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GENERAL MANAGEMENT
OF POISONED PATIENTS
Prepared by Prof.Dr. Yüksel KESİM
Ondokuz Mayıs University Medical Faulty
Department of Pharmacology
2014-2015
General Information
 All chemicals have potential to be
poisons if given a large enough dose
 Poisoning occurs when exposure to a
substance adversely affects function of
any organ system
3
Paracelsus (1493-1541)
‘Grandfather of Toxicology’
“The dose makes the poison”
"All things are poison and
nothing is without poison,
only the dose permits
something not to be
poisonous."
therapeutic
effect
toxic
effect
increasing dose
Lecture objectives
 After this lecture, and further reading as
required, students will be able to:
• describe the manifestations of toxicity
• Approach to the poisened patient
 Toxidromes
 History, examination, Laboratory Studies and detective
work
 İnitial menagement and spesialized treatment of poisining,
including methods of supportive care, prevention of poison
absorption, enhancement of elimination of poison and
administration of antidotes
Toxicology
 the study of the effect of poisons on the
function of living systems.
 Toxicokinetic:denotes the absorption,
distribution, excrection,and metabolism
of toxines, toxic doses of therapeutic
agents, and their metabolits.
 Toxicodynamics: is used to denote the
injurious effects of toxic substances on
vital function.
Toxicokinetics
 Overdose of a drug can alter the usual
pharmacokinetic processes, and this
must be considered when applying
kinetics to poisened patients,
For example, dissolution of tablets or
gastric emptying time may be slowed so
that absorption and peak toxic effects
are delayed.
Toxicokinetics
 Drugs may injure the epithelial barrier
of the Gastrointestinal Tract(GIT) and
thereby increase absorption.
 With a dramatic increase the
concentration of drug in the blood,
protein binding capasity may be
exceeded, resulting in an increased
fraction of free drug and grater toxic
effect.
Toxicokinetics
 If the plasma concentration is very high
and normal metabolism is saturated,
the rate of elimination may become
fixed. This change is kinetics may
markedly prolong the apperent serum
half-life and increase the toxicity.
THE POISONED OR
OVERDOSED PATIENT
 Poisonings and drug overdoses can cause quick
physical and mental changes in a person.
Bystanders usually are the ones who must initiate
care and call a poison control center or emergency
number.
 The most common routes of exposure in poisoning
are inhalation, ingestion, and injection.
 Toxic chemical reactions compromise
cardiovascular, respiratory, central nervous system,
hepatic, gastrointestinal (GI), and renal systems.
9
 Chemical agents that cause toxicity
include:
 Drugs
 Insecticides/herbicides
 Plant toxins, Animal toxins
 Chemical weapons,
 Radioactive elements
Drugs
 Poisoning can occur in the health care
environment when a medication normally
given only by the subcutaneous or
intramuscular route is given intravenously, or
when the incorrect medication is injected.
 Poisoning by injection can also occur in the
setting of substance abuse, as when a heroin
addict inadvertently (without knowledge or
intention) injects too much heroin.
Household cleaning products
 Poisoning may result from the improper
mixing of household cleaning products.
 The ingestion of poisons and toxins
occurs in various settings and in
different age groups.
 Poisoning in the home usually occurs
when children ingest household
cleaners or medicines. Improper
storage of these items contributes to
such accidents.
Household cleaning products
 Plants, pesticides, and paint products
are also potential household poisons.
 Because of mental or visual impairment,
illiteracy, or a language barrier, older
adults may ingest incorrect amounts of
medications.
Toxic fumes
 Most exposures to toxic fumes occur in
the home. Burning wood, gas, oil, coal,
or kerosene produces carbon monoxide
(CO). CO gas is colorless, odorless,
tasteless, and nonirritating, which
makes it especially dangerous.
 Cellular hypoxia may occur in spite of
adequate ventilation and oxygen
administration when poising is due to carbon
monoxide, cyanide, hydrogen sulfide, and
other poisons that interfere with transport or
utilization of oxygen.
 In such patients, cellular hypoxia is evident
by the development of tachiycardia,
hypotension, severe lactic asidosis, and
ischemia
Substance Abuse and
Overdose
 Admission of most poisoned patients to a critical
care unit is for an intentional or suspected suicidal
overdose. As part of their histories, these patients
frequently have mental illness, substance abuse
problems, or both.
 Often, withdrawal symptoms complicate the
assessment of potential toxidromes.
 A toxidrome is a group of signs and symptoms
(syndrome) associated with overdose or exposure
to a particular category of drugs and toxins.
16
 Commonly observed poisonings or drug
overdoses are caused by (but certainly not
limited to) carbon monoxide, salicylates,
acetaminophen, nicotine, alcohol, heroin,
marijuana, narcotic analgesics,
benzodiazepines, tricyclic antidepressants,
amphetamines, and cocaine.
17
Approach to the poisened
patient
 How does the poisoned patient die?
 Many toxins depress the Central
Nervous System(CNS), resulting in
coma.
 Patients under the influence of
hallucinogens such as LSD may die in
fights or falls from high places.
 Comatose patients frequently lose their
airway protective reflexes and their
respiratory drive. Thus they may die as a
result of airway obstruction by the flaccid
tongue, aspiration of gastric contents into the
tracheobronchial tree, or respiratory arrest .
 These are the most common causes of death
due to overdose of narcotics and sedative-
hypnotic drugs.
 Cardiovascular toxicity is also frequently
encountered in poising. Hypotension
may be due to depression of cardiac
contractility; peripheral vascular collaps
due to blockade of alpha adrenoceptor-
mediated vascular tone or cardiac
arrhythmias.
 Hypothermia or hyperthermia due to
exposure as well as the temperature
dysregulating effects of many drugs can
also produce hypotension.
 Hyperthermia may result from sustained
muscular hyperreactivity and can lead
to muscle breakdown and
myoglobinuria, renal failure, lactic
asidosis, and hyperkalemia.
 Letal arrhythmias such as ventricular
tachycardia and fibrillation can occur
with overdoses of many cardioactive
drugs such as epinephrine,
amphetamines, cocaine, digitalis and
theophylline; and drugs not usually
concidered cardioactive, such as
tricyclic antidepressants, antihistamines,
and some opioid analogs.
 Seizures, muscular hyperactivity, and
rigidity may result in death.
 Seizures may cause pulmonary
aspiration,hypoxia, and brain demage.
 Drugs and poisons that often cause
seizures include antidepressants,
isoniazid, diphenhydramine, cocain, and
amphetamines.
 Some organ system damage may occur after
poisoning and is sometimes delayed in onset.
 Pulmonary fibrosis may begin sevral days
after ingestion.
 Massive hepatic necrosis due to poisoning by
acetaminophen or certain mushrooms result
in hepatic encephalopaty and death 48-72
hours or longer ingestion.
ASSESSMENT
 A health care facility’s systematic
approach to the assessment of the
poisoned or overdosed patient includes
performing triage,
 A) Obtaining the patient’s history,
 B) Performing a physical examination, and
 C) Conducting laboratory studies.
25
Triage
 Triage is always the first step performed in the
emergency department.
 Two essential questions to be considered in the
triage evaluation are:
1. Is the patient’s life in immediate danger?
2. Is the patient’s life in potential danger?
26
Initial management of the
poisoned patient
 If the patient’s life is in immediate danger, the
goals of immediate treatment are patient
stabilization and evaluation and management of
airway, breathing, circulation and dextrose
(ABCDs).
 Stabilization;First the airway should be cleared of
vomitus or any other obstruction and an oral airway or
nasotracheal or endotracheal intubation may be
necessary to adequately maintain and protec the
patient’s airway.For many patients is sufficient to move
the flaccid tongue out of the airway.
27
Breathing
Breathing should be assesed by
measuring arterial blood gases.
Mechanical ventilation may be necessary
to support the patient.
Many drugs and toxins, such as heroin,
depress the respiratory drive. Patients
therefore may require ventilator
assistance until the drugs or toxins are
eliminated from the body.
