Relationship between pupil size and acetylcholinesterase activity in patients exposed to sarin vapor.
OBJECTIVE
To elucidate the effect of sarin vapor on pupil size and erythrocyte acetylcholinesterase activity (AchE).


METHODS
Retrospective observational survey.


METHODS
Emergency department of an urban teaching hospital.


METHODS
80 patients who were exposed to sarin in a terrorist attack in Tokyo subways.


RESULTS
Pupil size and AchE activity on the day of exposure were measured. Among the 80 patients, the pupils were miotic (< 3 mm) in 50 patients (62.5%), while AchE activity was below the normal range (< 1.2 U) in 34 patients (42.5%). AchE was significantly lower in the miotic group than in the group with normal pupils (1.0 +/- 0.5 U vs 1.5 +/- 0.3 U, p < 0.01). In the miotic group, AchE activity was lower than normal in 32 patients (64.0%) but was decreased in only 2 patients in the normal pupil group (6.7%) (p < 0.01).


CONCLUSIONS
Miosis is a more sensitive index of exposure to sarin vapor than erythrocyte AchE. Systemic poisoning is apparently less likely to develop if the patient's pupil size is normal on arrival at the hospital.
Nozaki
H
H
Department of Emergency and Critical Care Medicine, School of Medicine, Keio University, Tokyo, Japan.
Hori
S
S
Shinozawa
Y
Y
Fujishima
S
S
Takuma
K
K
Kimura
H
H
Suzuki
M
M
Aikawa
N
N
D000110:Acetylcholinesterase / Q000097:blood / Q000187:drug effects*; D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D005260:Female; D005739:Gas Poisoning / Q000175:diagnosis; D006801:Humans; D008297:Male; D008875:Middle Aged; D015877:Miosis / Q000209:etiology*; D012189:Retrospective Studies; D012524:Sarin / Q000506:poisoning*; D014218:Triage / Q000379:methods
D012524:Sarin; D000110:Acetylcholinesterase