Electrophysiological assessment of peripheral nerves and neuro-muscular junctions in patients following self-poisoning with paraquat

Paraquat is neurotoxic. We aimed to study the electrophysiological effects of peripheral nerves and neuromuscular junction (NMJ) in the survivors of paraquat poisoning. A cohort study was conducted on patients following paraquat poisoning. Controls were recruited. The assessments were performed around one and six weeks after the exposure. Motor nerve conduction velocity (MNCV), amplitude of compound muscle action potential (CMAP), sensory nerve conduction velocity (SNCV), F-wave studies, cardiovascular response to different stimuli, sympathetic skin response (SSR) studies, and exercise modified supramaximal slow repetitive stimulation (RNS) and electromyography (EMG) were performed. There were 28 (21 males) patients and 56 controls. The mean (SD) age of the patients and the controls were 29 (12) and 31 (11) years. Significant impairment at the first assessment in the SNCV of ulnar nerve, amplitude of ulnar nerve CMAP on distal stimulation, and F-wave occurrence in median, ulnar and tibial nerves; change of systolic blood pressure three minutes after standing and SSR amplitude ( vs controls) was observed. All parameters reverted to normal at six weeks after the exposure. There was electrophysiological evidence for somatic nerve, autonomic, and NMJ dysfunction following acute paraquat poisoning which was not seen at six weeks after the exposure.

Reasons for under-reporting of paraquat poisoning in India

Background Paraquat is an inexpensive herbicide used in agriculture because it is easily available and the cost of labour for manual clearance of weeds is prohibitive. Paraquat is toxic to human beings and is also used for committing suicide. We studied the reasons for under-reporting of paraquat poisoning including those related to the training of doctors. Methods In this mixed-methods study, we describe a series of patients with paraquat poisoning. We recorded their demographic data, clinical features, treatment and outcome with an intention to explore the reason for an initial misdiagnosis. We also explored whether deficiencies in curricula contributed to the misdiagnosis. Results The patients of paraquat poisoning (n=28) were mostly young illiterate men driven by impulsive behaviour rather than chronic depression. Paraquat was consumed by patients from non-agricultural background as well, implying easy access to the poison. Many patients could not name the agent and so initial treatment was directed at organophosphorus poisoning. The diagnostic signs included paraquat tongue, renal failure and jaundice. Most of the casualty medical officers and residents were unfamiliar with the symptoms and signs of paraquat poisoning as was evident by their answers to the questionnaire. Knowledge of medical students about paraquat poisoning was not assessed in the theory examinations and viva. Conclusion Factors contributing to the limitation in establishing the diagnosis are illiteracy and ignorance of the patients, lack of specific signs and lack of training of medical officers in treating patients with paraquat poisoning.

Efficacy of combined use of Xuebijing and ulinastatin for paraquat poisoning: A systematic review and meta-analysis of randomized controlled trials

Background: There are no clinically effective antidotes for paraquat poisoning, which progresses rapidly with a poor prognosis and high mortality. The addition of Xuebijing (XBJ) and ulinastatin (UTI) combination to conventional therapy has been reported as a novel treatment approach.Objective: To compare the effectiveness of Xuebijing combined with ulinastatin and conventional treatment group in the treatment of paraquat poisoning.Methods: The CNKI, VIP, WanFang, PubMed, EMBASE, and MEDLINE databases were searched for publications on randomized controlled clinical trials that compared the XBJ+UTI combination as an additional treatment to conventional therapy versus conventional therapy alone.Results: Quality assessment of the selected publications was performed and data were extracted for analysis. The final analysis included five publications, reporting 588 patients with paraquat poisoning. The control and XBJ+UTI groups comprised 294 patients each; 138 and 100 patients in the control and conventional therapy plus XBJ+UTI groups died, respectively. The combined analysis showed that the mortality relative risk (RR) was 0.72 and I2 was 46.2%. Three publications reported of pulmonary fibrosis (PF) and multiple organ dysfunction syndrome (MODS), in which 134 patients were included in each of the control and XBJ+UTI groups. MODS occurred in 117 and 88 patients in the control and conventional therapy plus XBJ+UTI groups, respectively. The combined analysis using the random-effects model showed that the RR was 0.75 and I2 was 0.0%. PF occurred in 99 and 68 patients in the control and conventional therapy plus XBJ+UTI groups, respectively. The combined analysis using the random-effects model showed that the RR was 0.69 and I2 was 0.0%.Conclusions: We preliminarily demonstrated that compared with those of conventional therapy alone, the addition of XBJ+UTI combination for the treatment of paraquat poisoning could reduce the mortality rate and incidence of MODS and PF.