الفهرس 
Bronchial asthmaOnly 14 pages are availabe for public view
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Abstract
Asthma is a heterogenous disease , usually characterized by chronic airway inflammation which affect whole respiratory tract ,from central to peripheral airway.
Many children do not achieve sufficient asthma control in spite of the availability of efficient drugs. Lack of adherence to prescribed therapy is a major factor but peripheral airway dysfunction and inflammation could contribute to failed asthma control.
This cross-sectional aimed to assess small airway function in asthmatic children and to correlate this to level of control , bronchial hyperresponsiveness (which assessed by spirometery and IOS pre- and post-bronchodilator and quality of life among them.
This study was conducted on 90 children ; 60 asthmatics with clinically definite asthma and Thirty healthy non asthmatic controls . Both asthmatics and controls were age and sex matched.
All studied cases were subjected to full history taking, complete clinical examination and anthropometric measurements. Assessment for effect of asthma on quality of life were done by spirometry and IOS (Resistance at 5 and 20 Hz, R5 and R20 respectively , R5-20 and AX were done pre- and post-bronchodilator.
Asthmatic patient were classified into asthamtics with small airway impairment (SAI) and those without small airway impairment (NSAI) according to MEF25/75 % impairement (<60% of predicted) and HRCT was done for selected patients of SAI patient group (n=10) to confirm evidence of small airway affection.
*The current study revealed that :
• There was statistically insignificant difference between studied asthmatics and controls concerning age distribution; p>0.05.
• Studied asthmatics and controls were well matched regarding gender and residency distribution (p>0.05 for both). Meanwhile studied asthmatics had significantly higher frequency of family history of asthma and exposure to second hand smoke compared to controls (p=0.01, 0.025 respectively).
• There were statistically insignificant differences between studied asthmatics andcontrols concerning frequency distribution of different categories of weight and height percentiles, and BMI; (p=0.111, 0.331, 0.241 respectively).
• FEV1 was used in the current study as a parameter of disease control among studied asthmatics; 38.3% were controlled, 53.4% were partially controlled, and 8.3% were uncontrolled.
• Mean value of FEV1 (% of predicted) was significantly lower among enrolled uncontrolled asthmatics compared to those who were partially controlled or controlled; p=0.001.
• There were statistically insignificant differences between studied asthmatics and controls concerning mean values of pre-bronchodilator FEV1, FVC, FEV1/FVC, and PEF (% of predicted); p>0.05 for all while MEF25/75 (% of predicted) was significantly lower in studied asthmatics prior to bronchodilator administration compared to controls.
• There were statistically insignificant differences between studied asthmatics regarding mean values of pre and post-bronchodilator measured spirometric parameters: FEV1, FVC, FEV1/ FVC, MEF25/75, PEF (% of predicted); p > 0.05 for all.
• Mean values of R5, R5-R20, and AX were significantly higher in studied asthmatics prior to bronchodilator administration compared to controls (P=0.011, 0.001, and 0.030respectively) signifying higher small airway resistance and higher reactance in enrolled asthmatics compared to controls while there was statistically insignificant difference between both groups regarding R20 (p=0.724).
• Mean values of post-bronchodilator R5, R5-20, and AX showed significant reduction when compared to pre-bronchodilator mean values of the same parameters in studied asthmatics (p=0.046, 0.015, and 0.019 respectively); signifying improved small airway resistance and airwayreactance after bronchodilator administration while there was statistically insignificant difference regarding R20; p=0.404.
• Enrolled asthmatics who were proven to have SAI using MEF25/75 < 60% of predicted were 16.7% compared to 11.7% diagnosed by IOS parameters (R5>150% and R20 lower than R5).
• There were statistically insignificant differences between asthmatics with and without SAI regarding mean values of age, age of asthma onset, and duration of illness; (p=0.466, 0.457, 0.419 respectively).
• Studied asthmatics with proven SAI had significantly lower FEV1/FVC and MEF25/75 (% of predicted); p=0.013, 0.001, respectively, compared with controls while there were statistically insignificant differences between both groups regarding FEV1,FVC, and PEF (% of predicted); (p=0.290,0.224, and 0.135 respectively).
• There was a significant improvement of MEF25/75(% of predicted) in asthmatics with SAI after bronchodilator administration compared to the same parameter before it; p=0.008,while there was statistically insignificant differences regarding FEV1, FVC, FEV1/FVC, and PEF (%of predicted);p>0.05 for all.
• MEF25/75 (% of predicted) was significantly lower in asthmatics with SAI compared to those without it both before and after bronchodilator administration while other measured spirometric parameters showed insignificant differences; p > 0.05 for all.
• All the measured IOS parameters were significantly higher in asthmatics with SAI before administration of bronchodilators when compared with controls (p < 0.01) except for R20 ( p> 0.05).
• Mean value of R20 was significantly lower in asthmatics with SAI after bronchodilator administration compared to it before such administration (p = 0.048) while other measured IOS parameters showed insignificant statistical differences; p > 0.05 for all.
• Studied asthmatics with SAI had significantly higher mean values of R5,R20,AX before bronchodilator administration when compared with asthmatics without SAI while the former group had only significantly higher AX compared with the latter group after bronchodilator administration.
• Asthma poorer control was significantly more prevalent among asthmatics with SAI compared to those without it (p=0.00001).
• Asthmatics with SAI had significantly more frequent woken by asthma, limited activities, and shortness of breath, and higher total score of ACQ compared to asthmatics without SAI.
• Asthmatics with SAI had significantly lower activities and total score of Mini Asthma Quality of life Questionnaire (MAQLQ) compared to those without SAI.
• There was a statistically significant positive correlation between MEF25/75 and MAQLQ score among studied asthmatics (r=0.314, p=0.02) while other studied quantitative parameters showed insignificant correlations.
• All asthmatics with SAI showed presence of abnormal airways in the form of branching airways and mosaic appearance and half of them (5= 50%) showed centrilobular nodules in addition to the abnormal airways.
• IOS is complementary to spirometry in assessing lung functions especially small airway disease in young age and handicapped children as it is more easy to perform and less effort dependent and the procedure is easier to understand &perform