Poisons - 01/18 General Poison Management

What is the epidemiology of ODs?

• 81k drug ODs in 1yr ending in May 2020

• Increased during pandemic

What are the parts of info gathering for poisonings?

• Name, number, address, age, weight

• Substance and quantity

• Time of ingestion, route

• Severity

• If symptomatic or potential to be, take containers to hospital

How long do you have for poisonings?

• 6 to 8hrs for ingestion

• 24hrs for inhalation

When is ipecac used in poisonings?

Only if transport delayed or not available

What are the parts of initial eval of poisonings?

• TREAT PATIENT

• Airway

• Breathing

• Circulation

• Disability: altered consciousness merits O2, glucose, naloxone

• Exposure: evaluate toxidrome

Why is airway important in initial eval of poisonings and what should be done?

• Major factor in death

• Assess 1st and may require intubation

What is done for breathing during initial eval of poisonings?

• Rate, depth, pattern, cyanosis

• Presence of methadone yawn

• Use O2 or mech ventilation

What is done for circulation during initial eval of poisonings?

• Check pulse and BP

• If low, depressant probably

• If high, stimulant probably

• If HoTN + functional myocardium,

• Lay flat

• Then fluids

• Then pressors (dopa or catecholamines)

How is the severity of poisonings found?

• History

• Neurologic status

• Physical eval

What are the important aspects of history in determining severity of poisonings?

• Poor historians w. 50% reliable

• Dont assume single toxin or look at LD50

What are the important aspects of neurologic status evaluation in determining severity of poisonings?

• Need to classify b/c status changes quickly

• Need same person to do evaluation

What can be part of the supportive care for poisonings?

• Determine severity

• IV

• Naloxone

• Nalmefene

• Thiamine

• D50W

• Flumazenil

• Aspiration prevention positioning

What are the gradings of coma due to poisonings?

• 0: asleep, rousable, answer questions

• 1: coma, intact reflexes, withdraw from painful stimuli

• 2: coma w/ reflexes, but no withdrawal from painful stimuli nor resp/circ depression

• 3: coma w/o reflexes but no resp/circ depression

• 4: coma w/o reflexes and circ/resp fail

What are the gradings of hyperactivity due to poisonings?

• 1+: restless, irritable, insomnia, tremor, hyperreflexia, sweat, flush

• 2+ confused, HTN, tachypnea, tachycardia, extrasystoles, sweat, mild hyperpyrexia

• 3+: delirium, self-injury, marked HTN, tachyarrhythmia

• 4+: convulsions, coma, circ collapse + other hyperactivity symptoms

What are the parts of physical for determining severity of poisoning?

• Vitals (BP, RR, HR)

• Skin color

• Muscle tone

• DTRs

• Abnormal movement

• Pupils

• CV

• Lungs

What are the types of pupils seen in poisonings?

• Pinpoint

• Dilated and reactive

• Dilated and unreactive

• Horizontal nystagmus

• Vertical and horizontal nystagmus

What causes pinpoint pupils?

Opioids besides demerol

What causes dilated and reactive pupils?

• Stimulant, sympathomimetics

• Ex: cocaine

What causes dilated and unreactive pupils?

Anticholinergics and some psych meds

What causes horizontal nystagmus pupils?

• Alcohol

• Barbiturates

• Dilantin (phenytoin)

What causes vertical and horizontal nystagmus pupils?

PCP

What are the lung findings that point towards opioids?

• Noncardiogenic pulm edema

• Frothing breath

When is naloxone used and what is the MoA?

• Symptoms consistent w/ narcotic OD: coma, lethargy, miosis, HoTN, resp depression

• Pure narcotic antag that reverses CNS and resp depression

What is the initial dosing of naloxone?

• Adult: 2mg

• Child: 0.01mg/kg then 0.1mg/kg

• Monitor pupil response

• If no response in 3min, repeat x2 and higher dose if suspect fentanyl, propoxyphene, methadone OD

How is naloxone readministered?

Q60 to 90min IVP or 2mg/250ml D5W at 0.4mg/hr to maintain on level of consciousness

What is nalmefene and the advantages/disadvantages?

• IV narcotic antag

• HL of 4 to 8hrs

• Can cause withdrawal thats not reversible

What is the purpose of thiamine in poisoning?

• 100mg IV

• Helps metabolize dextrose

How and why is D50W in poisoning?

• 50ml D50W if comatose or stupor

• Do rapid DextroStix when placing IV

What are the parts of coma cocktail?

Naloxone + thiamine + D50W

What is the MoA and use of flumazenil?

• Used in benzo OD

• NOT NARCAN FOR BENZOs: pharmacological activity

How is flumazenil administered in poisonings?

• 0.2mg over 30sec

• If no response after 30 sec: 0.3mg over 30sec

• If no response: 0.5mg over 30sec at 1min intervals

• NOT IF COINGESTION OF TCA or BENZOS FOR SEIZURE

What is the positioning to prevent aspiration?

Trendelenburg w/ head to side depending of consciousness and presence of gag reflex

What are the labs that can be done for poisonings?

• Blood as needed

• ABG, lytes, ETOH

• Tox screen

• Urine screen

• Gastric content

• Plasma screen

• Specific serum assays

When is ABG used for poisonings?

Coma patient

When is ETOH screen used for poisonings?

ALL POISONINGS

What does bright venous blood point towards?

Cyanide

When is tox screen used for poisonings?

ALL get alcohol and tylenol esp tylenol

What is anion gap?

• Na - HCO3 - Cl

• Normally 12

• If high, AT MUDPILES

What can cause a high anion gap?

