Environ/Toxic/Integ Flashcards
What does the activated charcoal formulation “Actidose-Aqua” have in it and how does that affect bloodwork findings?
Propylene glycol and glycerol
Mean serum osmolality, osmolal gap and lactate concentration were significantly increased after suspension administration, increasing at 1 hour, peaking at 4 hours and returning to baseline at 24 hours.
Dose of naloxone
0.01-0.04 mg/kg IV IM or SC
Dose of flumazenil and what toxicity can it be used for?
0.01-0.02 mg/kg IV
sleep aid toxicosis
What can be used to reverse amitraz collars and imidazole decongestants ?
These toxins have alpha agonist activity so can be reversed with alpha antagonists such as yohimbine (0.1mg/kg IV) or atipamezole (50 mcg/kg IV or IM)
Reported SE of intralipid
Fat embolism Fat overload syndrome Pancreatitis worsening of ARDS coagulopathy
What complications can occur if charcoal filter is used without HD ?
hypocalcemia, hypoglycemia, thrombocytopenia
Two pathways for acetaminophen metabolisM/
conjugation with sulfate and glucuronide (90% of ingested dose)
cytochrome-p450- 5%
At what dose of acetominophen are toxic signs seen in dogs vs. cats
100 mg/kg dogs
10 mg/kg cats
What effect does pH have on volume of distribution of salicylate?
Decrease in blood pH increases the VD as drug diffuses out of intravascular space.
What effects do COX1 vs. COX2 have on coagulation
COX2 produces prostacyclin (PGI2) from epithelial cells that inhibits platelet aggregation and causes vasodilation
COX1 mediates production of TXA2 from platelets, which increases platelet aggregation and causes vasoconstriction.
what drugs can have an increased bioavailability and thus potentially increased toxicity when giving NSAIDs
other anti-inflammatories warfarin phenytoin penicillins sulfonamide abx digoxin
will DECREASE lasix
what dose of ibuprofen is associated with GI signs? kidney dz? death?
100 mg/kg - GI
kid fail- 175 mg/kg
600 mg/kg- acute death
toxic dose of aspirin? single dose? daily dose x 2 days?
single dose 400 mg/kg
75 mg/kg x 2 days
cats 25-100 mg/kg/day - GI ulcers
what dose of naproxen is associated with adverse events?
5-10 mg/kg
what dose of meloxicam has been shown to cause GI upset? RF?
GI- 0.15-0.2 mg/kg/day x 3 days
RF- 0.6-1 mg/kg/day x 3 days
Arrange the following NSAIDS in order of increasing elimination half life in dogs: aspirin carprofen deracoxib firocoxib ibuprofen meloxicam naproxen
deracoxib- 3 hours ibuprofen -5 hours Firocoxib- 6 hours Aspirin 7.5 hours Carprofen 11-14 hours Meloxicam 24 hours Naproxen 74 hours
Arrange the following NSAIDS in order of increasing elimination half life in cats: aspirin carprofen deracoxib firocoxib meloxicam
deracoxib 8 hours firocoxib 12 hours meloxicam 15-26 hours carprofen 21 hours aspirin 37.5 hours
MOA acepromazine
Blocks postsynaptic dopamine and alpha1-adrenergic receptors
Is baclofen enterohepatically recirculated?
no
What is the cellular effect of opioid receptor activation?
inhibition of adenyl cyclase activity, activation of receptor-operated potassium currents, suppression of voltage-gated ca currents.
These effects cause hyper polarization of the cell membrane, decreased NT release and reduced pain transmission
what are the effects of the mu opiate receptor?
analgesia resp depression euphoria bradycardia constipation vomiting physical dependence temperature change (hypothermia dogs, hyperthermia in cats)
what are the effects of the delta opioid receptor?
analgesia
what are the effects of the sigma opioid receptor?
autonomic stimulation
dysphoria
hallucinations
what are the effects of the kappa opioid receptor
analgesia, sedation
What are the effects of the epsilon opioid receptor
analgesia
What is the primary mechanism of opioid metabolism?
glucuronidation
What drugs will opioids interact with that may potentiate their effects?
