Specific Toxins Part II. Infectious Agents Bacterial Food Infection/Poisoning Signs/Symptoms...

Specific Toxins

Part II

Infectious Agents

Bacterial Food Infection/Poisoning

• Signs/Symptoms – Nausea, vomiting– Abdominal cramps– Diarrhea– History of eating same foods in same place

as others with similar symptoms

Bacterial Food Infection/Poisoning

• Management– Prevention

• Cook thoroughly• Keep hot foods hot• Keep cold foods cold

– Replace lost fluids, electrolytes– Antiemetic agents

Botulism

• Pathophysiology– Neurotoxin from Clostridium botulinum– Produced in anaerobic environment at pH >4.6– Boiling will destroy toxin– Toxin binds to cholinergic nerve terminals;

Blocks acetylcholine release

Botulism

• Signs/Symptoms– GI upset– Dry mouth – Double vision (diplopia)– Drooping eyelids – Slurred speech– Descending paralysis - respiratory arrest

Botulism

• Management– Support ABC’s– Antitoxin

Common Cardiac Medications

Beta Blockers

• Signs/Symptoms– Bradycardia– Hypotension, shock– AV blocks– Prolonged QRS complex– Heart failure– Bronchospasms

Beta Blockers

• Management– ABC’s– Oxygen– Bronchospasms

• Inhaled 2 agents

Beta Blockers

• Management– Bradycardia

• Atropine 0.5 - 1.0 mg• Glucagon 5mg every 30’• Cardiac pacing

– Hypotension• Glucagon 5mg every 30’• Dopamine 5mcg/kg/min

Calcium Channel Blockers

• Signs/Symptoms– Bradycardia– Hypotension, shock– AV blocks– Heart failure– QRS prolongation does NOT occur

Calcium Channel Blockers

• Management– Calcium reverses decrease in contractility– Fluid infusion increases BP

Digitalis

• Signs/Symptoms– Central Nervous System

• Headache• Irritability• Psychosis• Yellow-green vision

– Gastrointestinal• Anorexia• Nausea, vomiting

Digitalis

• Signs/Symptoms– Cardiac

• Atrial tachycardia with block• Non-paroxysmal junctional tachycardia• PACs, PJCs, PVCs

Tachyarrhythmias + Blocks =>Digitalis toxicity

Digitalis

• Management– ABC’s, oxygen– Check electrolytes, correct hypo/hyperkalemia– Atropine: bradycardia with hypotension– Dilantin: ectopy– Lidocaine/magnesium sulfate: ventricular ectopy– Digtalis immune Fab Fragments (Digibind)

Digitalis

• Precautions– Cardioversion, pacing attempts may cause VF– Vagal stimulation may cause bradycardia, AV

blocks– Calcium may worsen ventricular arrhythmias

Tricyclic Antidepressants

TCAs

• Examples– Elavil– Tofranil– Sinequan– Surmontil– Vivactil

TCAs

• Mechanism of Toxicity: Cardiovascular– Alpha-adrenergic blockade: vasodilation– Anticholinergic effects: tachycardia, mild hypertension– Quinidine-like effects: myocardial depression– Inhibition of sodium channels: conduction defects– Metabolic or respiratory acidosis may contribute to

cardiotoxicity by inhibition of fast sodium channels

TCAs

• Mechanism of Toxicity: CNS– Anticholinergic effects: sedation, coma– Inhibition of NE, serotonin re-uptake: seizures

TCAs

• Three major toxic syndromes– Anticholinergic effects– Cardiovascular effects– Seizures

Anticholinergic Effects

• Sedation, coma, delirium• Dilated pupils• Dry skin, mucous membranes• Tachycardia• Decreased bowel sounds• Urinary retention• Myoclonic jerking (often mistaken for seizures)

Cardiovascular Effects

• Arrhythmias, abnormal conduction, hypotension• Prolongation of PR, QRS, QT intervals

