Analogue device for measurement of area under the maximum expiratory flow-volume curve

Bunn, Anthony E.; Brandt, H.; Vermaak, J.C.

doi:10.1007/bf02440920

Cited by 10 publications

(19 citation statements)

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“…All medications for asthma were discontinued 12 h prior to antigen challenge. Challenge was only carried out if the patient was asymptomatic and had an A V/V (area below the maximum expiratory flow volume curve (Bunn et al, 1979)) of more than 90% of his expected prechallenge value. These eight patients had previously participated in an antigen challenge study and had known reproducible predominantly early, biphasic or predominantly delayed responses to a specific antigen; Figure 1 …”

Section: Patientsmentioning

confidence: 99%

“…This is a composite measure of lung function impairment (includes peak flow, flow at all lung volumes and measurement of vital capacity) and has been found to be a more sensitive parameter than FEV, in detecting delayed reactions to antigen (Bunn et al, 1979). The maximum expiratory flow volume curve was obtained using a Collins dry rolling-seal spirometer (Model 06503).…”

Section: Antigen Inhalation Challengementioning

confidence: 99%

“…The maximum expiratory flow volume curve was obtained using a Collins dry rolling-seal spirometer (Model 06503). The area below this curve, AVN, was processed directly by an analogue integrating device coupled to the spirometer, and displayed on a digital voltmeter in units of square litres/s (Bunn et al, 1979). At each time point the average of two nearly identical best efforts was used as the result.…”

Section: Antigen Inhalation Challengementioning

confidence: 99%

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Lung function and plasma levels of thromboxane B2, 6‐ketoprostaglandin F1 alpha and beta‐thromboglobulin in antigen‐induced asthma before and after indomethacin pretreatment.

Shephard¹,

Malan²,

Macfarlane³

et al. 1985

Brit J Clinical Pharma

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1 The effect of specific antigen challenge on the lung function of eight allergic asthmatic patients after placebo and indomethacin pretreatment has been investigated. 2 Plasma levels of thromboxane B2(TxB2), metabolite of thromboxane A2, 6-ketoPGFia, metabolite of epoprostenol, (prostacyclin, PGI2) and ,-thromboglobulin (,TBG) following antigen challenge in these eight patients have also been measured after placebo and indomethacin pretreatment. 3 Each patient underwent two antigen inhalations 1 week apart. One challenge took place after 4 days pretreatment with indomethacin capsules 25 mg four times daily, and the other took place following 4 days placebo pretreatment, one matched capsule four times daily. The order of administration was random but balanced and blind with respect to the patient. 4 Following placebo pretreatment two patients presented with an early antigen response only, four presented with a biphasic antigen response and two presented with a delayed antigen response only. The asthmatic response for each patient was consistent on reexposure. 5 Indomethacin pretreatment suppressed the delayed antigen induced asthmatic response. This suppression was reproducible. 6 There was a rise in plasma TxB2 levels on antigen challenge following placebo pretreatment but not following indomethacin pretreatment, whereas there was a rise in 6-keto-PGF1I after antigen challenge following indomethacin but not placebo pretreatment.7 No significant change in plasma ,BTBG or platelet counts from control values was observed following antigen challenge with either placebo or indomethacin pretreatment. 8 It is suggested that the production of PGI2 and suppression of TxA2 by indomethacin pretreatment contribute to the suppression of the delayed antigen induced asthmatic response and that platelets play a minimal role in this process.Keywords thromboxane B2 6-keto-prostaglandin Fla P-thromboglobulin platelets indomethacin antigen-induced asthma

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Section: Patientsmentioning

confidence: 99%

Section: Antigen Inhalation Challengementioning

confidence: 99%

Section: Antigen Inhalation Challengementioning

confidence: 99%

See 1 more Smart Citation

Lung function and plasma levels of thromboxane B2, 6‐ketoprostaglandin F1 alpha and beta‐thromboglobulin in antigen‐induced asthma before and after indomethacin pretreatment.

