25.3.1 Corrosive Compounds Poisoning
Examples—sodium hydroxide (Soaps-drain/oven cleaners), potassium hydroxide, acids, bleaches or disinfectants.
Non-Pharmacological Treatment
- Give small volume of water as soon as possible-beneficial within 30mins
- Give oxygen therapy if respiratory distress
Surgical review
- Arrange for surgical review to check for:
- Esophageal damage/rupture, if severe.
- Perforation, mediastinitis and peritonitis if suspected
Note: Do not induce vomiting or use activated charcoal
25.3.2 Petroleum Compounds Poisoning
Examples—kerosene, turpentine substitutes and petrol
Diagnostic Criteria:
- GIT-abdominal pain, bloody stool, vomiting
- RS-Throat swelling, pneumonitis and/or pulmonary oedema-cough, tachypnea, cyanosis, crepitation and rhonchi
- CNS-Headache, dizziness, euphoria, restlessness, ataxia, convulsion, encephalopathy and coma
Non-Pharmacological Treatment
- Remove the patient from source
- Remove contaminated cloth and thoroughly wash the skin with soap and water
- Give supplemental oxygen if needed
- If large amount of petroleum compound has been ingested less than an hour earlier lavage may be considered and the patient should be intubated
Note: Do not induce vomiting
25.3.3 Organo-Phosphorus and Carbamate Compounds Poisoning
These can be absorbed through the skin, ingested or inhaled. Examples:
- Organophosphorus – Malathion, Parathion, Tetraethyl Pyrophosphate (TEPP), mevinphos and
- Carbamates – methiocarb and carbaryl.
Diagnostic Criteria
- Vomiting, diarrhoea, blurred vision or weakness.
- Signs of excess parasympathetic activation: salivation, sweating, lacrimation, slow pulse, small pupils, convulsions, muscle weakness/twitching, then paralysis and loss of bladder control, pulmonary oedema, and respiratory depression.
Non-Pharmacological Treatment
- Remove poison by irrigating eye or washing skin (if in eye or on skin).
- Give activated charcoal if ingested and within 1 hour of the ingestion.
- Do not induce vomiting because most pesticides are in petrol-based solvents.
- In a serious ingestion where activated charcoal cannot be given, consider careful aspiration of stomach contents by NG tube (the airway should be protected).
- Auscultate the chest for signs of respiratory secretions and monitor respiratory rate, heart rate and coma score (if appropriate)
- Give oxygen if oxygen saturation is less than 90%
Pharmacological Treatment
- If there are signs of excess parasympathetic activation (see above) give:
A: Atropine, boluses of 5mg IV- Repeat every 10minutes until satisfactory atropinization (i.e. no chest signs of secretions, HR>80b/min, Systolic BP >80mmHg, pupils no longer pinpoint, Dry axillae) 9.
- Paediatric patient can start at 0.05mg/kg, then double the dose every five minutes, stop doubling the dose when parameters have improved
S: Obidoxime (a cholinestarase activator) 5mg/kg IV if <24 hours. It may be given 5minutes after the first dose of atropine, if available.
- If muscle weakness give:
S: Pralidoxime (cholinesterase reactivator) 50mg/kg diluted with 15 ml water for injection by IV infusion over 30 minutes- Repeated once to twice
- Followed by 10–20 mg/kg/hour, as necessary.
25.3.4 Paracetamol Poisoning
Paracetamol (N-acetyl-p-aminophenol) is a common antipyretic and analgesic, that is used worldwide. It is the commonest taken drug overdose.
Diagnostic Criteria
- Phase-1: 0.5–24 hours after ingestion: asymptomatic, to nonspecific symptoms (anorexia, nausea, vomiting and malaise). Pallor , diaphoresis
- Phase-2: 18–72 hours after ingestion: Right upper quadrant abdominal pain, anorexia, nausea and vomiting, Tender right upper quadrant, tachycardia, hypotension and oliguria.
- Phase-3: 72–96 hours after ingestion: all of the above and jaundice, coagulopathy, hypoglycemia and hepatic encephalopathy, Acute Renal failure.
- Phase-4: 4th day to 3weeks after ingestion: patient who survive critical illness in phase 3, have complete recovery.
Investigation
- Liver Function Test- ALT, AST, ALP, PT with INR (International Normalization Ratio)
- Glucose
- Renal Function Test: Electrolytes, BUN, creatinine
- ABG-Arterial Blood Gas
Non-Pharmacological Treatment
- Rescucitation
- Usually there is no immediate threat to the airway, breathing and circulation with paracetamol poisoning
- Correct hypoglycaemia (Give glucose or sugar or honey)
- If within 1 hour of ingestion of 150mg/kg or more paracetamol give activated charcoal, if available, or induce vomiting.
Pharmacological Treatment
A: Activated charcoal (1gm/kg, up to 50gm) if less than 2 hours.
If more than 8 hours after ingestion, or the patient cannot take oral treatment, give:
- C: Acetylcystein 150mg/kg IV in 200mls of 5% Dextrose over 20 minutes, then 50mg/kg in in 500mls of 5% dextrose over 4 hours, then 100mg/kg in 1 liter of 5% dextrose over 16 hours.
