VEGETABLE ACID POISONSHYDROCYANIC ACID(CYANOGEN OR PRUSSIC ACID)

CHARACTERISTICSGas: colourlessSmell bitter almondsLiquid acid highly volatile -- colourless -- transparentCombines with bases of metals, alkalis CYANIDES (salts) white powder

USES OF CYANIDESPhotography ElectroplatingMetallurgyTanningFumigation of shipsAgriculture

FOUND NATURALLYPeach PlumAppleBitter almonds Leaves of cherryExists as Glucoside amygladin harmless.Enzyme emulsion hydrolyses it hydrocyanic acid

Cyanides + Acids hydrocyanic acidToxic --- inhaledCyanides rapidity of action depends on HCL in stomach.

MODE OF ACTIONProtoplasmic poisoning Inhibits cytochrome oxidase system for oxygen utilization. Other enzyme system also inhibited.Cyanides --- corrosive effect on mucus membrane.Prevent formation of ATP.Death cytotoxic or histotoxic anoxia (blood may contain normal oxygen content)

SIGNS & SYMPTOMSMOST RAPID OF ALL POISONS

Inhalation of gas : Instantaneous deathLarge dose swallowed Symptoms occur at once.Some times interval of one minute which allows victim to perform voluntary acts.Death delayed (few minutes).Agonizing dyspnoeaConvulsions Dilated pupils

SMALL DOSE SWALLOWED Head ache ConfusionGiddinessNauseaLoss of muscular power.

Smell of bitter almonds (mouth).Violent convulsions.Loss of consciousness.Fine froth (mouth)Death

INGESTION OF SALTS(POTASSIUM CYANIDE)Symptoms appear after 10 20 minutesActed upon by HCL to liberate hydrocyanic acidSYMPTOMS:GiddinessDyspnoeaDilated and fixed pupilsConvulsive seizures Loss of muscle power

Epigastric painVomiting Cyanosis of faceJaw clenchedFroth mouthRespiration spasmodicPulse imperceptible Death (respiratory paralysis)

CHRONIC POISONINGREPEATED EXPOSURE TO NON LETHAL DOSES SEEN IN:-PhotographersGildersSYMPTOMS:HeadacheVomitingDiarrhoeaMental disturbancesChronic cachexia

FATAL DOSE:Pure acid: 50 60 mgPharmacopoeial Preparation:30 dropsCrude oilBitter almonds : 60 dropsPotassium cyanide : 200 mg

FATAL PERIODDeath: immediate: Hydrocyanic acid:2 10 minutes.Sodium or potassium cyanide: 30 minutes.

TREATMENTImmediate treatment may be of value AIM:Reverse cyanide cyrochrome combinationHaemoglobin methaemoglobin + cyanide cyanmethaemoglobin (Non-toxic).

If Pt survives for 4 hrs ---- recoverTwo 20 ml ampoules of 1.5 % dicobalt tetracemate IV.20 ml of 50% glucose.50 ml of 1% solution of methylene blue(methyl thioneine chloride) IV.

ANTIDOTE converts haemogloben to methaemogloben.

POTASSIUM CYANIDE OR DILUTE HYOROCYANIC ACID POISONINGGastric lavage with 10 to 50% Nathiosulphate or Mixture of sulphates of iron

Followed by:Solution of Potassium Carbonate to formPrussion blue (inert)Emetics (stomach tube not available)

Inhalation of hydrocyanic acid gas (cyanogas)Remove the patient to fresh airArtificial respiration100% O2Sodium nitrite

Sodium thiosulphateI.V

Postmortem appearanceAsphyxia

EXTERNAL:Smell bitter almondsFace, lips, body surface irregular pink patches.Skin --- livid or cyanosed.Nails blueEyes glistening, dilated pupils.Cherry red postmortem staining.Rigor-Mortis early (convulsive seizures)

INTERENAL P.M APPEARANCESmell of bitter almonds :StomachSerous cavities.BrainStomach, mucous membrane pinkOther organs : pink (cynmethaemoglobin)Trachea or bronchi blood stained froth.Brain or meninges hyperaemic.

Potassium cyanide poisoningCorrosion MouthReddening of gastric mucous membraneFrank or altered blood in stomach from erosions.

ORGANS FOR CHEMICAL ANALYSISBrainLungsStomach contents Urine Vomitus

PRECAUTIONS FOR DISSECTORRubber glovesMaskPrevent inhalation of cyanides from stomach contents.

MEDICOLEGAL ASPECTSSuicidal agents: Hydrocyanic acidCyanides (commonly used)Accidental:FumigationDisinfectionHomicidal (Rare)Smell and taste

Cattle PoisonDouble cyanidesPotassium ferrocyanidePotassium ferricyanide Taken with acid

PoisonousNon Toxic

Judicial ExecutionStrapped to a chairCyanide Eggs strong acid cyano gasInhalation immediate death