Emergency Medicine Flashcards
(116 cards)
1
Q
Dx
- IgE-mediated, immediate onset reaction to protein antigen
- prior sensitizing exposure to antigen required
A
Anaphylaxis
2
Q
Dx
- occurs on initial exposure to antigen
- not IgE mediated but clinically identical to anaphylaxis
A
Anaphylactoid reaction
3
Q
When does biphasic anaphylactic reaction occur?
A
4-32h after initial episode
- due to release of secondary mediators, causing late-phase response
- > IL4, IL5, TNF-alpha
4
Q
What is protracted anaphylaxis?
A
- refractory resp distress or hypotension despite appropriate medical rx
5
Q
Type of hypersensitivity reaction
- immediate hypersensitivity - IgE mediated (e.g. urticaria)
A
Type I
6
Q
Type of hypersensitivity reaction
- cytotoxic reaction - IgM and IgG mediated (e.g. Goodpasture syndrome)
A
Type II
7
Q
Type of hypersensitivity reaction
- immune complex reaction - soluble immune complexes and complement mediated (e.g. serum sickness)
A
Type III
8
Q
Type of hypersensitivity reaction
- delayed-type reaction - lymphocyte mediated (e.g. contact sensitivity)
A
Type IV
9
Q
What cells degranulate in anaphylaxis?
A
Mast cells and basophils
- release of preformed primary mediators (histamines, proteases, eosinophil and neutrophil chemotactic factors, and heparin)
- due to membrane bound IgE on cells
10
Q
Common causes of urticaria?
A
- IgE mediated
- direct mast cell release
- complement mediated
- arachidonic acid metabolism
- physical (cold, sun, etc)
- mastocytosis
11
Q
Management of anaphylaxis?
A
ABCs
- d/c antigen exposure
- 2 large bore IV
- cardiac and O2 monitoring
EPI
- 0.3-0.5 mg IM adults
- 0.01 mg/kg IM kids (max dose 0.3mg)
- repeat 5-15min x1 if no response
- epi drip if no response and pt in extremis
0. 1mL of 1:1,000 epi diluted in 10cc NS at 1-2cc/min IV
methylprednisolone 1-2mg/kg IV (leukotriene production in delayed phase response)
diphenhydramine 1mg/kg IV (block H1 receptors)
ranitidine 1mg/kg IV (block H2 receptors)
- observe 6-8h
12
Q
Standard management in bites?
A
- irrigate!!!
- tetanus, rabies vaccine, prophylactic abx prn
- check FB in wound
13
Q
What do you administer to hypotensive pt not responding to bolus treated for anaphylaxis, if pt on b-blocker?
A
refractory hypotension = glucagon IV
14
Q
What us Skeeter syndrome?
A
- local immune reaction to mosquito bites
15
Q
What are mosquito vectors?
A
- malaria
- West Nile virus
- yellow fever
- dengue
- filariasis
16
Q
What are tick vectors?
A
- Rocky Mountain spotted fever
- Lyme disease
17
Q
What is potential pathogen in human bites that is resistant to Piperacillin and Ticarcillin?
A
- Eikenella corrodens
18
Q
Treatment for human/dog/cat bite with established infection or prophylaxis for high risk bite?
A
Amoxicillin/Clavulante or Doxycycline (kid>9 yr), Ceftriaxone
19
Q
Treatment mod-severe infection from human/dog/cat bite?
A
Ceftriaxone IM/IV +/- metronidazole
or Ticaricillin/clavulante or Pip-Tazo
if Pen allergy in adult
Ciprofloxacin +/- clindamycin
Pen allergy in kid
TMP/SMX +/- clindamycin
20
Q
3 distinct zones of tissue in full thickness burns?
A
- zone of coagulation - white, charred central portion, necrotic tissue
- zone of stasis - red, may blanch with pressure initially but fragile blood supply may give way to AVN
- zone of hyperaemia - red, blanches with pressure, intact blood supply
21
Q
Classification of burns
A
- thermal
- electric
- chemical
- radiation
22
Q
Sequelae of electric burns?
