Lecture 7: Environmental Emergencies (Elkins) Flashcards
1
Q
What is heat illness?
A
Inabiity to regulate body temperature adequately
2
Q
What characterizes Heat Edema & how do you tx?
A
- Mild swelling of extremities
- Tx: Self-limiting, just rest, ice, elevate, drink water
Cutaneous and muscular vasodilation redistributes intravascular volume to the periphery of the body. Volume loss and prolonged standing (pooling in the lower extremities) also contribute to the development of inadequate central venous return and insufficient cerebral perfusion.
3
Q
What is heat syncope and what is the clinical presentation?
A
- Heat syncope is syncope after exerting yourself in the heat.
- NORMAL CORE TEMP
- Skin will be cool, sweaty; weak pulse, transient hypotension
2 pathophysiologic processes:
vasodilation of the skin and muscles redistributes intravascular volume to the periphery of the body
volume depletion in addition to prolonged standing leads to inadequate cardiac return and cerebral perfusion
4
Q
How do you manage heat syncope?
A
- R/o other possible causes
- Lie supine, elevate legs, cool externally and rehydrate IV/PO
Get them out of the heat and rehydrate.
5
Q
What are heat cramps and the clinical presentation?
A
- Painful muscle spasms of abd + ext due to salt depletion
- NORMAL or SLIGHTLY ELEVATED CORE TEMP
- +/- muscle fasciculations
- Skin can be anything (dry or moist, cool or warm)
6
Q
What would you see on labs for heat cramps if you decided to order them?
Rarely indicated.
A
- Low to normal Na
- Low to normal K
- Low to normal Mg
Just some lyte depletion
I think of bananas for cramps, so cramps = electrolyte issue
7
Q
Management of heat cramps?
A
- Remove from heat, externally cool
- Oral electrolytes (pedialyte/gatorade) or IV NS
- Replace K and Mg PRN
Discharge home and rest for 1-3 days.
8
Q
What characterizes Heat Exhaustion?
A
Inability to maintain adequate CO d/t physical exercise and environmental heat stress
Will lead to heat stroke if no intervention!
Running on Empty, no output
9
Q
What are the two underlying types of heat exhaustion?
A
- Hypernatremic (Primary water loss): LACK OF WATER
- Hyponatremic (Primary salt loss): Only getting free water instead of water + lytes
10
Q
How does heat exhaustion present clinically?
A
- Mild core temp elevation up to 104F
- Diaphoresis, HA, N/V, malaise, weakness
- Cramps, dizziness, +/- dark urine
- Tachy, hypotensive
- NO EVIDENCE OF CNS DYSFUNCTION (Key distinguishing from heat stroke)
11
Q
What is a key feature of the clinical presentation that suggests heat exhaustion over heat stroke?
A
No evidence of CNS dysfunction
12
Q
What UA finding suggests subclinical rhabdomyolysis?
A
- UA showing blood
- Microscopy showing little to no RBCs
13
Q
If a patient presents with suspecteed heat exhaustion, what will your workup include?
A
- BMP
- UA
- CK
- LFTs
- ABG
- EKG
Rhabdo + lyte abnormalities
14
Q
What are the management steps for heat exhaustion?
A
- Remove from heat
- Externally cool
- PO lytes if they can
- If not, IV NS or LR.
- If primarily marked hyponatremic due to water intoxication, use hypertonic
15
Q
When would you admit for heat exhaustion?
A
- Mod-severe
- Cormorbid illnesses
- Old af or young af
- Lab abnormalities
- Social concerns
16
Q
What is the underlying mechanism that characterizes heat stroke?
A
Dysfunction of heat regulation, leading to hyperthermia & end-organ damage
17
Q
What tissues and cells are MOST SENSITIVE to heat stress?
A
- Neural tissue (Brain)
- Hepatocytes (Liver)
- Nephrons (Kidney)
- Vascular endothelium (blood vessels)
Brain, liver, kidney, blood
18
Q
Define hyperthermia
A
Core body temp > 104F or 40C
19
Q
What are the two types of heat stroke?
A
- Exertional (rapid)
- Non-exertional (slow)
20
Q
What are the primary S/S that suggest heat stroke over anything else?
