Renal failure and corrosive airway and gastrointestinal injury after ingestion of diluted diquat solution

Lethal diquat poisoning manifests as acute central nervous system injury and circulatory failure: A retrospective cohort study of 50 cases

BACKGROUND

The mortality rate of patients with diquat (DQ) poisoning is extremely high due to insufficient understanding of DQ-induced injury. This study aimed to summarize the characteristics of DQ poisoning as well as analyse the correlation between plasma DQ concentration and patient outcomes, thus providing a new strategy for diagnosis and treatment.

METHODS

This single-centre retrospective cohort study was conducted at the Emergency Department of the First Affiliated Hospital, Zhejiang University School of Medicine, China, between Oct 9, 2019 and March 10, 2022. 50 patients, whose plasma or urine samples tested positive for diquat and negative for paraquat by high performance liquid chromatography-tandem mass spectrometry, were included in the study.

FINDINGS

The mortality rate of acute DQ poisoning was 25 (50%) of 50. Compared with the survival group, the death group presented significantly higher initial plasma DQ concentration (Cp₁), aspartate aminotransferase, alanine aminotransferase, serum creatinine, and creatine kinase-MB (P < 0.05). We found that six (24.0%) patients died of central nervous system injury, six (24.0%) patients died of refractory circulatory failure, and 13 (52.0%) patients died of central nervous system injury combined with circulatory failure. Receiver operator characteristic curve analysis showed that the area under the curve of Cp₁ was 0.967 (95% CI: 0.911, 1.000), and the cut-off value was 3516.885 ng/mL (sensitivity, 90.9%; specificity, 96.0%).

INTERPRETATION

Lethal DQ poisoning is primarily associated with serious brain and vascular injury, as well as a high rate of mortality. Further research into the mechanisms of refractory circulatory failure and central nerve system damage could help reduce mortality.

FUNDING

There are no funding sources to declare.

Acute diquat poisoning causes rhabdomyolysis

We studied the case of a 36-year-old female patient who self-administered about 30 ml of diquat solution (200 g/L) during a suicide attempt. She developed nausea, vomiting, dizziness, and weakness in her limbs and was admitted to the emergency department of our hospital 4 h later. The patient developed progressive swelling and pain in both calves 12 h after admission. Based on symptoms, lower limb color Doppler ultrasound, and elevated levels of myoglobin and creatine kinase, the patient was diagnosed with rhabdomyolysis caused by diquat poisoning. The patient recovered and was discharged after treatment with hemoperfusion, continuous venovenous hemodialysis, acid suppression, liver protection, low-dose glucocorticoids, etc. Rhabdomyolysis caused by diquat poisoning has not been previously reported. We attempted to analyze the mechanism of this symptom through a literature review. We recommend the routine monitoring of creatine phosphokinase (CK) and myoglobin (MYO) in patients with diquat poisoning to avoid missed diagnosis. Further, the mechanism of this poisoning symptom was discussed through the literature review.

Diquat Poisoning: Care Management and Medico-Legal Implications

Acute chemical intoxication represents one of the major causes of Emergency Room admittance, and possible errors in diagnosis are extremely frequent, especially when patients present generic and non-specific symptoms. Diquat, a bipyridyl class of herbicides, exerts high intrinsic toxicity as a consequence of free oxygen radicals, leading to cellular death and organ dysfunctions. Following ingestion, with the major source of absorption for suicidal purposes, the chemical induces local irritating effects; systemic symptoms appear later, while specific symptoms can occur in the following 48 h. A smoker and hypertensive 50-year-old man arrives at the E.R., reporting that an episode of herbicide inhalation occurred few hours earlier. Physical examination evidenced alkalosis with hypoxemia, leucocytosis, mild hyperglycaemia and moderate increase in creatine kinase and myoglobin. Despite blood creatine kinase and myoglobin values that were higher than normal, he was prescribed with hydration and anti-pain therapy. During the night, the man left the hospital; he returned the next morning at 8:45 a.m., with cardiorespiratory arrest, medium fixed non-reactive mydriasis, diffused cyanosis of the skin and of the mucous membranes, as well as imperceptible pulse and peripheral pressure. Despite resuscitation attempts, the patient died at 9:30 a.m.; the body was immediately transferred to the morgue. Autopsy and toxicological analyses were carried out nine days later, evidencing paraquat ingestion for suicidal purposes. GC/MS analyses to verify the presence of diquat were performed on body fluids and gastric and colon contents; all specimens resulted positive, thus confirming the cause of death as herbicide ingestion (blood diquat concentration of 1.2 mg/L; more than twice the minimum to observe a systemic poisoning). The procedure followed for patient management resulted to be not in line with the provisions of both guidelines and good clinical practices. Staff did not perform clinical-diagnostical monitoring of the patient’s condition or ask for more specific analyses (i.e., serum creatine phosphokinase monitoring). This misconduct led to a decrease in the patient’s chances to survive.

