# Case Report: A case of subarachnoid hemorrhage secondary to elbow intravenous injection of diquat poisoning in young male

## TL;DR

A young man died shortly after injecting a large amount of diquat, a toxic herbicide, into his vein, causing severe brain damage and highlighting the dangers of this method of poisoning.

## Contribution

Reports a rare and fatal case of intravenous diquat poisoning leading to subarachnoid hemorrhage and rapid death.

## Key findings

- Intravenous diquat injection caused subarachnoid hemorrhage and elevated blood pressure within minutes.
- The patient died of respiratory and circulatory failure six hours after admission despite emergency treatment.
- High diquat concentrations in plasma and urine confirmed the poisoning and suggested rapid entry into the brain.

## Abstract

With the prohibition of paraquat, the use of diquat (DQ) as a substitute herbicide has increased significantly, and the number of poisoning cases has also increased. As a highly toxic herbicide, DQ has a high fatality rate. Currently, there is no specific antidote for its poisoning, posing a serious threat to public health.

This paper reports a case of a 23-year-old male patient who self-injected about 120 mL of DQ (20 g/100 mL) by elbow vein injection due to emotional excitement 1 h before admission. Nausea, vomiting, and pain occurred 10 min after injection. After admission, emergency head CT showed subarachnoid hemorrhage (SAH) and elevated blood pressure to 207/115 mmHg. Although the patient was admitted to the emergency intensive care unit (EICU) of our hospital for further treatment and given symptomatic treatment such as blood purification, massive rehydration, promotion of excretion, anti-oxidation, protection of organ function, and sedation as soon as possible, the patient still died of respiratory and circulatory failure 6 h after admission. Liquid chromatography–tandem mass spectrometry (LC–MS/MS) results showed that the DQ concentrations were 31.10 μg/mL in plasma and 147.60 μg/mL in urine.

This case suggests that a massive dose of intravenous DQ poisoning can lead to severe central nervous system injury and rapid death. Based on the clinical presentation and existing literature, the mechanism may be related to the extremely high concentration of DQ rapidly crossing the blood–brain barrier and entering brain tissue, thereby causing tissue cell damage or reduction–oxidation (redox) cycle. This highlights that we need to be highly vigilant against the clinical hazards caused by the unconventional poisoning pathway of DQ.