Monday, June 9, 2008

General line of treatment of Poisoning

General line of treatment of poisoning

I. General non-specific measures

(a) Stop giving contaminated feed (selenium, nitrate, cyanide, oxalate, lead, alfalfa, molybdenum and ergot) and water (fluorine, nitrate, heavy metals like lead etc.).

Provide feed and water from known source.

(b) Elimination of toxicant from its region of absorption

(Eyes, skin, stomach, intestinal tract)

If the exposure is through ocular route - never rub the eyes: irrigate eyes with clean water.

Skin:
Wash the skin with copious amounts of water and scrub gently the area of exposure.
In pesticide poisoning, do not apply soap as it enhances absorption of pesticide.
Mercurial ointments (dermally toxic) if applied to be cleaned.
In acid / alkali poisoning wash the external parts of mouth with large quantity of water.

Stomach: Empty the contents by,
Gastric lavage: in dogs with 10 ml/kg of an isotonic solution of sodium chloride (or sodium bicarbonate). Proper precaution is to be taken by passing a rubber tube with a cuff attached to prevent aspiration. Repeat the procedure till clear fluid comes out from the stomach.

Rumenotomy - in ruminants in cases of plant poisons (now a days plastic bags are commonly ingested). Replace rumen contents by suitable feeds and micro flora through cuds.

Emetics:
Apomorphine in dogs - 0.05 - 0.1 mg / kg S/C or I/M.
Causes arrhythmias and CNS depression. Vomition in 3-5 min.
Not to be used in pigs and cats.
Xylazine in cats and dogs - 0.25 - 0.5 ml of 2% solution S/C.
Vomition in 10-20 min.
Tr. Ipecacaunha (10% syrup) - 10-20 ml/dog: 2-5 ml / cat.
Vomition in 20-30 min.
Alternatively,

Large crystal of NaCl / Sod. carb. (washing soda) on the posterior side of pharynx.
Salt (1-3 tsp) in warm water.
o Copper sulphate is preferred in pigs only (4% solution, 60 ml orally)
Hydrogen peroxide orally, 1 ml/kg.
Emesis is contra - indicated in poisoning by volatile oils, hydrocarbons and petroleum products, old animals, unconscious and semi-comatose patients the problem being aspiration. In acid / alkali poisoning - further damage to oesophageal lining is the disadvantage.


Purgation:
Sodium / Magnesium sulphate by mouth or as enema (up to 20% solution)
Small animals - 2-2.5 gm.
Large animals - 100 - 200 gm (max 400 g)
Liquid paraffin (Mineral oil) - orally
Dogs 5 - 15 ml
Cats - 2-6 ml
(2) Reduce the rate of absorption and resorption.

By administering suitable chemical antidotes.

· Tannic acid (general antidote) ppts. - Al, Pb, Ag, Alkaloids, Co, Cu, Hg, Ni, Zn apomorphine, strychnine, cocaine, nicotine and pilocarpine.
Tannic acid is of no value in - Arsenic, antimony and atropine.
Universal antidote - Powdered charcoal - 2 parts (adsorbent)
Tannic acid - 1 part (precipitant)
Mg oxide - 1 part (Purgative)
Mix with water - make slurry and administer
Tr. iodine solution - 15 drops of Tr.iodine in 1/2 glass of water. ppts. Pb, Hg & Ag. and alkaloids like strychnine & quinine.
Neutralization for Acids / Alkalis is best through large amount of water / milk as this dilutes the acid / alkali.
Administration of weak alkali like lime water and magnesium or weak acids like vinegar (5% acetic acid), lemon juice, citric acid (5-10 % sol.) tartaric acid (5-10% sol.) in acid / alkali poisoning respectively has the potential to release energy and gas resulting in perforation of stomach.

Milk & Egg white neutralize heavy metals & phenols, but milk is contraindicated in lipophilic poisons.
· To neutralize irritant mucosa - demulcents like – raw white of an egg, milk, gruel and sugar solution can be administered.

Activated charcoal is the best bet,
for large animals 250-500 g.
small animals 5- 50 g.
charcoal is not effective for cyanide and absorbs vitamins and minerals.
cholestyramine resin is used to break the enterohepatic cycle.
(3) Blockade of actions with non-specific antidote and specific antidote. (list appended).
(4) Hastening of metabolic inactivation and excretion of the toxin.
(a) Metabolic inactivation through enzyme inducers - phenobarbitone.
(b) Excretion – through diuresis.
Increasing diuresis by giving osmotic diuretics.
5% glucose slow I/V. 10% glucose slow I/V.
Large animals 2-5 ml Kg/24 hrs. Large animals 0.5%-1 ml /Kg/24 hrs.
Small animals 5-20 ml/Kg/24hrs. Small animals 1-2 ml / Kg/ 24 hrs.
10% Mannitol solution. Frusemide I/M / I/V.
Large animals 1-2 ml/ Kg/24 hrs. Large animals (LA) 0.5 - 1 mg/Kg.
Small animals 2 ml / Kg/ 24 hrs. Small animals (SA) 2.5 - 5 mg/Kg.

Acidification of urine to eliminate weak bases by
Ammonium chloride - orally LA - 20 - 40 gm. SA - 2 -5 gm.
Arginine chloride - I/M or I/V. LA - 7-10 g. SA 0.1 - 0.2 g/Kg.
Ascorbic acid (IV): all sps . 40 mg/Kg.
Alkalinize the urine to eliminate weak acids.
Sodium bicarbnate 1.4% solution I/V. LA - 2-4 ml /Kg/24 hrs.
Ringers lactate I/V. All species. 5 - 10 ml /Kg/ hr.
Heamodialysis & charcoal haemoperfusion if no specific antidotes are available.

(5) Symptomatic therapy - To revive cardiac & respiratory functions, analeptics to be administered. Doxapramine: Dog / Cat 2mg/Kg I/V. repeat if necessary.
Caffeine and Theophylline (cardiac and respiratory stimulants.)
Dose 100 - 250 mg / kg. I/M or S/C.
· Nikethamide: Dog 22 - 44 mg /kg. I/M or S/C.
(respiratory stimulant)
Astringents, Anti-histamines, sedatives, etc,
(6) Supportive therapy.

Ø I/V fluids

Ø liver tonics

Ø vitamins

Ø minerals

Ø herbal immunomodulators.

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