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.
This study's objective was to investigate whether QTc can predict mortality in paraquat-poisoned patients.
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.
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.
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.
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- Epidemiology of paraquat poisoning.in: Bismuth C. Hall A.H. Paraquat poisoning: mechanism, prevention, treatment. Marcel Dekker, New York1995: 37-52
- Paraquat poisonings: mechanisms of lung toxicity, clinical features, and treatment.Crit Rev Toxicol. 2008; 38: 13-71
- Epidemiology of paraquat in Japan and a new safe formulation of paraquat.Hum Toxicol. 1987; 6: 87-88
- The epidemiology and prevention of paraquat poisoning.Hum Toxicol. 1987; 6: 19-29
- The epidemiology of paraquat intoxications in Surinam.Trop Geogr Med. 1989; 41: 266-269
- Paraquat intoxication in subjects who attempt suicide: why they chose paraquat.Korean J Intern Med. 2009; 24: 247-251
- Taiwan National Poison Center: epidemiologic data 1985–1993.J Toxicol Clin Toxicol. 1996; 34: 651-663
- Paraquat poisoning: significance of plasma-paraquat concentrations.Lancet. 1979; 2: 330-332
- A new statistical approach to the prognostic significance of plasma paraquat concentrations.Lancet. 1984; 2: 1222-1223
- Prognostic value of plasma and urine paraquat concentration.Hum Toxicol. 1987; 6: 91-93
- Further evidence of the usefulness of Acute Physiology and Chronic Health Evaluation II scoring system in acute paraquat poisoning.Clin Toxicol (Phila). 2006; 44: 99-102
- QT interval prolongation predicts cardiovascular mortality in an apparently healthy population.Circulation. 1991; 84: 1516-1523
- Prolonged QT interval predicts cardiac and all-cause mortality in the elderly. The Rotterdam Study.Eur Heart J. 1999; 20: 278-284
- Assessment of QT interval and QT dispersion for prediction of all-cause and cardiovascular mortality in American Indians: the Strong Heart Study.Circulation. 2000; 101: 61-66
- Prolonged QTc interval and risk of sudden cardiac death in a population of older adults.J Am Coll Cardiol. 2006; 47: 362-367
- QTc prolongation indicates a poor prognosis in patients with organophosphate poisoning.Am J Emerg Med. 1996; 14: 451-453
- Paraquat poisoning: clinical features and immediate general management.Hum Toxicol. 1987; 6: 41-47
- Prognosis and treatment of paraquat poisoning: a review of 28 cases.J Toxicol Clin Toxicol. 1982; 19: 461-474
- The changing pattern of paraquat poisoning in man.Histopathology. 1980; 4: 171-183
- Massive poisoning by paraquat with early death (19 hours). Apropos of a case with ultrastructure study.Ann Pathol. 1982; 2: 332-335
- Initial accumulation of paraquat in the heart leading to acute death.Nihon Hoigaku Zasshi. 1990; 44: 6-11
- Recovery from severe paraquat poisoning following forced diuresis and immunosuppressive therapy.J Ir Med Assoc. 1971; 64: 69-71
- Combined paraquat and acetaminophen toxicity.J Toxicol Clin Toxicol. 1982; 19: 483-491
- Functional distribution of right and left stellate innervation to the ventricles. Production of neurogenic electrocardiographic changes by unilateral alteration of sympathetic tone.Circ Res. 1966; 18: 416-428
- Electrocardiographic changes induced by the stellate ganglion block in normal subjects.J Electrocardiol. 1981; 14: 169-174
- Nonuniform recovery of excitability in the left ventricle.Circulation. 1988; 78: 1365-1372
- QT interval lengthening in cardiac disease relates more to left ventricular systolic dysfunction than to autonomic function.Eur J Heart Fail. 2000; 2: 265-271
- Severity index of paraquat poisoning.Lancet. 1988; 1: 1333
- Correlating the severity of paraquat poisoning with specific hemodynamic and oxygen metabolism variables.Crit Care Med. 2000; 28: 1877-1883
- A cardiac lesion secondary to paraquat.Arq Bras Cardiol. 1992; 59: 95-98
- Herbicides.in: Shannon M.W. Borron S.W. Burns M.J. Haddad and Winchester's clinical management of poisoning and drug overdose. Saunders, Maryland Heights, MO2007: 1195-1211
Published online: July 21, 2014
Accepted: February 8, 2014
Received in revised form: December 10, 2013
Received: September 7, 2012
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