Corrosive Poisons PDF

Corrosive Poisons Inorganic Acids: Example: – concentrated sulphuric – Nitric – hydrochloric acid. Action: is local corrosion only. Oral fatal dose is 4 ml. Poisoning is: – accidental by skin contamination, ingestion or inhalation of fumes – homicidal throwing of concentrated...

Corrosive Poisons Inorganic Acids: Example: – concentrated sulphuric – Nitric – hydrochloric acid. Action: is local corrosion only. Oral fatal dose is 4 ml. Poisoning is: – accidental by skin contamination, ingestion or inhalation of fumes – homicidal throwing of concentrated acid on the face. Corrosive burns  Clinical signs : – Local corrosion on skin – If taken orally it will cause the follwing: Severe burning pain from mouth to stomach. Severe colic and bloody vomitus with pieces of gastric mucosa, vomitus is strongly acidic, – dark due to acid haemation – black charring in sulphuric acid – yellow in nitric. Dehydration with thirst  Oligouria and constipation. Shock with weak rapid pulse and hypotension. Evidence of corrosion on lips and mouth. Oedemaof the glottis and stridor and cyanosis. Death in few hours from shock and dehydration or few days from perforation and peritonitis. If the patient survives, oesophogeal stricture may occur with dysphaga. – Inhalation of Acid Fumes presents with: Burning pain in chest. Severe cough and dysnoea. Oedema of glottis and stridor. Pulmonary oedema. Cyanosis and death from asphyxia. Broncho pneumonia may occur.  Treatment: – Emetic and gastric lavage are contraindicated for fear of gastric perforation, also carbonates and bicarbonates due to evolution of CO2 causing gastric distension and rupture. – Give water orally to dilute the acid. – Antidote neutralization by weak alkalies as magnesium oxide or lime water (Ca hydroxide) or soap solution. the best is milk to avoid heat production, egg albumin, olive oil, or butter. – Morphine 8-15 mg I/V to relieve pain, shock and pulmonary oedema – I/V fluids for dehydration. – Tracheostomy for oedema of glottis and treat pulmonary oedema. – Antibiotics + corticosteroids are recommended by some to avoid strictures + surgical treatment for perforation and strictures. – Contaminated skin is washed by soap and water then surgically treated. Corrosive Alkalies (K+ and Na+ Hydroxide): – Potassium hydroxide (caustic potash) and sodium hydroxide are widely used in houses for washing purposes and so are common in accidental poison in children. – Fatal dose 3-5 grams of the solid or the corresponding amount of solution.  Picture: Same as corrosive mineral acids with the following diffrences: – The mucosa of the mouth is white. – The vomitus is whitish, slimy (soapy) alkaline, and containing blood. – Diarrhoea may occur. – Perforation of the stomach is more delayed and oesophogeal strictures are very common.  Treatment: – The same as in corrosive acids avoiding emetics and lavage. – The antidote: is weak acid to neutralize the alkali as lemon or orange juice diluted with water or 15 ml of vinegar (3-5% acetic acid) in a glass of water. – Corticosteroids and symptomatic – surgical treatment. Organic Acids: Acetic Acid: Glacial acetic acid is a strong corrosive orally or by inhalation of the fumes. It produces the same picture of acid corrosives with the smell of vinegar. Treatment: as for corrosive acids. Carbolic Acid (Phenol):- – It is in the form of white crystals with a strong characteristic smell. – The crude form is a solution used for toilet disinfection. – Its other forms e.g: Lysol, Cresol and Dettol produce the same effects.  Action: – Local: Coagulative necrosis with thickening of the tissue supeficial ulcers with local anasthetic effect on sensory nerve endings gangrene of skin if applied for a long time. – After absorption: produces CNS and respiratory depression acute toxic glomerulonephritis.  Fatal Dose:- 2-4 gm of the solid phenol or the corresponding amount of the crude acid. Poisoning: – Mainly accidental ingestion in children or by skin contamination because it is rapidly absorbed by the intact skin. – Used suicidally because it is available and known to be painless.  Picture:- – Temporary burning pain from mouth to stomach – then colic and vomiting – the pain soon stops due to local aneasthetic effect. – Whitish buccal mucosa and brownish carbolic eschars on lips and chin which become brown due to oxidation. – Drowsiness then coma due to CNS depression. – Central respiratory depression leads to slow difficult respiration, cyanosis, pulmonary oedema and death due to asphyxia after few hours. – Pupils are contracted but dilate just before death. – Smell of phenol from breath. – Acute toxic glomerulorephritis with oliguria, albuminuria, haematuria and casts, the urine turns to green if left in air due to oxidation of hydroquinone and pirocatechin which are the excreted products of phenol with anuria. – Delayed death from anaemia may occur after 7-10 days.  