Circulation
 should be assesed by continious
monitoring of pulse rate, blood
pressure, urinary output and evaluation
of peripheral perfusion
 Some toxic drug ingestions impair
myocardial contractility, cause cardiac
conduction delays and arrhythmias and
fluid overload may result because of the
heart’s inability to pump effectively.
 In these cases, fluid balance needs to be
carefully controlled.
 Invasive monitoring (e.g., central venous
pressure, pulmonary artery catheter, Foley
catheter with urometer) and drug therapy
may be necessary to prevent or minimize
complications such as pulmonary edema
30
 Every patients with altered mental
status should receive a concentrated
Dextrose. Adults are given 25g (50ml of
50% dextrose solution) i.v. Children
0.5g/kg(2ml/kg of 25% dextrose).
 Hypoglycemic patients may appear to
be intoxicated , and there is no rapid
and reliable way to distinguish them
from poisened patients.
History and Physical
examination
 Once the essantial initial ABCD
interventions have been instituted ,
 one can begin a more detailed
evaluation to make a spesific
diagnosis.This includes gathering any
available history and performing a
toxicologically oriented physical
examination.
 The history of the drug(s) or toxin(s)
involved may not be reliable or even
known, especially when patients are found
unconscious or have attempted suicide
33
A.History
 A history of the patient’s exposure provides a
framework for managing the poisoning or
overdose.Need to obtain as much info as
possible about exposure
 Key points include identifying the drug(s) or
toxin(s), type of exposure, the time and
duration of the exposure, amount or dose,
empty bottles or containers, houshold
products, over the counter drug (OCD),
smells or suicide not.
History
 First aid treatment given before arrival at the
hospital, allergies, and any underlying
disease processes or related injuries.
This information may be obtained from the
patient, family members, friends, rescuers, or
bystanders.
 In some cases, family or police may need to
search the patient’s home for clues.
 Number of exposed persons may supply
additional information.
B. Physical Examination
 Check clothing for objects or substances
 A quick but thorough physical
examination is essential.These include
vital signs and temperature, eyes and
mouth, skin, abdomen and nervous
system.
Toxidrome
 A toxidrome is a group of signs and
symptoms associated with overdose or
exposure to a particular category of
drugs and toxins.
 Recognizing the presence of a
toxidrome may help identify the toxin(s)
or drug(s) to which the patent was
exposed, and the crucial body systems
that may be involved.
1.Vital signs
 Careful evaluation of vital signs (blood
pressure, pulse, respirations, and
temperature) is essential in all
toxicologic emergencies. The critical or
potentially critical patient’s vital signs
and temperature are measured
frequently to track changes indicating
additional problems.
Lungs
 Wheezing?
 Rapid respirations are typical of
salicylates, CO,and other toxines that
produce metabolic acidosis or cellular
asphyxia.
CV system
 rhythm, rate, regularity
 Hypertension and tachycardia are typical with
amphetamines, cocain and anticholinergic
drugs. Hypotension and bradycardia are
characteristic features of overdose with
calcium channel blockers, beta blockers,
clonidine, and sedative hipnotics.
 Hypotension with tachycardia is common with
tricyclic antidepressants, vasodilators and
beta agonists.
 Hyperthermia may be associated with
sympathomimetics, anticholinergic,
salicylates, and drugs producing
seizures or muscular rigidity.
 Hypothermia can be caused by any CNS
depressant drug.
2.Eyes
 The eyes are a valuable source of
toxicologic information.
 Exam eyes for pupils size, nystagmus,
reactivity, increased lacramaiton
 Miosis is typical of opioids,
cholinesterase inhibitors (e.g.
Organophosphate insecticides), and
deep coma due to sedative drugs.
Eyes
 Mydriasis is common with
amphetamines, cocaine, LSD, atropine
and other anticholinergic drugs.
 Horizontal nystagmus is characteristic of
intoxication with alcohol and other
sedative drugs. The presence of both
vertical and horizontal nystagmus is
strongly suggestive of phencyclidine
poising.
3. Mouth
 The mouth may show signs of burns
due to corrosive substances, or soot
from smoke inhalation.
 Typical odors of alcohol or ammonia
may be noted.
4.Skin
 Exam skin for hot, and dry, flushing,
bruising, cyanosis,
 Cyanosis may be caused by hypoxemia
or by methemoglobinemia.
 Icterus may suggest hepatic necrosis.
 Excessive sweeting occurs with
organophosphates, nicotine and
sympathomimetic drugs.
5. Abdomen
 Hyperactive bowel sounds, tenderness
abdominal cramping and diarrhea are
common in poisoning with
organophosphatase, iron, arsenic,
teophylline, Amanita muscaria and
phalloides.
6. Nervous system
 A careful neurologic examination is essantial
 Assess general appearance
 Agitation or confusion
 reflexes, muscle tone coordination, cognition
 Focal seizures or motor deficits suggest a
structural lesions.
 Extremities: fasiculations, tremor,
 muscular rigidity can be caused by anti-
psychotic agents, serotonin syndrome
and by strychnine.
 Nystagmus and ataxia are typical of
phenytoin, alcohol or other sedative
intoxication.
CNS Examination
 Physiologic excitation – anticholinergic,
sympathomimetic, or central hallucinogenic
agents, drug withdrawal
 Physiologic depression – cholinergic
(parasympathomimetic), sympatholytic,
opiate, or sedative-hypnotic agents, or
alcohols
 Mixed state – polydrugs, hypoglycemic
agents, tricyclic antidepressants, salicylates,
cyanide
Mentation
 Many factors can affect the patient’s
mental status.
 Hypoglycemia and hypoxemia; that can
be life-threatening but easily addressed
by administering oxygen and IV
dextrose until laboratory results are
available.
C.Laboratory Studies
 Relevant clinical laboratory data are
vital to the assessment of the poisoned
or overdosed patient.
 Tests that provide clues to the agent(s)
taken by the patient include arterial
blood gases (ABGs), electrolytes,
serum osmolality tests, urinalysis,
complete blood count,
electrocardiography , imaging findings
and hepatic function.
Acid–base balance and
electrolyte homeostasis
 Electrolyte abnormalities and metabolic
acidosis frequently occur and may
require serial measurements of
electrolytes and arterial blood gases
(ABGs), and other specific laboratory
tests.
1.Arterial Blood Gases (ABGs)
 Hypoventilation will result in an elevated
PCO2 (hypercapnia) and a low PO2(hypoxia).
 The PO2 may also be low with aspiration
pneumonia or drug induced pulmonary
edema.
 Signs of inadequate ventilation or
oxygenation include cyanosis, tachycardia,
hypoventilation, intercostalmuscle retractions,
and altered mental status.
2. Electrolytes
 Acute poisoning can cause an imbalance in a
patient’s electrolyte levels, including sodium,
potassium, chloride, bicarbonate, carbon
dioxide, magnesium, and calcium.
 Serum level measurements are also available
for carbamazepine, iron, ethanol, lithium,
aspirin, and valproic acid and may be
obtained if these agents are suspected in an
overdose.
 The anion (A negatively charged ion)
gap represents the difference between
unmeasured anions and cations (An
ion or group of ions having a positive
charge ) in the blood.
 Anion gap = (Na + K) - (HCO3 + Cl)
 The normal value for the anion gap is
approximately 8 to 16 mEq/L.
 An anion gap that exceeds the upper normal value
can indicate metabolic acidosis caused by an
accumulation of acids in the blood.
 Drugs, toxins, or medical conditions that can
produce an elevated anion gap include iron,
isoniazid (INH), lithium, lactate, carbon monoxide,
cyanide, methanol, ethanol, metformin, ethylene
glycol, salicylates, hydrogen sulfide, ,diabetic
ketoacidosis, uremia, seizures, and starvation.
56
3. Serum osmolality
 The osmolal gap is the difference between
the measured osmolality and the calculated
osmolality.
 The calculated osmolality is derived using
laboratory values for the major osmotically
active substances in the serum, such as
sodium, glucose, and blood urea nitrogen
(BUN).
