Hypovolemic shock is a condition characterized by inadequate blood volume to deliver oxygen to tissues, often resulting from dehydration or blood loss. Key clinical signs include tachycardia, pale mucous membranes, and hypotension, necessitating prompt assessment and fluid therapy to restore vascular perfusion. Treatment options include isotonic crystalloids, colloids, and hypertonic saline, with a focus on patient stabilization and careful monitoring.

1. HYPOVOLEMIC SHOCK
By: Abigail Schmidt

2. What is shock?
 Shock is a syndrome that is the clinical result
of oxygen delivery insufficiency to the cell
requirements of the body
 Hypovolemic
 Absolute: loss of blood volume or fluid
 Relative: cardiogenic problem or venous
obstruction
 OR
 Hyperdynamic
 Most common in septic animals

3. HYPOVOLEMIC SHOCK
 Most common type
 Inadequate circulating volume to deliver
oxygen effectively to tissues
 Loss of intravascular volume
 Dehydration i.e. vomiting
 Blood loss i.e. splenic rupture
 3rd spacing of fluids i.e. into distended stomach

4. Signs of Hypovolemic Shock
 Compensatory events take place:
 Tachycardia (low preload = reduces cardiac output)
 Peripheral vasoconstriction
 Hypotension
Decreased perfusion to essential organs,
development of acidosis

5. Primary Clinical Signs
 Pale MMs
 Prolonged CRT
 Tachycardia
 Tachypnea
 Cool extremities
 Poor peripheral pulses
(bounding in early stage)

6. Triage Primary Assessment
ABCD:
 AB: Airway & Breathing
 Is P breathing? Is airway patent?
 Is P working too hard to breathe?
 C: Circulation
 Is heart beating effectively?
 ASSESS FOR SHOCK
 MM/CRT, BP, Pulse Assessment
 D: Debilitating Disease
 Neuro assessment
 Minimum BW: renal parameters, PCV/TP, ALT,
Glucose, E-lytes

7. Triage 2
 Secondary Survey
 Respiratory
 RR, RE, MM, URT (inspiratory) vs LRT (expiratory)
 LOCALIZE
 Cardiovascular
 Arrhythmias, tissue perfusion (BP, lactate, CRT, MM)
 SHOCK
 Neurological
 Abdominal

8. VITAL 1st STEPS
 Necessary to increase tissue perfusion via
fluids
 NEED to exclude:
 Heart disease
 Respiratory disease
 Intracranial disease
BEFORE loading patient with shock-dose rate fluids

9. Heart Disease
 Failure of pump, caused by:
 Heart disease
 Cardiac tamponade
 Arrhythmias
 Thoracic auscultation
 Murmurs
 Pulmonary edema heard as crackles
 Ascites/Jugular distension
Large volume fluid
administration
contraindicated!!!

10. Respiratory Disease
 Tachypnea/Dyspnea with increased sounds
heard on auscultation
 Crackles, wheezes, etc.
 ALTERNATIVELY: dullness indicates pleural
effusion, another contraindication to shock fluids
 Altered mentation/increased ICP
 Neurologic signs
 Seizures, Blindness, Absent PLR, Incoordination etc.
Intracranial Disease

11.  Low BP  activation of sympathetic nervous
system
 Tachycardia
 PeripheralVasoconstriction
 Fluid retention
 Protective response may make patients seem
more stable than what they truly are.
Pathological Consequences
In attempt to
maintain BP and
perfusion

12. What to do BEFORE referring
 Check important parameters:
 HR, BP, temperature
 BP may initially be normal due to sympathetic NS
 Then decline/drop low
 MM, CRT, Pulse rate/quality, RR
 Cats vs. Dogs
 Dogs: bradycardia
 worsening “shock” state = worse prognosis
 Cats often don’t present tachycardic (less scary)
 Cats more susceptible to fluid overload
 Monitor respiratory rate/effort!
 Cats more prone to hypothermia  active warming

