99Tcm-Technegas and krypton-81m ventilation scintigraphy: a comparison in known respiratory disease.

Krypton-81m gas, by virtue of its imaging characteristics, is often considered the "gold standard" for ventilation scintigraphy but its use is restricted by its high cost and limited availability. The new radiopharmaceutical 99Tcm-Technegas, a suspension of ultrafine technetium-99m labelled carbon particles, produces high-quality images of ventilation and has the advantage of continuous availability. As part of our evaluation of Technegas the two were compared in 40 patients with a variety of established respiratory diseases. Disparities were seen in five patients in five diagnostic groups and may be a consequence of the differing physical properties of the two agents and the different inhalation techniques used. In addition two interesting features were noted on the Technegas images. (1) Hot spots were seen in 50% of patients, particularly in those with a degree of airways obstruction; (2) preferential basal deposition of activity was seen in 30%, particularly in patients with idiopathic pulmonary fibrosis. Both features were significantly associated with parameters of pulmonary function indicating obstructive lung disease in the former case and restrictive lung disease in the latter.

The incidence and severity of hypoxia associated with 99Tcm Technegas ventilation scintigraphy and 99Tcm MAA perfusion scintigraphy.

Inhalation of the ventilatory radiopharmaceutical 99Tcm Technegas leads, in some patients, to symptoms that may be attributed to temporary lowering of oxygen saturation. In order to evaluate this, oxygen saturation was measured by pulse oximetry in a series of patients undergoing Technegas ventilation scintigraphy. A decrease in oxygen saturation was recorded in 87% of the patient group. The mean change, as a percentage of the initial value, was 8.3% (range 1-24%). Hypoxia arising in association with Technegas administration may be reduced by pre-oxygenation. In patients who were pre-oxygenated, oxygen saturation did not fall below 85% (PaO2: 50 mmHg) but in 39% of those not pre-oxygenated the value fell below this level. Oxygen saturation was also monitored in a series of patients undergoing perfusion scintigraphy. In 17% of patients a decrease was recorded (range 2-11%). In view of the large number of perfusion scans performed annually in this department and elsewhere without untoward effect, such temporary decreases in oxygen saturation presumably present no hazard to the patient.

Airways obstruction and bronchiectasis: correlation with duration of symptoms and extent of bronchiectasis on computed tomography.

Many patients with bronchiectasis have diffuse airways obstruction and this may be the dominant symptom. This study was performed to assess whether the severity of airway obstruction in these patients is related to duration of bronchiectatic symptoms or to the extent of bronchiectasis demonstrated by computed tomography (CT). Twenty-six patients were studied. The severity of airflow obstruction was measured by standard physiological testing and the extent of bronchiectasis demonstrated by CT was assessed using a scoring system. Correlation was measured by Kendall's rank correlation coefficient. A highly significant correlation between FEV1 and CT score was demonstrated and a significant correlation was also observed between FEV1 and duration of symptoms. A weak correlation was present between CT score and symptom duration.

Androgen associated hepatocellular carcinoma with an aggressive course.

The hepatocellular carcinomas that develop in patients treated with androgens have previously been associated with a benign clinical outcome. We describe a man who developed a hepatocellular carcinoma after 24 years of androgen treatment, whose tumour initially showed partial regression after withdrawal of androgens but subsequently pursued an aggressive and fatal course.

Treatment of malignant pleural effusions with intrapleural Corynebacterium parvum or tetracycline.

Thirty two patients with malignant pleural effusion were randomly allocated to treatment with intrapleural Corynebacterium parvum or tetracycline hydrochloride in an attempt to prevent symptomatic recurrence of pleural fluid. Success in preventing recurrence of fluid at one month, using up to 2 doses of each drug, was 14 of 16 cases for Corynebacterium parvum, 5 of 9 for tetracycline given via an intercostal needle, and 6 of 7 for tetracycline given through an intercostal tube. These difference were not statistically significant. Corynebacterium parvum was significantly more likely to produce pyrexia equal or greater than 38 degrees C (P less than 0.001) and pain requiring analgesia (P less than 0.05) than tetracycline hydrochloride. Corynebacterium parvum is a useful agent for the management of malignant pleural effusion, but is associated with more side effects than tetracycline.

High serum thyroxine-binding globulin--an important cause of hyperthyroxinaemia.

Four patients are described who had a significant elevation of serum thyroxine-binding globulin (TBG). Review of these patients indicated that inappropriate therapy for thyrotoxicosis had been given in three cases. A study of our laboratory records revealed that significant TBG elevation was a relatively common phenomenon which occurred in approximately 0.45% of our hospital population. Patients with this abnormality have serum thyroxine levels which are comparable to those with clinical thyrotoxicosis. Tri-iodothyronine is frequently elevated though less so than in patients with clinical thyrotoxicosis. Measurement of TBG is indicated in all cases of hyperthyroxinaemia in which the clinical features of thyrotoxicosis are doubtful. The TRH test was found to be most useful in evaluating the thyroid status of these patients.

Cutaneous vasculitis and immune complexes in severe bronchiectasis.

Four patients with severe bronchiectasis (chronic bronchial suppuration) are described who developed cutaneous lesions associated with exacerbations of their respiratory disease. The skin abnormalities consisted of purpuric lesions in three patients and an erythematous vasculitis in one. Circulating immune complexes were present in all patients and in three skin biopsy specimens showed deposition of C3, IgG, and IgA in dermal blood vessels. Haemophilus influenzae had been isolated from the sputum of all four patients and in two patients was present at the time the cutaneous lesions appeared. It is suggested that local immune complex deposition was responsible for the skin lesions which occurred during acute exacerbations of bronchiectasis.

Immunological abnormalities in patients with chronic bronchial suppuration: a possible relationship with endotoxaemia.

Chronic bronchial suppuration has been associated with elevations in immunoglobulin levels, circulating autoantibodies and immune complexes but the cause is obscure. In order to investigate one possible explanation we studied eight male subjects (mean age 54.9 years, range 39-68) and 16 female subjects (mean age 45.2 years, range 24-68) with bronchial suppuration attributed to bronchiectasis. Gram-negative organisms were found in the sputum of 95% of subjects. Forty per cent (10 subjects) had elevations in immunoglobulin levels and 60% (15 subjects) had circulating autoantibodies. Eighty-eight per cent (21 subjects) had mild-moderate increases in the level of C-reactive protein. Endotoxin was detected using the limulus amoebocyte lysate test in 50% (12 subjects). Endotoxin was found only in patients with an immunological abnormality and was more likely to be detected in those with both elevated immunoglobulins and circulatory autoantibodies. It is suggested that the endotoxin may be of aetiological significance in the development of autoantibodies and elevations of immunoglobulin levels.

Comparison of nebulized salbutamol with nebulized ipratropium bromide in acute asthma.

Twelve patients admitted to hospital with an acute attack of bronchial asthma were studied. Six were treated initially with nebulized salbutamol solution by inhalation and 1 hour later by ipratropium bromide given in the same way; the other six were treated first with ipratropium bromide and 1 hour later by salbutamol. Ipratropium bromide was shown to be as effective as salbutamol when used as the initial bronchodilator but salbutamol produced significant further improvement when given 1 hour after ipratropium.