 Like the anion gap, it is a simple, cost-
effective tool for evaluating the poisoned
patient for certain drugs or toxins
 The calculated serum osmolality can be
estimated from the following formula;
 2 X Na(meq/L) + Glucose(mg/dl) /18 +
BUN(mg/dl) / 3
 This calculated value is normally
280-290mOsm/L
Diagnostic tools include the
following
4. Electrocardiography: can provide
evidence of drugs causing arrhythmias
or conduction delays (e.g., tricyclic
antidepressants).
5.Radiology
Many substances are radiopaque, or can be
visualized using a contrast-enhanced
computed tomography (CT) scan (e.g.,
heavy metals, button, batteries, some
modified-release tablets or capsules,aspirin
concretions, cocaine or heroin containers).
Chest radiographs provide evidence of
aspiration and pulmonary edema.
6. Renal function tests
 Some toxines have direct nephrotoxic,
in other cases renal failure is due to
shock or myoglobinuria.
 BUN and creatinine levels should be
measured and urinanalysis performed.
7.Toxicology screens
A toxicology screen is a laboratory
analysis of a body fluid or tissue to
identify drugs or toxins. Saliva, spinal
fluid, and hair may be analyzed, blood
or urine samples are used more
frequently.Each screen tests for specific
drugs or agents.
 The sample must also be properly collected,
and there must be a laboratory near enough
to obtain results quickly.
 The test sample must be collected while the drug or
toxin is in the body fluid or tissue used for testing.
 For example, cocaine is a rapidly metabolized
drug; however, its metabolite, benzoylecgonine,
can be detected in the urine for several hours after
cocaine use.
63
 MANAGEMENT
 Management of the poisoned or overdosed patient seeks
to prevent absorption of and further exposure to the agent.
 Treatment begins with first aid at the scene and continues in
the emergency department and often the intensive care unit
(ICU).
 Advanced general management involves further steps to
prevent absorption and enhance elimination of the agent.
For instance, antidotes, antivenins (the treatment of
venomous bites or stings) or antitoxins may be
administered.
64
General- management
 I.provision of supportive care
 II.prevention of poison absorption
 III.enhancement of elimination of
poison
 IV.administration of antidotes
I. Supportive care
 Vital signs, mental status, and pupil size
 cardiac monitoring, ECG
 Protect airway
 Intravenous access
 cervical immobilization if suspect trauma
 Rule out hypoglycaemia
II.Preventing absorption
 Decontamination;
 A) dermal,
 B) ocular,
 C) inhalation, and
 D) ingestion exposures follow.
A) DERMAL EXPOSURE
 Generally; achieved by; undressing
patients and washing them thoroughly
with copious amounts of lukewarm
water for 15 to 30 minute
 All towels and clothing should be put
into hazardous waste bags
 Some toxins may require further
decontamination. For example, three separate
soap and water washings or showers are
recommended to decontaminate
organophosphate pesticides (e.g., Malathion or
Diazinon).
 Protective clothing should be worn to reduce the
risk for toxicity while handling contaminated
clothing or assisting with skin decontamination.
69
B) Eyes
 Many substances can accidentally splash into
the eyes.
 When this happens, the eyes must be flushed
to remove the agent.
 Immediate irrigation with lukewarm water or
normal saline is recommended.
 Continuous flooding of the eyes with a large
glass of water or low-pressure shower should
be done for 15 minutes.
 The patient should blink the eyes open and
closed during the irrigation.
 If necessary, the pH of the eyes can be
tested. If the pH is abnormal, irrigation should
continue until the pH normalizes.
 An ophthalmologic examination is needed
when ocular irritation or visual disturbance
persists after irrigation.
C) INHALATION EXPOSURE
 A victim of an inhalation exposure
should be moved to fresh air as quickly
as possible.
 The responder must also protect himself
or herself from the airborne toxin.
 Further evaluation is needed if the
patient experiences respiratory irritation
or shortness of breath.
D) GI Decontamination
 Three general methods involve removing
toxin from stomach via the mouth, binding it
inside gut lumen, or mechanically flushing it
through GI tract
 Each method has benefits and risks
 Milk or water dilutes ingested irritants
such as bleach or caustics such as
drain cleaner.
After such an ingestion, adults or children
should drink milk or water (children
based on their size).
 Further evaluation is necessary after
dilution if there is mucosal irritation or
burns.
 Because of the risk of aspiration,
ingestions should not be diluted when
they are accompanied by seizures,
depressed mental status, or loss of the
gag reflex.
 Again, neutralization is not used
because of the risk of thermal burn.
Gastrointestinal Decontamination
 1. Vomiting,
 2. Gastric lavage,
 3. adsorbents (is the adhesion of
molecules of gas, liquid, or dissolved
solids to a surface),
 4. cathartics, and
 5. whole-bowel irrigation
are used to prevent absorption toxins.
1. Induced Vomiting Ipecac
 Risk of aspiration Emesis: achieved by using
syrup of ipecac
 Dosing: 15 ml for 1-12 years old and 30 ml for
adults; may repeat once if no emesis in 12 hr
 90% vomit within 20 minutes of first dose
and 97% vomit with second dose
 Usually 3-5 episodes of emesis and resolve in
two hours; if protracted emesis occurs
consider toxin as etiology
Ipecac con’t
 Use of Ipecac very limited
 Contraindications: ingestions with potential
for change in mental status, active or prior
vomiting, caustic ingestion, toxin with more
pulmonary than GI toxicity (hydrocarbons),
ingestion of toxins with potential for seizures
 The American Academy of Pediatrics no
longer recommends the use of emetics (such
as syrup of ipecac) for GI decontamination.
2.GASTRIC LAVAGE
 Fluid (usually normal saline) is introduced into
the stomach through a large-bore orogastric
tube and then drained in an attempt to
reclaim part of the ingested agent before it is
absorbed.
 A small-bore nasogastric tube is ineffective
for lavage because particulate matter such as
tablets or capsules are too large to pass
through the tube.
If airway protection is necessary, the patient
should be intubated before lavage begins.
Orogastric lavage con’t
 Contraindications: Not in unconscious patient
unless intubated (risk aspiration)
 caustic ingestion or hydrocarbons with a high
aspiration potential, airway integrity not
secured, more toxic to lung than GI
 Because of the associated risks and the lack
of clear evidence supporting its use, gastric
lavage should be used only if the patient has
ingested a life-threatening amount of a
substance and the procedure is undertaken
within an hour of the ingestion.
GASTRIC LAVAGE
 Complications: insertion into trachea,
esophageal or gastric perforation,
decreased O2, pulmonary aspiration,
electrolyte imbalance, tension
pneumothorax, and hypothermia (when
cold lavage solutions are used).
 Charcoal should be used before
withdrawal of tube
GASTRIC LAVAGE
 The contents of the stomach can then be
collected for drug or toxin identification.
 Drug removal range from 35-56%.
 Indicated if in 1 hr of ingestion.
 For the lavage, the patient is positioned in the
left. lateral decubitus position, with the head
lower than the feet.
3. ADSORBENTS
 An adsorbent is a solid substance that has
the ability to attract and hold another
substance to its surface (“to adsorb”).
 Activated charcoal is an effective nonspecific
adsorbent of many drugs and toxins.
 Activated charcoal adsorbs, or traps the drug
or toxin to its large surface area and prevents
absorption from the GI tract.
ADSORBENTS
 Activated charcoal is a fine, black powder that is
given as a slurry with water, either orally or by
nasogastric or orogastric tube, as soon as possible
after the ingestion.
 Commercially available activated charcoal products
may be mixed with 70% sorbitol to decrease
grittiness (composed of or covered with relatively
large particles, increase palatability (Acceptable to
the taste) , and serve as a cathartic. The usual
dose that is given is one 50-g bottle.
84
Activated Charcoal
• binds non-specifically
• timing - use within 1 hour
 Safety proven in adults and children
 Dose 1g/kg
Activated Charcoal
 Indications: any drug known to absorb it or
after unknown ingestions. Activated charcoal
is used cautiously in patients with diminished
bowel sounds and is contraindicated in
patients with bowel obstruction.