A
- cardiac arrhythmia
- MSK injury to muscle/ligament/bone (high resistance of tissues) - compartment syndrome +/- rhabdo
- renal ATN due to CK
- CNS LOC, paralysis, resp depression, amnesia
- eye cataracts and keraunoparalysis from lightening (fixed dilated pupils)
23
Q
Do you neutralize acid/alkali burns?
A
NO - exothermic reaction can worsen burn
-> irrigate with WATER
24
Q
Do alkali burns cause coagulation or liquefaction more commonly?
A
- Liquefaction
alkali dissolves protein and collagen (liquefaction) penetrating deeper than acid burns
25
What systems more commonly affected by radiation burns? Best prognostic factor?
GI and hematologic (rapidly dividing cells)
| - best prognostic indicator is absolute lymphocyte count within 48h of whole body exposure
26
How do you estimate TBSA?
Rule of 9s
- hand 1%
- head 9% (4.5% each front/back)
- trunk 18% front, 18% back
- arms 9% (4.5% front/back)
- legs 18% (9% front, 9% back)
- groin 1%
27
Indications of transfer to burn centre?
- partial thickness >10% BSA
- burns involving face, hands, feet, genetalia, perineum, major joints
- any third degree burn
- electrical (incl lightening) or chemical burns
- preexisting medical condition with potential impact on recovery
- concomitant trauma where burn = worst thing
- kids in hospital without peds
- special emotional/social/rehab required
28
Dx degree of burn
- red
- epidermis involved
- ++painful, tender to touch, intact 2 point discrim
- complete healing ins several days
Superficial (first degree)
29
Dx degree of burn
- red/blanched white, fluid-filled blisters
- epidermis, superficial (papillary) +/- deep (reticular) dermis involved
- ++ painful, tender to touch, 2 point discrimination intact or diminished
+/- scarring, may be hypertrophic with contractors across joints, healing 2wk
Superficial-Partial thickness (superficial second degree)
30
Dx degree of burn
- white and leathery or black and charred
- epidermis and both layers of dermis involved
- numb with loss of 2 point discrimination
- extensive time to heal (3-4wk) but may require wound excision and skin grafting
Deep partial thickness (deep second degree)
31
Dx degree of burn
- white and leathery or black and charred
- epidermis, dermis and subcutaneous tissues (fascia/ muscle/ bone) involved
- numb with loss of 2 point discrim
- extensive debridement, reconstruction of specialized tissues, skin grafting
Full thickness (third degree)
32
Management burns
- Td immunization prn
- neomycin/ polymyxin B or Bacitracin creams -> ensure good antimicrobial coverage without risk of allergic reaction and able to be removed easily to view wound bed
+/- blister debridement
Foley to monitor ins and outs
Analgesia
Fluids - Parkland formula
33
How do you decrease half life of CO-Hbg in blood?
100% O2
34
When do you use gastric tube for burn pt?
>20% BSA can develop ileus lasting 4-5d
| - increased metabolic rate requires nutritional support too
35
Parkland formula
fluid requirement = 4x body wt x % TBSA (partial and full thickness only)
- half in first 8h and the other half over next 16h
- electrical and full thickness require more fluids
- adjust based on urine output (adult = 0.5 mL/kg/h; child = 1mL/kg/h; infant = 2 mL/kg/h) and vitals
36
Investigations for burn pt?
- CBCD, lytes, BUN, Cr, glucose, INR, PTT, ABG with CO-Hgb, b-hCG
- ECG, CK-MB, trop, UA for urine Mgb
- type and screen if anticipate OR debridement
- CXR, CT head if altered LOC, bronchoscopy if serious inh injury
37
Key Q on facial injury pt?
- is your bite normal (malocclusion)
- any numbness (trigeminal nerve injury)
- seeing double (orbital #/ impaired EOMs)
38
Hyperthermia - is it pathologic or adaptive?
- hyperthermia is pathologic thermoregulatory failure
| - fever is adaptive, cytokine-mediate response
39
Define hyperthermia
- core body temp >38 not due to fever
- rise in body temp above hypothalamic set point when heat-dissipating mechanisms are impaired (drugs/ disease) or overwhelmed by extern or internal heat
40
Where are peripheral thermoreceptors?
Skin
41
Where are central thermoreceptors?
Anterior hypothalamus
42
Where is the central integrative area?
