Pediatric Toxicology-3 Nursing CEs

Author: Kristi Hudson RN, MSN, CCRN

Written: March 25, 2007

Updated: October 14, 2009

Course Description

This course is designed to provide information regarding the care and management of a pediatric patient who has suffered from poisoning. The appropriate use of Ipecac Syrup, Gastric Lavage, Activated Charcoal and Cathartic Therapy will be presented. Focus will be placed on the signs and symptoms, assessment and treatment options for iron and lead poisoning. Treatment options/antidotes for medication overdoses (including Heparin) will also be presented.  Possible complications associated with pediatric poisoning and patient/family poison prevention education will be the final focus of this course.

Course Objectives

Upon completion of this course the student will be able to:

• Differentiate between four types of gastric decontamination (ipecac, gastric lavage, activated charcoal and cathartic therapy).
• Describe the procedure for gastric lavage.
• Discuss the treatment options for iron poisoning.
• Explain the signs and symptoms of pediatric lead poisoning.
• State the possible complications of both iron and lead poisoning.
• Discuss the medication antidotes for benzodiazepine, alcohol and Heparin overdose.
• List 3 ways to prevent pediatric poisoning.
• Describe patient/family interventions if pediatric poisoning is suspected.

Definition of Poisoning:

Poisoning is defined as a substance which when introduced or absorbed by a living organism (child in this case), causes injury or death. There are a number of substances that can be considered to be poisonous.

Facts about Poisoning:

• Due to their normal hand to mouth behavior, children between the ages of 5 months and 6 years of are the age group at greatest risk for ingesting caustic or poisonous substances (children between 1 ½ years and 2 years old are at even greater risk).
• Their natural curiosity, spontaneous activity, innocent teething and/or copying adult behavior is what puts them at greatest risk.
• Poisoning may also occur due to insecurity, protest, punishment and/or attention seeking behaviors.
• Male children are more at risk for poisoning then females due to their increased activity levels.
• Family disturbance has been correlated with increased childhood poisoning (possibly due to distraction of one or both parents).
• Incidence of poisoning tends to be higher in lower socio-economic families due to improper storage of substances.

Types of Gastric Decontamination:

Gastric Lavage – Gastric Lavage which involves the passage of an orogastric tube into the stomach and then administration and aspirations of small volumes of liquid. The purpose is to remove the toxic substance present in the stomach and should only be employed if the procedure can be undertaken with in 60 minutes of poisonous ingestion. Airway protection must be monitored closely when gastric lavage is used. The procedure is contraindicated in cases where hydrocarbons or corrosive substances have been ingested and when there is a high risk for aspiration.

The Procedure for Gastric Lavage Includes:

• Placing the child on his/her left side with the head slightly lower then the body.
• Placement of a large bore orogastric tube (checking placement by injecting air into the tube and auscultating the stomach region, listening for gurgling sounds).
• Using Normal Saline solution, inject 15ml/kg boluses until clear (max. 400 ml).
• Once the substance returns clear, activated charcoal or other antidotes can be injected.
• Initial aspirate should be saved and sent to the lab for toxicology testing.

Activated Charcoal – Activated charcoal is considered to be the most effective single agent for treating poisoning. It is estimated that activated charcoal can reduce approximately 60% of the poisonous substance that is being absorbed. Activated Charcoal works by absorbing the chemical and thus reducing the affects of toxicity (it absorbs chemical throughout the entire GI tract). The following are characteristics of activated charcoal:

• It is a black powder
• It is odorless
• It is tasteless
• It is non-toxic

The Procedure for Administering Activated Charcoal:

• Activated Charcoal is often given after gastric lavage (an orogastric tube should be present, but activated charcoal can be taken PO).
• The dosing for activated charcoal is a 1 gram per kg dose with a maximum of 50 grams.
• It is recommended that the first dose be given with a sorbital or cathartic in order to increase removal of poisonous substance.
• Repeat doses should be ½ of the original dose and can be repeated every 4 hours.

Ipecac Syrup – Ipecac syrup is a medication that comes from a plant extract. When swallowed, it irritates the stomach and induces vomiting. Ipecac syrup is the only recommended method of inducing vomiting after the ingestion of poison (avoid finger gagging and salt water as an intervention to induce vomiting as they are not only considered to be ineffective, they can actually be harmful).