(QRS > 0.12 is a good predictor of toxicity) • Various degrees of AV block• Hypotension caused by vasodilatation• Cardiogenic shock• Pulmonary edema

Seizures

• Common with TCA toxicity• Recurrent or persistent• Combined with diminished sweating can lead to

– Severe hyperthermia, – Rhabdomyolysis– Brain damage– Multisystem failure– DEATH

Death

• Usually occurs within hours due to :– Ventricular fibrillation– Intractable cardiogenic shock– Status epilepticus with hyperthermia

TCAs

• The three C’s

– Coma

– Convulsions

– Cardiac arrhythmias

TCAs

• Overdose Evaluation– Most have narrow therapeutic index– Doses <10x therapeutic daily dose may

produce severe poisoning– 10-20 mg/kg can be life threatening– In children one tablet can cause death

TCAs

• Management of Toxicity– ABCs– Decontamination

(Lavage even up to 4-6 hours post ingestion may be useful due to decreased GI motility)

– Activated charcoal

TCAs

• Management of Toxicity– Sodium Bicarbonate (1-2 mEq/kg)

• Maintain pH of 7.45 to 7.55• Protects cardiac membrane, corrects acidosis

– Hyperventilation to induce respiratory alkalosis can work for short time

TCAs

• Management of Toxicity– Pacing for bradyarrhythmias, high-degree

AV block– Overdrive pacing for Torsades des pointes– Do NOT use type 1a or 1c antiarrhythmic

agents for V-tach; can aggravate cardiotoxicity

TCAs

• Management of Toxicity– Hypotension

• Fluids• Vasopressors

– Seizures • Diazepam, phenobarbital. • If these do not work, paralyze patient

Iron

• Incidence (1995 AAPCC Annual Report)– 28,039 Exposures– 378 moderate, major effects– 3 deaths

Iron

• Overdose Evaluation– How much elemental Fe could have been

ingested (mg/kg)?• < 20mg/kg: not considered toxic, can be left at

home• 20-60mg/kg: mild to moderate toxicity, some

treatment required• > 60mg/kg: high toxicity; hospitalization required

Iron

Signs and Symptoms

Occur in five stages

Stage I

• 30 minutes-6 hours post ingestion• GI irritation, due to iron’s corrosive effects

– Nausea, vomiting– Epigastric pain – GI bleeding– Drowsiness– Hypotension– Metabolic acidosis– Leukocytosis– Hyperglycemia

Stage II

• 6-24 hours post ingestion

• Sometimes absent in severely poisoned patients

• Patient seem to improve; feels, looks better

Stage III

• 6-48 hours post ingestion

• Metabolic, systemic derangement – Cardiovascular collapse– Coma– Seizures– Coagulopathy– Pulmonary edema

Stage IV

• 2-7 days post ingestion– Hepatotoxicity (jaundice) – Coagulopathy– Metabolic acidosis– Renal insufficiency

Stage V

• 1-8 weeks post ingestion

• Primarily delayed GI complications– Gastric/duodenal fibrosis– Scarring of pylorus– Intestinal obstruction

Iron

• Overdose Treatment– Decontamination

• Lavage useful if done within first 60 minutes post ingestion

• Iron does NOT bind to activated charcoal

– Whole bowel irrigation

Iron

• Overdose Treatment– Desferal ( desferoximine )

• Chelating agent • Binds free iron, complex is excreted renally• “Vin rose’” urine color depending on urine pH

Isoniazid

Carbon Monoxide

• Produced by incomplete combustion (autos, home heaters)

• Colorless, odorless, tasteless

• Binds to hemoglobin - blocks oxygen carrying capacity

Carbon Monoxide

• Signs/Symptoms– Headache, N/V, ringing in ears,

incontinence, seizures, coma, pulmonary edema

– Cherry-red skin - usually a terminal event– Suspect with a lot of “sick” patients at one

location

Organophosphates

• Pathophysiology– Block cholinesterase. – Cause build-up of acetylcholine in

synapses. – Produce cholinergic crisis.

