Which agents cause reactive airways Which agents cause reactive airways dysfunction syndrome dysfunction syndrome (RADS)?(RADS)?
M. S. Shakeri , F. D. Dick and J. G. Ayres 2008
Dr.salmaniDr.salmani
Aim: To identify agents associated with RADS.
Method: A systematic review
Keywords: Asthma; irritant-induced asthma; reactive airways dysfunction
Background:Background:• Brooks(20 years ago):
– RADS – Symptoms within 24 h of a single, massive, chemical
exposure.
• SWORD:– prevalence of asthma :• intensity and length of acute exposure• the duration of follow-up • suspected agent
Methods:Methods:
systematic review of RADS using Brooks' criteria
searching MEDLINE, EMBASE and CINAHL from 1985 to 2005
search was complemented (hand-searching) : conference abstracts published in the American
Review of Respiratory & Critical Care Medicine European Respiratory Journal and Thorax
Results:Results:
84 articles and abstracts were found but 25 of the articles were excluded:
no cases meeting RADS criteria
duplicate publications follow-up studies
Results...Results...
• 633 cases in the 59 articles: – 63 cases met Brooks' criteria – 570 had insufficient data
• 63 RADS cases:– 38 (60%) male– 12 (19%) female – 13 (21%) gender was not reported.
• mean age:– 37.8 (SD 11.6) years– age was not reported for 7 people
Results...Results...
Agents:
– chlorine (9 subjects)
– TDI (6 subjects)– oxides of nitrogen (5 subjects)– Acetic acid (4 subjects)– sulphur dioxide (4 subjects) – paint (4 subjects)
Results...Results...
location of exposure:
workplace (n = 51) environment (8 subjects), home (3 subjects) not reported (1 subject)
Results...Results...
• Atopic:
–The proportion of non-atopic patients was higher than atopic patients
– 41% of RADS group atopic status was not reported.
Results...Results...
Symptoms:– common symptoms: Dyspnoea, cough & wheeze.
• 71% dyspnoea (n = 45)• 65% cough (n = 41)• 43% wheeze (n = 31)• 43% chest tightness (n = 27)• 29% upper respiratory irritation (n = 18)• 25% eye irritation (n = 16)• 16% mucus production (n = 10)• 6% cyanosis (n = 4)
Results...Results...
• symptom duration:
The median and interquartile range (IQR) for symptom duration in patients who met Brooks' criteria was 13 (6.5–43.5) months.
Results...Results...
• In 63 RADS:
– 19 (30%): smokers
– 21 (33%) patients were non-smokers– 7 patients (11%): ex-smokers – 16 (25%): no information
Summery:Summery:
most agents: Chlorine, TDI , oxides of nitrogen
Most exposures: in the workplace and affected men (60%).
commonest symptoms: Dyspnoea (71%) and cough (65%)
Median symptom duration: 13 months