately available, narrow the differential diagnosis of the exudate, and may expedite patient management. The pH of pleural fluid should be measured whenever a diagnostic thoracocentesis is performed.

Emergency room intubations--complications and survival.

Forty-three consecutive patients requiring endotracheal intubation in an emergency room were studied prospectively to define the complications associated with intubation and the survival of these patients, and to evaluate emergency room policies. The indications for intubation were acute respiratory failure (ARF) in 22 patients and cardiopulmonary arrest (CPA) in 21 patients. Thirty-eight complications occurred in 24 of the 43 patients. The department or level of training of the intubator did not affect the rate of complications. Furthermore, specific complications did not influence survival. Seventeen patients survived, all in the ARF group. Age less than 40 years and admission PaO2 greater than 40 mm Hg also were associated with increased survival. We conclude that the complication rate of emergency room intubations is high and would not appear to be lowered by limiting intubations to physicians from specific departments or with certain levels of training. The underlying diagnosis and condition on admission to the emergency room appear to be more important factors relating to survival than complications during intubation.

Systemic lupus erythematosus: an unusual cause of bilateral hilar lymphadenopathy.

Systemic lupus erythematosus is usually not associated with bilateral hilar adenopathy. We report a young woman with arthralgias, fever, pleuritic pain, peripheral and hilar lymphadenopathy, high titer ANA, and a low serum complement. Transbronchial lung biopsy revealed interstitial pneumonitis. SLE should be considered an unusual cause of hilar adenopathy.

Cavitary pulmonary metastases from vulvar carcinoma.

A patient with vulvar carcinoma and multiple cavitary pulmonary metastases was diagnosed by transbronchial lung biopsy. The patient had no pulmonary symptoms, and the lesions regressed radiographically with combination chemotherapy. Although unusual, vulvar carcinoma can metastasize to distant organs.

The pathogenesis of low glucose, low pH malignant effusions.

Possible mechanisms to explain the finding of a low pH, low glucose, malignant pleural effusion include: use of glucose and acid production by pleural fluid constituents including leukocytes and free malignant cells; pleural membrane metabolism, especially by malignant cells; abnormal transfer of glucose, carbon dioxide, and hydrogen ion across a diseased pleural membrane. To determine the pathogenesis of low glucose, low pH effusions, we performed incubation and glucose and gas transport studies in 5 patients with malignant effusions, 3 with a low pH (less than 7.30) and 2 with a pH greater than 7.30 (control patients). After 24 h of incubation, there was no significant difference in the metabolic activity of pleural fluid between low pH fluids and control fluids. Transport studies confirmed impaired glucose transfer both into and out of the pleural space and impaired efflux of CO2 from the pleural space in patients with low pH effusions, whereas control patients demonstrated free transfer across the pleural membrane. It appears that an abnormal pleural membrane (tumor or fibrosis), rather than increased acid production, results in a low glucose concentration from impaired glucose transfer from blood to pleural fluid and a low pH from impaired hydrogen ion efflux in some malignant effusions.

The contribution of leukocytes and bacteria to the low pH of empyema fluid.

Empyema fluid characteristically has a low pleural fluid pH, and it has been demonstrated that this fluid has a high acid-generating capacity. To evaluate the contribution of leukocytes and bacteria to the low pH of empyema fluid, an experimental model of empyema was used. After the production of a sterile pleural effusion by turpentine in both normal and neutropenic New Zealand white rabbits, either live Streptococcus pneumoniae, killed Streptococcus pneumoniae, or Acinetobacter, an organism that does not undergo fermentation or produce substantial acid, were injected into the pleural fluid. With these manipulations, the contribution of leukocytes and bacteria alone could be assessed. The results showed that both leukocyte phagocytosis and bacterial metabolism contribute to the low pH of empyema fluid and that the number of polymorphonuclear leukocytes per se in clinically observed ranges is not critical to the change in pleural fluid pH.