Lethal diquat poisoning manifesting as central pontine myelinolysis and acute kidney injury: A case report and literature review

Diquat is a nonselective herbicide that is used as a contact and preharvest desiccant to control terrestrial and aquatic vegetation. Increasing numbers of cases of diquat poisoning have recently been reported. Organs commonly affected by diquat poisoning include the kidney, liver, and lung. Neurological involvement of diquat poisoning is relatively rare. A 21-year-old man ingested 100 mL of diquat (20 g/100 mL) 5 hours before admission. Fifteen minutes after ingestion, he developed nausea and vomiting. The patient was sent to the emergency intensive care unit, and gastric lavage was performed. Continuous renal replacement therapy and continuous venovenous hemodiafiltration with hemoperfusion were performed, and methylprednisolone was administered. Five days after admission, the patient developed disturbance of consciousness and positive bilateral Babinski signs. Head computed tomography demonstrated hypodensity in the pons. At 11 days after admission, brain magnetic resonance imaging showed acute pontine demyelination. At 15 days after admission, the patient died of multiple organ dysfunction syndrome. We encountered a case of diquat poisoning with central pontine myelinolysis and acute kidney injury. This case highlights the clinical value of neuroimaging examination for early diagnosis of central pontine myelinolysis.

Human and experimental toxicology of diquat poisoning: Toxicokinetics, mechanisms of toxicity, clinical features, and treatment

Diquat (1,1'-ethylene-2,2'-bipyridinium ion; DQ) is a nonselective quick-acting herbicide, which is used as contact and preharvest desiccant to control terrestrial and aquatic vegetation. Several cases of human poisoning were reported worldwide mainly due to intentional ingestion of the liquid formulations. Its toxic potential results from its ability to produce reactive oxygen and nitrogen species through redox cycling processes that can lead to oxidative stress and potentially cell death. Kidney is the main target organ due to DQ toxicokinetics and redox cycling. There is no antidote against DQ intoxications, and the efficacy of treatments currently applied is still unsatisfactory. The aim of this work was to review the most relevant human and experimental findings related to DQ, characterizing its chemistry, activity as herbicide, mechanisms of toxicity, consequences of poisoning, and potential therapeutic approaches taking into account previous experience in developing antidotes for paraquat, a more toxic bipyridinium herbicide.

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

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.

Spectrum of corrosive esophageal injury after intentional paraquat ingestion

INTRODUCTION

This is an observational study that examines the clinical features, the degrees of esophageal injury, physiological markers, and clinical outcomes after paraquat ingestion and seeks to determine what association, if any, may exist between these findings.

METHODS

The study included 16 of 1410 paraquat subjects who underwent endoscopies at Chang Gung Memorial Hospital between 1980 and 2007.

RESULTS

Corrosive esophageal injuries were classified as grade 1 in 8, 2a in 5, and 2b in 3 patients. No patients had grade 0, 3a, or 3b esophageal injuries. After paraquat ingestion, systemic toxicity occurred, with rapid development of hypoxia, hepatitis, and renal failure in many cases. Hypoxia occurred in 1 (12.5%), 5 (100%), and 3 (100%) patients with grades 1, 2a, and 2b esophageal injury, respectively. There were more hypoxic patients with grades 2a and 2b than those with grade 1 esophageal injury (P < .05). The nadir Pao(2) was lower in patients with grades 2a and 2b than those with grade 1 esophageal injury (P < .05). However, there were no significant differences in terms of acute hepatitis, peak serum alanine aminotransferase, acute renal failure, and peak serum creatinine between the 3 groups (P > .05). Kaplan-Meier analysis did not find any difference in survival between the groups (P > .05).