- In severe poisoning a further 100mg/kg may be given over the next 24 hours
Children <20kg: Give loading dose of 150mg/kg in 3ml/kg of 5% glucose, over 15 minutes, followed by 50 mg/kg in 7 ml/kg of 5% glucose over 4 hours, then 100 mg/kg IV in 14 ml/kg of 5% glucose over 16 hours.
For conscious and not vomiting or when there is severe reaction to Nacetylcysteine give:
- S: Methionine (<6 years: 1 gram every 4 hours – 4 doses; 6 years and above: 2.5 grams every 4 hours for 4 doses).
25.3.5 Acetyl Salicylic Acid (Aspirin) and other Salicylates Poisoning
Diagnostic Criteria
- Initial signs and symptoms
- Tinnitus and impaired hearing, rapid breathing (acidotic-like breathing), vomiting, dehydration, fever, double vision and feeling faint
- Late signs
- Drowsiness, bizarre behavior
- Unsteady walking and coma
Investigations
- Blood gases
- pH and bicarbonates and serum electrolytes
Non-Pharmacological Treatment
- Give activated charcoal within one hour of ingestion if available. If charcoal is not available and a severely toxic dose has been given, then perform gastric lavage or induce vomiting as above
- Replace fluid losses (Plasma potassium concentration should be corrected before giving sodium bicarbonate as hypokalaemia may complicate alkalinisation of urine)
- Monitor blood glucose every 6 hours and correct as necessary
- Monitor urine pH hourly.
Pharmacological Treatment
C: Sodium bicarbonate (IV) 1 mmol/kg over 4 hours to correct acidosis and to raise the pH of the urine to above 7.5 so that salicylate excretion is increased.
- Give 0.9% sodium chloride as maintenance requirements
- Hemodialysis is required if the concentration exceeds 700mg/liter or in presence of severe metabolic acidosis
25.3.6 Iron Poisoning
Diagnostic Criteria
- Nausea, vomiting, abdominal pain and diarrhoea.
- The vomitus and stools are often grey or black.
- In severe poisoning there may be gastrointestinal haemorrhage, hypotension, drowsiness, convulsions and metabolic acidosis.
- Gastrointestinal features usually appear in the first 6 hours and a patient who has remained asymptomatic for this time probably does not require antidote treatment.
Non-Pharmacological Treatment
- Gastric lavage if potentially toxic amounts of iron were taken.
Pharmacological Treatment
- Give antidote treatment:
D: Deferoxamine (deep IM injection) 50mg/kg up to a maximum of 1g by repeated every 12 hours; if very ill, give IV infusion 15 mg/kg/hour to a maximum of 80mg/kg in 24 hours.
25.3.7 Carbon-monoxide Poisoning
Carbon monoxide is a byproduct of burning organic compounds, and may of its exposure occur in private residences. So its toxicity is usually due to improper use of gasoline portable generators and indoor use of charcoal for cooking and heating.
Diagnostic Criteria
- Dull headache, general body weakness
- Dizziness, nausea or vomiting
- Shortness of breath, blurred vision, loss of consciousness
Investigations
- Blood gases and serum electrolytes
Non pharmacological Treatment
- Give 100% oxygen to accelerate removal of carbon monoxide (note patient can look pink but still be hypoxemic) until signs of hypoxia disappear.
25.3.8 Opiod Poisoning
Opiate intoxication can occur any time from birth (Delivery/ maternal opiod usage) to terminal care. Drugs that may be involved include: Codeine, Diamorphene, Di Hydrocodeine, Fentanyl, Heroin, Loperamide, Methadone, Morphine, opium, Tramadol (etc.) alone or in combination.
Risk factors for Toxicity
- Drug users
- Social disadvantaged
- People who had used the drug earlier for treatment
- Those using alcohol and other sedatives
Diagnostic Criteria
- Acute toxicity: drowsiness, nausea and vomiting
- Chronic toxicity: constipation, loss of appetite± nausea and vomiting
- Respiratory depression, tachycardia, hypotension and pin point pupils
Non Pharmacological Treatment
- Check the airway
- Intubate the patient who cannot protect their airway
- Give oxygen
Pharmacological Treatment
Antidote:
C: Naloxone
- Hypoventilating patient with spontaneous ventilation Naloxone
- Adults & children> 20kg: Initial dose 0.5mg titrated upward until Respiratory Rate is ≥12
- Children (<20kg): 01mg/kg IV (Maximum 2mg/dose), increase till hypoventilation resolves
Patients with apnoea:
- Newborn with apnoea secondary to maternal opiod: 0.01mg/kg IV/IM (Maximum 0.4mg/kg/dose)
- Children: <20kg 0.1mg/kg (Maximum 2mg/dose) start then repeat doses with continuous infusion as required.
- Adults and children>20kg Higher dose of naloxone (0.2-1mg and titrate to clinical response
For life threatening Opioid toxicity
- Pediatrics (< 20kg) dosing: 0.1mg/kg/IV (Maximum 2mg/dose). Repeat dose/continuous infusion as required
- Adults and children (More than 20kg): 2mg IV.
- The dose should be repeated every 3 min until improvement of Respiratory Distress Syndrome
- If maximal cumulative dose of 10mg is reached and the respiratory insufficiency has not improvement, consider other pathology
NOTE: Withdrawal reaction might be life threatening in neonatal period, hence low doses should be given
