Shock Flashcards
Is shock a disease or a syndrome?
Syndrome associated with many disease conditions
what are the 10 clinical signs of shock
- decreased mentation
- cool extremities/hypothermia
- poor peripheral pulses
- prolonged CRT
- pale MM
- tachycardia in dogs/bradycardia in cats
- increased RR and effort
- decreased BP
- decreased urine production
- GI ulceration/decreased GI blood flow
what are the 3 hallmarks of FELINE shock
- bradycardia
- hypothermia
- hypotension
You have a cat presenting with hypothermia, bradycardia and hypotension… Understanding that hypothermia decreases the ability to cope with fluid load, what is your next step?
Start fluid resuscitation but do not blast with fluids until you determine the patients response to rewarming
what is the physiologic response to shock
- increased sympathetic output (release of E/NE)
- increase in HR, cardiac contractility and vasoconstriction
describe the vasoconstriction that happens during shock, what receptors are key?
vasoconstriction of organs with high numbers of α1 receptors (sphanchnic organs, kidneys, skin, skeletal mm) but maintenance of perfusion to the carotid, hepatic and coronary arteries
in terms of endocrine responses, what occurs within:
- IMMEDIATELY
- MINUTES
- HOURS
IMMEDIATELY: release of NE/E from the adrenal gland and vasomotor endplates
MINUTES: release of ADH from pituitary to increase water conservation (increase blood volume)
HOURS: activation of RAAS in kidneys to conserve Na and water (increase blood volume)
what are the 3 STAGES of shock
1) early compensatory
2) early decompensatory
3) late decompensatory/terminal
what are the signs of early compensatory shock
- TACHYCARDIA
- normal to elevated BP
- hyperemic MM
- normal to increased pulses
- CRT < 1s
what are the clinical signs of early decompensatory shock
the same as the general signs of shock:
- tachycardia
- tachypnea
- pale MM
- CRT prolonged
- decreased mentation
- hypotension
- hypothermia
- poor peripheral pulses
what is happening during early decompensatory shock
the compensatory mechanisms are tiring; redistribution of blood from the GI, skin, kidney, mm
what are the clinical signs of late decompensatory shock
- absent CRT
- weak/absent pulses
- decreased HR
- pale/cyanotic MM
- mentally unresponsive/coma
- severe hypotension
- hypothermia
- no urine production
what is the prognosis to the different stages of shock
- early compensatory: good response to volume replacement, good outcome
- early decompensatory: fair to good with immediate intervention
- late decompensatory: poor, generally irreversible
what are the 4 TYPES of shock
1) hypovolemic
2) cardiogenic
3) obstructive
4) distributive (= hyperdynamic)
T/F a patient can suffer from more than 1 category of shock
T
hypovolemic shock is characterized by
profound decrease in intravascular blood volume; generally loss of >30-40% blood volume or >10-15% dehydration
what are the 2 etiologies of hypovolemic shock
1) blood loss/hemorrhage (internal or external)
2) dehydration (burns, GI, polyuria, 3rd space losses)
what are the fluid shifts during hypovolemic shock
to address the hypoperfusion of tissues, fluid shifts from the interstitial/intracellular spaces to the intravascular spaces
what happens during phase 1 of hypovolemic shock
1) water moves from interstitial space to intravascular space, diluting PCV and TS
2) splenic contraction in dogs/horses raises PCV slightly
what are indicators of BLEEDING in a trauma patient on bloodwork
low TS and normal PCV
what are signs of CONTINUED hemorrhage in a patient on bloodwork
low TS and dropping PCV
what happens during phase 2 of hypovolemic shock and what do we see on the blood work
water retention via activation of RAAS -> further drop in PCV/TS
what is obstructive/non-cardiogenic shock
diminished CO secondary to compression of vascular system or obstruction to blood flow
what does obstructive shock behave like
hypovolemic shock
what are some examples of obstructive shock
