تشخيص و علاج التسمم الحاد

الناقل : elmasry | الكاتب الأصلى : حيـــــاه على طاعـــه | المصدر : sayadla.com


: In This Course , We Are Going To Take



 

Symptoms and signs



 

I. General management of the poisoned patient


 

:II. Industrial and household toxicology
Acids and Alkalis
Chlorine Gas
Cyanide
Iodine
Iron
Kerosene
Lead poisoning
Mercury poisoning
Naphthalene
: Pesticides
o Organophosphate and Carbamates insecticides
o Chlorinated insecticides
o Pyrethroids
o Paraquat (herbicides
o Warfarin
o Zinc phosphide
o Temic
Phenol


 

:III. Medical toxicology
Anticholinergics
Antihistaminics
B-blockers
Calcium channel blockers
Digitalis
Muscle relaxants
Paracetamol
Salicylates
Tegretol
Theophylline


 

IV. Psychiatric drugs
Antidepressants
Antipsychotics
Lithium



 

V. Drugs of abuse
Amphetamines
Sedatives
Hypnotics:
o Barbiturates
o Benzodiazepines
o Chloral hydrate
Cocaine
Volatile inhalants:
o Toluene (Kolla)
o Paint thinners (Tiner)


 

Alcohols:
o Ethyl alcohol
o Methyl alcohol
Opioids
L.S.D
Marijuana (Cannabis, Hashish




VI . Environmental toxicology
Carbon monoxide
Food poisoning
Botulism
Castor oil
Insect sting
Scorpion sting
Snake bite
Jellyfish stings
Venomous fish stings
Supportive treatment
Precautions
 

Recommended antidotes for common poisons

 
Symptoms and Signs
 
 
Patients suffering from acute poisoning present with Different symptoms and signs according to the substance and the original health state , symptoms and signs may ****************************** *****:
Headache
Fever
Weakness and illness
Skin rash and burns
Abdominal pain
Nusea or nusea with vomiting
Diarrhea
Anorexia
Bluish of lips
Chest pain
Difficulties in respiration
Tachypnea
Abnormal odour in respiration
Palpitation, Cardiac abnormalities
Excitement, Agitation
Mental confusion
Numpness in the limbs and parathaesia
Muscle fasciculation and tremors
Convulsions
Giddiness, dizziness, vertigo, ataxia
Anurea or uncontrolled urination
Drowsiness, stupor, somnolence and semi conciousness
Loss of conciousness , coma

 

General Management of the Poisoned Patient
Management of the poisoned patient passes into 2 stages



Home or first aid

Ingested poison
Cal the poison control center.
Dilute the ingestant by giving the patient a cup of water or milk to drink, do not force the patient to drink if he is drowsy, unconscious or having a seizure.
Induce emesis.

Emesis is contraindicated if
The patient is drowsy, unconscious or having a seizure, or
The ingestant is a strong acid or ********************, petroleum product, or
Has the ability to induce seizures e.g. strychnine, TCA (tri cyclic antidepressants), isoniazid...,
# The substance has ant emetic properties.(chlorpromazineFor emesis use ipecac, dose: 1-12 years 15 ml then repeat if no emesis in 20 min. Follow the dose with 200 ml water or clear juice (not milk).
Twelve years or more dose: 30 ml.
N.B.: Do not stick a finger or other object to induce vomiting; (ineffective and dangerous), do not give salt solution. (fatal hypernatremia)
If the patient does not vomit bring him to the emergency department as soon as possible

Inhaled toxins
Remove the patient from the vicinity of the toxic fumes.
Loosen the patient clothing.
Begin cardiopulmonary resuscitation then transfer the patient to the hospital.


Contact Poison
Remove the clothing adjacent to the affected area.
Flood the skin with water then transfer to the hospital.
Eyes: irrigate with copious amounts (4-6 L) saline or water.
Hospital Management

Rapid primary evaluation, physical examination and history taking.

Resuscitation of vital signs, attention to ABC (Airway-Breathing-Circulation)

Secondary assessment leading to initiation of definitive care.

4. Disposition (is consultation required? should the patient be admitted? does the condition warrant intensive care?)


ECG monitor is placed

Oxygen administration in patients with altered mental status or unknown diagnosis, poisoning associated with cardiac arrhythmia and underlying illness (except paraquat poisoning).

I.V. access should be established immediately for laboratory diagnosis, and arterial blood gases should be done.