CONCLUSION

Paraquat, a mild caustic agent, produces only grades 1, 2a, and 2b esophageal injury. Our findings showed a potential relationship between the degree of hypoxia, mortality, and degree of esophageal injury, although such a low number of study subjects limits the conclusions that can be made by this study.

Oral mucosal response to exposure to diquat: a rare occupational injury

Diquat is a quaternary ammonium herbicide closely related to paraquat, and is used commonly by commercial and domestic gardeners. The systemic toxicity of this group of compounds is well-known, but isolated human oral mucosal responses to topical exposure are not well-reported. We present details of an accidental mucosal exposure to diquat during manufacture and the resultant injury, and give guidance for appropriate management of such an exposure.

Toxic nephropathy: environmental chemicals

The kidney is the target of numerous xenobiotic toxicants, including environmental chemicals. Anatomical, physiological, and biochemical features of the kidney make it particularly sensitive to many environmental compounds. Factors contributing to the sensitivity of the kidney include: large blood flow, the presence of a variety of xenobiotic transporters and metabolizing enzymes, and concentration of solutes during urine production. In many cases, the conjugation of environmental chemicals to glutathione and/or cysteine targets these chemicals to the kidney where inhibition of renal function occurs through a variety of mechanisms. For example, heavy metals such as mercury and cadmium target the kidney after glutathione/cysteine conjugation. Trichloroethlene and bromobenzene are metabolized and conjugated to glutathione in the liver before renal uptake and toxicity. In contrast, renal injury produced by chloroform and aristolochic acids is dependent on renal cytochrome P450 metabolism to toxic metabolites. Other compounds, such as paraquat or diquat, damage the kidney via the production of reactive oxygen species. Finally, the low solubility of ethylene glycol metabolites causes crystal formation within the tubular lumen and nephrotoxicity. This chapter explores mechanisms of nephrotoxicity by environmental chemicals, using these example compounds. What remains to be accomplished and by far the most difficult process is the elucidation of the detailed mechanisms of tubular cell injury after toxicant uptake and metabolism. The large number of individuals experiencing a decline in renal function with age makes the search for these mechanisms very compelling.

Mechanisms of toxicity, clinical features, and management of diquat poisoning: a review

USES: Diquat (1,1'-ethylene-2,2'-bipyridilium) is a nonselective bipyridyl herbicide, related structurally to paraquat, which is used both as a contact herbicide and a preharvest desiccant. In comparison to paraquat, diquat is used much less widely in agriculture.

MECHANISMS OF TOXICITY

Diquat is a potent redox cycler and is readily converted to a free radical which, in reaction with molecular oxygen, generates superoxide anions and subsequently other redox products. These products can induce lipid peroxidation in cell membranes, and potentially cause cell death.

FEATURES

Over the period 1968-1999, only 30 cases of diquat poisoning were reported in detail in the literature, of which 13 (43%) were fatal. Local and systemic effects have been reported following diquat exposure, with systemic features being invariably associated with ingestion. In severe and usually fatal cases, gastrointestinal mucosal ulceration, paralytic ileus, hypovolemic shock, acute renal failure, and coma have been reported.

MANAGEMENT

After rapid confirmation of the diagnosis using a qualitative urine test, gut decontamination may be considered in patients who present within 1 hour of a life-threatening ingestion (>6 g). Supportive measures including fluid and electrolyte replacement should then be employed. Although hemofiltration and hemodialysis are of proven value if renal failure supervenes, there is no clinical evidence that hemodialysis or hemoperfusion removes toxicologically significant amounts of diquat, thereby reducing the risk of organ failure and preventing a fatal outcome in severe cases.