 Should not be given if esophageal or gastric
perforation suspected or emergent endoscopy
possibly needed.
 Complications rare; aspiration or impaction
possible
Drugs/Toxins Well
Adsorbed
by Activated Charcoal
■ Acetaminophen
■ Amphetamines
■ Antihistamines
■ Aspirin
■ Barbiturates
■ Benzodiazepines
■ Beta blockers
■ Calcium channel blockers
■ Cocaine
■ Opioids
■ Phenytoin
■ Theophylline
■ Valproic acid
Drugs/Toxins Not Well
Adsorbed
by Activated Charcoal
■ Acids
■ caustic alkalis
■ Alcohols
■ Iron
■ Lithium
■ Metals cyanide
mineral acids,
organic solvents,
87
4. CATHARTICS
 A cathartic is a substance that causes or
promotes bowel movements.
 In theory, cathartics decrease the absorption
of drugs and toxins by speeding their
passage through the GI tract, thereby limiting
their contact with mucosal surfaces.
88
Cathartics
 Osmotic cathartic usually given with activated
charcoal
 70% sorbitol (1 g/kg) or 10% Mg citrate
 Shown to decrease transit time of activated
charcoal
 No definitive clinical human data suggest that
a cathartic limits toxins bioavailability.
5. WHOLE-BOWEL IRRIGATION
 The goal of whole-bowel irrigation is to
give large volumes of a balanced
electrolyte solution rapidly (1 to 2
L/hour) to flush the patient’s bowel
mechanically without creating
electrolyte disturbances.
 Commercial products used in whole-bowel
irrigation include GoLYTELY and Colyte.
 Both products are dispensed (To prepare
and give out ) as powders and are given after
adding water.
 Whole-bowel irrigation is contraindicated in
the patient with bowel obstruction or
perforation.
91
Whole-Bowel Irrigation
 Common indications: Heavy metals, Iron, Lithium,
Sustained or delayed release formulations
 End point is clear rectal effluent
 Antiemetic frequently required
 Avoid phenergan (slows gut motility)
 Contraindications: absent bowel sounds or
obstruction
 Complications: bloating, cramping, rectal
irritation
 As a result, absorption is delayed, and
the development of toxic effects, such as
hypokalemia, metabolic acidosis, and
respiratory alkalosis, may not be observed for
several hours.
93
III.Enhanced Elimination of the
Drug or Toxin
 The absorption rate, body distribution,
metabolism, and elimination must be
considered when choosing methods to
eliminate the drug or toxin from the
body.
There are six methods of enhanced
elimination:
1. Multiple-dose activated charcoal
2. Alteration of urine pH
3. Chelation
4. Hemodialysis
5. Hemoperfusion
6. Hyperbaric oxygenation (HBO) therapy
1. Multi-Dose Charcoal
 One dose usually sufficient
 Indications for multi-dose activated charcoal:
ingestion of large doses, substances that slow
release toxins, toxins that slow gut function,
toxins with enteroenteric circulation,
repetitive doses useful to enhance the
elimination of certain drugs (eg, theophylline,
phenobarbital, carbamazepine, valproic acide,
aspirin)
MULTIPLE-DOSE ACTIVATED
CHARCOAL
 Repeat dose is 0.25-0.5 g/kg
 Multiple-dose activated charcoal is
given orally, by nasogastric tube, or by
orogastric tube every 2 to 6 hours.
 Complications of multipledose activated
charcoal include aspiration and bowel
obstruction.
2. ALTERATION OF URINE pH
 Alkalinization:Alkalinizing the patient’s
urine enhances excretion of drugs that
are weak acids by increasing the
amount of ionized drug in the urine.
 This form of enhanced elimination is
also termed ion trapping.
Alkalinization achieved by IV dose of
bicarb at 1-2 mEq/kg, followed by
intermittent boluses or continuous
bicarb drip for urine pH 7.5-8.0
 Used to eliminate acidic drug that
mainly excreted by the kidney eg
salicylates overdose.
 Complications of alkalinization include
cerebral or pulmonary edema and
electrolyte imbalances.
 Need expert monitoring
Acidification of Urine
 Urine acidification is no longer recommended
because of low drug clearance and the risk of
complications such as rhabdomyolysis.
Rhabdomyolysis is the breakdown of muscle
fibers resulting in the release of muscle fiber
contents into the circulation. Some of these
are toxic to the kidney and frequently result in
kidney damage.
 Can somewhat enhance elimination of
amphetamines, phencyclidine, and some
other drugs.
3. CHELATION
 Chelation involves the use of binding
agents to remove toxic levels of metals
from the body, such as mercury, lead,
iron, and arsenic.
Examples of chelating agents are
dimercaprol (BAL in oil), calcium
disodium edetate (EDTA), and
deferoxamine.
4.HEMODIALYSIS
 Hemodialysis is the process of altering
the solute composition of blood by
removing it from an artery, diffusing it
across a semipermeable membrane
(between the blood and a salt solution),
then returning it into a vein.
Hemodialysis
 It is used in moderate to severe intoxications
to remove a drug or toxin rapidly when more
conservative methods (e.g., gastric lavage,
activated charcoal, antidotes) have failed or
in patients with decreased renal function.
 Hemodialysis requires consultation with a
nephrologist and specially trained nurses to
perform the procedure and monitor the
patient.
Hemodialysis
 Drug should be dialyzable. Low molecular
weight, low protein binding, and water
solubility are factors that make a drug or toxin
suitable for hemodialysis.
 may also be used temporarily or as long term
if the kidneys are damaged due to the
overdose.
 Dialysis reserved for specific toxins:
salicylates, methanol, lithium, theophylline,
amanita (mushrooms)
Dialysis con’t
 Benefits: removal of toxins already absorbed
by gut, ability to remove parent compound
and active metabolite,
 Dialysis rarely contraindicated
 No dialysis for small children, exchange
transfusion should be considered
5.HEMOPERFUSION
 Hemoperfusion removes drugs and toxins
from the patient’s blood by pumping the blood
through a cartridge
of adsorbent material, such as activated
charcoal.
 An advantage of hemoperfusion over
hemodialysis is that the total surface area of
the dialyzing membrane is much greater with
the hemoperfusion cartridges.
HEMOPERFUSION
As in hemodialysis, drugs that have high tissue-
binding characteristics and a large volume
distributed outside the circulation are not
good candidates for hemoperfusion because
little drug is found in the blood.
 Although rarely used in the poisoned and
overdosed population, hemoperfusion has
been used successfully in patients
experiencing a theophylline overdose
6.HYPERBARIC OXYGENATION
THERAPY (HBO)
 In HBO therapy, oxygen is administered
to a patient in an enclosed chamber at a
pressure greater than the pressure at
sea level (e.g., 1 atmosphere absolute).
This therapy has been used in carbon
monoxide and methylene chloride
poisonings (methylene chloride is
metabolized to carbon monoxide in the
body).
 Complications of HBO therapy include
pressure-related otalgia (ear pain),
sinus pain, tooth pain, and tympanic
membrane rupture.
 anxiety, convulsions, and tension
pneumothorax also have been observed
in patients receiving HBO therapy.
IV. Antidotes (Antitoxins) and
Antagonists),
 In pharmacology, an antagonist is a
substance that counteracts the action of
another drug.
 Although the general public often
believes there is an antidote for every
drug or toxin, the opposite is closer to
the truth.
 There are, in fact, very few antidotes.
 Antitoxins neutralize a toxin.
For instance, botulism(food poisoning from
ingesting botulin)(potent bacterial toxin)
produced by the Clostridium botulinum
that causes botulism; can be used as a
bioweapon)
111
 Antivenins are antitoxins that neutralize the
venom of the offending snake or spider.
 Antitoxin trivalent (equine) is available through
the Centers for Disease Control and Prevention
to counteract the effects of botulism.