Posterior hypothalamus
43
Dx temp >37.5
- cramping of most worked muscle groups
- caused by replacement with isotonic fluid after ++ perspiration
Heat cramps
44
Dx temp >37.5
- ventilation -> orthostatic pooling -> increased ADH/ aldosterone
- commonly seen in non acclimatized or elderly pt
Heat edema
r/o other causes of edema
45
Dx temp >37.5
- similar mechanism as heat edema
- commonly in elderly
- transient LOC
Heat syncope
r/o other causes syncope
46
Dx temp >37.5
- superficial pruritic vesicles on erythematous base
- generally confined to clothed areas
Prickly heat rash/ malaria rubra/ lichen tropicus/ sweat rash
47
Dx
- temp 37.5 - 40.5
- mental function intact
- malaise, fatigue, headache
- increased HR, orthostatic hypotension, clinically dehydrated
Heat exhaustion
48
Dx
- temp >40.5
- CNS dysfunction (ataxia, coma, sz)
- liver dysfunction (delayed 24-48h - leaking of transaminases from centrilobular necrosis)
- up to 80% mortality if untreated
Heat stroke
- ataxia often first CNS sign because cerebellum most sensitive to heat
- 20% will have persistent neurologic dysfunction
49
Management rhabdomyolysis (in setting hyperthermia)?
- +++ fluids
- mannitol
- HCO3
50
Management MH, possibly NMS (setting hyperthermia)?
- dantrolene (lowers myoplasmic Ca++ by blocking Ca channels in sarcoplasmic reticulum of muscle fibres)
51
Cooling techniques
first line
- evaporation
- ice water submersion
adjuncts
- ice packs to axilla/ groin
- cooling blankets
- cardiopulmonary bypass (ECHMO)
not recommended
- cool fluid lavage
- cold IV fluid (worsen preexisting edema)
52
Rule of resuscitation re: minimum pt body temp?
At least 35 degrees
53
Define hypothermia
Core temp <35
- disruption in balance between heat production and heat dissipation
mild 32.2 - 35
moderate 28 - 32.2
severe <28
54
ECG moderate hypothermia?
- junctional bradycardia and afib; Osborn waves
55
Management hypothermia?
- external rewarming
- warm crystalloids
- invasive active rewarming
56
Toxidrome category of
- antihistamine
- TCAs
- phenothiazine
- atropine
Anticholinergic
57
Toxidrome category of
- insecticides
- nerve agents
- nicotine
- pilocarpine
- urecholine
Serotonergic
58
Toxidrome category of
- heroin
- morphine
- benzos
- barbiturates
- meprobamate
- EtOH
Cholinergic
59
Toxidrome category of
- MAOIs
- SSRIs
- meperidine
- TCA
- benzos
- L-tryptophan
Opioid/ sedative/ hypnotic
60
Toxidrome category of
- cocaine
- amphetamines
- MDMA
- ephedrine
- theophylline
Sympathomimetics
61
Causes elevated osmolar gap?
- EtOH
- isopropyl alcohol
- ethylene glycol
- methanol
- ethanol
62
Causes of elevated anion gap acidosis?
MUDPILES
- methanol
- uremia
- diabetic/ alcoholic ketoacidosis
- paraldehyde
- isoniazid/ iron
- lactate
- ethylene glycol
- salicylate
63
Causes of narrow AG?
HARDUPS
- hyperventilation
- acetazolamide, acids, Addision disease
- renal tubular acidosis
- diarrhea
- ureterosigmoidostomy
- pancreatic fistula
- saline
64
Increase in OG or AG first noticed in toxic alcohol ingestion?