MAOIs- potentiate morphine. May potentiate serotonin syndrome with some opioids and MAOIs.
phenothiazines and erythromycin potentiate opioids
cimetidine prolongs duration of action
what opioids have SSRI effects?
fentanyl, meperidine, methadone, tramadol, dextromethorphan
Why is morphine not used in people with biliary or pancreatic dz?
causes spasms of the sphincter of Oddi
What is the cellular mechanism of beta2 agonist induced hypokalemia?
Agonist binding of b2 receptor stimulates formation of cyclic AMP which acts through protein kinase A to phosphorylate and activate N/K/ATPase pump, leading to influx of potassium into cells.
What are CCB effects on insulin?
inhibit insulin secretion.
what are beta blocker effects on glucose balance?
impairs lipolysis, glycogenolysis, and insulin release.
What effect does LOW insulin have on the heart?
prevents uptake of glucose by myocytes- decreasing inotropy
Describe signalling pathway when epinephrine binds its beta receptor
Epi binds and stimulates beta receptors which are a G-protein coupled receptor. This activates adenylate cyclase, which catalyzes the conversion of ATP to cAMP. cAMP activates protein kinase A, which stimulates the opening of Ca channels in the sarcoplasmic reticulum, increasing intracellular ca which can then bind and cause muscle contraction via actin and myosin.
What is the mechanism of MAOI, amphetamines, TCA and SSRIS?
MAOI- inhibits mAO which is responsible for the breakdown of serotonin in the brain.
Amphetamines increase serotonin release
TCA- block reuptake of serotonin
SSRIs- block reuptake of serotonin.
Where is most of the serotonin in the body synthesized and stored?
enterochromaffin cells and myenteric plexus in the GIT.
Effects of serotonin in the peripheral nervous system?
vasoconstriction, platelet aggregation, uterine contraction, intestinal peristalsis, bronchoconstriction
Clinical signs of serotonin syndrome
Neuromuscular: hyperreflexia, inducible clonus, peripheral hypertonicity, shivering
Autonomic: tachycardia, mydriasis, diaphoresis, increased borborygmi, diarrhea
mental: agitation, delirium
Occasional: cardiac arrhythmias, DIC, resp compromise, rhabdomyolysis
What were most common signs of ingestion of TCA in 456 companion animals reported to APCC?
Hyperexcitability and vomiting **
Then - ataxia, lethargy, tremors.
Brady cardia seen late.
Death in 7% of those showing adverse signs
Does diuresis help enhance elimination of serotonergic medications?
no bc highly protein bound
With serotonin syndrome, what is mechanism of hyperthermia?
excessive muscle activity - fever reducers not indicated and should actively cool.
What medications can be used with serontin syndrome?
chlorpromazine- 5-HT2 receptor antagonist - SE- sedation and hypotension
Cyproheptadine- 5HT1a and 5HT2 receptor antagonist.- more effective than chlorpromazine
What medications increase serotonin-release?
amphetamines, ecstasy, cocaine
What medications can stimulate the serotonin receptors?
LSD, lithium, buspirone, sumatriptan
What are examples of SSRIs?
fluoxetine, citalopram, paroxetine, sertraline, venlafaxine, tramadol, fentanyl, pethidine, methadone, meperidine, dexxtromethorphan
What are examples of TCA?
Amitriptyline, clomipramine, dose-in, imipramine, mirtazipine, trazodone
what is the half life of factor 7?
6 hours
In a retrospective study evaluating PT prolongation in 151 dogs receiving GI decontamination within 6 hours of anticoagulant rodenticide ingestion _____% required VitK1 therapy and ___ had adverse events develop during time period between ingestion and starting Vit K
8.3%
none
List 5 medications that increase renal calcium excretion
lasix steroids calcitonin bisphosphonates saline
What SE is of concern when using calcitonin?
anaphylaxis (salmon origin)
What is LD 50 of bromethalin in dogs?
4.7 mg/kg dogs, 1.8 mg/kg cats = LD50
causes severe muscle tremors, hyperthermia, extreme hyper excitability, focal or generalized seizures within 24 hours.