All patients with altered mental status should be given 20% dextrose 50 ml(after immediate reagent strip for blood glucose), naloxone 2 mg and thiamine 100 mg I.V (adults)

Initiate antidote therapy if diagnosis is established or highly suspected.

Wash any eye or skin contact with the poison.
 
Airway Management
 
Indications for endotracheal intubation
Respiratory arrest, hypoventilation unresponsive to naloxone.
Impaired protective airway reflexes.
Coma
Status epilepticus.
Need for gastric lavage in unconscious patient.
 
Indications for mechanical ventilation
Respiratory arrest.(apnea)
Severe hypoxemia.(acute respiratory failure)
Hypoventilation and respiratory acidosis.
Shock.
Coma
Administration of curariform agents. (succinil choline)
 
 
Initial parameters for mechanical ventilation
1. Tidal volume 10-15 ml/kg body weight.
2. Rate: 10/min.
3. FIO2 100%.


 
Prevention of Absorption
 
External decontamination
Skin: remove corrosive substances by gently flushing with water for 15 minutes
Eyes: begin removal of foreign material from eyes immediately after exposure, with copious amounts of saline or water (4-6L).
Inhalational exposure
Removal from hazardous environment
 
100% oxygen
Assisted ventilation
Bronchodilator if necessary(aerosol
 
Internal decontamination
Dilution
Indications: caustic ingestion
Contraindications: neutralization of ingested acid or alkali by dilution with alkali or acid diluents respectively could be harmful causing exothermic reaction
Dosage: about 200-300 ml milk
Emesis
Syrup of ipecac: gastric irritant and stimulate medullary chemo receptors
Contraindications
 
Alkali or acid
Altered level of consciousness.
Depressed gag reflex.
Absent bowel sounds
Seizures.
Infants < 6 month age.
Drug ingestions that may lead to rapid change in patients' condition or level of consciousness (TCA tri cyclic antidepressants, B blockers, propoxyphene, isoniazid, strychnine, chloroquine, ethanol, sedative- hypnotics).
N.B.: H2-receptor antagonist (Ranitidine) or anti-emetics may control persistent vomiting caused by ipecac.
Dosage
One -Twelve years: 15 ml
Older Than Twelve years: 30 ml
Gastric lavage
Techniques
Put the patient in left lateral and Trendelenburg position with knees flexed.
Aspirate first for toxic screen.
¨ Lavage is done with normal saline or water by 300 ml until lavage become clear.(100 ml for children)
Sizes of gastric tubes used are ----> adult = 36 - 40 F, child = 26 - 28 F.
Lubricant is used to easify introduction.
Leave the tube for administration of charcoal.
Indications
When gastric emptying is indicated and emesis is contraindicated.
Comatose patients or will be in the next 30 min.
Recent ingestions of large quantity of lethal toxin or rapidly absorbed toxin.
Awake patient after ingestion of toxin with serious seizures-causing potential.(TCA, isoniazid, chloroquine,…..)
Patients who have ingested a substance not bound to charcoal (Iron, lithium, ….)
Contraindications
Ingestions of corrosives.
Hemorrhagic diathesis.
Petroleum products.
Precautions
Do not use naso-gastric tubes because they are not effective in evacuating the stomach properly due to their small diameter.
Complications
Nasopharyngeal trauma.
Perforation of the pharynx
Esophageal perforation
Tracheal intubation.
Aspiration
Cardiovascular dysfunction and arrest due to vagal stimulation
Adsorption
Slurry of charcoal is administered orally or via gastric tube after lavage
Activated Charcoal
Indications
¨ After gastric lavage or failed emptying procedure.
¨ For any substance with entero-hepatic circulation. Administer every 4 hours, especially useful for theophylline, phenobarb and digitalis.
¨ For sustained released tablets
Precautions
The longer the delay between ingestion of poison and administration the less effective it will be.
Contraindications
Caustic acids and alkalis (ineffective and may obscure injured areas making endoscopy difficult)
Ineffective against lithium, iron, lead, ethanol, methanol, . . .)
Absent bowel sounds
Intestinal perforation, obstruction or peritonitis
Comatosed patient
Dosage
Child: 15-30 gm in 100 ml water
Adult: 50-100 gm (1 g/kg) in 200 ml water
Dose of charcoal should be followed by cathartic to speed elimination of charcoal-toxin complex.
Complications
    •  
    • Aspiration(pneumonitis, bronchiolitis obliterans)
    •  
    • Constipation
 