OG
65
AG calculation
```
AG = [Na] - [Cl] - [HCO3]
normal = 8-14
```
66
Osmolar gap calculation
OG = difference between measured serum osmolality and calculated serum osmolarity
normal <10 mOsm/L
Osm(calc) = 2 (Na) + BUN + Glucose
67
Dx
- increased BP, HR, temp +/- RR
- delirium
- increased pupils
- reduced bowel sounds
- dry, red skin
Anticholinergic
- hot as a hare, dry as a bone, red as a beet, blind as a bat, mad as a hatter
68
Dx
- increased RR +/- BP/HR, normal temp
- n/depressed LOC
- +/- pupils (nicotinic dilates; muscarinic constricts)
- increased bowel sounds
- wet skin
Cholinergic
- sludge (muscarinic sx - salivation, lacrimation, urination, diarrhea, GI distress, emesis)
- the Killer Bs (bronchospasm, bronchorrhea)
- fasciculations/ muscle cramps (nicotinic sx)
69
Dx
- decreased vitals
- depressed LOC
- reduced bowel sounds
- normal skin
- reduced reflexes, ataxia
Opioids and sedative/hypnotics
70
Dx
- labile BP; increased HR, RR, temp
- tremor, agitation, hallucination
- increased bowel sounds
- wet skin
- increased reflexes, vomiting
Serotonergic
71
Dx
- increased vitals
- agitated, increased psychomotor activity
- increased pupils
- increased bowel sounds
- wet skin
- tremors, seizures
Sympathomimetics
72
Dx
- increased vitas
- agitated, hallucinations
- increased pupils
- increased bowel sounds
- wet skin
- tremors, seizures
Withdrawal of sedatives/ EtOH
73
Dx
- vitals usually increased, temp can be normal
- anxious
- increased pupils
- increased bowel sounds
- wet skin
- GI upset, yawning, rhinorrhea, piloerection
Withdrawal of opioids
74
Methods of decontamination
- orogastric lavage
- whole bowel irrigation
- activated charcoal/ multi-dose activated charcoal
75
Antidote of acetaminophen
N-Acetylcysteine (NAC)
76
Antidote of opioid OD
Naloxone
77
Antidote of Warfarin
Vit K and/or prothrombin complex
78
Antidote of ethylene glycol/ methadone
Fomepizole or ethanol
79
Antidote of flumazenil
Benzo
80
Antidote of carbon monoxide
O2
81
Antidote of TCAs
sodium bicarbonate
82
Antidote of CCB
IV calcium
83
Antidote of b-blocker
glucagon
84
Antidote of organophosphates/ insecticides
atropine
85
Dx
- reduced LOC, ataxia, lethargy, coma
- blurry vision, reduced VA, snowstorm vision
- Parkinsonism in late stage
- delated presentation common
Tx?
Methanol
- hepatic metabolism by alcohol dehydrogenase to formic acid and depletion of folate stores
Rx - fomepizole or EtOH drip
- hemodialysis if severe
- folate
86
Salicylate toxic ingestion - pathophys, toxic dose and rx?
- resp alkalosis due to CNS chemoreceptors
- metabolic acidosis late
- toxic dose = 150mg/kg
rx - fluids +++
+/- K, dextrose
- urinary alkalization
- hemodialysis if severe
87
Acetaminophen toxicity - pathophys, 4 phases and rx?
- toxic metabolites conjugated in liver using glutathione
- glutathione depleted in OD -> metabolites = hepatotoxicity
toxic dose >150mg/kg or >7.5g
4 phases
- 24-48h - GI upset and diaphoresis
- d2-3 - GI improves, mild abdo pain, transaminases climb
- d3-4 - GI upset, jaundice, metabolic acidosis
- d>5 - multi organ failure with improvement or death
rx
- 4h post ingestion levels -> Rumack-Matthew nomogram
- NAC protective within 8h
88
TCAs - pathophys, dx, rx?
- block Na channels and serotonin reuptake
- anticholinergic and antihistaminic effects
- sx within 6h
- clinical dx (no labs) - nonspecific presentation with dizziness, agitation, confusion +/- anticholinergic effects
- ECG - long QRS, QT or PR +/- RAD of terminal 40ms of QRS
rx
- supportive
- charcoal if <2h
- NaHCO3 if ECG changes
- benzo for seizure
89
Wounds through what skin layer scar?
Through dermis
90
Timing to close wounds?
Within 12h, 24h if on face
91
Can you put chlorhexidine in wound to clean?
No - causes tissue damage
92
Maximum dose of lidocaine? + epi?
5 mg/kg
| + epi = 7 mg/kg
93
Maximum dose of bupivacaine? + epi?
