[Evaluation of smoking in chronic severe respiratory insufficiency patients treated with long-term oxygen at home]

Two hundred and fifty patients with chronic respiratory insufficiency (202 men and 48 women), being treated by oxygen therapy at home were included in a study, which aim was to estimate the proportion of patients who were either smokers or exposed to passive smoking, by the use of a questionnaire and measurement of cotininuria. Urinary sample and autoquestionnaire collection was carried out by the nurses of the Lorraine's association of home respiratory assistance. Urinary continine was measured by radio immuno assay. Twenty one smokers, 186 ex-smokers and 43 non-smokers were identified through the questionnaire. Of the 21 self confessed smokers 20 had a urinary cotinine level over 250 ng/ml, 1 smoker lower than 250 ng/ml; among the professed non-smokers, 42 had a level lower than 100 ng/ml and 1 over 250 ng/ml but the contininuria creatinuria ratio classified this latter in the non-smokers non exposed to passive smoking group. Among the 186 declared ex-smokers, 20 over 250 ng/ml were probably smokers, 160 lower than 100 ng/ml could be considered as non-smokers, and finally 100 in between could be assessed as non-smokers exposed to passive smoking. The results enabled 43 smokers (17%) and 5 (2%) exposed to passive smoking to be identified. They confirm the unreliability of smoking habits questionnaires and the importance of cotininuria in the detection of nicotine poisoning.