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Diagnosis of acute poisoning
Medical expert of the article
Clinical diagnosis of acute poisoning - the most accessible method, used both in the prehospital stage and in the hospital, is concluded in the detection of symptoms characteristic for the exposure of the body to a toxic substance by the principle of its selective toxicity. By acting on the toxicity receptor, a substance or group of substances with the same or similar mechanism of action causes the body to respond in the form of certain symptoms characteristic of a particular type of affected receptors.
Most chemicals found in everyday life as toxic agents, when ingested, cause rapid development and clinical manifestation of the main characteristic symptoms of poisoning. For example, the comatose state develops rapidly when poisoning with hypnotics and neuroleptics, ethyl alcohol, muscarinic and nicotine-like symptoms in case of poisoning with anticholinesterase poisons, rhythm and conduction of the heart in case of poisoning with substances by cardiotropic action, blood damage (hemolysis, methemoglobinemia) in case of "blood" poisons . Identify a specific effect is difficult when poisoning with substances of hepato- and nephrotoxic action. To determine hepato- and nephropathy during routine examination, without laboratory data, and also without symptoms in patients with jaundice, uremia, edema and other symptoms is impossible, since they appear no earlier than 3-4 days after taking the poison. A similar situation occurs when methanol is poisoned, in which the toxic eye damage manifests itself not earlier than 2-3 days after poisoning, when the pathological process becomes irreversible. Later - after a few days (up to 7-10) - the toxic damage of the peripheral nervous system (polyneuropathy, polyneuritis) during poisoning with metal compounds, organophosphorus compounds manifests itself.
In such cases, clinical diagnosis is performed on the basis of the data of the history (if any), and also taking into account nonspecific pathognomonic symptoms for many poisonings. One of the most frequently observed in poisoning is a syndrome of gastrointestinal lesions in the form of gastroenteritis, a chemical burn of the digestive tract. Vomiting and diarrhea are considered characteristic signs for poisoning with salts of heavy metals, dichloroethane, some surrogates of alcohol, organophosphorus compounds, poisons of plant origin. When poisoning with methanol, ethylene glycol, chlorinated hydrocarbons, the symptomatic complex described in the literature as toxic encephalopathy, which includes somatovegetative manifestations (facial hyperemia, injection of sclera, AH, tachycardia) and impaired consciousness (inadequacy of behavior, disorientation, agitation, sometimes convulsive seizures ).
In those cases where it is impossible to accurately determine the name of the substance that caused acute poisoning, the diagnosis is made according to the leading or leading pathological syndromes developed in the patient. For example, "poisoning with anticholinesterase action or organophosphate", "poison cauterizing action", etc. The widely used diagnosis of "poisoning with an unknown poison" should be considered incorrect, since there is no "nonspecific poison" in its own nosological form. It is more correct to use the term on ICD-10 - "unspecified substance".
Chemical-toxicological diagnostics is considered to be the most reliable way of diagnosing poisoning, as it is not always possible to determine a specific substance in the clinical picture, especially if several poisonous substances are used or against the background of alcoholic intoxication. There is a special chromatographic system of fast, reliable, sufficiently sensitive and reproducible laboratory identification of toxic substances in the most accessible biological environments of the body (blood, urine).
Clinical and biochemical laboratory diagnostics of acute poisoning, without specificity, can be a valuable addition, allowing to reveal the changes characteristic of certain poisonings, in particular the definition of CBS in the poisoning of alcohol substitutes such as methanol, ethylene glycol, higher alcohols, blood damage (anemia, leukopenia , neutropenia, etc.) in poisoning with a group of aromatic hydrocarbons, an increase in the activity of liver enzymes, CK, LDH, bilirubin, urea and creatinine, a blood test toxicity (pool of middle molecules) in the defeat poisons gepato- nephrotropic action.
Functional or instrumental diagnostics of acute poisoning complements the clinical picture and the data of a laboratory chemical-toxicological study. Unlike the latter, it is non-specific and is aimed at identifying an important syndrome, without indicating the specific substance that caused the poisoning.
Most often in clinical practice, esophagogastroduodenoscopy is used to detect a chemical burn of the digestive tract. Esophagogastroduodenoscopy allows to determine the nature of the lesion, the degree of severity, the extent, the presence of esophageal-gastric bleeding. The observed pattern is described as a catarrhal, erosive or fibrinous-erosive, necrotic lesion of the mucosa of the digestive tract.
The ECG makes it possible to reveal a specific disturbance of the rhythm and conduction of the heart, the so-called primary cardiotoxic effect, pathognomonic for poisoning with organophosphorus compounds, barium compounds.
When poisoning with hepatitis and nephrotropic poisons, radioisotope hepatorenography is used to detect abnormalities in the secretory and excretory functions of these organs, as well as ultrasound of the liver and kidneys.
Bronchoscopy is used for the early detection of toxic lesions of the respiratory tract (toxic tracheobronchitis, OL) during poisoning with chlorine, ammonia and other gases of irritating, cauterizing action.
For differential diagnosis of coma, EEG and CT of the brain are widely used.