ĐẶC ĐIỂM LÂM SÀNG VÀ CẬN LÂM SÀNG CỦA BỆNH NHÂN NGỘ ĐỘC N2O TẠI TRUNG TÂM CHỐNG ĐỘC BỆNH VIỆN BẠCH MAI

Abstract

Background: Since its synthesis in 1793, nitrous oxide (N₂O), also referred to as laughing gas, has been used in both industrial and medical settings. Hospitalizations for neurological complications have increased as a result of its recent recreational misuse, raising concerns about public health. Numerous clinical manifestations associated with various pathophysiological mechanisms are indicative of N₂O-induced neurotoxicity. Objective: Describe the clinical and paraclinical characteristics of nitrous oxide poisoning patients. Methods: A descriptive study was carried out on 35 patients with confirmed N₂O intoxication, diagnosed via patient history, clinical examination, and laboratory tests, who received treatment therapy at the Poison Control Center, Bach Mai Hospital, from June 2024 to May 2025. Results: Of the 35 patients in the cohort, 65.7% were female, and their mean age was 24.5 ± 7.4 years. Patients reported a median weekly consumption of 20 N₂O balloons (range: 10–50), equivalent to approximately 40–200 liters. Limb weakness (68.6%) and paresthesia (100%) were the most common symptoms. Clinical results showed decreased or absent deep tendon reflexes in the lower limbs (94.3% and 88.6%, respectively), muscle weakness (68.6%), and impaired vibration sensation (97.1%). The mean Total Neuropathy Score-clinical (TNSc) prior to treatment was 10.7 ± 3.7. Laboratory results indicated elevated homocysteine levels in 82.9% of patients and reduced serum vitamin B12 in 14.3%. MRI identified cervical spinal cord lesions in 83.3% of cases, predominantly affecting the C2–C5 segments (88.9%). Axonal neuropathy in 46.4% of lower limbs and 35.7% of upper limbs was confirmed by electromyography. Conclusion: In summary, this study clarifies the various clinical and paraclinical signs of nitrous oxide poisoning, emphasizing the significance of healthcare providers' awareness for prompt diagnosis and treatment.