Flashcards in Shock (MR) Deck (81):
Circulatory system failure to supply O2 and nutrients to meet metabolic and cellular demand
Equation for BP?
BP = CO * SVR (systemic vascular resistance)
Equation for CO?
CO = HR * SV
What does Stroke Volume depend upon?
Preload Afterload Contractility
Equation for Delivery of O2 (DO2)?
CO * CaO2 (Arterial O2 Content)
Equation for CaO2?
CaO2 = [Hb]*1.34*SaO2 + (PaO2 * 0.003)
What does SaO2 mean?
Arterial O2 Saturation
TQ!!! What are the Abnormalitites in Perfusion Parameters (6)? When is shock likely?
Mentation CRT MM Color Extremity Temp Pulse Quality An abnormality in ANY of them!
Why does mentatin represent perfusion?
Brain O2 dependent perfusion
Why do Mucous Membranes represent perfusion?
White/pale = Vasocontriction & Anemia Red – Vasodialation Venous pooling
Why does CRT represent perfusion? What Lengthens CRT? Shortens?
Time to refill capillaries after digital pressure Vasoconstriction Vasodialation
How does pulse quality represent perfusion?
Shows fullness or body of pulse
How does ↓ Extremity Temperature represent pulse?
How does HR represent perfusion?
HR will ↑ to ↑ CO
What are the 3 parts of the Circulatory System?
Pump Fluid Tubes
What are the tube types?
Low Pressure High Pressure
Low pressure tubes?
Systemic Capillaries -> Right Heart -> pulmonary circ -> left atrium
High Pressure tubes?
Left ventricle to capillaries
When patient comes in and you are assessing for shock, what will you check?
A = Airway B = Breathing C = Circulation D = Disability E = External
How will you check Airway?
What will you check for Breathing?
RR, Posture, Effort, Character, Breath Sounds
How will you assess circulation?
MM color CRT Pulse Cardiac Auscultation
What is CRT < 1 sec? What else can you assess to find this condition? What causes it?
Hyperdynamic Pulse Anemia or Sepsis
How will you assess pulse?
1 per Heart Beat Strength
Things to asses upon auscultation?
Rate Rhythm Murmurs
What should be assesed for disability?
Level of consciousness Ambulation Sensation
What to assess Externally?
Fractures Open Wounds Augulations/Deformities Crepitus Hernias Hemorrhage Swelling/Bruising
What type of event is shock?
Cellular - Inadequate cellular energy production
3 Main types of Shock?
How many types can a patient have at once Hypovolemia - The Fluid Cardiogenic - The Pump Distributive - The Tubes ≥ 1
Events leading to shock?
↓ effective circulating VOLUME Reduced O2 Carrying Capacity ↓ Pump Efficiency Changes in Vascular Tone & Responsiveness
How do the tissues initially deal with ↓ O2 delivery (DO2)?
They pull more blood from circulation for O2
What is critical point?
A critical ↓ in DO2 (Delivery of O2 to tissues) where Shock ensues.
When O2 isnt available what happens?
Anaerobic metabolism -> Lactic Acidosis
What are high leels of Lactic Acidosis correlated with?
What is Lactic Acidosis created by? What is produced?
Anaerobic glycolysis Lactate & H+
Where does Lactate accumulate? What does this Reduce?
INTRAcellularly EXTRAcellulat HCO3-
What conditiondoe lactic acidosis contribute to?
Stages of Shock?
Compensated Uncompensated Terminal/Reversible
Describe compensated shock?
Blood Flow: Normal -> ↑ Possibly Maldistributed Vital Organ Function= Maintained
Describe Uncompensated Shock?
Micro-vascular perfusion compromised Significant reduction in circulating volume
Describe Terminal/Irreversible shock?
Inadequate perfusion to bvital organs Irreparable damage Incompatible with life
What is hypovolemic shock?
↓ Effective Circulating Volume (ECV)
What is ECV?
Volume of Arterial Blood perfusing Tissues
Severely reduced tissue perfusion leads to?
Cellular hypoxia and eventually death
Causes of hypovolemic shock?