Cathartics
Indications
Elimination of activated charcoal-toxin complex from GIT.
Prevention of constipation.
Contraindications
Diarrhea.
Absent bowel sounds
Trauma to the abdomen.(perforation or peritonitis)
Intestinal obstruction.
Renal failure.
Very old or very young patients
Caustics and corrosives
Dosage
Adult: sorbitol 50 ml 70%(1ml/kg body wt.) or magnesium sulfate 30 gm
Child: magnesium sulfate 250 mg/kg
Or sorbitol 1ml/kg body weight
N.B.: sorbitol is not recommended for children less than 3 years
 
Enhancement of Elimination
 
Simple diuresis (without ion trapping technique
Indications
In overdose with lithium or bromide
Contraindications
1. Any patient with heart or kidney failure
2. Any drug producing cardiogenic or non-cardiogenic pulmonary edema (narcotics, TCA...).
Administer sufficient fluids and diuretics to maintain urine flow rate at 300 ml/hour.
 
Diuresis with ion trapping technique
Indication: urine alkalanisation: (salicylates, barbiturates
Insert swan gang catheter if patient at high risk of pulmonary edema.
I.V. solution composed of 2 amp Na bicarb. ( 8.4%) in 1 L 5% dextrose in 1/2 normal saline. Administer at a rate of 300 ml/hour (if the patient is haemodynamicaly stable)
Check urine pH in 1 hour (should be at least 7.5 and preferably 8).
N.B.: Effective alkaline diuresis requires correction of potassium deficits and monitoring of serum electrolytes and arterial blood gases
 
Acids and Alkalis
 
Inorganic acids
Sulfuric, nitric, hydrochloric...
Inorganic alkalis
Caustic soda, caustic potash...
Clinical Picture
Dysphagia, drooling, refusal to eat
Stridor
Severe abdominal pain
Hypotension, tachycardia, shock
Treatment
Demulcents as cold milk and egg white by mouth (250 ml).
Care of respiration.
¨ Dextrose 5% and saline 0.9% 500 ml I.V. to correct fluid and electrolyte imbalance.
Pethidine for severe pain.
Steroids should be started by giving prednisone 1-2 mg/kg in alkali poisoning. This should be continued for 3 weeks and decrease dose gradually.
Antibiotics if there is indication, or concurrently with steroids.
Endoscopy: usually performed within 12-24 hours of injury.
DON’T Give bicarbonate or alkalis because they produce exothermic reaction -----> heat ----> more destruction to the tissues.
DON’T Induce emesis.
DON’T do gastric lavage.
DON’T give Charcoal
DON’T give Cathartics

 
Chlorine Gas
 
Clinical picture
Conjunctivitis, keratitis, rhinitis, pharyngitis, tracheobronchitis, pulmonary edema, chemical burns and GIT disturbances (epigastric pain)
Treatment
Decontamination
Care of respiration: artificial respiration, O2 inhalation 100% for 15 min which may be repeated if necessary. Oxygen administration with intermittent positive pressure is more effective
Sedative cough syrup is useful
Aminophylline or salbutamol for bronchospasm
4. Hydrocortisone 100 mg I.V. 6 hourly is helpful for pulmonary edema

 
Cyanide
 
Clinical picture
Initial symptoms: giddiness, headache, palpitation, dyspnea, ataxia, coma, seizures and death (it may lead to death in few minutes by inhalation).
Nausea and vomiting can occur after ingestion of cyanide salts
Cardiac arrhythmias
Treatment
Care of respiration: artificial respiration, O2 inhalation 100%, ECG monitor
Break amyl nitrite pearls in a handkerchief and allow the patient to inhale for 30 seconds every minute to relief laryngeal spasm and form metHB
Fill a syringe with 10 ml of 3% solution of sodium nitrite and another with 50 ml 25% solution of sodium thiosulfate; inject slowly I.V
If cyanide is taken by mouth, do gastric lavage using copious amounts of water then by 5% sodium thiosulfate till the odor of cyanide disappears from the lavage fluid
Hydroxycobolamine (vit. B12a): combines with cyanide to form cyanocobolamine
(vit. B12): 50 mg/kg body weight slowly I.V. over 20 min.(total dose 4gm (adult) )
Kelocyanor (Dicobalt EDTA) combines directly with cyanide to form a stable,
inactive complex (not available