poisoning and ingestions Flashcards
(100 cards)
1
Q
initial mgmt when presented with a poisoned pt?
A
- Gross decontamination beforehand
- ABC, VS
- Cont. Cardiac monitoring, ECG
- IV access - Large bore or central line
- HoTN: IV crystalloid bolus - Bedside glucose
- ABG
- Mental status, Pupil size, Skin check
2
Q
Toxin-induced QRS interval prolongation can be seen with what medications?
A
Antidepressants, antipsychotics, antihistamines, organophosphate insecticides
3
Q
SVT can be caused by what meds?
A
Sympathomimetics, Anticholinergics
4
Q
V Tach can be caused by what meds?
A
Sympathomimetics, TCA
5
Q
bradycardia can be caused by what meds?
A
cholinergics, opioids, sedative-hypnotics
6
Q
initial tx for AMS
coma cocktail
A
- dextrose
- naloxone (Narcan)
- thiamine
7
Q
initial tx for seizures
poisoned pt
A
- IV lorazepam - Double the dose if no improvement within a few mins
- seizure persists - IV phenobarbital, intubate
- Isoniazid-induced - pyridoxine
8
Q
What medication is ineffective for stopping seizures caused by most poisonings?
A
Phenytoin
9
Q
how/what to obtain a brief hx about the poisoned pt?
A
- Pt may be unreliable - correlate with pt’s sx
- Get hx from others - EMS, police, family, friends, etc
- Inquire about exposures
- Other ill contacts - CO, foods, chemical and biological warfare agents
10
Q
The ____, ____, and ____ help classify the pt into either a state of physiologic excitation or depression
A
mental status, VS, and pupillary examination
11
Q
- signs of physicologic excitation?
- what meds can cause this?
A
- CNS stimulation, mydriasis
- Tachycardia, inc BP, RR and temp
- Etiologic toxidromes: anticholinergic, sympathomimetic, serotonin syndrome, hallucinogens
12
Q
- signs of physiological depression?
- what meds can cause this?
A
- AMS, miosis, Low BP, RR and temp
- Etiologic toxidromes: sedative-hypnotic agents, opiates, cholinergics
13
Q
what meds can cause Mydriasis?
A
- anticholinergics
- sympathomimetics
dilated pupils
14
Q
what meds can cause Miosis?
A
- cholinergics
- opioids
small pupils
15
Q
what meds can cause Nystagmus?
A
Ethanol, phenytoin, ketamine, PCP
16
Q
what med can cause Excessive lacrimation
A
cholinergics
17
Q
- what meds can cause hypersalivation?
- excessive dryness?
A
- cholingerics
- anticholingergics
18
Q
possible findings of abominal exam from a poisoned pt?
signs and their meds
A
- bowel sounds - diminished in anticholinergic and opiates
- enlarged bladder - anticholinergic
- abdominal tenderness or rigidity - ASA, anticholinergic
19
Q
what meds can affect muscle tone and tremor or fasciculation
A
cholinergics,serotonin
20
Q
general w/u for poisoned pt?
A
- Abd XR
- CXR
- Tox screen
- Concentrations of common coingestants
- UA
21
Q
When is a tox screening not needed?
A
- non-intentional ingestion and asx OR
- clinical findings consistent with MHx
22
Q
individual tox screening may be needed to determine specific tx for what 2 meds?
A
lithium, digoxin
23
Q
what 3 specific concentrations should always obtain in any person with unknown ingestion
A
APAP, ethanol, and salicylate
24
Q
Calcium oxalate crystals may be present with what type of poisoning
A
ethylene glycol (antifreeze)
25
preferred method of gastric decontamination?
Activated Charcoal (AC) 1g/kg
* absorbs toxins in stomach
* not able to bind _metals, corrosives or alcs_
26
indication for activated charcoal?
* if ingestion < 1 hr prior to arrival
* can be used after 1 hour if toxins that slow GI transit (anticholinergics) and those that form bezoars (salicylate)
27
CI for activated charcoal?
unable to protect airway
28
* removes non-absorbed toxins
* High risk of aspiration - avoid unless pt is intubated or airway protective reflexes are intact
which type of gastric decontamination?
lavage
29
indications for gastric lavage?
