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Abril 2016

ARTÍCULOS DE INVESTIGACIÓN The effect of benzodiazepines on bronchoconstriction in asthma patients - M. Miric et al of inhaled methacholine is shown in Figures 1 and 2. Figure 1 shows the effect of methacholine on the value of VC of patients with asthma, before and after inhalation of diazepam. On the first day of testing, giving methacholine provoked the dose-dependent response and reduction of VC. After inhalation of 6 mg/ml of methacholine, the values od VC significantly fell from 4.2 L to 2.7 L. Even 30 minutes after the provocation, VC values did not return to normal. However, in panel A it is shown that on the second day of testing, prior to the administration of diazepam, VC was 3.74 L in the same patient. After administration of the diazepam and methacholine (dose of 6 mg/ml), change in values of VC were significantly higher, 3.98 L, which means that VC increased and not decreased as compared to the initial value. VC was not significantly changed even after 30 minutes of testing (3.72 L) (Figure 1). Figure 2 shows the effect of methacholine on the value of FEV1 in patients with asthma, before and after inhalation of diazepam. In the first day of testing, methacholine inhalation (6 mg/mL) led to a significant drop in the value of FEV1 from 2.98 L to 1.69 L. On the second day of study, in the same patients, pretreatment with diazepam reduced the changes of FEV1, so that upon inhalation of methacoline the values of FEV1 droped from 2.48 L to 2.21 L. 437 Table 1. Anthropometric measures of patients treated with methacholine and benzodiazepines Anthropometric measures X ± SD (SE) Age (years) 48.5 ± 10.9 (3.1) Body height (cm) 164.2 ± 8.5 (2.4) Body weight (kg) 73.7 ± 12.6 (3.6) Broca index (%) 115.5 ± 21.3 (6.1) Number of respondents 12 Table 2. Mean values of lung function of asthmatic patients who are treated by methacholine and benzodiazepine Parameters of lung function X ± SD (SE) VC (%) 92.9 ± 16.0 (4.6) FEV1 (%) 83.3 ± 31.4 (9.0) 100 x FEV1/VC (%) 68.0 ± 23.2 (6.7) Rt 0.1 ± 0.06 (0.02) ITGV (L) 1.74 ± 0.6 (0.2) Srt (kPa • s) 0.3 ± 0.16 (0.04) PaO2 (mmHg) 75.3 ± 5.9 (1.7) PaCO2 (mmHg) 35.4 ± 10.3 (2.9) pH 7.4 ± 0.02 (0.006) Number of respondents 12 Panel A Panel B Figure 1. Effect of methacholine on the value of vital capacity (VC) in patients with asthma before and after inhalation of diazepam. Panel A: On the first day of study, methacholine given by inhalation caused dose-dependent response, and reduction of VC. On the second day test, previously given diazepam significantly decreased the change of VC. Panel B: shows motion of the value in VC, and response on methacholine in relation to time (30 minutes), before (2.7 L) and after (2.21 L) inhalation of diazepam. Rev Med Chile 2016; 144: 434-441


Abril 2016
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