Shephard¹,

Malan²,

Macfarlane³

et al. 1985

Brit J Clinical Pharma

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“…The area below' the expiratory flow volume curve (Av/V,.-) was determined electronically and was employed to determine postchallenge lung function changes [18). Patients performed max imal expiratory maneuvers on a Collins dry seal rolling spirometer until identical curves, or 2 with less than 5% difference in the Av/ V£ were obtained.…”

Section: Methodsmentioning

confidence: 99%

“…Patients performed max imal expiratory maneuvers on a Collins dry seal rolling spirometer until identical curves, or 2 with less than 5% difference in the Av/ V£ were obtained. The Av/Vf is a sensitive parameter of airway obstruction and parallels changes in forced expiratory volume (FEV,) -a correlation coefficient value of 0.88 has been found by multiple linear regression between FEV/FEV,,, and Av/V,./Av/ [19]. Blood samples for salbutamol determinations were obtained through an intravenous catheter.…”

Section: Methodsmentioning

confidence: 99%

Inhaled and Oral Salbutamol: How Effective in the Prophylaxis of Asthma?

Roux

Kotze²,

Wium³

et al. 1991

Respiration

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Inhaled and oral salbutamol were compared in 12 asthmatic patients for prophylaxis in antigen-induced asthma. The patients were pretreated with 0.2- and 1.0-mg doses of inhaled salbutamol and with the standard oral 4- and 8-mg slow-release (SR) salbutamol preparations. Bronchodilatation was monitored over the ensuing 3 h and protection against antigen challenge at the end of the period. On each study day the degree of baseline airway hyperreactivity was determined by histamine challenge. Precautions were taken during the antigen challenge to ensure a reproducible response. Blood levels of salbutamol were monitored at hourly intervals for the 3 h after treatment and during the asthmatic reaction subsequent to challenge. Both the 0.2- and 1.0-mg inhalations caused immediate bronchodilatation as compared to a placebo (p < 0.05), but only the 1.0-mg dose protected subjects against antigen challenge (p < 0.05). In comparison to the placebo, no bronchodilatation was achieved with the standard 4-mg oral preparation in spite of measurable blood levels, nor were the patients protected against antigen challenge at 3 h after pretreatment. However, the 8-mg SR salbutamol caused significant bronchodilatation within 2 h and suppressed antigen challenge responses as compared to placebo (p < 0.05). It can be concluded that doses of inhaled salbutamol higher than the conventional 0.2- or the standard 4-mg oral preparations are required to protect asthmatics against inadvertent antigen exposure. In patients who are unable to use inhalers effectively, the SR preparation can be considered as an alternative

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Non‐Steroid Anti‐Inflammatory Drugs in Asthma: Dangerous or Useful Therapy?

Joubert

Shephard

Mouton

et al. 1985

Allergy

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The therapeutic potential of non-steroid anti-inflammatory drugs in clinical asthma is offset by the real possibility of hypersensitivity and induction of severe airways obstruction. The influence of indomethacin on the antigen-induced asthmatic response was tested. Early and delayed asthmatic responses were recorded after antigen challenge in 13 subjects. Indomethacin pretreatment totally or partially inhibited the delayed asthmatic response in 10 of 11 subjects. Inhibition by indomethacin of products of the arachidonic cascade which participate in the pathogenesis of the delayed asthmatic response could explain this phenomenon. A similar therapeutic response was documented without adverse drug reactions when five subjects were restudied after several months. In the same group the early asthmatic response was suppressed in six, enhanced in two and unchanged in four of 12-subjects. This variable response indicates that spasmogenic prostaglandin breakdown products may be important for certain individuals, but are generally of less importance in the early asthmatic response. Clinical trials with indomethacin as a steroid saving agent in allergic asthma appear feasible and can be conducted safely.

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Analogue device for measurement of area under the maximum expiratory flow-volume curve

Cited by 10 publications

References 1 publication

Lung function and plasma levels of thromboxane B2, 6‐ketoprostaglandin F1 alpha and beta‐thromboglobulin in antigen‐induced asthma before and after indomethacin pretreatment.

Lung function and plasma levels of thromboxane B2, 6‐ketoprostaglandin F1 alpha and beta‐thromboglobulin in antigen‐induced asthma before and after indomethacin pretreatment.

Inhaled and Oral Salbutamol: How Effective in the Prophylaxis of Asthma?

Non‐Steroid Anti‐Inflammatory Drugs in Asthma: Dangerous or Useful Therapy?

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