 There are several antitoxins; each is active
against a specific venom.
112
Continuous Patient Monitoring
 Seriously poisoned or overdosed
patients may require continued
monitoring for hours or days after
exposure.
 Physical examination, the use of
diagnostic tools, and careful
assessment of clinical signs and
symptoms provide information about the
patient’s
3290_56890_2547.ppt

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3290_56890_2547.ppt

  • 1. GENERAL MANAGEMENT OF POISONED PATIENTS Prepared by Prof.Dr. Yüksel KESİM Ondokuz Mayıs University Medical Faulty Department of Pharmacology 2014-2015
  • 2. General Information  All chemicals have potential to be poisons if given a large enough dose  Poisoning occurs when exposure to a substance adversely affects function of any organ system
  • 3. 3 Paracelsus (1493-1541) ‘Grandfather of Toxicology’ “The dose makes the poison” "All things are poison and nothing is without poison, only the dose permits something not to be poisonous." therapeutic effect toxic effect increasing dose
  • 4. Lecture objectives  After this lecture, and further reading as required, students will be able to: • describe the manifestations of toxicity • Approach to the poisened patient  Toxidromes  History, examination, Laboratory Studies and detective work  İnitial menagement and spesialized treatment of poisining, including methods of supportive care, prevention of poison absorption, enhancement of elimination of poison and administration of antidotes
  • 5. Toxicology  the study of the effect of poisons on the function of living systems.  Toxicokinetic:denotes the absorption, distribution, excrection,and metabolism of toxines, toxic doses of therapeutic agents, and their metabolits.  Toxicodynamics: is used to denote the injurious effects of toxic substances on vital function.
  • 6. Toxicokinetics  Overdose of a drug can alter the usual pharmacokinetic processes, and this must be considered when applying kinetics to poisened patients, For example, dissolution of tablets or gastric emptying time may be slowed so that absorption and peak toxic effects are delayed.
  • 7. Toxicokinetics  Drugs may injure the epithelial barrier of the Gastrointestinal Tract(GIT) and thereby increase absorption.  With a dramatic increase the concentration of drug in the blood, protein binding capasity may be exceeded, resulting in an increased fraction of free drug and grater toxic effect.
  • 8. Toxicokinetics  If the plasma concentration is very high and normal metabolism is saturated, the rate of elimination may become fixed. This change is kinetics may markedly prolong the apperent serum half-life and increase the toxicity.
  • 9. THE POISONED OR OVERDOSED PATIENT  Poisonings and drug overdoses can cause quick physical and mental changes in a person. Bystanders usually are the ones who must initiate care and call a poison control center or emergency number.  The most common routes of exposure in poisoning are inhalation, ingestion, and injection.  Toxic chemical reactions compromise cardiovascular, respiratory, central nervous system, hepatic, gastrointestinal (GI), and renal systems. 9
  • 10.  Chemical agents that cause toxicity include:  Drugs  Insecticides/herbicides  Plant toxins, Animal toxins  Chemical weapons,  Radioactive elements
  • 11. Drugs  Poisoning can occur in the health care environment when a medication normally given only by the subcutaneous or intramuscular route is given intravenously, or when the incorrect medication is injected.  Poisoning by injection can also occur in the setting of substance abuse, as when a heroin addict inadvertently (without knowledge or intention) injects too much heroin.
  • 12. Household cleaning products  Poisoning may result from the improper mixing of household cleaning products.  The ingestion of poisons and toxins occurs in various settings and in different age groups.  Poisoning in the home usually occurs when children ingest household cleaners or medicines. Improper storage of these items contributes to such accidents.
  • 13. Household cleaning products  Plants, pesticides, and paint products are also potential household poisons.  Because of mental or visual impairment, illiteracy, or a language barrier, older adults may ingest incorrect amounts of medications.
  • 14. Toxic fumes  Most exposures to toxic fumes occur in the home. Burning wood, gas, oil, coal, or kerosene produces carbon monoxide (CO). CO gas is colorless, odorless, tasteless, and nonirritating, which makes it especially dangerous.
  • 15.  Cellular hypoxia may occur in spite of adequate ventilation and oxygen administration when poising is due to carbon monoxide, cyanide, hydrogen sulfide, and other poisons that interfere with transport or utilization of oxygen.  In such patients, cellular hypoxia is evident by the development of tachiycardia, hypotension, severe lactic asidosis, and ischemia
  • 16. Substance Abuse and Overdose  Admission of most poisoned patients to a critical care unit is for an intentional or suspected suicidal overdose. As part of their histories, these patients frequently have mental illness, substance abuse problems, or both.  Often, withdrawal symptoms complicate the assessment of potential toxidromes.  A toxidrome is a group of signs and symptoms (syndrome) associated with overdose or exposure to a particular category of drugs and toxins. 16
  • 17.  Commonly observed poisonings or drug overdoses are caused by (but certainly not limited to) carbon monoxide, salicylates, acetaminophen, nicotine, alcohol, heroin, marijuana, narcotic analgesics, benzodiazepines, tricyclic antidepressants, amphetamines, and cocaine. 17
  • 18. Approach to the poisened patient  How does the poisoned patient die?  Many toxins depress the Central Nervous System(CNS), resulting in coma.  Patients under the influence of hallucinogens such as LSD may die in fights or falls from high places.
  • 19.  Comatose patients frequently lose their airway protective reflexes and their respiratory drive. Thus they may die as a result of airway obstruction by the flaccid tongue, aspiration of gastric contents into the tracheobronchial tree, or respiratory arrest .  These are the most common causes of death due to overdose of narcotics and sedative- hypnotic drugs.
  • 20.  Cardiovascular toxicity is also frequently encountered in poising. Hypotension may be due to depression of cardiac contractility; peripheral vascular collaps due to blockade of alpha adrenoceptor- mediated vascular tone or cardiac arrhythmias.
  • 21.  Hypothermia or hyperthermia due to exposure as well as the temperature dysregulating effects of many drugs can also produce hypotension.  Hyperthermia may result from sustained muscular hyperreactivity and can lead to muscle breakdown and myoglobinuria, renal failure, lactic asidosis, and hyperkalemia.
  • 22.  Letal arrhythmias such as ventricular tachycardia and fibrillation can occur with overdoses of many cardioactive drugs such as epinephrine, amphetamines, cocaine, digitalis and theophylline; and drugs not usually concidered cardioactive, such as tricyclic antidepressants, antihistamines, and some opioid analogs.
  • 23.  Seizures, muscular hyperactivity, and rigidity may result in death.  Seizures may cause pulmonary aspiration,hypoxia, and brain demage.  Drugs and poisons that often cause seizures include antidepressants, isoniazid, diphenhydramine, cocain, and amphetamines.
  • 24.  Some organ system damage may occur after poisoning and is sometimes delayed in onset.  Pulmonary fibrosis may begin sevral days after ingestion.  Massive hepatic necrosis due to poisoning by acetaminophen or certain mushrooms result in hepatic encephalopaty and death 48-72 hours or longer ingestion.
  • 25. ASSESSMENT  A health care facility’s systematic approach to the assessment of the poisoned or overdosed patient includes performing triage,  A) Obtaining the patient’s history,  B) Performing a physical examination, and  C) Conducting laboratory studies. 25
  • 26. Triage  Triage is always the first step performed in the emergency department.  Two essential questions to be considered in the triage evaluation are: 1. Is the patient’s life in immediate danger? 2. Is the patient’s life in potential danger? 26
  • 27. Initial management of the poisoned patient  If the patient’s life is in immediate danger, the goals of immediate treatment are patient stabilization and evaluation and management of airway, breathing, circulation and dextrose (ABCDs).  Stabilization;First the airway should be cleared of vomitus or any other obstruction and an oral airway or nasotracheal or endotracheal intubation may be necessary to adequately maintain and protec the patient’s airway.For many patients is sufficient to move the flaccid tongue out of the airway. 27
  • 28. Breathing Breathing should be assesed by measuring arterial blood gases. Mechanical ventilation may be necessary to support the patient. Many drugs and toxins, such as heroin, depress the respiratory drive. Patients therefore may require ventilator assistance until the drugs or toxins are eliminated from the body.