* ingestion has occurred < 1 hr prior to presentation
* no antidote
* toxin has a poor response to supportive care
30
how to perform gastric lavage?
* Insert 36F-40F orogastric tube
* LLD w/ HOB tilted down
* 200 ml of warm tap water instilled into stomach and removed via gravity or suction
31
what gastric decontamination is indicated for:
* ingestion of chemicals poorly adsorbed to charcoal (lithium, iron, lead)
* ingestion of drug-filled packets
Whole bowel irrigation
32
how to perform Whole bowel irrigation?
Instil a electrolyte polyethylene glycol soln (**GoLYTELY**) to flush out entire intestinal tract
* via NG tube, 1–2 L/h (400–500 mL/min in children)
* Continue until rectal effluent is clear (3–5< hr)
33
CI of whole bowel irrigation
absent bowel sounds or suspected ileus or obstruction
34
indications, CI, and caution of multi-dose activated charcoal?
* carbamazepine, dapsone, phenobarbital, quinine, and theophylline
* unprotected airway, absent BS
* ingestions resulting in reduced GI motility
35
what method of enchanced elimination ionizes acidotic toxins preventing resorption back across the renal tubule
Urinary alkalinization
36
indications and caution for Urinary alkalinization
* moderate-severe salicylate toxicity
* hypokalemia will reduce the alkalinity of the urine
37
how to perform urinary alkalinization?
1. Give **IV NaHCO3 +/- KCl**
1. monitor serum K and HCO3 q 2-4 h
- **Serum K goal 4-4.5** mEq/L range
1. assess urine pH q 15-30 min
- **pH goal 7.5-8.5**
38
which type of Extracorporeal removal is more effective at clearing **highly protein-bound drugs and lipid-soluble drugs**?
hemodialysis
39
when to use hemoperfusion as a choice for enhanced elimination?
for clearing **water-soluble low molecular wt substances**
40
4 indications for antidotes?
1. exposure to toxin where a antidote exists
1. severity of toxicity warrants use
1. benefits outweigh its associated risk
1. no CIs
41
MOAs of antidotes?
1. Prevent absorption
1. Bind and neutralize poisons directly
1. Antagonize end-organ effects
1. Inhibit conversion to more toxic metabolites
42
how to decontaminate for Inhaled Poisons?
1. Give O2
1. Water aerosol inhalation - dilute irritants in nasopharynx
1. Be alert for delayed upper airway obstruction or pulmonary edema
43
how to decontaminate/tx contaminated eyes?
* Irrigate eyes w/ plain water or NS ASAP
* Assess pH of eye after _2 L of irrigated fluid_
44
how to manage contaminated skin?
* avoid direct secondary self-exposure
* Wash immediately with water and dilute soap solution
* Discard contaminated clothes in a marked plastic bag
45
how can US Poison Control be helpful?
1. Obtain info on unknown pills or chemicals found
1. immediate assistance in selecting labs
1. Recommend preferred methods of decontamination, patient-specific care recommendations, or use of antidotes
1. Advise on pt disposition
46
criteria for a poisoned pt that can be discharged?
Asx pts with non-toxic exposures after observation, access to further consultation and a safe DC destination
47
3 questions must be addressed to determine a non-toxic exposure
1. Was exposure unintentional and a clearly identified single substance?
1. How much of agent was ingested or amount of exposure?
1. Can Poison Control Center (or other source) confirm substance as nontoxic in reported dose?
48
mainstay for poisoned pt?
supportive
| “Treat the patient, not the poison”
49
supportive care for poisoned pt?
1. Airway protection, Temp control
1. HoTN: isotonic saline; +vasopressors if unresponsive
1. HTN
- agitated - BZD
- risk of end-organ damage - CCB, phentolamine, labetalol or nitroprusside
1. arrhythmia: correct hypoxia, acid-base, and give antidote; NaHCO3 if wide QRS
2. naloxone (IV, IM, nasal): diagnostic and therapeutic
50
avoid what med in sympathomimetic toxicity d/t unopposed a-adrenergic stimulation causing vasoconstriction when controlling HTN in poisoned pt?
B-blockers
51
Temps indicative of hyperthermia and hypothermia?
