title: Heart rate-corrected QT interval helps predict mortality after intentional organophosphate poisoning.
abstract: BACKGROUND
  In this study, we investigated the outcomes for patients with intentional organophosphate poisoning. Previous reports indicate that in contrast to normal heart rate-corrected QT intervals (QTc), QTc prolongation might be indicative of a poor prognosis for patients exposed to organophosphates.
  
  
  METHODS
  We analyzed the records of 118 patients who were referred to Chang Gung Memorial Hospital for management of organophosphate poisoning between 2000 and 2011. Patients were grouped according to their initial QTc interval, i.e., normal (<0.44 s) or prolonged (>0.44 s). Demographic, clinical, laboratory, and mortality data were obtained for analysis.
  
  
  RESULTS
  The incidence of hypotension in patients with prolonged QTc intervals was higher than that in the patients with normal QTc intervals (P = 0.019). By the end of the study, 18 of 118 (15.2%) patients had died, including 3 of 75 (4.0%) patients with normal QTc intervals and 15 of 43 (34.9%) patients with prolonged QTc intervals. Using multivariate-Cox-regression analysis, we found that hypotension (OR = 10.930, 95% CI = 2.961-40.345, P = 0.000), respiratory failure (OR = 4.867, 95% CI = 1.062-22.301, P = 0.042), coma (OR = 3.482, 95% CI = 1.184-10.238, P = 0.023), and QTc prolongation (OR = 7.459, 95% CI = 2.053-27.099, P = 0.002) were significant risk factors for mortality. Furthermore, it was revealed that non-survivors not only had longer QTc interval (503.00±41.56 versus 432.71±51.21 ms, P = 0.002), but also suffered higher incidences of hypotension (83.3 versus 12.0%, P = 0.000), shortness of breath (64 versus 94.4%, P = 0.010), bronchorrhea (55 versus 94.4%, P = 0.002), bronchospasm (50.0 versus 94.4%, P = 0.000), respiratory failure (94.4 versus 43.0%, P = 0.000) and coma (66.7 versus 11.0%, P = 0.000) than survivors. Finally, Kaplan-Meier analysis demonstrated that cumulative mortality was higher among patients with prolonged QTc intervals than among those with normal QTc intervals (Log-rank test, Chi-square test = 20.36, P<0.001).
  
  
  CONCLUSIONS
  QTc interval helps predict mortality after intentional organophosphate poisoning.
authors.affiliation: Division of Clinical Toxicology, Department of Nephrology, Chang Gung Memorial Hospital and College of Medicine, Chang Gung University, Taipei, Taiwan.
authors.forename: Shou-Hsuan
authors.initials: SH
authors.lastname: Liu
authors.forename: Ja-Liang
authors.initials: JL
authors.lastname: Lin
authors.forename: Cheng-Hao
authors.initials: CH
authors.lastname: Weng
authors.forename: Huang-Yu
authors.initials: HY
authors.lastname: Yang
authors.forename: Ching-Wei
authors.initials: CW
authors.lastname: Hsu
authors.forename: Kuan-Hsing
authors.initials: KH
authors.lastname: Chen
authors.forename: Wen-Hung
authors.initials: WH
authors.lastname: Huang
authors.forename: Tzung-Hai
authors.initials: TH
authors.lastname: Yen
mesh_terms: D015415:Biomarkers / Q000097:blood; D004562:Electrocardiography; D005260:Female; D006329:Heart Conduction System / Q000187:drug effects* / Q000503:physiopathology*; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D062025:Organophosphate Poisoning; D011379:Prognosis; D012044:Regression Analysis; D012189:Retrospective Studies; D013997:Time Factors
chemical_list: D015415:Biomarkers