  • 29. Circulation  should be assesed by continious monitoring of pulse rate, blood pressure, urinary output and evaluation of peripheral perfusion  Some toxic drug ingestions impair myocardial contractility, cause cardiac conduction delays and arrhythmias and fluid overload may result because of the heart’s inability to pump effectively.
  • 30.  In these cases, fluid balance needs to be carefully controlled.  Invasive monitoring (e.g., central venous pressure, pulmonary artery catheter, Foley catheter with urometer) and drug therapy may be necessary to prevent or minimize complications such as pulmonary edema 30
  • 31.  Every patients with altered mental status should receive a concentrated Dextrose. Adults are given 25g (50ml of 50% dextrose solution) i.v. Children 0.5g/kg(2ml/kg of 25% dextrose).  Hypoglycemic patients may appear to be intoxicated , and there is no rapid and reliable way to distinguish them from poisened patients.
  • 32. History and Physical examination  Once the essantial initial ABCD interventions have been instituted ,  one can begin a more detailed evaluation to make a spesific diagnosis.This includes gathering any available history and performing a toxicologically oriented physical examination.
  • 33.  The history of the drug(s) or toxin(s) involved may not be reliable or even known, especially when patients are found unconscious or have attempted suicide 33
  • 34. A.History  A history of the patient’s exposure provides a framework for managing the poisoning or overdose.Need to obtain as much info as possible about exposure  Key points include identifying the drug(s) or toxin(s), type of exposure, the time and duration of the exposure, amount or dose, empty bottles or containers, houshold products, over the counter drug (OCD), smells or suicide not.
  • 35. History  First aid treatment given before arrival at the hospital, allergies, and any underlying disease processes or related injuries. This information may be obtained from the patient, family members, friends, rescuers, or bystanders.  In some cases, family or police may need to search the patient’s home for clues.  Number of exposed persons may supply additional information.
  • 36. B. Physical Examination  Check clothing for objects or substances  A quick but thorough physical examination is essential.These include vital signs and temperature, eyes and mouth, skin, abdomen and nervous system.
  • 37. Toxidrome  A toxidrome is a group of signs and symptoms associated with overdose or exposure to a particular category of drugs and toxins.  Recognizing the presence of a toxidrome may help identify the toxin(s) or drug(s) to which the patent was exposed, and the crucial body systems that may be involved.
  • 38. 1.Vital signs  Careful evaluation of vital signs (blood pressure, pulse, respirations, and temperature) is essential in all toxicologic emergencies. The critical or potentially critical patient’s vital signs and temperature are measured frequently to track changes indicating additional problems.
  • 39. Lungs  Wheezing?  Rapid respirations are typical of salicylates, CO,and other toxines that produce metabolic acidosis or cellular asphyxia.
  • 40. CV system  rhythm, rate, regularity  Hypertension and tachycardia are typical with amphetamines, cocain and anticholinergic drugs. Hypotension and bradycardia are characteristic features of overdose with calcium channel blockers, beta blockers, clonidine, and sedative hipnotics.  Hypotension with tachycardia is common with tricyclic antidepressants, vasodilators and beta agonists.
  • 41.  Hyperthermia may be associated with sympathomimetics, anticholinergic, salicylates, and drugs producing seizures or muscular rigidity.  Hypothermia can be caused by any CNS depressant drug.
  • 42. 2.Eyes  The eyes are a valuable source of toxicologic information.  Exam eyes for pupils size, nystagmus, reactivity, increased lacramaiton  Miosis is typical of opioids, cholinesterase inhibitors (e.g. Organophosphate insecticides), and deep coma due to sedative drugs.
  • 43. Eyes  Mydriasis is common with amphetamines, cocaine, LSD, atropine and other anticholinergic drugs.  Horizontal nystagmus is characteristic of intoxication with alcohol and other sedative drugs. The presence of both vertical and horizontal nystagmus is strongly suggestive of phencyclidine poising.
  • 44. 3. Mouth  The mouth may show signs of burns due to corrosive substances, or soot from smoke inhalation.  Typical odors of alcohol or ammonia may be noted.
  • 45. 4.Skin  Exam skin for hot, and dry, flushing, bruising, cyanosis,  Cyanosis may be caused by hypoxemia or by methemoglobinemia.  Icterus may suggest hepatic necrosis.  Excessive sweeting occurs with organophosphates, nicotine and sympathomimetic drugs.
  • 46. 5. Abdomen  Hyperactive bowel sounds, tenderness abdominal cramping and diarrhea are common in poisoning with organophosphatase, iron, arsenic, teophylline, Amanita muscaria and phalloides.
  • 47. 6. Nervous system  A careful neurologic examination is essantial  Assess general appearance  Agitation or confusion  reflexes, muscle tone coordination, cognition  Focal seizures or motor deficits suggest a structural lesions.  Extremities: fasiculations, tremor,
  • 48.  muscular rigidity can be caused by anti- psychotic agents, serotonin syndrome and by strychnine.  Nystagmus and ataxia are typical of phenytoin, alcohol or other sedative intoxication.
  • 49. CNS Examination  Physiologic excitation – anticholinergic, sympathomimetic, or central hallucinogenic agents, drug withdrawal  Physiologic depression – cholinergic (parasympathomimetic), sympatholytic, opiate, or sedative-hypnotic agents, or alcohols  Mixed state – polydrugs, hypoglycemic agents, tricyclic antidepressants, salicylates, cyanide
  • 50. Mentation  Many factors can affect the patient’s mental status.  Hypoglycemia and hypoxemia; that can be life-threatening but easily addressed by administering oxygen and IV dextrose until laboratory results are available.
  • 51. C.Laboratory Studies  Relevant clinical laboratory data are vital to the assessment of the poisoned or overdosed patient.  Tests that provide clues to the agent(s) taken by the patient include arterial blood gases (ABGs), electrolytes, serum osmolality tests, urinalysis, complete blood count, electrocardiography , imaging findings and hepatic function.
  • 52. Acid–base balance and electrolyte homeostasis  Electrolyte abnormalities and metabolic acidosis frequently occur and may require serial measurements of electrolytes and arterial blood gases (ABGs), and other specific laboratory tests.
  • 53. 1.Arterial Blood Gases (ABGs)  Hypoventilation will result in an elevated PCO2 (hypercapnia) and a low PO2(hypoxia).  The PO2 may also be low with aspiration pneumonia or drug induced pulmonary edema.  Signs of inadequate ventilation or oxygenation include cyanosis, tachycardia, hypoventilation, intercostalmuscle retractions, and altered mental status.
  • 54. 2. Electrolytes  Acute poisoning can cause an imbalance in a patient’s electrolyte levels, including sodium, potassium, chloride, bicarbonate, carbon dioxide, magnesium, and calcium.  Serum level measurements are also available for carbamazepine, iron, ethanol, lithium, aspirin, and valproic acid and may be obtained if these agents are suspected in an overdose.
  • 55.  The anion (A negatively charged ion) gap represents the difference between unmeasured anions and cations (An ion or group of ions having a positive charge ) in the blood.  Anion gap = (Na + K) - (HCO3 + Cl)  The normal value for the anion gap is approximately 8 to 16 mEq/L.
  • 56.  An anion gap that exceeds the upper normal value can indicate metabolic acidosis caused by an accumulation of acids in the blood.  Drugs, toxins, or medical conditions that can produce an elevated anion gap include iron, isoniazid (INH), lithium, lactate, carbon monoxide, cyanide, methanol, ethanol, metformin, ethylene glycol, salicylates, hydrogen sulfide, ,diabetic ketoacidosis, uremia, seizures, and starvation. 56
  • 57. 3. Serum osmolality  The osmolal gap is the difference between the measured osmolality and the calculated osmolality.  The calculated osmolality is derived using laboratory values for the major osmotically active substances in the serum, such as sodium, glucose, and blood urea nitrogen (BUN).  Like the anion gap, it is a simple, cost- effective tool for evaluating the poisoned patient for certain drugs or toxins
  • 58.  The calculated serum osmolality can be estimated from the following formula;  2 X Na(meq/L) + Glucose(mg/dl) /18 + BUN(mg/dl) / 3  This calculated value is normally 280-290mOsm/L
  • 59. Diagnostic tools include the following 4. Electrocardiography: can provide evidence of drugs causing arrhythmias or conduction delays (e.g., tricyclic antidepressants).
