Effect of asthma severity on symptom perception in childhood asthma

Abstract

Individual ability to perceive airway obstruction varies substantially. The factors influencing the perception of asthma are probably numerous and not well established in children. The present study was designed to examine the influence of asthma severity, use of preventive medication, age and gender on the association between respiratory symptoms (RS) and peak expiratory flow (PEF) rates in asthmatic children. We followed 92 asthmatic children, aged 6 to 16 years, for five months. Symptom scores were recorded daily and PEF was measured twice a day. The correlations among variables at the withinperson level over time were analyzed for each child and for the pooled data by multivariate analysis. After pooling the data, there was a significant (P<0.05) correlation between each symptom and PEF; 60% of the children were accurate perceivers (defined by a statistically significant correlation between symptoms and PEF across time) for diurnal symptoms and 37% for nocturnal symptoms. The accuracy of perception was independent of asthma severity, age, gender or the use of preventive medication. Symptom perception is inaccurate in a substantial number of asthmatic children, independently of clinical severity, age, gender or use of preventive medication. It is not clear why some asthmatic patients are capable of accurately perceiving the severity of airway obstruction while others are not.

Correlations between pulse oximetry and peak expiratory flow in acute asthma

“…Significant changes in lung function may be present despite the lack of clinical manifestations (1,2,6), as first reported in the 1970's (1) and confirmed by subsequent studies (2)(3)(4)(5)(6)(7)(8)(9). The severity of acute asthma is classified as mild, moderate, severe, and very severe based on clinical and functional criteria (10), the most widely used being pulse oximetry (SpO 2 ) and peak expiratory flow (PEF).…”

“…Clinical findings are usually insufficient to properly determine the severity of acute asthma (1)(2)(3)(4)(5)(6)(7)(8)(9). Significant changes in lung function may be present despite the lack of clinical manifestations (1,2,6), as first reported in the 1970's (1) and confirmed by subsequent studies (2)(3)(4)(5)(6)(7)(8)(9).…”

Pico do fluxo expiratório no acompanhamento de crianças asmáticas

“…10 Cabral et al, followed 92 children aged 6 to 16 years for 5 months, also observing a significant correlation between PEF and symptoms, although a weak one and with a negative coefficient, (p < 0.05). 11 Liam et al …”

“…between alterations to PEF and symptoms suggestive of deteriorating pulmonary function. 3,8,10,11 However, analogous studies are scarce in Brazil and Latin America. 11 The objective of the work reported here was to attempt to correlate VEF 1 and PEF measurements with clinical parameters in clinically stable children and adolescents with moderate and severe asthma on inhaled corticoids, in addition to verifying the contribution that serial PEF measurements have to offer for the outpatients follow-up of these patients.…”

Peak expiratory flow monitoring in asthmatic children

“…A maioria dos estudos analisou crianças com asma moderada a grave, controladas com corticóide inalatório. Demonstrou-se que existe uma correlação fraca (r de Pearson variando de -0,34 a 0,5) entre alterações no PFE e sintomas sugestivos de piora da função pulmonar 3,8,10,11 . Por outro lado, são escassos os estudos análogos desenvolvidos no Brasil e América Latina 11 .…”