A
- Confusion
- Seizure
- Delirium
- Ataxia
- Coma
Neuro!
21
Q
What life-threatening condition can heat stroke cause?
A
DIC
22
Q
What would you order in a workup for heat stroke?
A
- CBC, PT/PTT (DIC)
- CMP (electrolytes and LFTs)
- Phosphate (hypo occurs due to renal dysfunction)
- UA
- CK
- EKG
- CXR
UA findings include protein, myoglobin, and tubular casts.
UA can be concentrated with protein due to kidney leakage.
23
Q
What is the first step in managing heat stroke?
A
RAPID COOLING
- Ice water submersion (preferred)
- Disrobe/spray water + fan blowing
- Cooling blanket with ice packs over great vessels
24
Q
If a patient is shivering severly in heat stroke, what can you give them?
A
IV BZD
25
What is the preferred temperature monitoring technique for heat stroke?
Rectal until its down to 102F
26
If Rapid cooling & IV BZDs all fail for heat stroke, what is your last resort?
Internal lavage
27
What is ideal Urine Output in Heat stroke?
50-100 mL/h
| Adjust IV fluids PRN to reach this.
## Footnote
Bolus 1-2L if hypotensive or rhabdo
28
When would you ventilate/intubate in heat stroke?
Significant AMS
29
When do you admit to ICU for heat stroke?
* Hemodynamic instability
* Severe LFTs
* Rhabdo
| Everyone else to med-surg
30
What are the unfavorable prognostic signs for heat stroke?
* Extreme hyperpyrexia (> 42C/107.6F)
* Persistent coma after cooling
* Markedly elevated LFTs
* Hyperkalemia + extensive rhabdo
31
How does mild frostbite present prior to re-warming?
* Paresthesias
* Pruiritis of tissue involved
* Loss of sensation and fine motor control
32
How does mod-severe frostbite present prior to re-warming?
* Decreased ROM
* Blister formation
* Edema
* Tissue appears white
* Firm/hard
* Cool to touch
33
How does frostbite present once you have rewarmed them?
* Stinging/burning/aching/throbbing/tender
* Tissue discoloration + loss of elasticity and mobility
* Profound edema, hemorrhagic blisters, necrosis, gangrene
34
Describe the 4 degrees of frostbite.
1. Erythema & edema, **no blister**, skin peeling
2. **serous blister**
3. Necrosis, **hemorrhagic blister**, SQ involvement
4. **Full-thickness down to bone**, dry, black, mummified eschar, ded
35
What are the 2 things to remember when treating frostbite initially?
* Treat systemic hypothermia first
* If you're gunna rewarm, you gotta do it completely!
36
How do you rewarm frostbite?
Rapid rewarming in circulating water at 98.6F-102.2F
| Can give NSAIDs cause it might hurt
## Footnote
15-60 minutes, until skin turns red-purple and pliable. Air dry.
37
After you rewarm some frostbitten fingers, what is next for wound care?
* Keep sterile
* **Topical aloe vera Q6h**
* Debridge in whirlpool if dead tissue
* Splinting to prevent contracture
* Elevate extremity to lessen edema
* **Update tetanus**
| Aloe vera helps with collagen recomposition.
38
When can you send frostbite home?
Only with a limited 1st degree injury.
| Everything else needs admit
39
Define hypothermia
Core body temp < 35C/95F
| Rectal, bladder, or esophageal thermometer
40
What usually causes primary hypothermia?
Out in the cold after drugs/alcohol use
41
Who is most at risk for impaired shivering?
* Age extremities
* Malnutrition
* Physical exhaustion
* Neuromuscular dz
42
How do cardiac arrhythmias progress in hypothermia? what stage do we see these arrhythmias in?
1. Bradycardia
2. Afib with slow response
3. VF
4. Asystole
remember in HT1 HR is increased
HT2 it drops
HT3 is arrhythmias
| Usually around HT 3, which is < 28C
43
What are the 4 levels of hypothermia?
1. Mild 32-35C
2. Moderate 28-32C
3. Severe < 28C
4. Pretty much dead < 24C (no vitals left)
44
First step in managing hypothermia 1 & 2
Warm em up
45
How is HT 1 managed?