Lower doses manifest c/s in 1-3 days- hind limb ataxia, paresis or paralysis, CNS Depression
What histopathologic changes are seen with bromethalin?
diffuse white matter vacuolation (spongy degeneration) with microgliosis.
What is MOA of strychnine?
prevents uptake of glycine at inhibitory synapses of Renshaw cells in CNS.
i.e., inhibits the inhibitory pathway…aka “disinhibition” ..results in a net excitatory effect.
what clinical signs are associated with zinc phosphide intoxication and what increases toxicity?
ingestion of food increases toxicity (increases acidity of stomach which increases hydrolysis)
Gi signs most common, also neuro signs, resp distress and cardiovascular compromise.
Def- 1st degree burn
superficial- epidermis only
Def- 2nd degree burn
Epidermis and dermis- may be varying degrees of dermis.
Def- 3rd degree burn
Full thickness- entire epidermis and dermis. Skin will appear black, leathery; eschar is present.
Def 4th degree burn
Full thickness with extension to muscle, tendons and bone
Describe how to estimate total body surface area in burn victims
"rule of 9s" head and neck - 9% each forelimb- 9% Each rearlimb- 18% Dorsal trunk-18% Ventral trunk- 18%
What % of TBSA burned indicates poor prognosis?
At what % can hypovolemic shock occur?
50%
20%
What is ideal syringe size and needle gauge to generate ____psi of pressure during lavage?
35 cc syringe, 19 guage needle = 8 psi
Effects of aloe vera?
Antithromboxane effects that prevent vasoconstriction and thromboembolic seeding of the dermal vasculature.
In patients that recover from CO poisoning, what residual deficits might they have?
hearing loss w/ no permanent effects.
permanent CNS abnormalities.
What is half life of CO at room air and at FiO2 100%?
250 minutes
26-148 minutes
What medications can be used in CN toxicity and what should be used specifically in smoke inhalation patients?
Sodium nitrite and sodium thiosulfate.
Sodium nitrite can cause methemoglobin and therefore should not be used in smoke inhalation.
What is prognosis for smoke inhalation?
In ppl- <10% if no dermal burn and 25-65% with dermal burn.
Dogs- 8/27 died or were euthanized in one study and 1/27 died in another study.
Smoke exposed dogs w/ neuro signs mortality of 46%
What are classifications of hypothermia based on temp and clinical signs?
Mild- 32-37 (90-98) shivering ataxia, vasoconstriction
Mod- 28-32 (82-90) decreased level of consciousness, hypotension, +/- shivering
Severe- < 82- complete loss of shivering, dysrhythmias, profound CNS deficits.
Main temperature sensors in the body?
prepotic and anterior hypothalamic nuclei.
What is often the initial dsyrhythmia with severe hypothermia?
a fib.
progresses to vtach and vfib
At temperatures below ____C, sensitivity to partial pressure of CO2 decreases, and CO2 production decreases by ___% with a ____C fall in body temperature.
At temperatures below 34 (93.2 F), sensitivity to partial pressure of CO2 decreases, and CO2 production decreases by 50% with an 8 C fall in body temperature.
For each 1 degree C drop in core body temperature, cerebral blood flow decreases ____%
6-10%
Solubility of CO2 is increased/ decreased in cooled blood.
increased -> increased CO2 content -> acidosis
Mech of thrombocytopathia with hypothermia
Decreased platelet aggregation secondary to decreased thromboxane B2
Decreased platelet granule secretion
Attenuation of P selection expression
Diminished expression of VWF receptor
Hct decreases/increases by ___% for every 1 degree C decline in temperature?
increases by 2% for every 1 degree decline in temp.
mech of hyperglycemia in hypothermic patients?
renal dysfunction; decreased insulin sensitivity, reduced insulin secretion.
What is rewarming shock
When surface re-warming causes peripheral vasodilation leading to relative hypovolemia
Define heat stroke
Hyperthermia associated with a systemic inflammatory response leading to a syndrome of MODS in which encephalopathy predominates.
What adaptations occur in humans to the heat and how long does it take to acclimatize?