Organophosphates• Signs and Symptoms

– Salivation– Lacrimation– Urination– Defecation– Gl Cramping– Emesis

– Pin-point pupils– Bradycardia– Bronchospasms– Muscle twitching– Weakness– Ventilatory failure

Organophosphates

• Management– 100% oxygen, assist ventilations– IV tko– Monitor ECG– Atropine 1mg IV, 2mg IM. Repeat until

atropinized– Pulmonary edema is non-cardiogenic in

origin; avoid lasix, morphine

Drug Abuse

Self administration of drug or drugs in manner not in accord with

accepted medical or social patterns

Drug Abuse

• Psychological Dependency (Habituation)– Drug necessary to maintain user’s sense of

well-being

• Physical Dependency– Physical symptoms if intake reduced

Drug Abuse

• Compulsive Drug Use– Preoccupation with obtaining drug– Rituals of preparing, using drug as

important as drug effects

• Tolerance– Increasing doses needed to obtain drug

effect

Drug Abuse

• Addiction– Includes

• Psychological dependence• Physical dependence• Compulsive use• Tolerance

– Plus, complete absorption with obtaining, using drug to exclusion of all else

Drug Abuse

• Suspect drug-related problem in patients with:– Altered LOC– Bizarre behavior– Seizures

Drug Abuse

• Ask EVERY patient about recreational drugs.• Be non-judgmental.• Keep drug box/cabinet secured.• Use discretion.• If held up, give them what they want!

Narcotics

• Opium

• Opium derivatives

• Synthetic opium substitutes

Narcotics

• Examples– Opium– Morphine– Heroin– Codeine– Dilaudid

– Oxycodone (Percodan)

– Meperidine (Demerol)– Propoxyphene

(Darvon)– Talwin– Fentanyl

Narcotics

• Effects– Analgesia– CNS depression

• Euphoria• Drowsiness• Apathy

– Antidiarrheal action– Antitussitive action

Narcotics

• Overdose– Mild to Moderate

• Lethargy

• Pinpoint pupils

• Bradycardia

• Hypotension

• Decreased bowel sounds

• Flaccid muscles

– Severe• Respiratory depression• Coma• Aspiration• Seizures with certain

compounds (meperidine, propoxyphene, tramadol)

Narcotics

• Overdose– Management

• Support oxygenation/ventilation• Vascular access• D50W 50cc• Narcan 0.4 to 2.0 mg

– Improve respirations–Do NOT awaken completely–Restrain before giving

Narcotics

• Associated Dangers– Skin abscesses– Phlebitis– Sepsis– Hepatitis– HIV– Endocarditis

– Adulterant toxicity– “Cotton fever”– Malnutrition– Tetanus– Malaria

Narcotics• Withdrawal

– Insomnia– Restlessness– Irritability– Anorexia– Tremors– Back, extremity pain

– Watery eyes– Yawning– Rhinorrhea– Sneezing– Diarrhea– Diaphoresis

Resembles Severe Influenza

Narcotics

• Withdrawal– Lasts 7 to 10 days– NOT life threatening

Sedative-Hypnotic Drugs

Categories

• Barbiturates

• Benzodiazepine

• Barbiturate-like non-barbiturates

• Chloral hydrate

Mechanism of Action

• Most overdoses of sedative-hypnotics are from benzodiazepines, barbiturates

• Both enhance effects of gamma-aminobutyric acid (GABA)

• GABA enhancement results in down-regulation of CNS activity

Sedative-Hypnotics

• Use more then a week leads to tolerance to effects on sleep patterns

• Withdrawal after long term results in “rebound” increase in frequency of occurrence, duration of REM sleep.

