Environmental Exposures: slide 75-131

Question 1

Pernio or chilblains are inflammatory lesions of skin caused by _______

Answer 1

long term intermittent exposure to damp

a non-freezing injury

Question 2

Does pain remain with pernio and chilblains?

Answer 2

Pain remains with Pernio only!

• Paresthesias pain with any pressure on foot
• Shoes are intolerable

vs
Chilblain–> No long term sequela

Question 3

Female snowboarder develops painful toe in the cold with red or violet painful skin lesions on her feet=

Answer 3

think chilblain or pernio

Question 4

Chilblain= _____ hours with _____ discolored vesicles

Answer 4

• 3-6 hours time from exposure
• blue discolored vesicles
• NO long term sequelae

Question 5

Pernio= _____ hours

Answer 5

12-3 days!

-skin sloughs off** –> chronic pain and inability to walk

Question 6

Tx for Chilblain/Pernio:

Answer 6

Warm
Dry
No massage
**nicardipine and occasionally steroids

Question 7

Trench foot=

-Sx?

Answer 7

=prolonged immersion in cold water

sx: **foot is pale and mottled.Trench foot has worse pathology than pernio
- -affected parts are first cold and anesthetic, then hyperemia with burning pain

Question 8

Cold extremity injury

Pathology: describe the stages

Answer 8

vasoconstriction with endothelial damage, extracellular then intracellular ice formation and cell death. (neurons damaged first, then muscle, endothelial cells last) note: arachidonic acid cascade

4 stages: starting with pre-freeze with no ice formation, progressing to ischemic phase when freezing and ice crystal formation has occurred, frostnip, frostbite

Question 9

Sx of trench foot:

Answer 9

Hyperhidrosis

Intolerance to cold

Pain- especially with the rewarming phase

Question 10

trench foot: sequelae

Answer 10

Dysfunction of extremity
Cold sensitivity

Hyperhidrosis- leading to chronic fungal infections

Raynaud’s

Swelling, chronic pain

Question 11

Stages of Frostbite:

Pre- freeze (1)

Answer 11

Superficial tissue cooling
**Increased viscosity of vascular contents
Endothelium damage

Question 12

Frostnip (1st degree)=

Answer 12

typically non-freezing temps. It is a non-freezing injury with excellent prognosis. May precede frostbite. Get patient to warm dry environment and they do well. People with PVD at risk.

Question 13

Frostbite=

Answer 13

Classified like burns first-4th degree. Once get to 3rd degree there is sub q involvement and worse prognosis, 4th degree is frozen muscle and bone.

Question 14

Tx of cold extremity injury:

Answer 14

-remove wet clothing
-Rapidly warm the extremity preferable in water bath of 102 F
-splint and pad to avoid further injury and
most important **do not let refreeze. Lots of experimental therapies
-tetanus status

Question 15

there are 3 zones of injury (in cold extremity injuries)

Answer 15

zone of coagulation : most severe and damage is irreversible

zone of stasis: severe but reversible cell damage

zone of hyperemia; damage is reversible

Question 16

Frostbite classifications: 3rd and 4th degree

Answer 16

third degree : injury to subdermal tissues (ie hemorrhagic blisters with skin necrosis= “feels like block of wood”

fourth degree=extension to subcutaneous tissue, muscle bone and tendons, “deep black mummified escar)

Question 17

Describe the process of Acclimatization to Heat

Answer 17

• Lowers the threshold for sweating
• mechanism is unclear
• Increased stroke volume
• Vasodilation of peripheral vessels
• Decrease of splanchnic flow (kidneys)
• Occurs in about 14 days

Question 18

Heat cramps occurs 2/2 _____

Answer 18

Electrolyte deficiency

-they are strong muscle contractions that occur at rest

Question 19

Heat edema occurs MC in which demographic?

Answer 19

Pt with no cardiac disease
Usually elderly
stasis caused by VD

Question 20

Milaria rubra=

Answer 20

Prickly Heat
Skin rash occurring in hot temperatures often found in small children
Vessicles that are due to the rupture of blocked sweat glands

Question 21

Heat exhaustion:
-occurs at a temp < _____ F

Characterized by?

Answer 21

<40.5 degrees F

characterized by:
1.Fatigue, weakness
2.Nausea and vomiting
3.Headache
4.Muscle cramps and myalgia
irritability

(this is a minor heat illness)

Question 22

Heat exhaustion:

occurs 2/2 primary ______ loss and primary _____ loss

Answer 22

dehydration (primary water loss) or sweating with hypotonic rehydration (primary sodium loss)
-temps up to 104 F

Question 23

Treatment of Heat Exhaustion=

Answer 23

Replace deficit over 48 hours

Usually will need admission

Question 24

Heat stroke=
temp > ____F

-______ symptoms are the hallmark signs of this diagnosis

Answer 24

> 104 F**

CNS symptoms= hallmark

i. e. Bizarre behavior, Hallucinations, AMS
* *muscle flaccidity and cramping

Question 25

Heat stroke tx/management

Answer 25

MUST have core thermometer in place (Rectal or foley)

Cool them down by conduction–> Cooling blanket
or Ice packs to groin and axilla

-Decrease Temp by evaporation

Wet them down (mist with fan) or water immersion

Question 26

Neuroleptic Malignant Syndrome=Autonomic dysfunction with ________

Answer 26

Extrapyramidal dysfunction

with Hyperthermia

Question 27

Neuroleptic Malignant Syndrome:

-list ex’s of extrapyramidal sx

Answer 27

• catatonia,
• generalized muscle rigidity
• parkinsonism, masked facies, tremors or akinesia
• Autonomic dysfunction causes: Labile BP, diaphoresis, urinary incontinence

Question 28

Neuroleptic malignant syndrome:
Pts can be on typical doses of Antipsychotics such as Phenothiazines or Haloperidol–> there is a depletion of dopamine–> tx is ______

Answer 28

**with Dantroline or Bromocriptine (dopa precursor)

Tx for rigidity: Benzos

Question 29

On physical exam how can you distinguish NMS from Heat stroke?

Answer 29

Diaphoresis–NMS
Rigidity–NMS

Liver function tests—Heat stroke (will be elevated in heat stroke Pt due to rhabdo)

Question 30

Serotonin Syndrome is due to:

Answer 30

increased endogenous CNS serotonin: very similar features to NMS (myoclonus and hyperreflexia, AMS)

2/2 serotonin agents: SSRIs, amphetamines

Question 31

Serotonin syndrome tx ?

Answer 31

cyproheptadine

Question 32

A patient after running a marathon presents to the first aid tent. He is slightly confused with temp of 103.4. Your next best action is which of the following?

-give tylenol and let him go home

• give po fluids and let him go home
• have him urinate and look for blood

-send to higher level of care for eval and treatment

Answer 32

send to higher level of care for eval and treatment

heat exhaustion