Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Small Animal Medicine Exam 3 (Spring 2016) > L28: Heat Stroke (Cooke) > Flashcards

L28: Heat Stroke (Cooke) Flashcards

1
Q

70% of total body heat loss is via what mechs?

A

Radiation

convection (movement of air across body to cool)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Mechanisms of heat dissipation

A

Radiation
Convection
Conduction
Evaporation (more difficult as humidity increases)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Relationship between CO and heat loss

A

Increased CO (due to increased HR and/or stroke volume) –> peripheral vasodilation –> increased circulation to skin –> facilitates heat loss through radiation, convection, and conduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

2 main predisposing causes of heatstroke

A

Decreased heat dissipation

Increased heat production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Causes of decreased heat dissipation

A 
Lack of acclimation
Confinement/poor ventilation
Increased humidity
Dehydration
Abnormal respiration (brachys, lar par, CNS dz)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Causes of increased heat PRODUCTION

A
  • exercise
  • seizures
  • hyperthyroidism
  • drugs/toxin (amphetamines, macadamia nuts)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

CS of heatstroke

A

Panting
Ataxia
Vomiting/diarrhea
Disorientation/seizures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Systemic effects of heatstroke (T > 106.9)

A 
Protein denaturation
Enzyme dysfx
Mitochondrial dysfx
Cell membrane dysfx
Cardiopulmonary effects (vasodilation, +/- dehydration)

–> SYSTEMIC CELL DEATH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Consequences of vasodilation +/- dehydration 2ary to hyperthermia

A

Decreased perfusion and heat dissipation –> cell death (esp. Of RBCs and endothelium)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Death of cardiac myocytes –>

A

Arrhythmias –> death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Death of pulmonary endothelium –>

A

ARDS –> vasculitis, leaking protein and fluid –> death

*any endothelium can be affected, but pulmonary endothelium most sensitive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Death of neurons –>

A

Cerebral edema –> seizures, coma –> death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Death of enterocytes –>

A

Hemorrhage, bacterial transduction –> anemia, sepsis –> DIC/death

*enterocytes extra susceptible b/c of long villi far from blood supply

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Death of hepatocytes –>

A

Necrosis, cholestasis –> hepatic failure –> DIC/death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Death of renal tubular cells –>

A

Tubular necrosis –> renal failure (acute anuric or oliguric) –> death

-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Death of RBCs/endothelium –>

A

Sludging
Hemolysis
Ischemia
Thromboplastin release

—> DIC –> death

Reason: cell damage –> protein exposure –> thrombus formation

Damaged endothelium allows for blood/fluid to leak out of vascular space, or for sludging, which sets up for DIC

17
Q

PE findings in EARLY heatstroke

A 
Increased temp
Tachycardia
Bounding pulses
Tachypnea +/- upper airway sounds
Hyperemic mm
CRT
18
Q

PE findings of LATE heatstroke

A

Inc. OR dec. temp
Tachycardia
WEAK pulses (2ary to hypovolemia or dec. CO due to cardiac myocardium dysfx)

Tachypnea +/- upper airway sounds
Pale/grey mm
CRT >2 sec
Demented, obtunded
May have blood on rectal, urine may be discolored, +/- petechia
19
Q

Initial Diagnostics of heatstroke patient**

A 
PCV/TP (dehydrated?)
Blood smear (thrombocytopenic?)
Basic Chem
Blood gas (acidemic? Lactate?) - can be venous
UA (what is SG? Evidence of myoglobin or hemoglobin?)
Coag status: ACT or PT/PTT (DIC?)
Arterial BP
Rectal exam (hemorrhage present?)

