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Biomedical subjects

D J Lane

Publications and source records attributed to D J Lane.

At least 55 records · Page 3Linked to original sources
PubMed1983

Current therapeutic practice in the management of acute severe asthma.

In a prospective study we have documented the treatment administered to patients before and during attacks of acute severe asthma, including cases managed at home by the general practitioner and those treated in hospital. In the course of 1 year, 261 consecutive episodes were studied. Five patients required artificial ventilation but there were no fatalities. In 28 patients (11.8%) no regular maintenance therapy was being taken before the index attack, and in 72 (30.3%) no regular treatment with a beta 2-adrenergic bronchodilator. Childhood asthmatics were receiving less maintenance therapy than adults, with the exception of cromoglycate. An increased dose of a beta 2-adrenergic bronchodilator was taken prior to medical consultation in 64.7% as the attack developed, but an increased dose of oral steroids in only 19.3%. The general practitioners gave intravenous steroids in 53 cases (61.6%), but rarely combined this with a bronchodilator. However, when a combination of a bronchodilator and intravenous steroids was given, there was a significant reduction in the need for hospital admission. In hospital the majority of patients received intravenous steroids as well as a nebulized beta 2-adrenergic bronchodilator and an intravenous xanthine bronchodilator, but one-third were not given oxygen. Sedatives were rarely used. Differing treatment patterns emerged when contrasting childhood with adult episodes, whether managed inside or outside hospital. Comparisons are made between the treatment observed in practice and that currently recommended for optimal treatment, and the implications are discussed.

Acute Disease↗
PubMed1983

Nocturnal hypoxaemia in chronic obstructive pulmonary disease.

1. Day and night arterial oxygen saturation (Sao2) has been measured in forty-one patients with chronic obstructive pulmonary disease (COPD), mean FEV1 0.84 (range 0.4-1.4)litres, and with a range of daytime Sao2 values of 67-95%. 2. The mean and biggest falls in Sao2 at night were much greater in the patients with lower daytime saturations. However, when falls in arterial oxygen tension (Pao2) were estimated from the decreases in Sao2, there was no correlation between the estimated biggest fall in Pao2 and daytime Sao2 and only a weak correlation between estimated mean fall in Pao2 and daytime Sao2. 3. Measurement of ventilation in four hypoxaemic patients with COPD (range 60-90% Sao2) by respiratory inductance plethysmography showed that nocturnal hypoxaemic dips were accompanied by diminished ventilation, which was not always shown by nasal thermistors. 4. Because nocturnal hypoxaemic dips are transient the ideal alveolar-arterial oxygen difference, which assumes a constant respiratory exchange ratio, cannot be used to assess the mechanism of hypoxaemia. 5. Erythrocyte mass was strongly correlated with daytime Sao2 but this correlation was not significantly improved by including nocturnal hypoxaemia in the regression. 6. The results suggest that greater falls in Sao2 at night are related to lower initial Sao2 values and that the cause may be a reduction in ventilation.

Circadian Rhythm↗
PubMed1983

Air-flow limitation in myasthenia gravis. The effect of acetylcholinesterase inhibitor therapy on air-flow limitation.

In a survey of 21 patients with myasthenia gravis receiving regular acetylcholinesterase inhibitor therapy, 8 were found to have air-flow limitation associated with their antimyasthenic therapy. In 6 of these subjects, detailed assessments were made of the effect of antimyasthenic therapy on airways function. Pyridostigmine was given together with either placebo or the anticholinergic bronchodilator ipratropium bromide (72 micrograms) by inhalation administered double blind on 2 consecutive days. Airways resistance (Raw) increased significantly after pyridostigmine and placebo inhaler (0.49 +/- 0.13 kPa/L/s basal versus 0.60 +/- 0.13 kPa/L/s at 2 h; mean +/- SEM, p less than 0.05), whereas a significant decrease in Raw followed the combination of pyridostigmine with ipratropium bromide (0.57 +/- 0.08 kPa/L/s basal versus 0.41 +/- 0.07 kPa/L/s at 2 h, p less than 0.05). Thus, acetylcholinesterase inhibitor therapy in subjects with myasthenia gravis with airflow limitation led to significant increase in airways resistance that could be completely reversed by the inhalation of the muscarinic receptor blocker ipratropium bromide.

