Stability of blood gases in ice and at room temperature.

Arterial blood samples from 75 patients were analyzed for PO2, PCO2, and pH at 0, 15, and 30 min. After the baseline analysis, 60 samples were kept in ice while 59 samples were left at room temperature. There was a statistically significant increase in the PO2 at 15 min and again at 30 min in both groups. There was a statistically significant decrease in the PCO2 at 15 min in both groups. There were no further changes in the PCO2 at 30 min in either group. There was a statistically significant decrease in the pH at 15 min in both groups. There was a further statistically significant decrease in the pH at 30 min in the group of blood samples left at room temperature but not in those in ice. There is no reason to keep arterial blood in ice if blood gas analysis is done within 30 min.

Regional and systemic CD4 and CD8 subsets in bronchogenic carcinoma.

We studied lung and blood lymphocytes from 12 asymptomatic patients with peripheral bronchogenic carcinoma. Bronchoalveolar lavage was performed in the lung segment with tumor and a contralateral uninvolved lung segment and analyzed separately. After partial removal of macrophages by plastic adherence, cells were labeled with markers for CD4 and CD8 and analyzed by flow cytometric analysis. We found no significant difference in the percentages of mononuclear cells in either immune subset when comparing the lung containing tumor with the uninvolved lung. We did find, however, a depressed CD4/CD8 ratio in the peripheral blood. We conclude that a lung carcinoma does not change the local immunologic milieu of the lung parenchyma containing the carcinoma. It is not clear if the immunologic findings in the lungs and blood are due to the bronchogenic carcinoma, smoking, or the underlying chronic obstructive pulmonary disease.

Needle aspiration of extrathoracic metastases from bronchogenic carcinoma.

Five patients with suspected metastatic bronchogenic carcinoma underwent needle aspiration of peripheral metastatic lesions instead of a diagnostic bronchoscopy. Aspirates were from the soft tissue of the proximal arm (three patients), an axillary mass (one patient), and a skin nodule (one patient). Two patients had non-small cell carcinoma, two had small cell carcinoma, and one patient had a nondiagnostic aspirate. The procedure had insignificant morbidity, was easy to perform, quickly established a diagnosis of metastatic disease, and obviated the need for a more invasive diagnostic procedure in four of the five patients.

Neoplastic obstruction of the trachea complicating pseudobulbar palsy.

We have reported a case of pseudobulbar palsy with airflow obstruction initially attributed to chronic aspiration and chronic airflow obstruction caused by cigarette smoking. The finding of stridor led to a detailed evaluation of the obstruction. Flow-volume loops, fiberoptic bronchoscopy, CT scan of the upper thorax, and fine-needle biopsy of a lesion of the trachea were required to make the diagnosis of non-small-cell carcinoma involving the trachea.

The effect of nasal flow on breathlessness in patients with chronic obstructive pulmonary disease.

Many patients with chronic obstructive pulmonary disease (COPD) receiving supplemental oxygen state that this treatment makes them less short of breath at rest. We postulated that this phenomenon may be related to improved arterial oxygenation, reduced ventilation, or stimulation of nasal receptors caused by the flow of gas. Eight patients who reported this phenomenon were studied in a quiet room. Each patient received zero flow, 2, or 4 L/min of air or oxygen through nasal cannula for 5 min at each level in random order in a single blind manner. At the end of each period, arterial blood gas composition was measured, and breathlessness was assessed with a visual analog scale. The scale was calibrated to read from zero (not at all breathless) to 100 (extremely short of breath). The entire protocol was repeated after application of topical lidocaine to the nasal passages. Results were assessed by analysis of variance. We found no significant effect of inspired oxygen concentration, gas flow, arterial oxygen tension, or arterial carbon dioxide tension on breathlessness. There was, however, a significant increase in breathlessness after nasal anesthesia from 44 +/- 3 SEM to 52 +/- 4 SEM (p less than 0.005). We suggest that the reduction of breathlessness in these patients by nasal oxygen is a placebo effect caused by wearing the nasal cannulas and is unrelated to gas flow or the increased arterial oxygen tension.

Ribavirin aerosol in the elderly.

Ribavirin aerosol is effective in treating respiratory syncytial virus and influenzal infections in children and young adults. It has not been studied in elderly patients. We evaluated the safety of ribavirin aerosol in eight elderly volunteers at high risk for influenza. Their mean age was 64 years; seven subjects had chronic obstructive pulmonary disease (COPD). Subjects received ribavirin aerosol for two or six hours with six hours between treatments. Regimens were continued for 96 hours. The drug was well tolerated. Subjects receiving ribavirin for 2 hours demonstrated a significant decrease in their forced expiratory volume in one second, peak expiratory flow rate and flow over the middle 50 percent of the forced vital capacity. These changes were small and the subjects' symptoms remained stable. Subjects receiving ribavirin for 6 hours had no significant changes in pulmonary function. We conclude that ribavirin aerosol is safe in elderly patients with underlying COPD.

