Search PubMed⌕ Search

Biomedical subjects

J V Collins

Publications and source records attributed to J V Collins.

At least 91 records · Page 5Linked to original sources

Patterns of recovery of airflow obstruction in severe acute asthma.

The speed and patterns of recovery of airflow obstruction were analysed in 209 patients receiving a standard therapeutic regime for severe acute asthma. Initial rates of recovery were rapid. Three-quarters of the patients had achieved 50% of their total improvement in peak expiratory flow rate (PEFR) within 24 hr. The time taken to reach eventual maximum PEFR was very much longer, 50% of the patients taking one week or more. Diurnal variation of moderate or severe degree was seen in 78% of patients. Length of history of asthma, time of deterioration and other measures of the severity of attack on admission did not differ in faster and slower responders. The rise of PEFR within 4 hr of starting treatment was highly significantly correlated with a higher PEFR at 24 hr and a shorter time to full recovery. Although the mean arterial PCO2 was higher (P less than 0.01) in the slower responding group and they were slightly older (P less than 0.05) and had lower mean FEV1 (P less than 0.02) and FVC (P less than 0.05) these differences were less helpful in predicting which patients responded fastest.

Acute Disease↗

"Acute" asthma in adults.

Forty-four adult patients with acute severe asthma were studied on admission to a general hospital to determine the mode of presentation and clinical severity of the acute illness. Most patients described poorly controlled wheezing for a mean period of five weeks before a more rapid deterioration, usually over 24 hours, caused them to seek medical attention. The clinical severity of the acute attach was not related to the duration of acute wheezing before admission to hospital. Recovery, studied in 11 of the patients, was slow, and most had reached only 70% of their predicted spirometric values after seven days' treatment in hospital. The rate of recovery was not influenced by the antecedent history of acute wheezing. Very sudden deterioration from a background of good control appears to be uncommon in adults with asthma who present to hospital as emergencies, and it is likely that improvement in the standard of routine management of asthmatics at home would prevent many such admissions.

Acute Disease↗

Changes in pulmonary function after naturally acquired respiratory infection in normal persons.

Changes in pulmonary function due to naturally occurring respiratory tract infection were examinated in 26 normal healthy volunteers during a period of 6 months. Forced expiratory maneuvers in each volunteer were recorded at 2-wk intervals throughout the study and daily during illness. Significant impairment of peak expiratory flow rate, forced vital capacity, forced expiratory volume in one second, and maximal mid-expiratory flow rate at 50% of the vital capacity was observed during infection, whereas changes in the maximal expiratory flow rate at 75% of vital capacity were nonsignificant. From these results, we conclude that large airways are certainly affected during uncomplicated respiratory infections in normal healthy persons and from the changes observed in FVC we suggest that more widespread involvement of the small airways may occur.

Adolescent↗

Transbronchial lung biopsy through the fibreoptic bronchoscope.

Fifty-five patients were investigated using transbronchial lung biopsy through the flexible fibreoptic bronchoscope under fluoroscopic guidance, 51 by the transnasal route under local anaesthesia, two via an endotracheal tube whilst undergoing assisted ventilation and two by the same route under general anaesthesia. Multiple specimens of lung tissue subjects with diffuse pulmonary disease and in 16 of 32 (50%) with localized lesions, giving a positive yield of 64% of all cases. The only complication was an haemoptysis of 50 ml in one patient. Our results suggest that transbronchial lung biopsy is a relatively safe procedure which gives results comparable with other lung biopsy techniques.

Adolescent↗

Serum IgM antibody and influenza A infection.

Sucrose density gradient ultracentrifugation followed by haemagglutination inhibition for demonstrating specific influenza IgM was evaluated as a means of confirming recent infection with influenza A viruses. Specific IgM antibodies were found in at least one serum obtained from 83% of patients with proven recent infection with influenza A viruses but in none of the sera from 21 individuals without evidence of infection. Influenza IgM antibodies persisted for up to 112 days after infection. The relative merits of detecting specific IgM and complement fixing antibodies for diagnostic purposes are discussed.

Antibodies, Viral↗

A digital computer and a lung function test service: efficiency and costs.

An off-line digital computer used to calculate the results of routine lung function tests saved an average of 20% (9.8 min) of the time required per patient when compared with the use of a simple electronic calculator. This saving would permit an increase in the work-load of the laboratory from 1250 to 1500 patients per year if the same tests were used. The cost of suitable computer equipment, however, would exceed that of employing an additional lung function technician.

Computers↗

High-dose corticosteroids in severe acute asthma.