* core temp >39°C (>102.2°F)
* core temp < 32°C (<90°F)
52
if aggressive cooling is ineffective for treating hyperthermia, what is the next step?
drug induced coma
*Drug-induced coma can lead to _hypothermia_*
53
complications of hyperthermia?
1. rhabdo
1. end-organ failure
1. DIC
54
how to calc anion gap?
normal value?
* Na - (Cl + HCO3)
* <10-15 mEq/L
55
caues of metabolic acidosis
| anion gap, mneumonic
* C - cyanide, CO
* A - alcoholic ketoacidosis
* T - toluene
* M - methanol, metformin
* U - uremia
* D - DKA
* P - propylene glycol
* I - inborn errors, iron, isoniazid, infection
* L - lactic acid
* E - ethanol, ethylene glycol
* S - salicylates, starvation ketoacidosis
56
mgmt of anion gap metabolic acidosis
1. **Address any lack of rsp compensation first**
1. **Address lyte abnormalities**
1. **Tx underlying cause**
1. Severe (pH < 7, hemodynamic instability): **NaHCO3** 0.5 mEq/L/kg
- raise pH to 7.1
- _No EMB of benefit_
57
7 Basic Toxidromes?
1. Opioid
1. Sympathomimetic
1. Cholinergic
1. Anticholinergic
1. Sedative/hypnotic
1. Serotonin Syndrome
1. Hallucinogenic
58
s/s of narcotic toxidome?
mgmt?
| mneumonic
CPR-3H
* coma
* pinpoint pupils
* rsp depression
* HoTN
* hypothermia
* hyporeflexia
**Naloxone 0.04mg**, titrate up if needed, rsp support
59
MOA of Sympathomimetics?
Examples?
mimic effects of endogenous agonists of the sympathetic nervous system (epinephrine, norepinephrine, dopamine)
Cocaine, Caffeine, Amphetamines, Cathinones (“bath salts”)
60
* s/s of Sympathomimetics?
* mgmt?
Sy**M**p**ATH**omimetic: *physiologic excitation*
* Mydriasis, muscle cell death
* agitation, arrhythmia, angina
* tachycardia
* HTN, hyperthermia, hyperactive BS
* seizures, sweating
Cooling, IV fluids, BZD if agitated/HTN/seizure
61
CI med for sympathomimetic toxidrome?
BB
62
MOA of cholingerics?
examples?
* **blocks acetylcholinesterase** = **inc acetylcholine**; Affects muscarinic and nicotinic receptors
* Organophosphate insecticides, Carbamate insecticides
63
s/s of cholinergic toxidrome?
*Crying all over, DUMBELLS*
* MC - Salivation, lacrimation, diaphoresis, bronchorrhea, inc urination and defecation, N/V, muscle fasciculations, weakness
* Additional: Bradycardia, rales, seizures, miosis/mydriasis, rsp failure, paralysis
64
mgmt for cholinergic toxidromes
1. Airway protection and ventilation
1. **Atropine** - blocks Ach receptors at muscarinic receptors
1. **Pralidoxime** + _atropine_ - reactivate cholinesterase at both muscarinic and nicotine receptors.
1. **Diazepam** - seizure, muscle fasciculation
65
MOA of anticholinergics?
examples?
**block acetylcholine muscarinic receptors** = inhibits PS nerve impulses
* Scopolamine
* Atropine
* Antihistamines
* TCA’s
* Antiparkinson agents
* Antispasmodics/Muscle relaxants
66
s/s of anticholinergic toxidrome
* hyperthermia, tachycardia, dry af, AMS, urinary retnetion, mydriasis, flushed/dry skin
* seizures, dec/absent BS, dysarhythmia, rhabdo, changes in BP
67
how is the presentation of antichoinergic toxidrome different from sympathomimetic?
dry skin and dec BS
68
mgmt for anticholinergic toxidrome?