• In high doses, sedative-hypnotics depress CNS to point of Stage III or general anesthesia

Sedative-Hypnotics

• Tolerance– Happens with all sedative-hypnotics– Appears very quickly even during short-term

use.– Discontinuation will bring receptor response

back to normal after drug has been metabolized

– Withdrawal symptoms may take up to a week to see in some patients

Chloral hydrate

• “Micky Finn” when mixed with alcohol

• Rapidly absorbed, acts quickly

• Drowsiness, sleep

• Alcohol, chloral hydrate compete for metabolism by same enzyme

• Prolonged action for both when mixed

• Not commonly abused

Barbiturates

• Introduced in 1903

• Replaced older sedative-hypnotics

• Quickly became major health problem

• In 1950’s-60’s barbiturates were implicated in overdoses; were responsible for majority of drug-related suicides

Barbiturates

• Short-acting– Amytal– Pentathiol

• Intermediate-acting– Nembutal– Seconal– Tuinal

• Long-acting– Phenobarbital

Barbiturates

• Initial overdose presentation – Slurred speech– Ataxia– Lethargy – Nystagmus– Headache – Confusion

Barbiturates

• As overdose progresses– Depth of coma increases

• Patient anesthetized with loss of neurologic function• EEG may mimic brain death

– Respiratory depression occurs– Peripheral vasodilation occurs

• Hypotension, shock• Hypothermia

– Blisters (bullae) form on skin

Barbiturates

• Early deaths– Respiratory arrest– Cardiovascular collapse

• Delayed deaths– Acute renal failure– Pneumonia– Pulmonary edema– Cerebral edema

Barbiturates

• Overdose management– Secure airway– Support oxygenation/ventilation– IV with LR or NS– Prevent heat loss secondary to

vasodilation– Bicarbonate to alkalinize urine (long-acting

only)

Barbiturates

• Withdrawal signs/symptoms– Apprehensiveness– Anxiety– Tremulousness– Diarrhea– Nausea– Vomiting– Seizures

Barbiturate-like, non-barbiturates

• Examples– Doriden (glutethimide)– Quaalude (methaqualone)– Placidyl (ethchlorvynol)– Noludar

• Overdose produces sudden, prolonged apnea• Highly addictive• Withdrawal resembles barbiturate withdrawal• Only Placidyl, Doriden remain available in U.S.

Placidyl (ethchlorvynol)

• “Pickles”, “jelly beans”, “Mr. Green Jeans”

• Produces vinyl-like odor on breath

• Concentrates in CNS, slow hepatic metabolism

• Half-life >100 hrs

• Prolonged deep coma (100 to 300 hrs), hypothermia, respiratory depression, hypotension, bradycardia

• EEG is flatline

• Keep patient on life support for a few days; they wake up, are ok

Doriden (gluthethimide)

• Abused in combination with codeine• “sets”, “hits”, “loads”, “fours and doors”• Prolonged coma (average 48 hours)• Hypotension, shock common• Anticholinergic signs: dilated pupils,

tachycardia, dry mouth, ileus, urinary retention, hyperthermia

Benzodiazepines

• Developed due to overdoses, deaths related to barbiturates, barbiturate-like non-barbiturates

• Relatively few deaths

• In 1993, prescription rate for barbiturates dropped to one-sixth that of benzos

Benzodiazepines

• Examples– Valium (diazepam)– Ativan (lorazepam)– Versed (midazolam)– Librium (chlorodiazepoxide)– Tranxene (chlorazepate dipotassium)– Dalmane (flurazepam)– Halcion (triaxolam)– Restoril (temazepam)

Benzodiazepines

• Adverse Effects– Weakness– Headache– Blurred vision– Vertigo– Nausea– Diarrhea– Chest pain

Benzodiazepines

• Overdoses– Relatively safe taken by themselves, even in

overdose– Can be lethal with other CNS depressants

especially alcohol – Look like other CNS depressant overdoses– Antidote is Romazicon ( flumazenil )

• Only recommended in known, controlled situations

• Can lead to seizures that cannot be controlled

Benzodiazepines

• Produce withdrawal syndrome similar to barbiturate withdrawal

Benzodiazepine-like non-benzos

• BuSpar (buspirone)– Used for generalized anxiety disorder– Less sedating than diazepam– Less potentiation by other CNS

depressants

• Ambien, Stilnox (zolpidem)– Used for short-term insomnia treatment– Toxic effects similar to benzos