 Because removal of “every type” poison is not necessary, a call to the local poison control center should be made for confirmation prior to giving Ipecac Syrup. Ipecac Syrup should not be used if the child has ingested a caustic substance such as acid or a petroleum product such as gasoline or kerosene. It should also be avoided in children who are unconscious.

Procedure/Dosing of Ipecac Syrup:

Cathartics – Cathartics are intended to decrease the absorption of poisonous substances in the GI tract by causing diarrhea and hence the rapid expulsion of the toxic substance. However; because most drug or poisonous absorption rapidly occurs in the upper GI tract, the benefit of cathartic therapy is thought to be minimal unless the drug or poison ingested is a slow acting substance.

Procedure/Dosing of Cathartics:

Magnesium Citrate 6% Solution

Common Types of Pediatric Poisoning With Treatment Modalities:

Iron Poisoning (most common) – Iron toxicity is the leading cause of poisoning in children under the age of 6 and is likely to occur if greater then 60 ml/kg of elemental iron has been ingested. Ingestion of doses that range from 20-60 ml/kg of elemental iron can also cause toxicity. Iron toxicity is  considered to be either corrosive (rusts) or cellular (ingested from vitamin supplements).

The signs and symptoms of iron toxicity develop in a five phase time sequenced event:

Phase One Symptoms (the first 6 hours):

• GI manifestations
• Hemorrhagic vomiting
• Non hemorrhagic vomiting
• Diarrhea
• Abdominal pain
• Early hypovolemic (due to diarrhea)
• Inflammation (due to third spacing)
• Tissue Hypoperfusion
• Metabolic acidosis
• Convulsions
• Shock
• Possible coma

Phase Two Symptoms (4 to 12 hours) – Phase two is known as the latent phase and is often associated with improved symptoms (especially when supportive care for phase one has been initiated). During phase two, iron is absorbed into various tissues increasing systemic acidosis. Lack of vomiting and diarrhea may falsely lead practioners to believe the child’s condition has improved. Lab results however will demonstrate the following:

• Progressive metabolic acidosis.
• The beginning of organ failure i.e. elevated transaminase levels.

Phase Three Symptoms (12 to 24 hours) – When ferrous iron is absorbed, it converts to ferric iron which liberates an unbuffered hydrogen ion. This exacerbates metabolic acidosis which in exchange rapidly contributes to cell death and tissue injury at the organ level. In this third phase, the following signs and symptoms will be present:

• Hypovolemic shock
• Decreased heart rate
• Decreased overall myocardial activity
• Decreased cardiac output
• Decreased myocardial contractility
• Increased pulmonary vascular resistance

Phase Four Symptoms (2 to 3 days post ingestion) – In this phase, iron is absorbed by Kupffer cells and hepatocytes which exceeds the storage capacity of ferritin and causes oxidative damage. Symptoms in this phase include:

• Swelling (peripheral edema)
• Peri-portal hepatic necrosis
• Continued elevation in transaminase levels (which may result in liver failure).

Phase Five Symptoms (2 to 6 weeks post ingestion) – This phase is characterized by late scarring of the GI tract with pyloric obstruction and hepatic cirrhosis.

Assessment and Lab Findings – Assess for the above symptoms and if iron toxicity is suspected or confirmed; it is imperative to put forth every effort to determine the degree of toxicity. Determining the time of ingestion is also very important so accurate observation periods can be determined. Different iron supplements contain different amounts of elemental iron. For example:

• Ferrous Sulfate (20% elemental iron)
• Ferrous Gluconate (12% elemental iron)
• Ferrous Fumarate (33% elemental iron)
• Ferrous Lactate (19% elemental iron)
• Ferrous Chloride (28% elemental iron)

The following example is a formula that can be used (in this case a 10 kg child who swallowed 10 320 mg tablets of Ferrous Gluconate which remember contains 12% elemental iron):

• 12% of 320 mg = 38.4 mg
• 38.4 x 10 tabs = 384 mg (this is the total amount of elemental iron ingested).
• 384 mg divided by 10 kg (the weight of the child) = 38.4 mg/kg of iron that has been ingested(remember that doses as small as 20 mg/kg can cause toxicity).