  • 60. 5.Radiology Many substances are radiopaque, or can be visualized using a contrast-enhanced computed tomography (CT) scan (e.g., heavy metals, button, batteries, some modified-release tablets or capsules,aspirin concretions, cocaine or heroin containers). Chest radiographs provide evidence of aspiration and pulmonary edema.
  • 61. 6. Renal function tests  Some toxines have direct nephrotoxic, in other cases renal failure is due to shock or myoglobinuria.  BUN and creatinine levels should be measured and urinanalysis performed.
  • 62. 7.Toxicology screens A toxicology screen is a laboratory analysis of a body fluid or tissue to identify drugs or toxins. Saliva, spinal fluid, and hair may be analyzed, blood or urine samples are used more frequently.Each screen tests for specific drugs or agents.  The sample must also be properly collected, and there must be a laboratory near enough to obtain results quickly.
  • 63.  The test sample must be collected while the drug or toxin is in the body fluid or tissue used for testing.  For example, cocaine is a rapidly metabolized drug; however, its metabolite, benzoylecgonine, can be detected in the urine for several hours after cocaine use. 63
  • 64.  MANAGEMENT  Management of the poisoned or overdosed patient seeks to prevent absorption of and further exposure to the agent.  Treatment begins with first aid at the scene and continues in the emergency department and often the intensive care unit (ICU).  Advanced general management involves further steps to prevent absorption and enhance elimination of the agent. For instance, antidotes, antivenins (the treatment of venomous bites or stings) or antitoxins may be administered. 64
  • 65. General- management  I.provision of supportive care  II.prevention of poison absorption  III.enhancement of elimination of poison  IV.administration of antidotes
  • 66. I. Supportive care  Vital signs, mental status, and pupil size  cardiac monitoring, ECG  Protect airway  Intravenous access  cervical immobilization if suspect trauma  Rule out hypoglycaemia
  • 67. II.Preventing absorption  Decontamination;  A) dermal,  B) ocular,  C) inhalation, and  D) ingestion exposures follow.
  • 68. A) DERMAL EXPOSURE  Generally; achieved by; undressing patients and washing them thoroughly with copious amounts of lukewarm water for 15 to 30 minute  All towels and clothing should be put into hazardous waste bags
  • 69.  Some toxins may require further decontamination. For example, three separate soap and water washings or showers are recommended to decontaminate organophosphate pesticides (e.g., Malathion or Diazinon).  Protective clothing should be worn to reduce the risk for toxicity while handling contaminated clothing or assisting with skin decontamination. 69
  • 70. B) Eyes  Many substances can accidentally splash into the eyes.  When this happens, the eyes must be flushed to remove the agent.  Immediate irrigation with lukewarm water or normal saline is recommended.  Continuous flooding of the eyes with a large glass of water or low-pressure shower should be done for 15 minutes.
  • 71.  The patient should blink the eyes open and closed during the irrigation.  If necessary, the pH of the eyes can be tested. If the pH is abnormal, irrigation should continue until the pH normalizes.  An ophthalmologic examination is needed when ocular irritation or visual disturbance persists after irrigation.
  • 72. C) INHALATION EXPOSURE  A victim of an inhalation exposure should be moved to fresh air as quickly as possible.  The responder must also protect himself or herself from the airborne toxin.  Further evaluation is needed if the patient experiences respiratory irritation or shortness of breath.
  • 73. D) GI Decontamination  Three general methods involve removing toxin from stomach via the mouth, binding it inside gut lumen, or mechanically flushing it through GI tract  Each method has benefits and risks
  • 74.  Milk or water dilutes ingested irritants such as bleach or caustics such as drain cleaner. After such an ingestion, adults or children should drink milk or water (children based on their size).  Further evaluation is necessary after dilution if there is mucosal irritation or burns.
  • 75.  Because of the risk of aspiration, ingestions should not be diluted when they are accompanied by seizures, depressed mental status, or loss of the gag reflex.  Again, neutralization is not used because of the risk of thermal burn.
  • 76. Gastrointestinal Decontamination  1. Vomiting,  2. Gastric lavage,  3. adsorbents (is the adhesion of molecules of gas, liquid, or dissolved solids to a surface),  4. cathartics, and  5. whole-bowel irrigation are used to prevent absorption toxins.
  • 77. 1. Induced Vomiting Ipecac  Risk of aspiration Emesis: achieved by using syrup of ipecac  Dosing: 15 ml for 1-12 years old and 30 ml for adults; may repeat once if no emesis in 12 hr  90% vomit within 20 minutes of first dose and 97% vomit with second dose  Usually 3-5 episodes of emesis and resolve in two hours; if protracted emesis occurs consider toxin as etiology
  • 78. Ipecac con’t  Use of Ipecac very limited  Contraindications: ingestions with potential for change in mental status, active or prior vomiting, caustic ingestion, toxin with more pulmonary than GI toxicity (hydrocarbons), ingestion of toxins with potential for seizures  The American Academy of Pediatrics no longer recommends the use of emetics (such as syrup of ipecac) for GI decontamination.
  • 79. 2.GASTRIC LAVAGE  Fluid (usually normal saline) is introduced into the stomach through a large-bore orogastric tube and then drained in an attempt to reclaim part of the ingested agent before it is absorbed.  A small-bore nasogastric tube is ineffective for lavage because particulate matter such as tablets or capsules are too large to pass through the tube. If airway protection is necessary, the patient should be intubated before lavage begins.
  • 80. Orogastric lavage con’t  Contraindications: Not in unconscious patient unless intubated (risk aspiration)  caustic ingestion or hydrocarbons with a high aspiration potential, airway integrity not secured, more toxic to lung than GI  Because of the associated risks and the lack of clear evidence supporting its use, gastric lavage should be used only if the patient has ingested a life-threatening amount of a substance and the procedure is undertaken within an hour of the ingestion.
  • 81. GASTRIC LAVAGE  Complications: insertion into trachea, esophageal or gastric perforation, decreased O2, pulmonary aspiration, electrolyte imbalance, tension pneumothorax, and hypothermia (when cold lavage solutions are used).  Charcoal should be used before withdrawal of tube
  • 82. GASTRIC LAVAGE  The contents of the stomach can then be collected for drug or toxin identification.  Drug removal range from 35-56%.  Indicated if in 1 hr of ingestion.  For the lavage, the patient is positioned in the left. lateral decubitus position, with the head lower than the feet.
  • 83. 3. ADSORBENTS  An adsorbent is a solid substance that has the ability to attract and hold another substance to its surface (“to adsorb”).  Activated charcoal is an effective nonspecific adsorbent of many drugs and toxins.  Activated charcoal adsorbs, or traps the drug or toxin to its large surface area and prevents absorption from the GI tract.