1. _Activated charcoal_ to dec drug absorption - *if applicable*
1. **Tx complications**
- Wide QRS - NaHCO3
- Agitation - BZD’s
- rhabdo - Fluids
- Hyperthermia - external cooling
1. **Physostigmine** - antidote
- cholinesterase inhibitor increases concentration of Ach at cholinergic receptor
- _indicated if conventional tx fail_
69
disposition of anticholinergic toxidrome
* **DC** if _resolve after 6 hrs observation_
* **Admit** if _more significant sx_ or receiving _physostigmine_
70
3 classes of sedatives/hypnotics
1. BZD
1. Non-BZD’s: carisoprodol, alc, hypnotics
1. Barbiturates
71
s/s of sedative/hypnotic toxidrome
*physiologic depression*
* MC - slurred speech , lethargy, CNS depression, rsp depression, confusion
* Additional: Bradycardia, HoTN, hypothermia, bradypnea, hyporeflexia
72
mgmt for Sedative/hypnotic toxidrome
1. _Supp_: vent/intubate, 2 large bore IVs; bolus for HoTN; Dop/NOR if bolus fails
1. AC: *if applicable*
1. _Barbiturates unresponsive to tx_ - enhanced excretion methods
1. _BZD_: flumazenil
- _ONLY IF_ confirmed **OD w/ rsp depression**
73
T/F: flumazenil is not used empirically for BZD ODs
T - can precipitate seizures
74
disposition for sedative/hypnotic toxidrome
* Admit if symptomatic after 6 hrs of management
* Consult psych for intentional OD
75
MOA of serotonin syndrome?
examples?
* increased serotonergic activity in CNS
* MAOI’s, SSRI’s, meperidine (Demerol), dextromethorphan, TCA’s, L-tryptophan
76
s/s of serotonin syndrome
**H** : **hyperthermia**, HTN
**A** : AMS, agitation
**T** : tremor, tone (inc muscle tone), tachycardia, tachypnea
**S** : seizures
| hyperthermia MCC of death
77
mgmt for serotonin syndrome
1. Vent support as needed
1. External cooling
1. BZD for agitation, tremors, seizures
- If failed: _cyproheptadine_
1. DC serotonergic drug
2. **admit all**
78
examples of hallucinogenics?
s/s?
mgmt?
1. LSD, PCP, shrooms (psilocybin), ecstasy, dextromethorphan, ketamine
2. physiologic excitation
3. Symptomatic tx
- Refractory sx - medically induced coma
- refractory HTN - Nitroprusside or phentolamine
Admit if persistent sx after adequate tx
79
Persons at increased risk for APAP toxicity
* chronic alcohol use
* AIDS
* anticonvulsant
* anti-TB therapy
80
A toxic exposure to acetaminophen in pt **>6 y/o** is suggested when…
* >10g or 200 mg/kg as single ingestion or over 24 hr
* >6g or 150 mg/kg per day for at least 2 consecutive days
81
A toxic exposure to acetaminophen in pt **< 6 y/o** is suggested when…
* >200 mg/kg as single ingestion or over an 8 h period
* 150 mg/kg per day for at least 2 consecutive days
82
stages of APAP toxicity
1. **Stage 1 (day 1 after ingestion)**: anorexia, N/V, and malaise; hypokalemia
1. **Stage 2 (days 2-3)**
1. improved 1st sx, RUQ pain; inc transaminases, bilirubin, PT
1. **Stage 3 (days 3-4)**: liver failure, met acidosis, coagulopathy, renal failure, encephalopathy, pancreatitis and recurrent GI sx
1. **Stage 4 (day >5)** - 2 outcomes
- survives - improvement and recovery
- continued deterioration to multi-organ failure and death
83
w/u for APAP toxicity
1. **_serum APAP_**
- **assessed even in asx**: delay in sx
- peak: 30-120 min after acute ingestion
- _Rumack-Matthew nomogram_: determines clinical outcomes, **_only after_ acute ingestion 4-24 hrs** post ingestion
84
mgmt for APAP toxicity
1. AC (if applicable)
1. **Acetylcysteine**
1. +/- Extra-corporal excretion
- If _severe intoxication who present too late_ and have _hepatic encephalopathy_
Admit if needed acetylcysteine
DC after 4-6 h observation and no acetylcysteine
85
MOA of Acetylcysteine
prevents metabolite from binding to hepatic cells (if given < 8 hr) and diminishes hepatic necrosis
86
s/s of ETOH toxicity
* ataxia, slurred speech, depressed sensorium, and nystagmus
* vasodilation = orthostatics and hypothermia
* hypoglycemia
complications: trauma, rsp depression, pulmonary aspiration, coma
87
w/u for ETOH toxicity
* BAC - if unknown ingestion
* Glucose level
* Tox or co-ingestant screening
* Labs to assess other organs
88
mgmt for ETOH toxicity
1. Supportives and observation
1. **IV dextrose** for hypoglycemia
1. **IV thiamine** if concerned about _chronic alc use_ and _Wernicke's encephalopathy_
1. Address other s/s: hypovolemia, hypothermia, trauma, rsp distress
- uncomplicated - observe until sober; no suicidal/homicidal ideations - d/c home
- Admit if have assoc dx that need admission
89
* de-icers and antifreeze
* colorless, odorless and sweet tasting
* metabolized in liver by alcohol dehydrogenase toxic metabolites (glycolic acid → oxalic acid) = met. acidosis and end-organ damage
what is this?