Impaired hypoxic ventilatory drive in diabetic patients with autonomic neuropathy.

The mortality of diabetic patients with autonomic neuropathy (DAN) is higher than that in those without autonomic neuropathy (DM). To test the hypothesis that this may be due to respiratory rather than cardiac dysfunction, we evaluated ventilatory responses to isocapnic-hypoxic and hyperoxic-hypercapnic conditions in 14 diabetic patients (8 DAN and 6 DM) and compared the results with those in 8 normal subjects. In all groups tested there was a significant linear correlation between end-tidal CO2 and minute ventilation and between end-tidal CO2 and mouth occlusion pressure (p100), as an index of the drive to breathe. There were no significant differences between the slopes and intercepts in the groups tested. A significant linear correlation was found between the O2 saturation and both minute ventilation and p100. There were no significant differences in the relationship between minute ventilation and O2 saturation, but the slopes and the intercepts of the regression lines of p100 vs. O2 saturation were significantly different in the DAN compared with those in normal subjects and DM. Additionally, five of eight patients with DAN lost their ventilatory drive and ventilatory responses to hypoxemia compared with only one of six DM. These findings suggest that a disorder in the ventilatory response to hypoxemia exists in some DAN.

Pleuropericarditis in sarcoidosis.

A 30-year-old woman with sarcoidosis had both pleural and pericardial involvement. Involvement of either organ is uncommon, and except for one autopsy case, simultaneous involvement has not been reported.

A history of resuscitation.

In the 1950s, researchers devised the best methods of ventilation. In the 1960s, a method of maintaining circulation and ventilation simultaneously was introduced. In the 1970s, refinements of the understanding of the mechanisms of blood flow during CPR were defined and were accompanied by an aggressive research effort to identify means to improve brain protection during and after cardiac arrest. It is hoped that the fruits of this work will lead to knowledge of better ways to effect resuscitation and will maximize the quality of life in survivors of cardiac arrest.

Cope needle biopsy.

I reviewed the results of 143 Cope needle biopsies in 121 patients. Diagnostic biopsies were obtained in 26 patients. Two patients with rheumatoid pleuritis had suggestive pleural fluid. Seventeen of the 19 patients with malignancy had diagnostic pleural fluid cytology. Seven additional patients with nondiagnostic biopsies had diagnostic pleural fluid cytology. In four of five patients with tuberculosis, Mycobacterium tuberculosis grew from cultures of pleural fluid. One additional patient with a nondiagnostic biopsy also had a pleural fluid culture that grew M tuberculosis. Pleural biopsy was the sole means of diagnosis in only two patients. Diagnostic yield was not increased in the 21 patients who had multiple biopsies. In the diagnosis of malignancy, pleural fluid cytology was superior to pleural biopsy. In the diagnosis of tuberculosis, pleural fluid culture was as good as pleural biopsy. Cope needle biopsy should be done only when a strong suspicion of pleural malignancy or tuberculosis exists.

Asymptomatic cryptococcal meningitis.

Two cases of asymptomatic cryptococcal meningitis are described. The disease was diagnosed only after Cryptococcus neoformans was cultured from lung tissue and urine. These cases represent 2 of 11 meningitis cases seen in a 10-yr period at this hospital. Of 11 cases of extraneural cryptococcosis, 6 had lumbar punctures and these 2 had positive culture results. Asymptomatic cryptococcal meningitis is not rare. Our experience suggested that lumbar punctures should be performed routinely in patients with cultures yielding Cryptococcus neoformans from extraneural sites.

Diagnosis of upper airway obstruction by pulmonary function testing.

We compared 11 patients with upper airway obstruction (obstruction at or proximal to the carina) to 22 patients with chronic obstructive pulmonary disease and to 15 normal subjects utilizing spirometry, lung volumes, airway resistance, maximal voluntary ventilation, single-breath diffusion capacity, and maximal inspiratory and expiratory flow-volume loops. Four values usually distinguished patients with upper airway obstruction: (1) forced inspiratory flow at 50 percent of the vital capacity (FIF50%) less than or equal to 100 L/min; (2) ratio of forced expiratory flow at 50 percent of the vital capacity of the FIR50% (FEF50%/FIF50%) larger than or equal to 1; (3) ratio of the forced expiratory volume in one second measured in milliliters to the peak expiratory flow rate in liters per minute (FEV1/PEFR) larger than or equal to 10 ml/L/min; and (4) ratio of the forced expired volume in one second to the forced expired volume in 0.5 second (FEV1/FEV0.5) larger than or equal to 1.5. The last ratio can be determined with a simple spirometer.