* Warm em up
* Active movement
* Warm oral sugary drinks
46
How do we manage HT 2?
* Full rewarming via blankets
* Warmed IV fluids
47
How do we manage HT 3?
1. Airway management
2. Rewarming can treat rhythms besides VF
3. **Defibrillate once prior to rewarming if in VF**
48
What is the ideal rewarming method for HT 3?
ECMO
49
How do we treat HT 4?
Cardiac arrest protocol (CPR, airway)
50
What is the coma cocktail for HT 4?
* Dextrose 50 mL
* Thiamine 100 mg
* Nalaxone 2g
51
How would you treat hypothyroidism in HT 4?
* Levothyroxine 400 mcg
* Hydrocortisone 100 mg
| Double hydrocortisone for hypoadrenalism.
52
What criteria must be met to NOT admit someone for hypothermia?
* No comorbidities
* No AMS
* Core temp must be > 34C
53
What is the MC type of sting reaction?
Localized reaction from a **bee string**
* Small, pruiritic, painful, erythematous, edematous lesion due to venom.
* Sometimes > 5 cm
54
How do fire ant stings present?
* Sterile pustule over 6-24h
* Can cause necrosis or scarring
55
How many stings usually are needed for a more systemic/toxic reaction?
> 50 stings
56
How does a systemic/toxic reaction present?
| Wasp, bees, ants
* N/V/D with urticarial lesions distant from sting site
* Only lasts around 48h
57
How quickly does analphylaxis occur?
**Usually 15 mins**, but can take up to 6 hours
58
When do you do lab evals for stings?
Systemic or anaphylactic rxn (but save their life first)
59
What 5 drugs are used for anaphylaxis?
1. Epi 1:1000 (0.5mg max in kiddos)
2. IV methylprednisolone 2mg/kg
3. IV Diphenhydramine 1mg/kg
4. IV Famotidine 0.5mg/kg
5. Nebulized albuterol (bronchospasms)
60
For a systemic sting reaction, what drugs are most appropriate?
* Methylprednisolone
* Diphenhydramine
* Famotidine
| Aka don't use epi
61
How do you remove a stinger?
Scrape it
62
When do you admit for systemic sting reactions?
* Child
* Elder
* Comorbidities
* 50+ stings
* Prolonged rxn (guessing over 48h?)
63
How do you observe/discharge a healthy patient with a systemic sting reaction?
* 6 hours of obs with NO rebound symptoms
* Repeat labs before d/c
* Rx them an EpiPen
* F/u with an allergist
64
What is the only systemically toxic scorpion in the US and where is it found?
Bark scorpion in the Southwest
| Most deadly to kiddos
65
How does a scorpion sting present?
* PAINFUL, but no initial erythema/swelling
* **tap sign** of light percussion causes immense pain
* Neuromuscular excitation
* CV toxicity
66
How do we manage a normal scorpion sting?
* Pain Meds
* BZDs for motor control
67
What is the antivenom for scorpion stings and what are the main SE?
Anascorp
* N/V
* Pyrexia
* Rash
* Pruiritis
68
What snakes are pit vipers?
* Rattlesnakes
* Copperheads
* Water moccasin
| **Triangle shaped head with heat sens depression pit between eyes**
## Footnote
They have **cytotoxic** venom
69
Clinical hallmark of a pit viper bite
* Fang marks
* Pain
* Edema
* Hemorrhage
* Necrosis
| 30minutes to 12 hrs
## Footnote
After 12 hrs of no S/S = DRY bite
70
What do we do to the snake bite?
* Immobilize bitten extremity (no constriction bands proximal)
* Serial wound eval Q30mins
* Mark area to monitor edema
71
When do we give CroFab?
Pit viper bites in which the envenomatio will be worse than the SEs of the antivenom.
72
What are the risks and SEs of CroFab?
* Urticaria, rash, nasuea, pruiritis, back pain
* HSR occurs in 5-19% of pts
* **Recurrent coagulopathy still occurred in 50%**
73
Who gets ICU admit for snake bites?
* Severe
* Used CroFab
74
Generally, when you do see high altitude sickness? (altitude)
> 1500 m or 4800 ft
| Pretty much a mile
75
How does the body adjust for hypoxia?