13. Circulatory & Hypovolemic Shock
Clinical Sign Vasodilatory Vasoconstrictory
Mild/ Moderate Severe/ Compensated Decompensated
Heart rate 130-150 150-170
170-200, may become
bradycardic
Pulse strength
Bounding (due to dilated
blood vessels)
Weak becoming absent.. …
Mm colour Bright red (hyperemic) Pink to Pale becoming.. White/grey
CRT
<1sec (blood pooling in
vessels)
~2 seconds >2 seconds
Temperature of
Extremities
Warm (vasodilation)
Cooler
(vasoconstriction)
Cool
Metatarsal pulse
palpable
Easily Just Absent

14. WHY give Fluids for
Hypovolemic Shock
- Lack of perfusion can kill animals quickly
OR
- Shock consequences can cause significant
mortality in the days following insult/injury
Cellular
Hypoxia
Free radical
generation
Inflammatory
Mediators

15. SIRS  MODS  DIC
 Systemic Inflammatory Response Syndrome
 Inflammatory mediators cause disruption of
homeostasis
 Loss of vascular tone
 Endothelial permeability barrier disruption
 Stimulation of coagulation
 Microvascular thrombosis resulting in…
 Multiple Organ Dysfunction Syndrome
 Disseminated Intravascular Coagulation
 IV activation of coagulation with loss of localization
DIC aka

16. Shock Treatment Aims
 Provide oxygen support
 Connect to appropriate monitoring
 Vascular access and BP
 Shock fluid boluses to restore vascular perfusion
and oxygen delivery to tissues
 Pain medications if needed
 Stabilize the patient and send to IndyVet! 

17. Isotonic Crystalloids
i.e. Hartmann’s aka LRS,
0.9% Sodium Chloride
 Same concentration of solutes as blood; same
osmotic pressure
 Small molecules freely pass out of BVs, able
to enter all body compartments
 1/5 of total volume given = actually remain in BVs
1-2 hrs later

18. Crystalloids 2
 “Shock doses” = 60-90 ml/kg, but given in
incremental boluses delivered over 15-20 min
 Assess P after each bolus; repeat if necessary
**Rapid expansion of blood volume with
crystalloids may worsen blood loss
**Risk of interstitial edema, dilution of RBCs
and clotting factors with repeated boluses

19. Colloids
i.e. Hetastarch, Dextran 70
 Large molecules which do NOT pass out of BVs
 Expand IV space by increasing oncotic pressure
 “Shock doses” = 20 ml/kg
 Given as boluses of 5-10 ml/kg
 Cons
 Synthetic can cause
acquired coagulopathy
 Expensive, not multi-
purpose
 Pros
 Less volume needed
 Useful with large Ps
 IV expansion lasts longer
(up to 12 hrs)

20. Hypertonic Saline
i.e. 7% NaCl
 Rapid expansion of IV compartment
 Draws H2O into vascular space from interstitial
compartment, endothelial cells, and RBCs
 “Shock dose” = 4-7ml/kg of 7% hypertonic saline
 Given over 20 min
 Cons
 Short-acting, benefits last
<1 hr
 Administration may result
in bradycardia &
arrhythmias
 CANNOT BE USED if P is
dehydrated or has marked
electrolyte disturbances
 Pros
 Small volumes needed
 CV function improvements
 Myocardial contraction,
 Head trauma, penetrating
wounds, reduces
inflammation

21. Blood Products
 NOT the 1st line of treatment for
shock
 Can’t be given fast enough
 Risk transfusion reactions
 Animals in shock don’t die of
anemia
 They die of LACK of vascular volume
 Transfusion may be needed after
initial resuscitation to keep
HCT > 20-25%
***Expensive

22. Pain Medications
 Avoid NSAIDs
 Opioids *critically ill patient
 Torb (Butorphanol) – 0.1-0.5 mg/kg,
IV, IM, SC q 2-6 hrs
 Buprenex (Buprenorphine) – 0.005-0.02 mg/kg,
IV, IM, SC q 4-12 hrs
 Hydromorphone – 0.05 to 0.2 mg/kg,
IV, IM q 1-4 hrs
 Injectable, varying effects (partial vs. full agonist)
 Partials better for respiratory compromised
 Reversible with Naloxone

23. Questions?