Airway Resistance↗
PubMed1983

Acute severe asthma: factors that influence hospital referral by the general practitioner and self-referral by the patient.

We describe a prospective study of 261 consecutive episodes of acute severe asthma occurring in 232 patients in 1 year. Sixty-seven episodes were treated at home by a selected group of 34 general practitioners, 148 episodes were treated in hospital following referral from general practitioners and 46 episodes were treated in hospital after self-referral, not having been seen by a general practitioner. All patients recovered fully. Comparisons between these groups of patients showed that those selected for hospital admission had higher pulse rates, lower peak expiratory flow rates and more severe grades of attack than those treated at home. Children were more likely to be admitted to hospital, as were patients living near to hospital, or those who were already receiving hospital outpatient supervision. There were self-referrals in all age groups. Several factors which influence the decision on admission, including the speed of onset and severity of the episode, justify some shift of the primary care role from the general practitioner to the hospital. If self-referral is to be encouraged there is a need for agreement on the types of patient and the nature of the attack that are best suited to this type of management.

Acute Disease↗
PubMed1982

The speed of onset and severity of acute severe asthma.

The speed of onset of attacks of acute severe asthma was prospectively studied in a total of 261 consecutive episodes. 82% of these episodes involved patients with 'extrinsic' asthma and 28% involved children. The speed of onset of an attack was rapid (defined as less than 24 hours) in 46% of episodes and was less than one hour in 13%. Rapid-onset attacks occurred more frequently in younger patients and were no more or less severe than attacks of slower evolution. Comparison of different measures of severity in our patients showed statistically significant but low correlations. Objective measures seemed no better than simple clinical assessment with the Jones index. We discuss the significance of these correlations and the place of emergency admission services for attacks of acute severe asthma of rapid speed of onset.

Acute Disease↗
PubMed1982

Formaldehyde asthma: challenge exposure levels and fate after five years.

Because of current concern regarding possible adverse health effects of formaldehyde, we have reinvestigated two renal dialysis unit nurses shown to have formaldehyde asthma by inhalation provocation tests in 1973 and 1975, respectively. Their original tests were repeated and the formaldehyde levels generated (previously unknown) were measured. One nurse had not worked with formaldehyde since 1976 and had had no further symptoms. Her 1981 test (15-minute exposure to 6 parts per million [ppm] formaldehyde) provoked no asthmatic response. The other nurse had continued to work with formaldehyde, though under much improved conditions, and mild intermittent attacks of asthma had continued. Her test (five-minute exposure to 3 ppm formaldehyde) provoked a late asthmatic reaction similar to that observed in 1975. We conclude that in sensitized subjects specific late asthmatic reactions may be provoked by brief exposures to formaldehyde at about the current Occupational Safety and Health Administration standard (3 ppm); and that while asthmatic responsiveness may persist with continuing low levels of intermittent exposure, it may be lost following complete cessation of exposure.

Adult↗
PubMed1981

Ponto-bulbar palsy with deafness (Brown-Vialetto-Van Laere syndrome).

The authors describe the clinical and electrophysiological features in 2 cases of ponto-bulbar palsy with deafness, and the clinical course and post-mortem findings in a sibling of one of these, who died in infancy, and who appears to have suffered from the same disease. The cases are compared with 17 previously published cases, and the disease is discussed in relation to other progressive neurological diseases of childhood.

Adolescent↗
PubMed1981

Pleural effusion in allergic bronchopulmonary aspergillosis: two case reports.

Two cases of pleural effusion associated with allergic bronchopulmonary aspergillosis are described. This association has not previously been reported. In one case the effusion cleared with prednisolone. It is suggested that the effusions were directly related to the aspergillosis.

Aspergillosis, Allergic Bronchopulmonary↗
PubMed1981

Pattern of carbon dioxide stimulated breathing in patients with chronic airway obstruction.