Twenty-six patients admitted to hospital for treatment of severe exacerbations of asthma unresponsive to bronchodilators were assigned to high-, medium-, or low-dose corticosteroid treatment regimens. The rates of recovery were assessed by changes in pulse rate, peak expiratory flow rate, and spirometric measurements and were not related to the dose of corticosteroids given. Very high systemic doses of corticosteroids do not offer significant advantages in treating severe exacerbations of asthma.

Adrenal Cortex Hormones↗

Effect of long-term ionized air treatment on patients with bronchial asthma.

Seven patients with bronchial asthma requiring continuous medication were subjected to eight weeks of nocturnal exposure to negatively ionized air, and their progress was followed using objective tests of lung function and clinical assessment. During exposure, four patients showed significant increases in morning PEFR, which in two of these patients was not sustained when exposure ceased. In two patients the observed increase in PEFR was accompanied by subjective improvement. From the results of all our assessments we conclude that, although this treatment may lead to an improvement in some patients with asthma, further objective studies are required to determine the value of negatively ionized air in the routine management of asthma.

Adult↗

Airway function in healthy subjects and patients with left heart disease.

1. In forty non-smoking healthy subjects and seventy-two patients with left heart diseases measurements were made of the volume expired in the first second of a forced expiration (FEV1) and the total volume expired in a forced expiration (FVC) before and after inhalation of salbutamol. Before and after salbutamol the healthy subjects and patients also inhaled maximally an inspirate, the first part of which contained 133Xe and, during controlled expiration, the radioactivity of the expirate was measured and plotted against its volume. the resulting curves were divided into phases of different slope by eye, the point at which phase 3 changed to phase 4 being nominated the closing volume. 2. In forty non-smoking healthy subjects inhalation of salbutamol was followed by significant increase in FEV1 but FVC and closing volume did not change. 3. Change in posture from seated erect to supine in thirty of these healthy subjects was accompanied by significant reduction in FEV1 and FVC and as closing volume was not significantly different in the two positions the ratio closing volume/vital capacity was increased with recumbency. 4. In seventy-two patients with left heart diseases without a history of cough or wheeze, FEV1, FVC, closing volume and the ratio closing volume/vital capacity were significantly different from values in the healthy subjects. There was no significant difference between non-smokers and ex-smokers amongst the patients. 5. Significant increase in FEV1, FVC and reduction in closing volume and the ratio closing volume/vital capacity followed inhalation of salbutamol in patients with heart diseases but the values remained significantly different from those recorded in the healthy subjects. 6. In twenty patients with heart diseases, FEV1 and FVC were reduced by change in posture from seated erect to supine but the ratio closing volume/vital capacity and the regression with age of this ratio were not significantly changed by change in position. 7. In patients with heart diseases the ratio closing volume/vital capacity was significantly correlated with severity of breathlessness and length of symptom-history but not with left ventricular end-diastolic or pulmonary vein wedge pressures.

Adult↗

Hypothalamo-pituitary-adrenal function in intrinsic non-atopic asthma.

Sixteen patients with intrinsic non-atopic asthma with persistent wheezing who had never been treated with corticosteroids showed normal adrenocortical responses to prolonged stimulation with Tetracosactin Depot. In a subgroup of six patients the hypothalamo-pituitary-adrenal (HPA) response to a standard insulin stress test was normal. It is concluded that impaired responsiveness of the HPA axis is unlikely to be a common factor in initiating or maintaining airways obstruction in patients with intrinsic asthma.

Adrenal Glands↗

The use of corticosteroids in the treatment of acute asthma.

A study of 23 patients admitted to hospital with severe acute asthma is reported in which plasma cortisol level on admission was significantly correlated with the degree of acidaemia and pulse rate. Patients who had not previously received treatment with corticosteroids responded satisfactorily to repeated daily injections of tetracosactrin depot, the rate of improvement being comparable to that observed in other patients treated with intravenous hydrocortisone hemisuccinate. A prompt and sustained rise in plasma cortisol was also seen following tetracosactrin. The total daily dose of hydrocortisone required to achieve plasma cortisol levels above 100 mug/100 ml was less when given by continuous intravenous infusion compared with intermittent injections, and a regime of 3 mg/kg body weight every six hours by infusion appeared satisfactory. Most patients reported subjective improvement by about four hours after starting treatment but objective evidence did not appear until about six hours from the start. Measurements of FEV1 and FVC proved to be the most reliable indices of the beginning of improvement although pulse rate was the first index to show maximum improvement. Previous maintenance treatment with corticosteroids in patients with asthma did not appear materially to affect the plasma half-life of intravenous hydrocortisone (4 mgm/kg body weight) when compared with healthy subjects or other patients with asthma who had not previously been treated with corticosteroids.

Acute Disease↗