Abstract
Background
Acute paraquat poisoning has a high mortality rate. Several prognostic factors have
been proposed to predict the mortality risk of paraquat-poisoned patients. However,
these prognostic factors are complex and some require a laboratory. Corrected QT (QTc)
has been used as a prognostic factor in several clinical conditions, such as acute
organophosphate poisoning. In addition, the measurement can be obtained in a reasonable
amount of time.
Study Objectives
This study's objective was to investigate whether QTc can predict mortality in paraquat-poisoned
patients.
Methods
This was a retrospective study. Potential prognostic factors such as QTc, vital signs
at admission, and certain biochemistry variables were analyzed with Cox regression
analyses for their ability to predict a patient's survival from paraquat poisoning.
Results
Sixty acute paraquat-poisoned patients were admitted to the emergency department during
the study period. The QTc of the survival group ranged from 0.35 to 0.48 s, whereas
the nonsurvivor group ranged from 0.32 to 0.63 s. The nonsurvivor group contained
a higher percentage of patients with QTc prolongation (≥0.45 s) compared with the
survivor group (p = 0.04). The hazard ratio of QTc prolongation for a patient's death was found to
be 2.47 (95% confidence interval [CI] 1.68–5.67) in patients with a lower potassium
level (<3.2 mEq/L) and 3.71 (95% CI 1.53–8.97) in patients with a higher potassium
level (≥3.2 mEq/L). In addition, hyperdynamic circulation was observed upon admission
of these poisoned patients.
Conclusion
QTc prolongation is a useful prognostic factor for predicting death in acute paraquat-poisoned
patients. Cardiovascular collapse may occur in some paraquat-poisoned patients. Physicians
can use QTc as an indicator of a patient's severity of poisoning and mortality risk.
Keywords
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Article info
Publication history
Published online: July 21, 2014
Accepted:
February 8,
2014
Received in revised form:
December 10,
2013
Received:
September 7,
2012
Identification
Copyright
© 2014 Elsevier Inc. Published by Elsevier Inc. All rights reserved.