The pattern of stimulated breathing during carbon dioxide inhalation was studied in a group of 21 patients with severe irreversible airways obstruction (mean FEV1 = 0.9 litre, mean FEV1/FVC% = 50%). Carbon dioxide rebreathing experiments were performed, the ventilatory response being defined in terms of total ventilation (V) and CO2 sensitivity (S). Breathing pattern was defined by the changes in tidal volume (delta VT) and respiratory frequency (delta f) and the maximum VT achieved (VTmax). Contrary to some previous studied no significant relationship could be demonstrated between the severity of airway obstruction (FEV1/FVC%, Raw) and the ventilatory response to rebreathing (V, S, delta VT, delta f, VTmax). However, measurements of dynamic lung volume (FEV1, FVC, IC) were found to be significantly correlated with the breathing pattern variables (delta VT, delta f, VTmax). Resting PaO2 and PaCO2 were significantly correlated with delta VT but not delta f. Results indicate that the degree of airway obstruction does not dictate the ventilatory or breathing pattern response to carbon dioxide induced hyperpnoea. In contrast it is the restriction of dynamic lung volume, by limiting the VT response, that appears to determine the ventilatory and breathing pattern response in patients with severe airway obstruction.

Airway Obstruction↗
PubMed1981

Tidal expiratory flow patterns in airflow obstruction.

Tidal expiratory flow pattern was analysed in 99 subjects with a view to assessing it as a quantitative measurement of airflow obstruction. Fifteen normal volunteers, nine patients with dyspnoea referred for investigation in whom airway resistance was within normal limits, 24 patients with restrictive lung disorders, and 51 patients with airway obstruction were studied. The expiratory flow pattern against time had a quadrilateral configuration in airway obstruction, which differed from the more sinusoidal form that is seen in subjects without airflow obstruction. The rapid rise to tidal peak flow was analysed in two ways, percentage of volume expired at tidal peak flow (delta V/V) and percentage of expiratory time to tidal peak flow (delta t/t). Both these indices correlated significantly with conventional measurements of airway obstruction. The pattern of expiratory flow in airflow obstruction during quiet breathing resembles that of a forced expiratory maneuver at similar lung volumes. In some cases this may be caused by dynamic compression occurring during tidal breathing. In others, the pattern may result from the static recoil of the lung being permitted to drive flow freely in expiration, rather than being braked by postinspiratory contraction of inspiratory musculature.

Adolescent↗
PubMed1980

Treatment of endobronchial amyloidosis by intermittent bronchoscopic resection.

In a patient with widespread endobronchial amyloidosis, the amyloid deposits resulted in severe disability over a ten-year period from obstruction of large airways and from recurrent chest infections and atelectasis. Repeated excision of small quantities of amyloid material during rigid bronchoscopy under general anaesthetic have resulted in symptomatic relief and measurable improvement of aiways obstruction.

Airway Obstruction↗
PubMed1980

HLA-A, B and C and HLA-DR antigens in intrinsic and allergic asthma.

Some 103 patients with asthma and 100 healthy volunteers have been typed for HLA-A, B and C and HLA-DR antigens. The 103 patients consisted of thirty-three with intrinsic asthma, thirty-four with extrinsic asthma, and thirty-six known to have precipitins to Aspergillus fumigatus. No increase in frequency of any of the A, B, C, or DR antigens was found to be significant after correction for the number of comparisons was made. However certain trends comparable to findings in other immunopathic disorders were noted. For example B12 was increased in the allergic asthmatics (46 vs 29% controls) and it is suggested that B12 is associated with the ability to produce the IgE antibodies. A3/B7/DRw2 (which are in linkage disequilibrium) all show a decreased frequency in intrinsic asthma (24, 12 and 9% vs 32, 26 and 24% respectively in controls). Finally B8 and DRw3, which showed a moderate increase in frequency in all three groups of asthmatics, were found in five of seven patients with low atopy but persisting antibodies to A. fumigatus. Further detailed studies of these asthmatic subgroups is warranted.

Adult↗