Neuroleptics

• Antipsychotics, major tranquilizers• Used in treatment of schizophrenia, other

psychoses• Examples

– Haldol– Mellaril– Thorazine– Stellazine– Compazine

Neuroleptics

• Extrapyramidal muscle contractions (dystonias)– Bizarre, acute, involuntary movements,

spasms of skeletal muscles– Reversible with Benadryl

Neuroleptics

• Acute Overdose Presentation– CNS depression– Hypotension– Anticholinergic symptoms: flushing, dry

mouth, hyperthermia, tachycardia, urinary retention

– Ventricular arrhythmias, including Torsades– Seizures

Neuroleptics

• Acute Overdose Management– ABCs– Fluid, vasopressors for hypotension– Lidocaine, phenytoin for ventricular

arrhythmia– Magnesium, isoproterenol for Torsades– Benzodiazepines, phenobarbital for

seizures

Neuroleptics

• Neuroleptic malignant syndrome– Life-threatening reaction– Signs, symptoms

• Hyperthermia• Muscular rigidity• Altered LOC• Tachycardia, hypotension

Neuroleptics

• Neuroleptic malignant syndrome– Management

• ABCs• Oxygen• Assist ventilation, as needed• Benzodiazepines• Rapid cooling• Volume for hypotension

Stimulants

• Examples– Cocaine– Amphetamines

• Benzedrine (bennies)• Dexedrine (dexies, copilots)• Methamphetamine (ice, black beauties)

– Ephedrine– Caffeine– Ritalin

Stimulants

• Produce – euphoria– hyperactivity– alertness– sense of enhanced energy– anorexia

Stimulants

• Overdose signs/symptoms– Euphoria, restlessness, agitation, anxiety– Paranoia, irritability, delirium, psychosis– Muscle tremors, rigidity– Seizures, coma– Nausea, vomiting, chills, sweating, headache– Elevated body temperature– Tachycardia, hypertension– Ventricular arrhythmias

Stimulants

• Overdose complications– Hyperthermia, heat stroke – Hypertensive crisis– CVA– Acute MI– Intestinal infarctions– Rhabdomyolysis– Acute renal failure

Stimulants

• Chronic effects– Weight loss– Cardiomyopathy– Paranoia– Psychosis– Stereotypic behavior: picking at skin

(“cocaine bugs”)

Stimulants

• Overdose management– Oxygen, monitor, IV– Activated charcoal for decontamination in first hour– Valium for sedation– Hypertension control

• Nipride

• Phentolamine

• Avoid beta-blockers, including labetolol (Why?)

– Body temperature reduction

Stimulants

• Withdrawal– Drowsiness– Profound depression (“cocaine blues”)– Increased appetite– Abdominal cramps, diarrhea, nausea– Headache

Hallucinogens

• Examples– Indole hallucinogens

• LSD (acid)• Morning-glory

seeds• Psilocybin• DMT

– Amphetamine-like hallucinogens

• Peyote• Mescaline• DOM• MDA• MDMA (ecstasy)

Hallucinogens

• Produce altered/enhanced sensation

• Effects highly variable depending on patient

• Increased dose does not intensify effect

• Toxic overdose virtually impossible

Hallucinogens

• Some patients may experience “bad trips”

• Depends on surroundings, emotional state

• Signs and symptoms– Paranoia, fearfulness, combativeness– Anxiety, excitement– Nausea, vomiting– Tachycardia, tachypnea– Tearfulness– Bizarre Reasoning

Hallucinogens

• Moderate Intoxication– Tachycardia– Mydriasis– Diaphoresis– Short attention span– Tremor– Hypertension– Hyperreflexia– Fever

