Toxidromes symptoms

Toxidrome is a term which is used to describe a constellation of signs and symptoms, which when taken collectively, may characterize the poison in question. This is particularly important if patient has altered sensorium, and there is no reliable informant for a medical history. It may be important to review physical features and the differential diagnosis of the... 

Chronic ingestion of greater than therapeutic amounts of atropine may produce symptoms of the anticholinergic toxidrome. 

Symptoms may begin within 1-4 h after ingestion. Jimson weed causes the anticholinergic toxidrome characterized by tachycardia, mydriasis, dry flushed skin, decreased bowel sounds, urinary retention, sedation, and hallucinations. Symptom resolution may vary from 1 day to 2 weeks. 

The toxidrome of acute and chronic toxicities is no defined. Subjective symptoms include nausea, vomiting, flatulence, fatigue, muscle weakness, headaches, and blurred vision. Controversy exists over whether excessive vitamin E may cause liver and renal damage. The plasma concentration levels for vitamin E vary among individuals. 

Toxic syndromes ( toxidromes ) are clinical syndromes that are essential for the successful recognition of poisoning patterns. A toxidrome is the constellation of clinical signs and symptoms that suggests a specific class of poisoning. The most important toxidromes are (1) anticholinergic, (2) cholinergic, (3) opioid and opioid withdrawal, (4) sedative-hypnotic and sedative-hypnotic withdrawal, and (5) sympathomimetic. Symptoms for these toxidromes are listed in Table 34-2. 

The primary emergency responders to chemical incidents carry out a primary reconnaissance using equipment mentioned above. This may produce an immediate identification of the agent concerned. Eye witness accounts are also important and a possible pattern (toxidrome) of signs and symptoms in victims (see Chap. 6). 

One of the main difficulties of a chemical incident is obtaining rapid information on the identity of the chemical or mix of chemicals involved and their health hazards. Disseminating this information is vital and allows medical management to proceed on an adequately informed basis. Evidence of the nature of the released chemical will come from the detection equipment deployed by the fire and special ambulance services and also from the primary assessment of the signs and symptoms of casualties to try and identify characteristic toxidromes. These are considered in Chap. 6. 

Muscarinic receptors are found in both the brain and the peripheral nervous system. In the latter, they are within the autonomic (involuntary) nervous system where they control functions within the respiratory, cardiac, alimentary and urogenital systems. This is important in understanding the toxidromes (characteristic collections of signs and symptoms) which arise after toxic exposure. In the central nervous system (CNS), the muscarinic receptors are present in high proportions within several difference subtypes which are listed in Box 6.3. 

There are a number of strains of BoTx. They act by preventing the formation of vesicles containing ACh which leads to reduced release. This in turn means that insufficient ACh is released with the arrival of a nerve impulse to ensure that a post-junctional electric impulse will be generated and therefore synaptic transmission becomes blocked. The most striking consequence of this is a descending neuromuscular paralysis which may be life-threatening due to the effects on the respiratory muscles. At the autonomic level, prodromal symptoms such as dry mouth are related to synaptic block. The toxidromes produced by BoTx are considered in Chap. 7. The most important clinical consequence of the pathophysiology of the toxin is the production of a potentially fatal respiratory failure and arrest. More information about BoTx will be found in Chap. 11. 

A toxidrome is a grouping of signs and symptoms which are important in establishing the cause of toxic trauma both individual and collective. A toxidrome can be established only after careful examination of the presenting signs and symptoms as detailed above. Toxidromes can indicate whether the patient has been affected by the deliberate release of any of the six main classes of chemical warfare agents or by one of the five main classes of toxic industrial chemicals. 

For many years, the identification of specific collections of signs and symptoms following exposure to toxic agents has formed the basis of early medical responses in diagnosis and treatment. This has particularly been the case in the military world for the management of chemical warfare agent exposure. In the civil setting where identification of the released substance may not be immediate, toxidromes have assumed an equal importance and are part of established paramedical pre-hospital response to HAZMAT incidents. 

In cholinergic syndromes, the presenting signs and symptoms are related to the build-up of acetylcholine (ACh) in the voluntary and autonomic nervous systems and the characteristic toxidrome has been described for many years. Most cases have been following pesticide exposure or pesticide self-poisoning, but there is also information about accidental and deliberate release of nerve agents. 

Signs and symptoms develop with different latencies depending on the ambient temperature. The latency of the appearance of the toxidrome reduces as the ambient temperature increases. 

Long latency of clinical expression of signs and symptoms (the equivalent of a natural incubation period) is characteristic of BW compared with CW agents. It is very important for emergency responders to be aware of this when considering the evolution of a syndrome characteristic of a disease compared with chemically induced toxidromes. 

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