Physical Med 2 Flashcards
Radiation
Acute Effects
Localized damage – to an exposed body part
Acute Radiation Syndrome – large dose to body
Bone marrow syndrome– infection, hemorrhage.
Gastrointestinal (GI) syndrome – GI tract & bone marrow damage infection, dehydration, & electrolyte imbalance – death w/in 2 weeks.
Cardiovascular (CV)/ Central Nervous System (CNS) syndrome – collapse of the circulatory system, intracranial edema / hemorrhage / infection – death w/in 3 days
Radiation – Acute Effects
Tx
WHO & CDC websites on treatment of acute illness
National Nuclear Security Administration – 24h expert consult line
Decontamination if needed
Monitoring & supportive care
Radiation – Delayed Effects
general
Occupational exposure
Radiation therapy
Medical imaging
Carcinogenesis – worse for prenatal & pediatric exposure; type / dose / duration of radiation also play a factor
Poisoning and overdose
Poisoning – exposure to a chemical that causes a negative effect
Overdose – a subcategory of poisoning – the chemical in this case is a medication or drug
Usually from ingestion – also from inhalation, skin / mucous membrane exposure, injection
Non-toxic ingestion
– exposure to
a known chemical
with no known exposure hazards
that happened accidentally
that resulted in no symptoms
OSMOLAR GAP
“MAD GAS”
M-Mannitol- diluent for drugs, kid laxative
A-Alcohols
D-DMSO degreaser, paint thinner, anifreeze
G-Glycerol sweetener
A-Acetone
S-Sorbitol sweetener for DM, cosmetics, pharma
Nl osmolar gap < 10 mOsm/L
Osm gap = Osm measured – Osm calculated
Measured = Lab determination
Calculated = 2(Na) + BUN/2.8 + Glucose/18
Resuscitation Concepts
Antidotes are rarely needed in the early management
Evaluation and stabilization of the ABCs should always come first
The prime exception would be cyanide poisoning where 100% O2, amyl nitrite inhaler, IV sodium nitrite and sodium thiosulfate are administered immediately
Decontamination
Charcoal
Activated charcoal
- owing to its large surface area, AC can absorb many drugs
- does not bind with lead, lithium, iron, or potassium but may be indicated for coingestions
- poorly binds with alcohols and cyanide
Multi-dose AC may enhance systemic elimination of some drugs
- Carbamazepine, dapsone, theophylline
Activated charcoal contraindications
Do not give in suspected esophageal or peptic ulcer perforation
Multi dose activated charcoal
One dose is usually effective
Some circumstances require multiple doses
Charcoal indications
Multi dose activated charcoal
Indications:
Ingestion of very large doses
Substances that form bezoars
Substances that slow gut function
After initial dose of 1gm/kg:
0.25-0.5 gm/kg q 1-4 hours
Cathartics and contraindications
Shown to decrease the transit time for the passage of the charcoal and subsequent adsorbed toxin
Should not be used for:
- children under 5
- substances known to cause diarrhea
- intestinal obstruction
- ingestion of a caustic material
“Coma cocktail”
D-dextrose
O-oxygen
N-narcan
T-thiamine (or: “thioglucan”)
“Don’t forget don’t”
- Abnormalities in breathing are not usually the direct effect of a toxin, but rather a result of the patient’s altered level of consciousness
Resuscitation Concepts
Glucose
50ml of D50 IV in adults
1gm/kg in children
Narcan
0.1-2.0mg IV
Competitive opioid antagonist
Consider restraints prior to admin
(may precipitate an acute withdrawal syndrome)
Thiamine
100mg IV
Indicated if you think there is a history of EtOH/malnutrition
Toxidrome
general
A toxic “fingerprint”
Physiologically based abnormalities that are known for many substances and typically helpful in establishing a diagnosis when the exposure is not well defined
ToxidromesThe term toxidrome refers to the collection of signs andsymptoms that are observed after an exposure to a substance(a toxic “fingerprint”). Toxidromes include grouped,physiologically based abnormalities of vital signs, generalappearance, skin, eyes, mucous membranes, lungs, heart,abdomen, and neurologic examination that are known for manysubstances and typically helpful in establishing a diagnosis whenthe exposure is not well defined (Table 151-2). Similarly, certainclinical findings may narrow the etiologic possibilities (Table 151-3).
Anticholinergic toxicity
general
Results from medications or plant metabolites that block the binding of acetylcholine to muscarinic receptors
TCAs, phenothiazines, antihistamines, antiparkinsonian, scopolamine, atropine, Jimsonweed, etc
Anticholinergics“Alice in Wonderland” (5)
“Mad as a hatter”
- auditory/verbal hallucinations
- confusion, severe agitation
“Blind as a bat”
- mydriasis (dilation of eye)
“Red as a beet”
- flushed skin from vasodilatation
“Dry as a bone”
- dry skin and mucous membranes
“Hot as a hare”
- hyperthermia
TOXIDROMES suspicions for anticholinergic
Always suspect anticholinergic toxicity in patients who present with unexplainable mental status changes
Antihistamine overdose (particularly diphenhydramine) is the most common presentation
In young children, “just a few pills” with anticholinergic properties, such as orphenadrine (Norflex), can cause significant toxicity
toxidromes
concerns in elderly
- Use of multiple medications with anticholinergic properties
- Toxicity may manifest itself as new-onset delirium
TOXIDROMES
Tx for severe anticholinergic syndrome
Supportive care for anticholinergic syndrome – may include cooling & sedation
Physostigmine for severe anticholinergic syndrome (agitated delirium) – avoid if long QT on EKG d/t risk of bradyarrhythmias
Sympathomimetics
examples
amphetamine(Evekeo)
cathinone(found inCatha edulis, khat)
cocaine(found inErythroxylum coca, coca)
ephedrine(found inEphedra)
lisdexamfetamine(Vyvanse)
MDMA(Ecstasy, Molly)
methamphetamine(Meth, Crank, Desoxyn)
methylphenidate(Ritalin)
oxymetazoline(Afrin,Vicks Sinex)
pseudoephedrine (Sudafed)
hot and wet
Cholinergic agents
general
organophosphate insecticides, herbicides, rodenticides
- nerve agents (VX, sarin)
Inhibit the enzyme cholinesterase in the nervous system leading to an accumulation of the neurotransmitter acetylcholine in the CNS, autonomic nervous system, and neuromuscular junction
CHOLINERGIC “SLUDGE”
S-Salivation
L-Lacrimation
U-Urination
D-Defecation
G-Gastrointestinal (cramping)
E-Emesis
plus “KILLER BEES” (bronchospasm, bronchorrhea, bradycardia)
cholinergic syndrome
Tx
First give atropine to reverse excess acetylcholine; may require repeat doses
Then give pralidoxime (2-PAM-Cl) to reactivate cholinesterase
agitation
eye decontamination
Eyes
IMMEDIATE COPIOUS irrigation with NS
Very uncomfortable-2 man procedure
May require topical anesthetic in order to tolerate irrigation
End point is a tear pH of about 7.5-8.0
pH of NS is 5.6-so, allow several minutes for the pH to level out after irrigation
Hemoperfusion
Most commonly used for
Dialysis + a charcoal filter
Helpful for the toxin with a large molecular weight or if protein bound
Most commonly used in theophylline overdose
