K.N.V. Palmer

AEROSOL BECLOMETHASONE DIPROPIONATE: A DOSE-RESPONSE STUDY IN CHRONIC BRONCHIAL ASTHMA

Abstract In fifteen patients with chronic bronchial asthma, increasing the daily dose of aerosol beclomethasone dipropionate from 400 μg. to 1600 μg. by 28-day increments of 400 μg. resulted in no further therapeutic benefit. No impairment of adrenal function was seen with the lower doses, but this became apparent at 1600 μg. per day.

The effect of an alpha-adrenergic receptor blocking drug on histamine sensitivity in bronchial asthma.

Abstract Histamine induced bronchoconstriction was significantly reduced in 6 patients with extrinsic bronchial asthma by thymoxamine, a specific α-adrenergic 3 . Mean pulse rate and blood pressure in 6 asthmatic patients after intravenous thymoxamine (0 · 2 μg/kg) Mean Mean pulse rate blood pressure Basal 77 124 79 Immediate 81 118 76 5 min 80 119 77 10 min 80 120 81 15 min 80 117 79 30 min 80 117 78 60 min 77 119 81 receptor blocking drug. This study suggests that there are α-adrenergic receptors in the bronchial muscle of asthmatics, and that histamine sensitivity in asthma is due to hypersensitivity of these receptors.

EXTRINSIC ALLERGIC ALVEOLITIS AND CONTAMINATED COOLING-WATER IN A FACTORY MACHINE

Symptoms and signs typical of extrinsic allergic alveolitis occurred in 24 workers in a stationery factory. The illness was caused by inhalation of a water aerosol contaminated by microorganisms, and although no specific organism has been incriminated, affected workers had serum precipitins to the contaminated water, and the illness could be reproduced by inhalation challenge tests.

EFFECT OF AEROSOL ISOPRENALINE ON BLOOD-GAS TENSIONS IN SEVERE BRONCHIAL ASTHMA

Abstract In 20 patients in status asthmaticus aerosol isoprenaline reduced airway obstruction but did not increase the lowered P a O 2 . It is suggested that isoprenaline by intensifying the ventilation/perfusion disturbance in the lung may be of no benefit to the patient in gas exchange, and should therefore be used with caution in status asthmaticus.

AEROSOL BECLOMETHASONE DIPROPIONATE IN CHRONIC BRONCHIA ASTHMA

Abstract The effect of beclomethasone dipropionate aerosol on spirometry, plasma-cortisol levels, and bronchodilator requirements was compared with placebo in a double-blind crossover trial in fifteen patients with moderately severe chronic bronchial asthma who were not receiving systemic corticosteroids. Significant improvement in forced expiratory volume in 1 second was seen whilst the patients were on beclomethasone, and no significant reduction in plasma-cortisol levels was found.

SPIROMETRY AND BLOOD-GAS TENSIONS IN BRONCHIAL ASTHMA AND CHRONIC BRONCHITIS

Abstract 22 asthmatic and 31 chronic-bronchitic patients with comparable airway obstruction had hypoxaemia of similar extent but the bronchitics had significantly greater arterial carbon-dioxide tensions than the asthmatics. Forced expiratory volume in 1 second (F.E.V. 1 ) increased in 4 asthmatics after isoprenaline, but there was no improvement in hypoxaemia. Reasons are given for regarding acute hypercapnia in the asthmatic as an important sign of impending deterioration, and the need for blood-gas-tension measurements in the management of the severe asthmatic is stressed.

EFFECT OF A SELECTIVE BETA-ADRENERGIC BLOCKER IN PREVENTING FALLS IN ARTERIAL OXYGEN TENSION FOLLOWING ISOPRENALINE IN ASTHMATIC SUBJECTS

Abstract Practolol, a cardio-selective beta-blocking drug, prevented the fall in arterial oxygen tension in 11 asthmatic subjects after isoprenaline without diminishing significantly the bronchodilator action of isoprenaline.

DYNAMIC AND STATIC LUNG VOLUMES AND BLOOD-GAS TENSIONS IN BRONCHIAL ASTHMA

Abstract The dynamic and static lung volumes, arterial blood-gas tensions, pH, and the single-breath carbon-monoxide transfer factor, were measured in seventy-two asthmatic patients with airway obstruction of increasing severity. As airway obstruction increased the lungs became progressively more hyperinflated and this was accompanied by increasing hypoxaemia. Hypocapnia occurred with milder degrees of airway obstruction, the P a CO 2 tending to return to normal as airway obstruction increased.

VENOUS/ARTERIAL PULMONARY SHUNTING AS THE PRINCIPAL CAUSE OF POSTOPERATIVE HYPOXÆMIA

Abstract THE effect of breathing 100% oxygen on arterial PO 2 was used to measure the venous/arterial pulmonary shunt before and after upper-abdominal surgery. An increased true shunt of 12·0% was found postoperatively. Since, in a previous study, an increased venous-admixture effect of 12·4% was found in comparable patients, it is concluded that postoperative hypoxaemia arises almost entirely from true pulmonary shunting probably as a result of spontaneous alveolar collapse. This collapse, in turn, is most likely due to progressive inactivation of the pulmonary surfactant through failure to take periodic deep breaths postoperatively.

SPIROMETRY FOR PREOPERATIVE ASSESSMENT OF AIRWAYS RESISTANCE

Abstract Chronic bronchitis is the most important single factor predisposing to the development of postoperative bronchopneumonia. The clinical diagnosis of early bronchitis is easily overlooked because symptoms are often absent or only intermittent, and physical signs are present only later. Preoperative spirometry showed that 35% of all patients having elective operations have unequivocal evidence of increased airways resistance although only 15% admitted to a productive cough. Spirometry is, therefore, a simple aid in the recognition of these high-risk patients, and should be used routinely.