2 weeks
Enhanced cardiac performance, salt conservation by kidney and sweat glands via activation of RAAS, increased capacity to sweat, plasma volume expansion, increased GFR, and increased ability to resist exertion rhabdomyolysis.
NRBC of ___ or more/ 100 leukocytes had high sensitivity and specificity of death in heat stroke?
18 or more- 91% sensitivity and 88% specificity
Do alternating or direct currents cause more injury?
Alternating.
What type of electric current typically causes muscular tetany
Alternating, not direct.
Theory that smaller or larger dogs are more susceptible to lightning injury?
dogs or people more susceptible?
Larger dogs are more susceptible and dogs more susceptible than people.
The retrospective study on drowning in vet med, what was the mortality rate?
36%
Most (85%) of submersion victims that survive are thought to have aspirated less than ___mL/kg water
22 mL/kg
Most common cause of hypoxemia in drowning victim
intrapulmonary shunt (no ventilation areas - aspirated water, bronchospasm, atelectasis (surfactant washout), pneumonitis, ARDS)
What is the dive reflex
When the face touches cold water (<41 F, <5 C), a reflex (mediated by trigeminal nerve) causes bradycardia, hypertension, and preferential shunting of blood to cerebral and coronary circulation.
Does cold/warm water or salt/fresh water have an effect on survival of drowning victim?
only cold water = better
What is recommended if epinephrine doesn’t work for anaphylaxis and what is MOA?
glucagon.
Inotropic, chronaotropic and vasoactive effects independent of beta receptors and causes endogenous catecholamine release.
50% of dogs with influx of air at ___mL/kg/min infused will overwhelm lung filter of air emboli.
0.35 mL/kg/min .
Pigs have tolerated a single bolus of 2 mL/kg, but dogs have more toleration to gas than pigs.
What inflation pressure is it recommended to stay under to reduce risk of air embolism?
15 mmHg
what toxin is in black widow venom
alpha-latrotoxin
mechanism of scorpion venom
blocks voltage-gated potassium and sodium channels in nervous tissue.
Lethal dose of ethylene glycol
- 4-6.6 mL/kg dogs
1. 5 mL/kg cats
Food increases/decreases EG absorption
decreases
Which EG metabolite is considered major mediator of toxicity and why
glyoxylic acid
long half life
Osmolal gap after ingestion of EG increases ___hours after ingestion, peaks at ___ hours, and remains elevated for ___ hours after ingestion.
Osmolal gap after ingestion of EG increases 1 hour after ingestion, peaks at 6 hours, and remains elevated for 18 hours after ingestion.
When does high anion gap metabolic acidosis develop after ingestion of EG? peak? lasts for __?
Develops within 3 hours of ingestion, peaks at 6 hours, lasts for 48 hours.
__% of intoxicated dogs w/ EG have ionized hypocalcemia
> 50%
Calcium oxalate crystalluria seen in ___hours of EG ingestion in cats and within ____ hours in dogs
3 hours in cats
4-6 hours in dogs
How long will urine fluroesce with woods lamp post ingestion of EG?
up to 6 hours.
Dose of chocolate causing GI vs. cardiac vs. seizures?
20 mg/kg GI
40 mg/kg cardiac
60 mg/kg seizures
Symptoms of macadamia nut toxicity?
weakness, vomiting, poss pancreatitis
Which lilies are and aren’t toxic to cats?
Lilium or Hemerocallis species toxic
Benign lilies include the Peace, Peruvian, and Calla lilies (do contain oxalates so may cause GI irritation)
Treatments for cyanide toxicity
Sodium thisulfate- converts cyanide to thiocyanate
Hydroxycobalabim- binds cyanide and excretes in kidneys
Sodium nitrite- only for severe cases- forms methemoglobin and then cyanomethemoglobin (potent vasodilator).
What binds lead?
Ca EDTA
Succimer
Penicillamine
Antidote for OP poisoning?
2-PAM
mech of botulism?
Binds pre-synaptic membrane of NM synapse, preventing Ach vesicles from fusing with membrane -> prevents release of Ach- > flaccid paralysis
