Spectrum of corrosive esophageal injury after intentional paraquat or glyphosate-surfactant herbicide ingestion

Hsiao-Hui Chen,¹ Ja-Liang Lin,¹ Wen-Hung Huang,¹ Cheng-Hao Weng,¹ Shen-Yang Lee,¹ Ching-Wei Hsu,¹ Kuan-Hsing Chen,¹ I-Kuan Wang,² Chih-Chia Liang,² Chiz-Tzung Chang,² Tzung-Hai Yen<sup>1

1</sup>Department of Nephrology and Division of Clinical Toxicology, Chang Gung Memorial Hospital and Chang Gung University, Taipei, Taiwan; ²Department of Nephrology, China Medical University Hospital and China Medical University, Taichung, Taiwan

Background: Data on the spectrum of corrosive injury to the esophagus after paraquat or glyphosate-surfactant ingestion are sparse in the literature and confined to case studies and brief reports. Therefore, this study aimed to examine the clinical features, degrees of esophageal injury, and clinical outcomes after paraquat or glyphosate herbicide ingestion, and sought to determine what association, if any, may exist between these findings.
Methods: We performed an observational study on 47 patients with paraquat or glyphosate ingestion who underwent endoscopic evaluation over a period of 11 years (2000–2011).
Results: Corrosive esophageal injuries were classified as grade 1 in 14 (glyphosate-surfactant) and three (paraquat), grade 2a in nine (glyphosate-surfactant) and 18 (paraquat), and grade 2b in one (glyphosate-surfactant) and two (paraquat) patients. No patients had grade 0, 3a, or 3b esophageal injuries. Therefore, the severity of corrosive injury was more severe in the paraquat group (P = 0.005). After toxin ingestion, systemic toxicity occurred, with rapid development of systemic complications in many cases. Neurologic complications occurred more frequently in the glyphosate-surfactant group (29.2% versus 0%, P = 0.005), although respiratory failure (4.2% versus 34.8%, P = 0.008), hepatitis (12.5% versus 52.2%, P = 0.004), and renal failure (20.8% versus 52.2%, P = 0.025) developed more frequently in the paraquat group. Patients with glyphosate poisoning had shorter hospital stays than patients with paraquat poisoning (13.3 ± 15.1 days versus 26.8 ± 10.2 days, P = 0.001). Nevertheless, there was no significant difference in mortality rate between the glyphosate-surfactant and paraquat groups (8.3% versus 13.0%, P = 0.601). We ultimately found that patients with grade 2b esophageal injury suffered from a greater incidence of respiratory (100.0% versus 5.9%, P = 0.001) and gastrointestinal (66.7% versus 11.8%, P = 0.034) complications than patients with grade 1 injury, regardless of herbicide type.
Conclusion: Paraquat and glyphosate are mild caustic agents that produce esophageal injuries of grades 1, 2a, and 2b only. Our data also suggest a potential relationship between the degree of esophageal injury and systemic complications.

Keywords: paraquat, glyphosate-surfactant, poisoning, suicide, esophageal injury