Man with dizziness, fatigue, and sweating

Abstract

A 39-year-old male arrived at the hospital reporting dizziness, fatigue, and sweating that had persisted for half a day. He was transferred to the emergency department because his initial peripheral capillary oxygen saturation (SpO₂) was critically low at 70%. Upon examination, the physician observed cyanosis in the patient's lips and fingertips (Figure 1).

Upon admission, the concentration of methemoglobin (MHb) in the blood was 41.9%. Given the suspected toxic ingestion, hypotension low SpO2 readings, as well as the extra high MHb concentration, the patient was diagnosised with nitrite poisoning (Figure 2). Treatment regimen: one liter of 0.9% normal saline was administered along with oxygen therapy, glucose, electrolyte solutions, ascorbic acid (vitamin C), and H₂ receptor blockers. Additionally, a 60 mg dose of methylene blue in 40 mL of 25% glucose solution was rapidly administered intravenously for 10 min. Note that 1.5 h following treatment, the methemoglobin concentration was measured at 6.7%. The patient's cyanosis gradually improved and blood oxygen saturation increased.

NaNO₂ affects vital organs, particularly highly perfused organs such as the brain and heart. Clinical manifestations may include cyanosis, hypoxia, altered consciousness, dysrhythmias, and death.^1-3 The severity of symptoms is dependent on the level of MHb. In a normal physiological state, the concentration of MHb does not exceed 1%–2%. However, levels of 10%–20% typically result in cyanosis. As MHb levels increase to 30%–40%, symptoms such as headache, fatigue, tachycardia, weakness, and dizziness may occur.^4-7

The authors declare no conflicts of interest.