Hallucinogens

• Life-threatening toxicity (rare)– Seizures– Severe hyperthermia– Hypertension, arrhythmias– Obtunded, agitated, or thrashing about– Diaphoretic, hyperreflexic– Untreated hyperthermia can lead to hypotension,

coagulopathy, rhabdomyolysis and multiple organ failure

Hallucinogens

• Management of “bad trip”– Rule out other causes of hallucinations

• Hypoglycemia• Alcohol, drug withdrawal• Infection

– Quiet, supportive environment– Benzodiazepines, haldol for agitation,

anxiety

Phencyclidine (PCP)

• Street names– Angel dust– Peace Pill– Hog – Krystal– Animal tranquilizer

• Used as veterinary anesthetic

Phencyclidine (PCP)

• Actions– Dissociative anesthesia– Generalized loss of pain perception– Little or no depression of airway reflexes or

ventilation– CNS-stimulant, anticholinergic, opiate, and

alpha-adrenergic effects

Phencyclidine (PCP)

• Low Doses

– Lethargy, euphoria, hallucinations– Slurred speech– Blank stare– Insensitivity to pain– Midposition to dilated pupils– Vertical and horizontal nystagmus– Occasionally bizarre or violent behavior

Phencyclidine (PCP)

• High Doses– Diaphoresis– Salivation– Hypertension– Tachycardia– Hyperthermia

• Localized dystonic reactions

• Wide-eyed coma• Rigidity• Seizures

Phencyclidine (PCP)

• Treatment– Maintain airway– Assist ventilations, as needed– Treat coma, seizures, hypertension,

hypothermia as needed– Quiet environment– Sedation if needed to control agitation

• Haldol• Benzodiazepines

Inhalants

• Examples– Hydrocarbons (solvents, paints, aerosols)– Gases (freon, halon fire extinguishing

agent)– Metallic paints (“huffing”)

Inhalants

• Effects– Dysrhythmias including VF– CNS depression– Seizures– Respiratory irritation– Epinephrine may increase risk of dysrhythmias

• Treatment– Oxygen– Treat symptomatically

“Date rape” drugs

• Flunitrazepam (Rhohypnol)

• Gamma hydroxybutyrate

Flunitrazepam (Rhohypnol)

• Street names– Rophies– Roofies– R2– Roofenol

– Roche– Roachies – La rocha– Rope– Rib


• Benzodiazepine• Similar to Valium but 10x more potent• Produced, sold legally in Europe, South

America• Uses

– Short-term treatment of insomnia– Sedative hypnotic– Preanesthetic medication


• Effects– Disinhibition and amnesia– Onset within 30 minutes, peak within 2

hours, may persist 8 hours or more– Frequently abused with alcohol or other

drugs– Enhances high produced by heroin


• Adverse Effects– Drowsiness– Dizziness– Confusion– Decreased BP– Memory impairment– GI disturbances– Excitability, aggressive behavior


• Management of overdose– Lethal overdose very unlikely– Oxygenate, ventilate– Intubate if necessary to control airway– Vascular access– ECG– Fluid for hypotension– Dextrostick (rule out hypoglycemia)– Treat trauma resulting from assault


• Withdrawal– Headache– Anxiety, tension– Numbness, tingling

of extremities– Restlessness,

confusion– Loss of identity

– Hallucinations– Delirium– Seizures (up to a

week after cessation)– Shock– Cardiovascular

collapse


• Management of withdrawal– Oxygen/ventilation– Intubate if necessary– EKG– Vascular access– Fluid for hypotension– Dextrostick– Diazepam for seizures

Gamma hydroxybutyrate

• Street names– Cherry meth– Liquid X– Liquid ecstacy

• Originally developed as anesthetic

• Banned in 1991 because of side effects

• Promoted as aphrodisiac

Gamma hydroxybutyrate (GHB)

• Effects– Odorless, nearly tasteless– Tremors– Seizures– Death

Specific Toxins Part II. Infectious Agents Bacterial Food Infection/Poisoning Signs/Symptoms...

Documents

Transcript of Specific Toxins Part II. Infectious Agents Bacterial Food Infection/Poisoning Signs/Symptoms...