Ethylene Glycol
90
s/s of ethylene glycol toxicity
* Progressive sx
* 1 hr - CNS depression
* 12 hrs - HF, pulmonary edema
* 24–72 hrs - renal tubule necrosis, flank pain, hematuria, and renal failure
91
w/u and findings for ethylene glycol
1. **ABG - wide AG met acidosis**
- may show 12-16 hrs after ingestion
2. **UA - fluoresce under Wood’s lamp; Ca oxalate crystals**
1. **Ethanol lvl**
1. CMP
2. **serum osmolality gap >50**
- *Measure (serum) Osm - Calculated osm = Osmolar Gap*
- Nml: -14 to +10
92
mgmt for ethylene glycol toxicity
1. ABC
1. IV NaHCO3 *only if pH < 7.2*
1. Metabolic Blockade: **fomepizole IV**; _ethanol_ PO/IV (alt)
1. +/- Hemodialysis
1. Adjunctive **Vit B** - no solid EBM
1. **Admit all EG ingestion**
- If uncertain - observe x 6 h
- DC if negative ethanol, asx, no osmolar gap or met acidosis
93
MOA of fomepizole
* **Inhibits alcohol dehydrogenase**
* an enzyme which catalyzes metabolism of ethanol and ethylene glycol to their toxic metabolites
* The slowed elimination of EG results in renal excretion
94
indications for hemodialysis for EG toxicity
severe acidosis, visual changes, hemodynamic instability, or renal failure
95
Meds that contain salicylate
ASA, combo pills with ASA, Pepto Bismol, liniments, flavoring agents
96
salicylate toxicity is at risk for ____ formation due to salicylate impairing gastric emptying
bezoar
97
presentation of salicylate toxicity
1. _chronic_ - mistaken for **"infection"** (F, hyperventilation, AMS w/ volume depletion, acidosis, hypokalemia)
1. _acute - dose dependent_
- _< 150_: tinnitus, hearing loss, dizziness, N/V
- _150–300_: tachypnea, hyperpyrexia, diaphoresis, ataxia, anxiety
- _>300_: AMS, seizure, heart/lung/renal failure, shock
98
w/u for salicylate toxicity
1. **salicylate lvl: > 30 mg/dL is toxic**
- peak in acute may not occur for 4-6 hrs: _repeat q 1-2 h until peak, then q 4-6 h_
2. CMP + Mg; ABG
- Early: rsp alkalosis
- Later: met acidosis
3. coingestants - APAP, tox screen
4. CXR and EKG
5. if bezore suspected: X-ray, US, CT or endoscopy
- Suspect if salicylate lvl keeps inc despite tx w/ lavage or AC
99
mgmt for Salicylate Toxicity
1. ABC’s
2. Correct volume depletion and metabolic derangements (hypokalemia)
3. GI decontamination - single dose **AC**
4. Reduce salicylate burden
- **Systemic/urinary alkalinization w/ NaHCO3** - _1st line for **mod-severe** toxicity_
- _Hemodialysis_ - if unresponsive severe tox or evidence of renal impairment
100
what are Bezoar formations
conglomerates of meds or med vehicles that get stuck in GI tract