Treatment: – Gastric lavage is done (due to thickening of the gastric mucosa) by the antidote which is magnesium sulphate 15-30 gm in a glass of water to precipitate the poison as magnesium sulphocarbonate. – If not available 10% ethanol or glycerine is used as dissolving antidote but must be rewashed to prevent absorption. – Contaminated skin is washed by soap and water then 10% alcohol followed by water. – General measures for care of coma and respiration are followed. – Atropine 1 mg I/V for stimulation and to decrease pulmonary secretions – Measures for controlling pulmonary oedema are performed – Impaired renal function is treated by 1.26% sodium bicarbonate I/V or dialysis. Snake bites  Introduction There are over 3,000 species of snakes on the Planet, but only 15% are considered to be dangerous Snakes are found on every continent except Antarctica Every State except Alaska, Hawaii, and Maine are home to at least 20 venomous snake species Each year there are 45,000 incidents of snake bites in the U.S. – 7,000 - 8,000 are from venomous snakes – On average 10 people die each year The literary word for snake is serpant which comes from Old French meaning “to creep”. The snake is also used as the symbol for medicine because of it’s relation to Asclepius, the Greek god of Medicine. www.wikipedia.org/snakebites  Snake Venom Snake Venom is a Toxin (Hemotoxin Neurotoxin, or Cytotoxin) A varied form of saliva It is excreted through a modified parotid salivary gland – Located on each side of the skull – Behind the eye Snake venoms are a combination of proteins and enzymes The flow of venom is produced through a pumping mechanism from an alveolar sac that stores the venom, proceeds through a channel, down a tubular fang which is hollow in the center to project the venom into the air or its prey Though the venom is dangerous, since it is not inhaled it cannot be considered a Poison  Benefits Although snakes have been deemed as one of the worlds most dangerous and disgusting critters on the planet, they actually have some benefits: – Help control the smaller members of the animal kingdom from becoming overpopulated – They save farmers a minimum of seventy-five dollars annually by ridding their fields of destructive rodents – Snakes eat harmful rodents (mice, rats, etc.) and insects that may carry harmful diseases – Snakes also possess an oil that can be harvested that is used to remedy pain in joints, such as rheumatoid arthritis. The fats and the oils extracted from the snakes have a high content of Eicosapentaenoic acid (EPA), hence it is thought to have inflammation reduction properties.  Snake Video Snake Bite Video  Venom 90% protein by dry weight and most of these are enzymes 25 different enzymes have been isolated from venoms and 10 of these occur frequently in most venoms Synergistic effects: different venoms contain different combinations of enzymes causing a more potent effect than any of the individual effects (very similar to drug synergism) Generally speaking, venoms are either neurotoxic, hemotoxic or cytotoxic and the enzymes in the venom are responsible for these effects  Mechanism of Action Toxic effects are the most common focus of snake venom but often the compounds responsible for these effects can be isolated and used for beneficial purposes Can range from anti-venom production, to multiple sclerosis treatment, and slowing of cancer growth and metastasis rates  Side Effects Respitory paralysis Fever Rapid Pulse Increased Thirst Dizziness Local Tissue Damage Blurred vision Nausea and vomiting Diarrhea Coma Death http://www.drugs.com/enc/snake-bite.html  Case Study # 1 41 year old male Bitten on left third finger by Gaboon Viper Necrosis and Blanching noticed upon arrival to ER Numbness and edema were also present to hand Prothrombin time was 15.53 (normal range 11.0-13.0) International normal ratio 1.2 There was moderate leucocytosis and normal platelets The patient was treated with intravenous antibiotics, diphenhydramine, hydrocortisone, and five 10ml vials of South African Institute of Medical Research (SAIMR) antivenin. Over next eight hours the patient developed lymphangitis of the left arm. The patient’s lymphangitis later resolved but he later required amputation of his left third finger..  Antivenin is made by injecting horses with toxins from venomous snakes and then monitored to make sure they survive. Then after the horse builds up an immunity the blood is extracted and processed into antivenin More than 2700 species of snakes world wide. In Africa: Echis carinatus saw – scaled or carpet viper Bitis arietans puff adder. Naja nigricollis black – necked spitting Cobra. Naja haje Egyptian Cobra. Dendroaspis mambas. Snake bites are occupational hazard among farmers in Africa.  Venom composition: 90% of dry weight is proteins enzymatic toxins non – enzymatic toxins. non toxic proteins. Carbohydrates (CHO) Metals. Lipid. Free amino acids. Experimental work in animals In vitro effect Real situation in man.  Enzymes: 1. Activation of mammalian blood clotting cascade. 2. Phospholipase A2, experimental damage to mitochondria, RBCs, leucocytes, skeletal muscles and vascular endothium. 3. Hydrolases; which increases vasclar permeability, oedema, blistering, bruising and local necrosis. 4. Neurotoxins prevent release of acetylcholine at the neuromuscular junctions. 5. Histamine and 5-HT( 5 hydroxy treptamine) which cause edema and local pain at the site of the bite. So snake venom is not a single toxin.  Cause of death: Shock and hypotension. Massive bleeding. Acute renal failure. Respiratory muscles paralysis ( bulbar paralysis).