Methylene blue for treating toxic encephalopathy due to acute nickel poisoning: A case report

Table 1 Clinical timeline and treatment milestones

Timepoint	Clinical status and diagnostic findings	Interventions and management
Day 1 (admission)	GCS 3 (E1V1M1); signs of cholinergic toxidrome (miosis, secretions, shock)	Intubation, mechanical ventilation, and IV atropine infusion
Day 1 (ICU)	Refractory shock; non-responsive to atropine. CECT shows grade 2 corrosive edema	Dual vasopressors (noradrenaline + vasopressin) initiated
Day 2	Comatose with fixed pupils. Refractory vasoplegic shock. Toxicology samples sent	First dose MB (100 mg IV) administered as rescue therapy
Day 2 (post-MB)	Significant hemodynamic stabilization; vasopressors tapered	MRI brain performed (revealing CLOCC pattern/toxic encephalopathy)
Day 3	Sensorium remains low. Toxicology confirms nickel toxicity (blood, urine, and CSF)	Second dose MB (100 mg IV); high-dose PPI continued
Day 4	Hemodynamics stable. Significant drop in serum nickel; spike in urinary clearance	Third dose MB (100 mg IV)
Day 5	Rapid neurological recovery; GCS improves to 11 (E4VTM6)	Vasopressors discontinued; patient successfully extubated
Day 7	Patient alert and oriented (GCS 15)	Transitioned to oral intake; prepared for discharge

CECT: Contrast-enhanced computed tomography; CLOCC: Cytotoxic lesions of the corpus callosum; CSF: Cerebrospinal fluid; GCS: Glasgow Coma Scale; ICU: Intensive care unit; IV: Intravenous; MB: Methylene blue; MRI: Magnetic resonance imaging; PPI: Proton pump inhibitor.

Table 2 Longitudinal nickel concentrations in relation to methylene blue administration

Timepoint	Blood nickel (μg/L)	Urine nickel (μg/L)	CSF nickel (μg/L)
Baseline (after 1st dose MB)	15.2	21.0	-
Before 3rd dose MB	7.4	8.8	55.5
After 3rd dose MB	4.8	51.9	-
48 hours post-3rd dose	3.7	1.8	-
72 hours post-3rd dose	2.1	5.6	-
96 hours post-3rd dose	0.0	0.0	-
Reference range	0.14-0.65	< 5.2	-

The ingested toilet cleaner concentration was 3468 μg/L. All levels were analyzed using inductively coupled plasma mass spectrometry. MB: Methylene blue; CSF: Cerebrospinal fluid.