A 36-year-old male, with no relevant medical history, presented to the emergency department with paresthesia in both upper extremities accompanied by somnolence.
Two hours before admission, she refers to the application of 270 g (9 bottles of 30 g) of anesthetic cream EMLA® (lidocaine 2.5%, prilocaine 2.5%) for hair removal and lower back laser.
The patient was conscious and oriented, with a tendency to sleep and presented with chronic cough.
Her blood pressure was 144/83 mmHg, her heart rate was 82 bpm, and her basal SaO2 was 91%. Treatment was initiated until SaO2 achieved 94%.
The rest of the examination was normal.
In the complementary tests (thorax X-ray and electrocardiogram), no significant pathological changes were found.
On admission analytical (4 hours after the application of EMLA®, see Table 1), highlights methaemoglobin level of 10.1%, so was diagnosed with severe methaemoglobinemia secondary to topical administration of EMLA® 2.5% (
Intravenous administration of 100 mg methylene blue was initiated within 10 minutes.
One hour after administration, the patient continued to have high methaemoglobin levels (2.7%), also presenting alkalosis, which was assessed by the Intensive Care Unit.
After transfer to the unit, continue therapy with mask to high flow, improving skin-mucosal color and achieving SaO2 96%.
Twenty-four hours after the application of EMLA®, the patients discharge status returned favorable to stable and methemoglobin levels decreased to 0.2 %, so it was decided to transfer the patient to the Internal Medicine Service, where he was admitted.