- GDV
- tension pneumothorax
- pericardial effusion
- pulmonary embolism
what is distributive/vasodilatory shock and what are some causes
failure to distribute blood flow
- sepsis
- hypoadrenocorticism
- anaphylaxis
- drug reactions
- anesthesia
- massive trauma
any TERMINAL stage of shock can cause what type of shock
distributive/vasodilatory
describe the sequence of events in vasodilatory/distributive shock that leads to the hyperdynamic phase
vasodilation -> underfilled venous pool/decreased arterial BP -> reduced SVR -> initially increased CO
what are the clinical signs of the hyperdynamic phase of vasodilatory/distributive shock
- tachycardia
- brick red MM
- increased CO
- rapid CRT
- bounding pulses
- warm extremities
what is the final pathway of all shock and what are the signs
decomposition:
- decreased CO
- decreased contractility
- pale MM
- prolonged CRT
- hypotension
- poor peripheral pulses
what clinical signs of shock are different for vasodilatory shock
1) rapid CRT
2) bounding pulses
3) injected MM
4) warm extremities
what variables do we monitor for patient assessment of shock (7)
1) HR and rhythm
2) MM and CRT
3) pulse quality and BP
4) PCV/TS
5) lactate
6) blood gases
7) urine output
how frequently should you be monitoring a shock patient
every 5-15m
what is normal blood pressure in small animals
S/D = 120/80
MAP = 100
Hypotension is indicated by what systolic and what MAP
systolic <90
MAP <60
what MAP is required for the following:
- cerebral perfusion
- renal perfusion
- muscle perfusion
Cerebral perfusion: >40
Renal perfusion: > 60
Muscle perfusion: >70
femoral pulses are absent once systolic BP drops below; peripheral pulses are absent once systolic BP drops below
40 mmHg; 60-70mmHg
what is normal urine production
1-2ml/kg/hr
what is normal lactate
<2 mmol/L
what is the best and most current way to note patient response to shock therapy
trending lactate (should be going downward)
what acid-base disturbance is shock associated with
metabolic acidosis
what does a blood-gas machine anaylse
- pH
- BE
- CO2
- O2
- HCO3
delivery of oxygen to tissues is dependent on
1) CO
2) oxygen content of arterial blood
what are the necessities for tissue perfusion (5)
- efficient pump
- adequate intravascular volume
- vasomotor tone
- adequate Hg/PVC
- good lung function
what are the 5 things on your resuscitation checklist
1) ensure patent airways and patient breathing
2) administer supplemental O2
3) intravascular volume support
4) pain medication
5) address primary problem
what is the endpoint of fluid therapy for a patient
normalization of vital signs
what is a good goal for rate of administering crystalloids to address shock
1/4 dose of shock rate per 15 min and re-assess
what catheter requirements are necessary for rapid IV fluid administration
short and large catheter
how should you administer colloids
1/4 aliquots over 5-10 min; repeat up to 4x as necessary
what happens to crystalloid requirements when colloids, hypertonic saline, or blood products are used
requirements are reduced by 50%
if you see your patient responding to fluid therapy, what should you do
decrease the bolus by half in the next 15 minutes
how should you address dehydration
1) with anesthesia
2) without anesthesia
1) replace 1/2 deficits before induction
2) replace over 12-24h
what is the conservative bolus of crystalloids that works to address shock most of the time
10 ml/kg in 15 min and reassess
what is the mainstay of analgesia in a shocky patient
opioids (minimal CVS and respiratory depression)
when should you administer antibiotics for resuscitation
- open wound
- bacteremia/sepsis a strong differential diagnosis
- immunocompromised patient
what is the best monitoring for shock
- clinical signs of shock (should see improving)
what are some possible consequences of shock
- GI hemorrhage/ulceration
- kidney failure
- bacterial translocation
- endotoxemia/sepsis
- DIC
- multiple organ failure
- respiratory failure
