Endogenous carbon monoxide production correlates weakly with severity of acute illness.
OBJECTIVE
The enzyme haeme oxygenase-1 is highly inducible by oxidative agents. Its product carbon monoxide is thought to exert anti-inflammatory properties. We recently showed, that critically ill patients produce higher amounts of carbon monoxide compared to healthy controls. In the present study we compare endogenous carbon monoxide production with the severity of illness of intensive care unit patients.


METHODS
Exhaled carbon monoxide concentration was measured in 95 mechanically ventilated, critically ill patients (mean age +/- SD, 59.5 +/- 15.7) on a carbon monoxide monitor. Measurements were taken every hour for 24 h in each patient. Data were analysed using Mann-Whitney rank sum test. Correlation analysis was performed with the Spearman's rank order correlation.


RESULTS
Carbon monoxide production correlated weakly with the multiple organ dysfunction score (R = 0.27; P = 0.009). Patients suffering from cardiac disease (median 22.5, interquartile range 16.2-27.4 microL kg(-1) h(-1) vs. median 18.2, interquartile range 14.2-21.8 microL kg(-1) h(-1), P = 0.008) and critically ill patients undergoing dialysis (median 25.0, interquartile range 21.4-30.2 microL kg(-1) h(-1), vs. median 19.4, interquartile range 14.7-23.3 microL kg(-1) h(-1), P = 0.004) produced significantly higher amounts of carbon monoxide compared to critically ill controls.


CONCLUSIONS
The findings suggest that endogenous carbon monoxide production might reflect the severity of acute organ dysfunction.
Scharte
M
M
Universitätsklinikum Münster, Klinik und Poliklinik für Anästhesiologie und Operative Intensivmedizin, Muenster, Germany. scharte@anit.uni-muenster.de
von Ostrowski
T A
TA
Daudel
F
F
Freise
H
H
Van Aken
H
H
Bone
H G
HG
D018806:APACHE; D001944:Breath Tests; D002248:Carbon Monoxide / Q000032:analysis / Q000378:metabolism*; D002318:Cardiovascular Diseases / Q000378:metabolism; D016638:Critical Illness / Q000145:classification*; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D009102:Multiple Organ Failure / Q000378:metabolism; D012121:Respiration, Artificial
D002248:Carbon Monoxide