  • 84. ADSORBENTS  Activated charcoal is a fine, black powder that is given as a slurry with water, either orally or by nasogastric or orogastric tube, as soon as possible after the ingestion.  Commercially available activated charcoal products may be mixed with 70% sorbitol to decrease grittiness (composed of or covered with relatively large particles, increase palatability (Acceptable to the taste) , and serve as a cathartic. The usual dose that is given is one 50-g bottle. 84
  • 85. Activated Charcoal • binds non-specifically • timing - use within 1 hour  Safety proven in adults and children  Dose 1g/kg
  • 86. Activated Charcoal  Indications: any drug known to absorb it or after unknown ingestions. Activated charcoal is used cautiously in patients with diminished bowel sounds and is contraindicated in patients with bowel obstruction.  Should not be given if esophageal or gastric perforation suspected or emergent endoscopy possibly needed.  Complications rare; aspiration or impaction possible
  • 87. Drugs/Toxins Well Adsorbed by Activated Charcoal ■ Acetaminophen ■ Amphetamines ■ Antihistamines ■ Aspirin ■ Barbiturates ■ Benzodiazepines ■ Beta blockers ■ Calcium channel blockers ■ Cocaine ■ Opioids ■ Phenytoin ■ Theophylline ■ Valproic acid Drugs/Toxins Not Well Adsorbed by Activated Charcoal ■ Acids ■ caustic alkalis ■ Alcohols ■ Iron ■ Lithium ■ Metals cyanide mineral acids, organic solvents, 87
  • 88. 4. CATHARTICS  A cathartic is a substance that causes or promotes bowel movements.  In theory, cathartics decrease the absorption of drugs and toxins by speeding their passage through the GI tract, thereby limiting their contact with mucosal surfaces. 88
  • 89. Cathartics  Osmotic cathartic usually given with activated charcoal  70% sorbitol (1 g/kg) or 10% Mg citrate  Shown to decrease transit time of activated charcoal  No definitive clinical human data suggest that a cathartic limits toxins bioavailability.
  • 90. 5. WHOLE-BOWEL IRRIGATION  The goal of whole-bowel irrigation is to give large volumes of a balanced electrolyte solution rapidly (1 to 2 L/hour) to flush the patient’s bowel mechanically without creating electrolyte disturbances.
  • 91.  Commercial products used in whole-bowel irrigation include GoLYTELY and Colyte.  Both products are dispensed (To prepare and give out ) as powders and are given after adding water.  Whole-bowel irrigation is contraindicated in the patient with bowel obstruction or perforation. 91
  • 92. Whole-Bowel Irrigation  Common indications: Heavy metals, Iron, Lithium, Sustained or delayed release formulations  End point is clear rectal effluent  Antiemetic frequently required  Avoid phenergan (slows gut motility)  Contraindications: absent bowel sounds or obstruction  Complications: bloating, cramping, rectal irritation
  • 93.  As a result, absorption is delayed, and the development of toxic effects, such as hypokalemia, metabolic acidosis, and respiratory alkalosis, may not be observed for several hours. 93
  • 94. III.Enhanced Elimination of the Drug or Toxin  The absorption rate, body distribution, metabolism, and elimination must be considered when choosing methods to eliminate the drug or toxin from the body.
  • 95. There are six methods of enhanced elimination: 1. Multiple-dose activated charcoal 2. Alteration of urine pH 3. Chelation 4. Hemodialysis 5. Hemoperfusion 6. Hyperbaric oxygenation (HBO) therapy
  • 96. 1. Multi-Dose Charcoal  One dose usually sufficient  Indications for multi-dose activated charcoal: ingestion of large doses, substances that slow release toxins, toxins that slow gut function, toxins with enteroenteric circulation, repetitive doses useful to enhance the elimination of certain drugs (eg, theophylline, phenobarbital, carbamazepine, valproic acide, aspirin)
  • 97. MULTIPLE-DOSE ACTIVATED CHARCOAL  Repeat dose is 0.25-0.5 g/kg  Multiple-dose activated charcoal is given orally, by nasogastric tube, or by orogastric tube every 2 to 6 hours.  Complications of multipledose activated charcoal include aspiration and bowel obstruction.
  • 98. 2. ALTERATION OF URINE pH  Alkalinization:Alkalinizing the patient’s urine enhances excretion of drugs that are weak acids by increasing the amount of ionized drug in the urine.  This form of enhanced elimination is also termed ion trapping. Alkalinization achieved by IV dose of bicarb at 1-2 mEq/kg, followed by intermittent boluses or continuous bicarb drip for urine pH 7.5-8.0
  • 99.  Used to eliminate acidic drug that mainly excreted by the kidney eg salicylates overdose.  Complications of alkalinization include cerebral or pulmonary edema and electrolyte imbalances.  Need expert monitoring
  • 100. Acidification of Urine  Urine acidification is no longer recommended because of low drug clearance and the risk of complications such as rhabdomyolysis. Rhabdomyolysis is the breakdown of muscle fibers resulting in the release of muscle fiber contents into the circulation. Some of these are toxic to the kidney and frequently result in kidney damage.  Can somewhat enhance elimination of amphetamines, phencyclidine, and some other drugs.
  • 101. 3. CHELATION  Chelation involves the use of binding agents to remove toxic levels of metals from the body, such as mercury, lead, iron, and arsenic. Examples of chelating agents are dimercaprol (BAL in oil), calcium disodium edetate (EDTA), and deferoxamine.
  • 102. 4.HEMODIALYSIS  Hemodialysis is the process of altering the solute composition of blood by removing it from an artery, diffusing it across a semipermeable membrane (between the blood and a salt solution), then returning it into a vein.
  • 103. Hemodialysis  It is used in moderate to severe intoxications to remove a drug or toxin rapidly when more conservative methods (e.g., gastric lavage, activated charcoal, antidotes) have failed or in patients with decreased renal function.  Hemodialysis requires consultation with a nephrologist and specially trained nurses to perform the procedure and monitor the patient.
  • 104. Hemodialysis  Drug should be dialyzable. Low molecular weight, low protein binding, and water solubility are factors that make a drug or toxin suitable for hemodialysis.  may also be used temporarily or as long term if the kidneys are damaged due to the overdose.  Dialysis reserved for specific toxins: salicylates, methanol, lithium, theophylline, amanita (mushrooms)
  • 105. Dialysis con’t  Benefits: removal of toxins already absorbed by gut, ability to remove parent compound and active metabolite,  Dialysis rarely contraindicated  No dialysis for small children, exchange transfusion should be considered
  • 106. 5.HEMOPERFUSION  Hemoperfusion removes drugs and toxins from the patient’s blood by pumping the blood through a cartridge of adsorbent material, such as activated charcoal.  An advantage of hemoperfusion over hemodialysis is that the total surface area of the dialyzing membrane is much greater with the hemoperfusion cartridges.
  • 107. HEMOPERFUSION As in hemodialysis, drugs that have high tissue- binding characteristics and a large volume distributed outside the circulation are not good candidates for hemoperfusion because little drug is found in the blood.  Although rarely used in the poisoned and overdosed population, hemoperfusion has been used successfully in patients experiencing a theophylline overdose
  • 108. 6.HYPERBARIC OXYGENATION THERAPY (HBO)  In HBO therapy, oxygen is administered to a patient in an enclosed chamber at a pressure greater than the pressure at sea level (e.g., 1 atmosphere absolute). This therapy has been used in carbon monoxide and methylene chloride poisonings (methylene chloride is metabolized to carbon monoxide in the body).
  • 109.  Complications of HBO therapy include pressure-related otalgia (ear pain), sinus pain, tooth pain, and tympanic membrane rupture.  anxiety, convulsions, and tension pneumothorax also have been observed in patients receiving HBO therapy.
  • 110. IV. Antidotes (Antitoxins) and Antagonists),  In pharmacology, an antagonist is a substance that counteracts the action of another drug.  Although the general public often believes there is an antidote for every drug or toxin, the opposite is closer to the truth.  There are, in fact, very few antidotes.
  • 111.  Antitoxins neutralize a toxin. For instance, botulism(food poisoning from ingesting botulin)(potent bacterial toxin) produced by the Clostridium botulinum that causes botulism; can be used as a bioweapon) 111
  • 112.  Antivenins are antitoxins that neutralize the venom of the offending snake or spider.  Antitoxin trivalent (equine) is available through the Centers for Disease Control and Prevention to counteract the effects of botulism.  There are several antitoxins; each is active against a specific venom. 112
  • 113. Continuous Patient Monitoring  Seriously poisoned or overdosed patients may require continued monitoring for hours or days after exposure.  Physical examination, the use of diagnostic tools, and careful assessment of clinical signs and symptoms provide information about the patient’s