Lab Findings – iron toxicity levels often correlate with clinical severity and are as follows:

• Iron levels less the 300 mcg/dl =  mild toxicity.
• Iron levels 300 to 500 mcg/dl – moderate toxicity.
• Iron levels greater the 500 mcg/dl = severe toxicity.
• WBC’s greater then 15,000 mcg/L with Glucose levels greater the 150 mg/dl are said to often correlate with iron levels greater then 300 mcg/dl (this assessment is used if iron levels are not readily available).
• Elevation in liver function tests.

Note: Iron levels drawn too early or too late post ingestion may not be accurate.

Treatment Modalities for Iron Toxicity:

• Ipecac Syrup is only recommended if iron toxicity has been clearly determined and treatment is early (within the first hour).
• Activated Charcoal is not and effective treatment modality for iron toxicity.
• Deferoxamine (Desferal) which is an iron chelating agent is the treatment of choice. Deferoxamine binds to iron and excreted in the urine. Deferoxamine does not bind to hemoglobin, myoglobin or other iron carrying proteins. Continuous IV infusion at 15mg/kg/hr ( not to exceed 6 grams in a 24 hour period) should be started and continue until metabolic acidosis has resolved, the child is asymptomatic and iron levels are less then 150 mcg/dl.
• If hypotensive begin 0.9% Normal Saline Solution at 10 to 20 ml/kg/hr.
• Maintain urine output at greater then 2 ml/kg/hr.
• Exchange transfusions is recommended in severely symptomatic patients with serum iron levels that are greater then 1000 mcg/dl.

Possible complications:

• Infection (Yersinia Enterocolitica Septisemia)
• Pulmonary (ARDS)
• Fulminating Hepatic Failure
• Liver Cirrhosis
• Pyloric or Duodenal Stenosis

Lead Poisoning – Lead which is a metal occurs naturally in the earths crust, it has been spread throughout the environment and can be found in paint, gasoline, contaminated soil, household dust, drinking water, lead glazed pottery and metal jewelry (to name just a few places). Drinking, breathing, eating or touching dirt or living with a parent who works with lead are all mechanisms for coming in contact with lead. Lead is especially dangerous for children because lead can accumulate in their nervous system as they grow and develop.

Signs and Symptoms of Lead Poisoning in Children (different than adults):

• Anemia
• Severe stomach ache
• Muscle weakness
• Lower IQ scores
• Brain damage
• Irritability
• Loss of appetite
• Weight loss
• Sluggishness
• Nausea/Vomiting/Diarrhea

Assessment and Lab Findings:

If potential risk factors (possible exposure based on history) and symptoms bring the practitioner to suspect lead poisoning, lead levels should be drawn. The results of lead levels in the blood are categorized in classes from Class 1 to Class 5 with Class 5 being the most severe and often constituting a medical emergency. The following list is how the class ranking breaks down:

• Class 1 – less then 10 mcg/dl
• Class 2A – 10 to 14 mcg/dl (intervention is required at this stage).
• Class 2B – 15 to 19 mcg/dl
• Class 3 – 20 to 44 mcg/dl
• Class 4 – 45 to 69 mcg/dl
• Class 5 – greater then 69 mcg/dl (this class is associated with encephalopathy).

Additional Lab Tests Include:

• Erythrocyte Protoporphyrin (this level is elevated to greater than 35mcg/dl due to the fact that lead inhibits the conversion of Protoporphyrin to Delta-aminolevulinic so Protoporphyrin levels remain high).
• Complete Blood Count (peripheral smear may show evidence of hemolysis, normochromic or hyochromic microcytic anemia [due to iron deficiency] and basophilic stippling of RBC’s).
• Reticulocyte Count (maybe elevated due to increased RBC destruction).
• Electrolytes (should be ordered if lead poisoning causes severe vomiting or diarrhea. Sodium abnormalities can lead to Syndrome of Inappropriate Anti-diuretic Hormone [SIADH] or Diabetes Insipidus).
• Renal Function Test (elevated BUN and creatinine maybe due to lead nephropathy).
• Urinalysis (an elevated urine specific gravity in a setting of decreased urine output maybe a also be a sign of SIADH or Diabetes Insipidus).
• Liver Transaminases ( this level maybe elevated due to acute lead poisoning).
• Pancreatic Function Test (acute Pancreatitis may result from lead poisoning).
• Thyroid Function Test (this level may reveal hypothyroidism which is common with chronic lead exposure).