* Increased RR
* Increased Bicarb excretion
* Increased sympathetics
* Increased oxygen carrying capacity
76
How does acute mountain sickness present?
Hangover within 48h of rapid ascent.
77
How do you tx acute mountain sickness?
* Stop ascending
* Descend if no improvement (300-1000m)
* Low-flow O2
* Tylenol for HA, Zofran for N/V
78
What would suggest a moderate presentation of acute mountain sickness and what can we do for it?
* No improvement in 36 hrs after ceasing ascent.
* Hyperbaric O2
* Acetazolamide + Dexamethasone
| Acetazolamide is also a prophylaxis for acute mountain sickness.
## Footnote
1 day prior to ascent, 2 days after reaching max altitude.
79
What characterizes High Altitude Pulmonary Edema?
| Extension of untreated acute mountain sickness
* MCC of death, can be fatal in hours.
* Hypoxic vasoconstriction
* Elevated **right heart pressures**
* **Noncardiogenic Pulmonary Edema**
80
How does High Altitude Pulmonary Edema present?
* 2-4 days after ascent
* **Decreased exercise capacity is initial symptom**
* 2 of the following must be present:
## Footnote
Dyspnea at rest, cough, rales, tachypnea, weakness, decreased performance, chest tightness, tachycardia, signs of pulmonary HTN
81
How do you manage HAPE?
1. Immediate descent is #1 tx
2. Supplemental O2 > 90%
3. Hyperbaric O2
4. PDE5 inhibitors or nifedipine to vasodilate (The least preferred options)
| Sildenafil, tadafil, nifedipine, which can also be used prophylactically
82
Discharge criteria for HAPE (3)
* >90% O2 on RA
* Symptom resolution
* Improved CXR
83
What characterizes high altitude cerebral edema?
End-stage of AMS or HAPE.
84
How does HACE usually begin?
A history consistent with AMS, but S/S of increased ICP.
| MRI will show cerebral edema
85
Management of HACE
* Supplemental O2 > 90%
* Immediate descent vs hyperbaric O2
* **Dexamethasone 8mg, then 4mg Q6h)**
* **Admit anyone symptomatic for >2h after descent.**
86
Why is aspirating water bad
Washes out your surfactant causing V/Q mismatch
87
How does near drowning present?
* Pulmonary injury
* ARDS (can occur 6-24 hrs after aspiration)
* Water aspiration
* Multiorgan failure if prolonged hypoxia
* Hypothermia (EVEN IF WATER WAS WARM)
| < GCS 13 = do more stuff
88
MCC of fire-related death
Smoke inhalation
89
What are the 3 ways inhaling can injure you?
* Thermal (it is hot af and burns you)
* Particulate matter (bronchospasm and edema)
* Toxic gases (CO or hydrogen cyanide)
90
Management of inhalation injuries
* Humidified 100% O2 via mask
* ET intubation
* Bronchodilators
* Pulmonary toilet
91
What is pulmonary toilet?
* Suctioning
* Chest physiotherapy
* Nasotracheal suction
* Bronchoscopy
* Incentive spirometry
* Use of analgesics
* Prone positioning
92
How does CO poisoning present?
* FLS
* Ha
* Dizziness
* Vision changes
* Confusion
* **Multiple ppl from the same residence will have the exact same presentation**
| CO has much higher affinity for Hgb than O2.
93
How do you evaluate CO poisoning?
* CO-oximetry (cannot use pulse ox)
* Carboxyhemoglobin elevation
* ABGs
94
Management of CO poisoning
* High flow O2
* Hyperbaric O2 if severe
| Severe: LOC, AMS, MI, Focal neuro deficit, or preggo.
## Footnote
DO NOT WAIT FOR CONFIRMATION
95
When can you d/c someone home with CO poisoning? (asymptomatic vs moderate vs severe)
* Asymptomatic: Safe home + was not a SI
* Mod (HA/N/V): Obs for 4 hrs with 100% O2
* Severe: Admit and consult with hyperbaric specialist
96
What is the rule of 9s for burns?
