Child: Male, 2 years and 7 months old, admitted to the hospital for "cyanosis around the mouth and at the end of the limbs for 2 hours".
Medical history: Perioral and cyanosis of the extremities after eating dinner at home 2 hours ago, the main food eaten was okra and egg sauce in the refrigerator for 2 days, plus a small half bowl of fresh noodles. Accompanied by drowsiness, occasional complaints of chest discomfort. No open mouth breathing, no coughing, no wheezing, no fever, no sweating, no nausea and vomiting, no abdominal pain, no convulsions, normal urination, no stool.
Previous health, denial of allergy history, no history of blood transfusions, vaccination in order. The child is G1P1, the eldest son of a twin, has a term caesarean section, has no birth injuries, and grows and develops consistent with that of children of the same age. Denial of family inherited metabolic diseases.
Admission: T: 36.7°C, P: 132 times/min, R:42 times/min, BP: 112/52 mmHg, TCSO2: 82%, WT: 18.4 kg. Drowsiness, wake up after the question and answer the question. The skin is dull, the lips are bruised, the skin at the end of the fingers and toes and the nail bed are cyanosis, there are no bleeding spots, and the skin is warm.
The double pupil is equally large, round, about 3 mm in diameter, sensitive to light reflection, and no hyperemia of the conjunctiva. No nasal flapping, no inspiratory triple concave signs, slightly coarse breath sounds on auscultation of both lungs, no dry and wet rales. Heart rate 132 beats per minute, strong heart sounds, neat rhythm, no noise. The abdomen is slightly puffed and soft, untouched under the hepatosplenal ribs, and the bowel sounds are 4 times per minute. There are no abnormalities in the appearance of the anus and genitals. Normal muscle strength and tone.
Source: This case
Source: This case
Adjunctive tests: WBC count 26.6 × 10^9/L, percentage of neutrophils 58.28%, erythrocytes 4.14 × 10^12/L, hemoglobin 119 g/L, platelet count 402 × 10^9/L. BR1
Blood gas analysis (arterial blood) :P H 7.297, partial pressure of carbon dioxide 31.4 mmHg, partial pressure of oxygen 80.7 mmHg, bicarbonate 15 mmol/L, residual base - 10.27 mmol/L, anion gap 16.4 mmol/L, glucose 11 mmol/L, lactic acid 6 mmol/L, oxygen saturation 99.7%, oxygenated hemoglobin 34%, methemoglobin 65.7%, carboxyhemoglobin 0.2%.
Coagulation function, liver and kidney function and myocardial enzyme profile are normal, and electrolytes are normal. Cardiac ultrasound: no abnormalities in the structure and blood flow of the heart, and the left ventricular systolic function is normal. Chest x-ray: no abnormalities.
Source: This case
Diagnosis of hospitalization: acute nitrite poisoning
After eating expired vegetables, children have cyanosis of the skin and mucosa, no organophosphorus poisoning, auxiliary examination of methemoglobin increase is obvious, it is not difficult to diagnose acute nitrite poisoning, and treatment can help confirm the diagnosis.
Emergency treatment: vital sign monitoring, nasal catheter oxygen (oxygen flow 1 L/min), gastric lavage with warm water, methylene blue 2 mg/kg, vitamin C intravenous pump for detoxification, intravenous fluids. Cyanosis subsides after 30 minutes of infusion of methylene blue and vitamin C.
Blood gas analysis and blood routine are reviewed 3 hours after treatment.
Blood gas analysis (arterial blood) :P H 7.441, partial pressure of carbon dioxide 31 mmHg, partial pressure of oxygen 110.3 mmHg, bicarbonate 18.4 mmol/L, residual base - 3.41 mmol/L, anion gap 13.4 mmol/L, glucose 4.8 mmol/L, lactic acid 1.3 mmol/L, oxygen saturation 98.5%, oxygenated hemoglobin 97%, methemoglobin 0.4%, carboxyhemoglobin 1.1%.
Complete blood count: white blood cell count 10.4 × 10^9/L, percentage of neutrophils 57.5%, red blood cells 4.10 × 10^12/L, hemoglobin 117 g/L, platelet count 262 × 10^9/L. CRP 3 mg/L。
Can you diagnose and treat urgently?
Finally, let's review nitrite poisoning...
●Nitrite poisoning refers to the occurrence of methemoglobinemia after the human body ingests more than 0.2 ~ 0.5 g of nitrite, and is related to intestinal origin, so it is also called enterogenic cyanosis, which can lead to severe hypoxia and peripheral circulation failure of the body, etc., if not treated in time, it can be life-threatening.
●Causes: Ingesting a large amount of spoiled green vegetables, pickled greens, overnight vegetables, pickled fish cured meat, spoiled seafood, etc., drinking bitter well water with high nitrites, and mistakenly taking industrial salt. In recent years, there have also been reports of methemoglobinemia in newborns or small babies fed homemade vegetable water.
●Clinical manifestations of toxicity: prominently manifested as cyanosis is disproportionate to hypoxia. Onset is usually sudden between half and three hours after eating, and rarely 10 to 15 minutes or up to 20 hours. After the onset of mild disease, the main symptoms are bruising of the skin and mucous membranes, especially the lips, perioral areas, and nail beds, and are often not accompanied by corresponding hypoxia symptoms. In severe cases, bruising worsens, dizziness, headache, fatigue, unresponsiveness, sweating, nausea, vomiting, bloating, diarrhea, chest tightness, palpitations, dyspnea, severe blood pressure drop, shock, coma, convulsions, respiratory failure, cerebral edema, etc., and even death.
●Poisoning mechanism: excess nitrite is absorbed into the blood through the digestive tract, so that normal hemoglobin (containing divalent iron) oxidation to produce methemoglobin (containing trivalent iron), methemoglobin itself is brownish-black, no oxygen carrying capacity. In the normal human body, no more than 0.2%, when the blood content is as high as 1.5%, the mucous membrane of the skin appears bruised; if 20% of hemoglobin is converted to methemoglobin, clinical hypoxia symptoms occur; if 40% turn to methemoglobin, the symptoms are severe; > 70% of methemoglobinemia is fatal.
●Treatment: General supportive care: vomiting, gastric lavage, diarrhea, oxygen inhalation, hydration, vital sign monitoring, etc.
Mild: methylene blue is given orally 3 to 5 mg/kg three times daily;
Severe: 1 to 2 mg/kg methylene blue immediately, slowly intravenously (5 to 10 minutes), symptoms do not disappear or reappear for 1 to 2 hours, and can be repeated again. or intravenously injected with a large amount of vitamin C 1 to 2 g + 10% glucose. Severely ill children may receive fresh blood transfusion or exchange.
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Source: Lilac Garden
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bibliography
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Hu Yamei Jiang Zaifang. Practical Pediatrics of Zhu Futang[M]. Eighth Edition. Beijing:People's Medical Publishing House,2015.]
[Sun Yiyang, Yu Hui, Yu Xifen, Treatment experience of 7 pediatric nitrite collective poisoning[J]. Chinese Journal of Practical Pediatrics,2008,8:630.]