which agents cause reactive airways dysfunction syndrome (rads)? which agents cause reactive airways...

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