2 mg/kg
| + epi = 3 mg/kg
94
```
Size of suture:
back/trunk
scalp
arms/legs
hands/feet
face
```
```
back/trunk: 3.0- 4.0
scalp: 4.0
arms/legs: 4.0 - 5.0
hands/feet: 5.0
face: 6.0
```
- smaller suture = bigger number
95
Type of closure
- immediate skin closure in wounds with low infection risk
- within 12h (24h if face)
CI?
Primary closure
CI
- punctures
- bites
- extensive crush or debridement
96
Type of closure
- would left open to heal by granulation and contraction
- for contaminated infected wounds
- wounds presenting outside acceptable time for primary closure
CI?
Secondary closure
CI
- cosmetics significant concern
- unable to control bleeding
97
Type of closure
- wound initially left open, kept covered with antimicrobial mesh dressing, then closed 3-5d later if no signs of infection
- for high risk of infection but significant cosmetic concern
- wounds with significant tension
CI?
Delayed primary closure
CI n/a
98
When do administer Td or Tdap? Tig?
Td or Tdap:
- uncertain or <3doses
- last booster >10yr (>3doses initially received)
- last booster >5yr for wounds not clean/minor
Tig
- uncertain or <3 doses in wounds not clean/minor
99
What is result when person's airway goes below surface of liquid?
Submersion -> resp impairment
100
What electrolytes can increase in dead sea submersions?
- increased Mg++ and Ca++ from absorption of sea water
101
What is the diving reflex?
cold water to face -> apnea + bradycardia -> shunting blood to brain and heart
- can be protective in infants and children
102
Systemic effects of submersion injuries?
CNS
- hypoxia and acidosis -> cerebral edema
CVS
- hypoxia, acidosis and hypothermia -> arrhythmia (CPR until core body temp >32)
Resp
- aspiration washes out surfactant -> pulmonary edema -> ARDS
+/- laryngospasm
Metabolic
- mixed resp/metabolic acidosis
- dead sea: lyte abnormalities
Renal
- hypoxia + acidosis -> myoglobinuria + ATN
103
Define shock
tissue hypoxia and end-organ dysfunction secondary to tissue hypo perfusion
104
Dx shock
- increased CO (HR/contractility)
- increased SVR (vasoconstriction)
- BP = narrow pulse pressure
- skin cold
Hypovolemic
105
Dx shock
- reduced CP (reduced preload)
- reduced SVR (vasodilation)
- BP = wide pulse pressure
- skin warm
Distributive
106
Dx shock
- reduced CO (reduced contractility)
- increased/normal SVR
- BP reduced
- skin cold
Cardiogenic
107
Dx shock
- reduced CO
- increased SVR (veno congestion)
- reduced BP
- cold skin
Obstructive
108
Is lactate increased or decreased in shock?
mitochondrial dysfunction -> anaerobic metabolism -> increased lactate
109
Is glucose increased or decreased in shock?
stress hormone release (catecholamines, glucocorticoids, glucagon) -> glyconeogenesis, lipolysis, insulin resistance -> increased glucose
110
Result of inflammatory events in shock?
inflammatory events -> activated neutrophils bind vascular endothelium -> release free radicals and proteolytic enzymes -> damage to cell membrane and DNA
111
Causes of multi-system organ failure in shock?
increased lactate, increased glucose, damage to cell membrane and DNA ->
ion pump malfunction -> cellular edema -> cellular dysfunction with dysregulation of intracellular pH -> cellular necrosis and death ->
multi system organ failure ->
death
112
Dx
- appears unwell
- tachycardia, tachypnea, hypotensive, hypoxemic
- increased serum lactate
- reduced u/o
hypovolemic shock
113
Can positive pressure ventilation affect pneumothorax?
Yes - can turn into tension pneumothorax
114
Areas where significant bleeding can occur?
- chest
- abdo
- pelvis (3L)
- thigh (1L each)
- retroperitoneal space
115
Investigations for trauma pt?
- CBC, type and screen, INR/PTT, lytes, BUN, Cr, b-hCG, lactate
+/- ABG/VBG, lipase, LFTs, toxicology workup
CXR, pelvic XR, spine films (re: C-spine rules)
XR suspected injuries
CT chest, abdo, pelvis, spines prn
116
Management of unstable pt with peritonitis?
Direct to OR for laparotomy
| -> NO imaging
