L M Guirau | PubMed Health

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[Non specific bronchial hyperreactivity in infants].

OBJECTIVE: To evaluate the presence of bronchial hyperreactivity (BHR) in Wheezing Babies (WB) and Normal Control Infants (C) employing the methacholine (M) bronchoprovocation test (BPT). METHODS: Fifty-one WB and 20 C, all under two years old and assisted at the Department of Pediatrics of UNIFESP-EPM, were submitted to BPT with M, having pulmonary auscultation as monitoring parameter to evaluate PCW (provocative concentration of M causing wheezing). For all tests, M diluted in saline at increasing concentrations of: 0.025, 0.125, 0.25, 0.5, 1.0, 2.5, 5.0, and 10.0 mg/ml was delivered with O2 (5 l/min) by a face mask. It was inhaled through the mouth and nose during 2 minutes of quiet tidal breathing via nebulizer with 2 ml of solution. RESULTS: None collateral effects were observed, except for tachypnea and tachycardia. There was statistically significant differences between WB (2.3 mg/ml) PCW value and C (9.2 mg/ml) (p < 0.05). At the PCW value of 2.5 mg/ml, 41% of the WB had statistically positive response (p < 0.05). This was not observed in the group C, when a positive response only occurred at the concentration of 5 mg/ml (25%). At this concentration we observed a clear cut difference between WB and C (p< 0.05). According to the severity, the highest M concentration was observed within the group displaying mild symptoms. CONCLUSIONS: We conclude that BPT utilizing PCW may be a good option for detecting BHR in young children. It is well tolerated by children, easy and safe to perform. Follow-up studies may clarify the real mean of the PCW.

English Abstract↗

PubMedDate not supplied

Bronchoprovocation with methacholine in children under two years old: a follow-up study.

Fifty-one wheezing babies (WB) under two years of age and 20 controls (C) within the same age range were submitted to a bronchial provocation test (BPT) with methacholine. The appearance of wheezing on pulmonary auscultation was used to determine PCW (provocative concentration of methacholine causing wheezing). For all tests, methacholine diluted in saline at increasing concentrations (0.025, 0.125, 0.25, 0.5, 1.0, 2.5, 5.0 and 10.0 mg/ml) was delivered with O2 (5 ml/min) via a face mask. Solution was inhaled through the mouth and nose during two minutes of quiet tidal breathing via a nebulizer containing a 2 ml volume. No collateral effects were observed, except for tachypnea and tachycardia. There was a statistically significant difference between the PCW for WB (2.3 mg/ml) and the PCW for C (9.2 mg/ml). A 5 mg/ml concentration of methacholine provides the clearest distinction between the WB and C groups. Indeed, we observed that 96% of WB and 25% of C demonstrated PCW below this concentration. In the WB group, those with mild symptoms had higher PCW values. When the BPT was repeated in 27 WB at an 8-month interval, statistically significant differences between the two PCV values were observed. The highest PCW values were evidenced in the second BPT. The use of BPT with methacholine could establish PCW as a parameter of bronchial hyperreactivity in infants.

Administration, Inhalation↗