Treatment Modalities for Lead Toxicity:

• Gastric Lavage or Cathartic Therapy for decontamination should be attempted.
• The primary treatment modality for lead poisoning is to remove the exposure (or remove the child from the exposure).
• Chelation therapy is indicated as soon as the diagnosis of severe lead toxicity is considered. Chelation agents function by binding with lead and forming a water soluble complex that is excreted in urine.
• The three recommended chelation agents for lead poisoning include; Dimercaprol (BAL) and Ca-Na2 (EDTA) which are administered parenterally while the third agent which is Dimercaptosuccinic acid (DMSA) is administered orally. This 3 agent combination therapy is indicated for children who are exhibiting signs of encephalopathy, severe headaches, seizures, altered mental status or coma.
• If hypotensive begin 0.9% Normal Saline Solution at 10 to 20 ml/kg/hr.
• Once circulatory volume is reestablished, daily fluid requirements can be based on calculated fluids and the ml per ml replacement of ongoing fluid losses.
• Maintain urine output at greater then 0.5 to 1 ml/kg/hr.
• Convulsions and status epilepticus are treated in a conventional manner with benzodiazepines and other anticonvulsant measures. Children with lead encephalopathy may require high doses of anticonvulsant medication.
• Manage brain edema carefully monitoring cerebral perfusion pressure (ICP monitor may need to be placed).
• Normal and maintain Co2 between 30 and 35 mmHg.
• Mannitol may be used to decrease cerebral edema and elevated ICP.

Possible complications:

• Nervous system or kidney damage
• Learning disabilities
• Speech, language and behavior problems
• Poor muscle coordination
• Decreased muscle growth
• Hearing impairments

Antidotes for Common Medication Overdoses:

• Narcotic or Propoxyphene Overdose – Naloxone (Narcan) 0.1 mg/kg (max dose 4 mg/kg) IV/IO/IM/ET. Maybe repeated every 2 minutes.
• Methanol or Ethylene Overdose – Ethanol 8-10 mg/kg (10% injectable solution) IV in D5W over 30 minutes. Then 0.8-1.4 mg/kg/hr. Maintain ethanol level at 100 -130 mg/dl.
• Carbon Monoxide Inhalation – 100% Oxygen therapy (may require hyperbaric therapy).
• Cyanide Ingestion – Amyl nitrate ampule should be broken open and the contents should be inhaled by the child for 30 seconds of every minute until sodium nitrate can be administered (a new ampule should be used every 3 minutes). When sodium nitrate available (3%) infuse IV at 0.33 ml/kg (max 10ml) over 5 minutes. ½ dose can be repeated times one after 30 minutes if there is an inadequate clinical response. Follow this with Sodium Thiosulfate1.65 mg/kg (25%) solution (max. 50 ml) IV.
• Digoxin Overdose – Digibind (number of vials = amount of Digoxin ingested by 0.6).
• Alcohol Overdose – Dextrose 0.5-1gm/kg (which equals 2-4 ml/kg of D25W or 5-10 ml/kg of D10W). Naloxone (Narcan) 0.1 mg/kg (max dose 2 mg/kg) IV/IO/IM/ET. Maybe repeated every 2 minutes. Valium 0.1-0.5 mg/kg IV for severe agitation (max dose 5mg is less then 5 yrs. old, 10mg if equal to or greater then 5 yrs. old).
• Benzodiazepine Overdose – Flumazenil (Romazicon) 0.01 mg/kg IV (max. 0.5mg). Dose may be repeated if symptoms return.
• Acetaminophen Overdose – Gastric Lavage/Activated Charcoal and Mucomyst (20% solution mixed 1:4 with a carbonated beverage) loading dose of 140mg/kg PO or NG then 70 mg/kg PO or NG every 4 hours for 17 doses.
• Theophylline Overdose – Gastric Lavage/Activated Charcoal/Cathartic treatment as there is no specific medication that works as an antidote.
• Anticholinergic Overdose – Physostigmine (Antillirium) 0.01-0.03 mg/kg IV/IM/SC may repeat in 15 to 30 minutes (max dose 2 mg).
• Organophosphate Overdose – Atropine 0.01-0.02 mg/kg IV (max dose 0.5 mg for children and 1 mg in adolescents). Pralidoxime (2-PAM) 20-50mg/kg IV/IM. Repeat in 1-2 hours if muscle weakness has not resolved then every 10 to 12 hours if cholinergic signs reoccur.

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