Disease relevance of Closing Volume

• Respectively, closing volumes increased from normal conditions to atrial fibrillation from 3.2 to 5.1 ml for Björk-Shiley, from 4.6 to 6.3 ml for Medtronic Hall, from 5 to 6.6 ml for St [1].
• "Closing volume" changes in alloxan-induced pulmonary edema in anesthetized dogs [2].
• Effects of salbutamol and propranolol on closing volume in extrinsic bronchial asthma [3].

High impact information on Closing Volume

• METHODS: We assessed 262 consecutive climbers of Monte Rosa (4559 m), before ascent and about 24 h later on the summit 1 h after arriving, by clinical examination, electrocardiography, oximetry, spirometry, carbon monoxide transfer, and closing volume [4].
• The slope of the alveolar plateau on the closing volume tracing showed a 271% increase 20 minutes after the prostaglandin administration, at which time the closing volume per cent (CV%) had decreased (P less than 0-01) and the closing capacity (CC%) had increased (P less than 0-05) [5].
• MEASUREMENTS: Measurements of static and dynamic lung volumes, diffusing capacity of the lung for carbon monoxide (as measured by the single-breath method), nitrogen slope of the alveolar plateau, and closing volume (as measured by the single-breath O2 test) [6].
• In two of three smokers the effect of airway pressure on closing volume was abolished by salbutamol [7].
• The sensitivity of the closing volume to airway pressure could not be reproduced in three non-smokers exposed to a histamine aerosol [7].

Biological context of Closing Volume

• In a group of asthmatics, intravenous histamine induced a significant decrease in the forced vital capacity, expiratory volume in the first second, and peak flow, while increasing the respiratory system resistance and the closing volume [8].
• Additional pulmonary measurements before and after exposure included lung compliance, airway resistance, density dependence of flow, nitrogen closing volumes, carbon monoxide diffusing capacity, and alveolar-arterial oxygen differences [9].
• Nitrogen and bolus closing volumes: differences after histamine-induced bronchoconstriction [10].
• In the supine (but not the sitting) position, (A-a)PO2 and venous admixture, breathing both air and O2, were more highly correlated with the difference between closing volume and expiratory reserve volume than with age [11].

Anatomical context of Closing Volume

• Superoxide anion production by macrophages, studies of small airway integrity (closing volume, closing capacity, and the slope of Phase III of the single-breath nitrogen washout curve), and evaluation of alveolar gas exchange (diffusing capacity of carbon monoxide) were similar in both nonsmokers and marijuana smokers [12].

Associations of Closing Volume with chemical compounds

• Closing volumes (CV) were determined using a single breath O2 test [13].
• Isoprenaline abolished the effect of pulmonary vascular congestion on closing volume [14].
• In normal subjects, PGF2alpha induced small but significant decreases of SGaw and spirometric parameters (FVC, FEV1), whereas there was no effect on the closing volumes [15].
• Two techniques were used, (a) "closing" volume (CV), measured from the expired nitrogen plateau and (b) tantalum bronchography, to measure the calibre of airways of 3-8 mm diameter in the upper (UZ), middle (MZ) and lower (LZ) zones [16].
• "Closing volume" (CV) was measured by the single-breath oxygen (SBO2) test in six dogs (alloxan group) before and after alloxan 100-200 mg/kg iv) was injected [2].

Gene context of Closing Volume

• Pulmonary function testing consisted of the single breath nitrogen test (SBN2) to determine the closing volume (CV) and slope of the alveolar plateau, and a maximum expiratory flow volume curve (MEFV) to determine expiratory flow at low lung volumes [17].
• 2. Immersion in water to the neck resulted in a small but significant fall in VC, FEV 1.0/FVC and TLC, and a rise in DLCO, but flow/volume curves and 'closing volume' were unchanged [18].
• The closing volume also seems to be abnormal in the early course of the disease, while elevated lysozyme and beta2-microglobulin levels rather seem to reflect the extent of the pulmonary affection [19].

References