*presence of myoglobin/Hb in UA negative prognostic indicator

20
Q

Common bloodwork, UA, and BP changes in heatstroke patient

A
  • Hemoconcentration INITIALLY with an increase in nRBCs
  • Anemia LATER (probably from damage to bone marrow)
  • azotemia (may be pre-renal)
  • thrombocytopenia
  • increased liver values (AST, ALT, bilirubin)
  • hypotension
  • hemoglobinuria/myoglobinuria
  • urinary casts
21
Q

Steps in treating heatstroke patient

A

1) start cooling ASAP!!
2) secure airway/O2
3) IV catheter, draw blood for MDB and hold samples for full CBC, Chem, UA
4) stop cooling at 103-103.5
5) indirect BP

22
Q

Fluid therapy guidelines

A
  • caution, not all heatstroke patients are dehydrated and they are susceptible to fluid overload if have leaky vessels
  • goal = support perfusion, correct acid/base abnormalities
  • crystalloids first choice
  • colloids indicated when can’t get HR/BP and acid/base status resolved, and may need to add pressors (plasma if evidence of coagulopathy, hetastarch/dextrans if no coagulopathy)
  • DON’T give entire shock dose! (Give 1/4 to 1/3 shock dose)
23
Q

Vasopressors you can use in heatstroke patients

A

Dopamine
Dobutamine
Vasopressin
Norepi

24
Q

Common sequelae of heatstroke

A 
ARF
GI ulceration/hemorrhage +/- sepsis
Hepatic failure
DIC
Seizures
Arrhythmias
ARDS
25
Q

Tx/prevention of ARF in heatstroke patient

A
  • support perfusion, ensure urine output (give fluids, pressors, monitor output)
  • reverse any oliguric failure
26
Q

Tx/prevention of GI ulceration (and subsequent hemorrhage, sepsis, vomiting) in heatstroke patient

A
  • goals: support perfusion to reduce formation and promote healing, control vomiting, reduce risk of sepsis
  • tx with fluids, pressors, famotidine (H2 blocker) OR pantoprazole (proton pump inhibitor), antiemetics, +/- abx
  • don’t give proton pump inhibitor if vomiting
27
Q

Tx/prevention of hepatic failure in heatstroke patient

A
  • major concerns: coagulopathy, hyoglycemia (2ary to sepsis), hypoalbuminemia (from leaky vessels or hepatic failure), hepatic encephalopathy
  • tx with plasma, dextrose fluids, lactulose PRN
  • SAMe, milk thistle, etc.
  • give plasma if hypoalbuminemia AND coagulopathic**
28
Q

Tx/prevention of DIC in heatstroke patient

A
  • monitor for evidence of petechia/ecchy, internal bleeding

- tx with plasma if above occurs or if coags become prolonged

29
Q

Calculate shock dose

A

90 mls/kg X BW (kg)

30
Q

Tx reduced urine production with

A

Furosemide

31
Q

Tx/prevention of Seizures in heatstroke patient

A
  • diazepam +/- mannitol (if there is cerebral edema)

- ideally should NOT give mannitol if not rehydrated yet!

32
Q

Tx/prevention of arrhythmias in heatstroke patient

A
  • monitor ECG
  • assess effect on CO
  • goal = prevent sudden death
  • lidocaine
  • don’t always tx VPCs unless having negative effect on CO
33
Q

Tx/prevention of ARDS in heatstroke patient

A
  • concerns: thromboembolism, vasculitis
  • want to avoid fluid overload and support resp. System
  • monitor RR, SpO2
  • O2 therapy, colloids PRN
34
Q

Negative prognostic indicators in heatstroke patients

A 
Comatose
Hypothermic
Persistent hypoglycemia
Progressive azotemia
DIC
Refractory hypotension
Hyperbilirubinemia
Oliguria
35
Q

Prognosis of heatstrok

A

Guarded to grave

  • complications can occur 12 hrs to 7 days later
  • should monitor for 24-48 hrs minimum
  • requires intensive management
  • can be very expensive
36
Q

4 main stages of heat-related injury in HUMANS

A

1) Heat cramps
2) Heat exhaustion
3) Heat prostration (headache, tachycardia, hypotension)
4) Heat stroke (CNS dysfx, circulatory insufficiency)

Small Animal Medicine Exam 3 (Spring 2016) (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions