2. Shock
Overview
• Definitions
• Initial Assessment – ABC
• Stages of Shock
• Physiologic Determinants of Shock
• Types of Shock
• Common Features of Shock
• H & P / Work-up
• Case scenarios and Management
• Take Home Points
3. Shock
Definitions
• Shock is a physiologic state characterized
by systemic reduction in tissue perfusion,
resulting in decreased tissue oxygen
delivery
• Hypotension is not a requirement
• Poor tissue perfusion
4. Shock
Initial Assesment - ABC
• Airway:
– Does pt have mental status to protect airway?
– GCS less than “eight” means “intubate”
– Airway is compromised in anaphylaxis
• Breathing:
– If pt is conversing with you, A & B are fine
– Place patient on oxygen
• Circulation:
– Vitals (HR, BP)
– 2 large bore (#16g) IV, start fluids (careful if
cardiogenic shock), put on continuous monitor
5. Shock
ABC “DE”
• In a trauma, perform ABCDE, not just ABC
• Deficit or Disability
– Assess for obvious neurologic deficit
– Moving all four extremities? Pupils?
– Glascow Coma Scale (M6, V5, E4)
• Exposure
– Remove all clothing on trauma patients
6. Shock
Stages / Spectrum of Shock
• “Preshock” aka compensated/warm shock
– Body is able to compensate for ↓perfusion
– Up to ~10% reduction in blood volume
– Tachycardia to ↑cardiac output & perfusion
• “Shock”
– Compensatory mechanisms overwhelmed
– See signs/symptoms of organ dysfunction
– ~20-25% reduction in blood volume
• “End-organ dysfunction”
– Leading to irreversible organ damage/death
7. Shock
Physiologic Determinants
• Global tissue perfusion is determined by:
• Cardiac output (CO)
– CO = Heart rate (HR) times Stroke Volume (SV)
– SV = function of Preload, Afterload, Contractility
• Systemic vascular resistance (SVR)
– Variables: Length, Inverse of Diameter, Viscosity
8. Shock
Types of Shock
• Hypovolemic shock – from ↓preload
– Hemorrhage
– Fluid Loss (Vomiting, Diarrhea, Burns)
• Cardiogenic shock – pump failure or ↓SV
– MI, arrhythmia, aortic stenosis, mitral regurg
– Extracardiac obstructive causes such as PE,
tension pneumothorax, tamponade
• Distributive (vasodilatory) shock - ↓SVR
– Septic, anaphylactic, and neurogenic shock
– Pancreatitis, burns, multi-trauma via activation
of the inflammatory response
9. Shock
Common Features of Shock
• Hypotension (not an absolute requirement)
– SBP < 90mm Hg, not seen in “preshock”
• Cool, clammy skin
– Vasoconstrictive mechanisms to redirect
blood from periphery to vital organs
– Exception is warm skin in early distrib. shock
• Oliguria (↓kidney perfusion)
• Altered mental status (↓brain perfusion)
• Metabolic acidosis
10. Shock
H&P / Work-up
• History to determine etiology
– Bleeding (recent surgery, trauma, GI bleed)
– Allergies or prior anaphylaxis
– Sx consistent with pancreatitis, EtOH history
– Hx of CAD, MI, current chest pain/diaphoresis
• Physical examination
– Mucous membranes, JVD, lung sounds,
cardiac exam, abdomen, rectal (blood), neuro
exam, skin (cold & clammy or warm)
• Labs/Tests directed toward suspected dx’s
11. Shock
Case 1
• 55yo male otherwise healthy who is fresh
post-op from a colon resection for CA
• Called for tachycardia, hypotension,
altered mental status, and abd distension
• On exam: pale, dry mucous membranes,
disoriented, abdomen is tender and tense
• UOP is 15mL over past hour
• What else do you want to know?
• What is the most likely diagnosis?
12. Shock
Case 1
• The one thing you want to know: Hct (Hgb)
• Dx: Hemorrhagic (hypovolemic) shock
• Management
– ABC (need intubation? IV access?)
– Wide open fluids and T&C 6 units PRBC
– Send coags when sending for CBC
– Make sure it’s not an MI (chest pain, EKG)
– Give blood & prepare for re-exploration in OR
13. Shock
Case 2
• 75yo male PMH CAD, PVD, DM who is
post-op from AAA repair complains of
crushing substernal chest pain
• Stat 12-lead EKG shows ST elevation in 2
contiguous leads
• What do you do?
• What is the diagnosis?
14. Shock
Case 2
• ABC, get good access, continuous monitor
• Dx: Acute ST elevation MI
• Treatment: “MONA”
– Oxygen, Aspirin, Nitroglycerin, Morphine
– Beta-blockade (no heparin or tPA due to surg)
– Plavix & GP IIb/IIIa inhibitor (i.e. eptifibatide)
– Stat cardiology consult for cardiac cath
15. Shock
Case 2, continued
• Cath reveals critical stenosis of left main
s/p balloon angioplasty
• 24 hrs later, in ICU intubated
• Vitals: 80/50
• On exam: cool, clammy extremities
• Echocardiogram: severe LV dysfunction
• What is the diagnosis & management?
16. Shock
Case 2, continued
• Dx: Cardiogenic shock 2ndary to STEMI
• Management
– Ventilator support (remember, ABC)
– Aspirin, Heparin (maintain coronary patency)
– Inotropes and Vasopressors
– Pulmonary artery catheter to optimize volume
status and cardiac function
– May need intra-aortic balloon pump
17. Shock
Case 3
• 60yo male heavy drinker brought in by
EMS with nausea, vomiting, severe
epigastric pain radiating to the back
• Tachycardic, hypotensive
• Altered mentation, dry mucous
membranes, minimal UOP after Foley
• What is the most likely diagnosis?
– Differential diagnosis?
• How do you manage this patient?
18. Shock
Case 3
• Acute pancreatitis
– DDx of acute abdomen: Perforated viscus,
acute mesenteric ischemia, cholecystitis,
SBO, Ruptured AAA, MI
• Hypovolemic shock from vomiting and
Distributive shock from the inflammation:
vasodilation, vasopermeability (3rd-space)
• These pts require heavy, heavy fluid resus
• Treatment: Push heavy fluids, NPO, NGT
• Can feed post-pyloric, consider CT scan
19. Shock
Case 4
• 55yo male also post-op from colon
resection for CA, epidural placed for post-
operative pain control
• Called by nurse for hypotension and
bradycardia
• Abdomen soft, no pallor, altered mentation
• Hct is 38
• Most likely diagnosis?
20. Shock
Case 4
• Neurogenic shock 2ndary to epidural
• Differentiated from hypovolemic due to
bradycardia
• Treatment is:
– IVF
– Turn down or turn off epidural
– If BP does not respond, then alpha-agonist
such as phenylephrine until above measures
stabilize patient, then wean the vasopressor
21. Shock
Case 5
• 25yo male presents with diffuse abdominal
pain of 1day duration, started initially as
epigastric pain after a meal. Takes
ibuprofen 3x a day.
• Vitals: hypotensive, tachycardic
• Tense abdomen, involuntary guarding,
altered mental status, oliguric
• What is the diagnosis & management?
22. Shock
Case 5
• Septic shock 2ndary to perf duodenal ulcer
– This patient has diffuse peritonitis
• Management:
– ABC, IV & resuscitation (requires heavy fluids)
– Broad-spectrum IV antibiotics
– Emergent OR for ex-lap, washout & repair
– If pt does not respond to fluids, may need
vasopressors (norepinephrine, dopamine)
• Have beta-agonist effects to help pump function as
well as alpha-agonist for periph vasoconstriction
23. Shock
Take Home Points
• Shock = poor tissue perfusion/oxygenation
– Know difference btw compensated/uncomp shock
• 3 types are based on physiology of shock
– Hypovolemic due to decreased preload
– Cardiogenic due to decreased SV or CO
– Distributive due to decreased SVR
• Know the common signs a/w shock
– Oliguria, AMS, cool/clammy skin, acidosis
• Work-up & management starts with ABC
• Aggressive resuscitation except if cardiogenic
• Vasopressors if hypotensive despite fluids