* Head 9%
* Front torso 18%
* Back torso 18%
* Arms 9%
* Groin 1%
* Legs 18%
| Primarily used for 2nd and 3rd degree burns
97
How do we grade burns?
Depth
* Superficial partial
* Deep partial
* Full thickness
98
What are the alternative methods to Rule of 9s for burns?
* Lung and browder (infants and children)
* Palmar (dorsal palm is 1%, use for small burns)
99
How do we manage burns?
* Vitals and monitor airway
* Opiates for pain
* Urinary cath for I&Os (0.5-1mL/kg/hr)
* IV LR via 2 IVs via parkland formula
100
What is the Parkland formula?
| Must know!
* LR 4 mL x wt in kg x % BSA burned over initial 24h.
* Give 1st half over 8h from onset.
* Give 2nd half over 16h.
* Example: 4 mL * 70kg * 40% burn = 11,200 mL over 24h.
| If child, use 3 mL instead.
101
For minor burns, how do we manage them wound care wise?
* Mild soap & water
* Drain/debride bullae > 2cm or over joints & give silvadene
* See PCP after
102
How do we manage mod-severe burns?
* Moderate: Sterile sheets + admit
* Severe: Send to burn center
103
How do acid burns on skin present?
* Coagulation necrosis leading to eschar formation that **limits the extent of damage**
* Partial-thickness with erythema & erosion.
| Only exception is hydrofluoric acid, which penerates deeply!!!!!!!!
104
How does an alkali burn on the skin present?
* Liquefaction necrosis
* Deeper damage
* Full-thickness, pale
* Leathery and slippery
105
How do we manage chemical burns?
1. Remove clothes
2. Tap water
3. **Elemental metals require mineral oil to prevent exothermic burns**
4. Poison control
5. The usual
| Metals: Na, Lithium, Ca, Mg
106
What are the two types of electrical injuries and MC demographic?
* High voltage: adults & > 1000V (powerlines)
* Low voltage: kids & < 1000V (house)
107
What are the 3 ways electricity causes injury?
* Direct damage (cardiac)
* Thermal damage (burns + rhabdo)
* Mechanical damage (fall or tetanic muscle contraction)
108
Management of an electrical injury
* Airway
* EKG
* Treat as blunt force trauma
* IVF with ideal UO of 2 ml/kg/h
* Treat everything as usual
109
When can you discharge an electrical injury?
* Low voltage
* Asymptomatic
* Normal PE
* Normal EKG
| Must meet everything
110
Whats the usual danger with stuff like tasers and stun guns?
* Pain
* Muscle contraction
* Incapacitated
| Just manage like blunt trauma or ingestion
111
What is the MCC of death when it comes to lightning injury?
Cardiac arrest
112
What is the pathognomic sign of a lightning injury?
Feathering or fern-shaped burns
113
What is dysbarism?
Complications associated with changes in ambient pressure or breathing compressed gases
## Footnote
Barotrauma
Decompression sickness
114
What characterizes middle ear barotrauma due to descent?
Rupture/bleeding of TM
115
What characterizes inner ear barotrauma due to descent?
* Rupture of round or oval window
* Tinnitus
* SN hearing loss
* Vertigo
116
What characterizes sinus ostia occulsion due to descent?
Bleeding from sinus cavity
117
What are the various presentations of barotrauma due to ascent?
* Lung overinflation
* Pneumomediastinum
* SQ emphysema
* Pneumothorax
* Cerebral arterial gas embolism
118
What causes decompression sickness?
Release of nitrogen gas bubbles from plasma during ascent
119
Classic situation of decompression sickness
Scuba diver who then goes on a flight
120
Describe each type of decompression sickness
1. Minor: deep aching pain in elbows and shoulders
2. Cardio/Neuro: Spinal cord embolism in scuba diving, cerebral gas embolism in flights, fatigue, ataxia, spinal paralysis, etc
121
Managment of Barotraumas
* Middle ear: Decongestants/analgesics, refer for TM rupture
* Inner ear: Rest with head upright, refer
* Pneumothorax: needle decompression
122
Management of decompresion sickness
* 100% O2 via mask for 2h
* Crystalloids IV
* Hyperbaric O2 for recompression