Hemorrhage - Whole blood or plasma ↓ in Na+ Excessive losses - dxa/vomit
Dehydration represents loss of fluid from what space?
What does Extracellular space is represented by?
interstitial and intravascular
How does body initially react to hypovolemia? How does it compensate?
↓ CO 2º to ↓ Venous Return Compensation: ↑ Sympathetic Tone - Vasoconstriction - 1º compensation ↑ Cardiac Contractability Tachycardia to ↑ CO – initially Microvasculature alteration - fluid from interstitium ↓ Renal Perfusion RAAS Activation - Na+ & H2O retention
Clinically what will hypovolemic shock patients look like?
Mildly depressed Normal -> slightly ↓ Pulse Quality Normotension Normothermia Sluggish - CRT 2 - 2.5 sec Pale MM color
Can patient in shock have normla BP?
What will Late shock patient look like clinically?
Severe Depression Poor Pulse Quality Hypotension Hypothermia CRT > 3 sec MM Pale
What does MODS mean?
Multiple Organ Dysfunction Syndrome
TQ!!! How are Cats different in Hypovolemic Shock?
Bradycardia! Dull Mentation Hypothermia
Shock organs for Cats?
Liver*** & Lungs
Shock organ for Dogs?
Dx of Hypovolemic Shock?
PCV/TS Lactate Blood Gas Analysis BUN/CRE SpO2 - Saturation O2 NIBP - non-invasive BP LATER - Radiographs, full CBC, Chem, UA
Distributive Shock (Vasodilatory): Loss of systemic vascular resistance is a problem with which part of the circulatory system? What is happening?
TUBES Maldistribution of Blood Flow
Why does Distributive shock occur?
Sepsis Vascular obstruction Anaphylaxis - MOST COMMON
What are the two phases of Distributive Shock?
Hyperdynamic - tachycardic, febrile, bounding pulses Hypodynamic
Hyperdynamic phase of Distributive look like?
Tachycardia to ↑ CO Febrile Bounding Pulses Rapid CRT < 1 sec Hyperemic Mucus Membranes - CYTOKINES
What is the cause of Peripheral vasodialation with Distributive Shock?
When does Hypodynamic phase of Distributive shock occur? CX?
after Hyperdynamic phase Compensation is failing Still Tachycardic – CYTOKINES Prolonged CRT Pale/Icteric MM Hypothermia
What will occur once in hypodynamic phase?
Organ damage or failure
Cardiogenic Shock: why?
PUMP failure CHF Arrhythmias Cardiac tamponade Drugs -> Myocardial Depression
What types of drugs lead to myocardial depression?
Anesthetics Beta-Blockers Ca2+ Channel Blockers
Is there a volume issure with cardiogenic shock?
What is failure of forward flow? What can cause this?
Systolic Failure Ventricular Tachycardia What type of failure is Restrictive Filling? Condition that can cause this? Diastolic Failure Hypertrophic Cardiomyopathy
Presentation in cardiogenic shock? Clues it is cardiogenic?
Low mentation Pale MM Weak Pulses Tachycardic Slow CRT Crackles, tachypnea, dyspnea, murmur, arrhythmia, abd distention, fluid thrill
What tells you if you are treating shock appropriately?
Terminal Shock: What occurs?
↓ Coronary Blood FLow - myocardial damage ↓ CNS Blood Flow – Vasoconstriction Cytokine Release - cell damage/death
What are the expected changes in vascular tone: Hypovolemic Shock?
What are the expected changes in vascular tone: Distributive Shock?
What are the expected changes in vascular tone: Cardiogenic Shock?
What are the expected changes in Cardiac Output: Hypovolemic Shock?
↑ with Vasoconstriction then ↓ with continued loss
What are the expected changes in Cardiac Output: Distributive Shock?
What are the expected changes in Cardiac Output: Cardiogenic Shock
What are the expected changes in Systemin Vascular Resistance: Hypovolemic Shock?
What are the expected changes in SVR: Cardiogenic Shock?
What are the expected changes in SVR: Distributive Shock?
What are the expected changes in mechanism of organ damage: Hypovolemic Shock?
ischemia Inflammatory Mediators