• Alcohol

• Toluene

• Methanol

• Uremia

• DKA

• Paraldehyde

• Iron, isoniazid

• Lactic acidosis

• Ethylene glycol

• Salicylate, strychnine

What are the parts of toxicology>

• Urine screen

• Gastric contents (not very helpful)

• Plasma screen

• Specific serum assay

What are the types of specific serum assays used in poisonings?

• Salicylate

• ETOH

• Phenobarbital

• Theophylline

• Tylenol

What are the general methods of preventing absorption?

Activated charcoal > emesis or lavage

What are the ideal characteristics of emetics?

• Easy admin

• High acceptance

• High success

• Short latency

• Efficiency emesis

• Not adsorbed by charcoal

• No dangerous ADRs

What is the MoA of ipecac?

• Cephaeline and emetine (alkaloids)

• Directly irritates GI mucosa and stimulates CTZ 30min later

What is the efficacy of ipecac?

• Takes 18min after 1st admin

• If no emesis, repeat and 93% of pt

• ONLY 1/3 REMOVED

What is the dosing of ipecac?

• <9m: never

• 9 to 12m: 10ml w/ H2O

• 1 to 12: 15ml w/ H2O (can repeat)

• >12y: 30ml w/ H2O (can repeat

What are the ADRs of ipecac?

• Cardiotox in extract and if syrup abused

• Slight CNS depression, diarrhea

• Caution in CNS depressants (alc, diazepam, diphenhydramine)

What are the CIs to emesis?

• Comatose

• No gag reflex

• Convulsing

• Acids or alkali

• Hydrocarbons

What are the indication for gastric lavage?

• Coma level 3 to 5

• No gag reflex

• Ipecac failure

• Convulsing

• Ingestion of lots of hydrocarbons

How is gastric lavage done?

• MEDICAL SUPERVISION

• Protect airway if needed (endotrach intubation w/ cuffed tube)

• Lateral trendeleberg to minimize aspiration

• Large bore tube passed and placement checked

• Do 3L or until clear using aliquots:

• Adults: 200 to 300mL

• Children: 100 to 200mL water and alt w/ NS

When can patients not protect airway?

• Coma

• Convulsing

• No gag reflex

• Volatile liquids

What is the MoA of activated charcoal?

• Insoluble residue from destructive distillation of organic material

• Binds and adsorbs drugs

What are the indications for activated charcoal use?

• ROUTINELY USED ON POISONED PT

• Sedatives, tranqs, TCA, cardiac glycosides, salicylates, etc.

• 1st line option

What are the considerations when using activated charcoal>

• Binds acetaminophen antidote but negligible effects

• Cant bind alcohols, cyanide, small MW ions

What is the dosing and admin for activated charcoal normally?

• Adult: 60g in H2O (1 to 2g/kg)

• Children: 30g in H2O (1g/kg)

• EVERY 4 to 6hr

• POWDER OR PREMIXED SLURRY

When are multiple dose activated charcoal (MDAC) indicated?

• Theophylline

• Phenobarbital

• Phenytoin

• Salicylates

What should be done if activated charcoal given after ipecac?

Wait 45 to 60min post-emesis to decrease aspiration and readmin resik

What are the ADRs of activated charcoal?

If aspirated, inert and no inflammatory rxn

What are cathartics and their efficacy?

• Increase GI transit rate but dont significantly decrease absorption

• Used w/ charcoal

What are the cathartics that are used and avoided in poisonings?

• Use sale: sodium sulfate, magnesium sulfate, magnesium citrate

• Avoid oil-based b/c aspiration and chemical pneumonia risk

What is the dosing of saline cathartics in poisonings?

• Mg sulfate: 250mg/kg or 30ml of 50% soln

• Na sulfate: 250mg/kg diluted 1:4

• Mg citrate: 200ml bottle

• Sorbitol: 30ml of 70% soln

How is elimination enhanced in poisoning?

• Forced diuresis

• Ion trapping: acidification, alkalinization

• Dialysis and hemoperfusion

When is forced diuresis considered and what should be considered?

• If largely eliminated renally

• Consider I/O to minimize fluid overload

When can urinary acidification be used?

Theoretically for amphetamines or phencyclidine

How is urinary acidification done and what should be considered?

• NH4+Cl 0.1g/kg/d in 4 doses or 1 to 2g IV Q6H IV/PO

• Ascorbic acid 1 to 2g Q6H IV/PO

• Urinary pH goal: 4 to 5

When can urinary alkalinization be used?

• Phenobarbital

• Salicylates

• Isoniazid

How is urinary alkalinization done and what should be considered?

• NaHCO3 1 to 2mEq/kg IV

• Urinary pH 7.5 to 8

What does the efficiency of dialysis depend on?

• Volume of dist <1L/kg (not too distributed)

• Rate of tissue equilibrium

• Protein binding

• MW

• Dialysis CL

What are the criteria for HD or hemoperfusion in OD?

• Severe intoxication w/ abnormal vitals

• Lethal dose ingestion

• Blood level in lethal level

• Sig circulating toxin that is metabolized to more noxious (methanol, ethylene glycol)

• Progressive clinical deterioration

• Prolonged coma w/ potential hazards of aspiration pneumonia, septicemia, peripheral neurop from pressure ischemia

• Delayed tox poisons (diquat)

• Dialyzable drugs

What are the examples of dialyzable drugs?

• Salicylates

• Methanol

• Ethylene glycol

• Long-acting barbs

• Li

• Theophylline

What are the signs of severe intoxication w/ abnormal vitals that indicate for HD in OD?

• HoTN despite fluids

• Apnea

• Severe hypothermia

What drugs can cause hypoglycemia?

• Beta-blockers

• Ethanol or toxic alcohols

• Salicylate

• SUs

• Valproic acid