Shock

Shock: Definitions Shock = inadequate tissue perfusion –Decreased O2 delivery, removal of metabolites Tissue perfusion is determined by: –Cardiac output (CO) = HR x SV SV = function of preload, afterload, contractility –Systemic vascular resistance (SVR)

Shock Shock: Types Hypovolemic Septic (high CO, low SVRI) Cardiogenic (high CVP) Neurogenic Anaphylactic Adrenal insufficiency

Shock Shock Types & Physiology ShockCVP/PCWPCOSVRI Hemorrhagic Septic Cardiogenic Neurogenic Hypoadrenal Anaphylactic

Shock Shock Types & Physiology ShockCVP/PCWPCOSVRI Hemorrhagic↓↓↑ Septic Cardiogenic Neurogenic Hypoadrenal Anaphylactic

Shock Shock Types & Physiology ShockCVP/PCWPCOSVRI Hemorrhagic↓↓↑ Septiceither↑↓ Cardiogenic Neurogenic Hypoadrenal Anaphylactic

Shock Shock Types & Physiology ShockCVP/PCWPCOSVRI Hemorrhagic↓↓↑ Septiceither↑↓ Cardiogenic↑↓↑ Neurogenic Hypoadrenal Anaphylactic

Shock Shock Types & Physiology ShockCVP/PCWPCOSVRI Hemorrhagic↓↓↑ Septiceither↑↓ Cardiogenic↑↓↑ Neurogenic↓↓↓ Hypoadrenal Anaphylactic

Shock Shock Types & Physiology ShockCVP/PCWPCOSVRI Hemorrhagic↓↓↑ Septiceither↑↓ Cardiogenic↑↓↑ Neurogenic↓↓↓ Hypoadrenaleither↓↓ Anaphylactic

Shock Shock Types & Physiology ShockCVP/PCWPCOSVRI Hemorrhagic↓↓↑ Septiceither↑↓ Cardiogenic↑↓↑ Neurogenic↓↓↓ Hypoadrenaleither↓↓ Anaphylactic↓↓↓

Shock Hypovolemic Shock Body’s response to hypovolemia –Rapid: peripheral vasoconstriction, increased cardiac activity –Sustained: arterial vasoconstriction, Na/water retention, increased cortisol 2/2 hemorrhage or fluid loss Classes of hemorrhage: I: 15% II: 30% = tachycardia III: 40% = decreased SBP, confusion IV: >40% = lethargy, no UOP Tx: stop source / fluids / blood

Shock Septic Shock SIRS = T >38C or 90, RR >20, PaCO2 12 or <4 Sepsis = SIRS + focus of infection Severe sepsis = sepsis + MSOF Septic shock = sepsis + refractory hypotension Remember: septic shock is a/w high CO Tx: fluids, antibiotics

Shock Cardiogenic Shock Cardiogenic shock 2/2 cardiac disease or cardiac compression –Cardiac disease: MI, arrhythmia, valve dysfunction, increased PVR or SVR, increased ventricular resistance –Cardiac compression: tension PTX, cardiac tamponade, positive pressure ventilation Look for Beck’s triad in tamponade (hypotension, JVD, muffled heart sounds) Tx: fluids, tx underlying cause (relieve PTX, pericardiocentesis, change ventilator settings)

Shock Neurogenic Shock Shock 2/2 spinal cord injury, regional anesthesia, autonomic blockade Mechanism: loss of vasomotor control, expansion of venous capacitance bed Signs: warm skin, normal or low HR, normal CO, low SVR Tx: Fluids / pressors / +- steroids

Shock Hypoadrenal Unresponsive to fluids or pressors Tx: steroids

Shock Shock: Signs Hypotension, tachycardia, tachypnea Change in MS, lethargy Decreased UOP

Shock Shock: Evaluation Airway: includes brief evaluation of mental status Breathing Circulation: includes placement of adequate IV access Disability: identification of gross neurologic injury Exposure: ensures complete exam History: OPQRST, review PMHx, PSHx, ALL, SHx PE: complete Labs: include ABG (pH, base deficit, lactate)

Shock Case 1 55y M post-op day 0 s/p colectomy Called for tachycardia, hypotension, altered mental status, abdominal distension, decreased UOP PE: pale, disoriented, abdomen tense, UOP 15mL/hr What is your diagnosis? What additional information should you obtain? What is the plan?

Shock Case 1: Continued Dx: hemorrhagic shock Additional information: CBC, coags, T&C Management –ABC (intubate, IV access) –Resuscitate (isotonic IVF) –Prepare for take-back

Shock Case 2 75y M h/o CAD, PVD, DM, POD 1 s/p AAA repair c/o nausea What do you need to think about? What is the plan?

Shock Case 2: Continued Dx: MI Plan: –ABC –MONA, beta-blockade –Labs/x-rays: cardiac enzymes Q8H x3 sets w/EKG, chemstick, BMP, CXR –Cardiology consult

Shock Case 2: Continued Cath w/critical stenosis of left main s/p balloon angioplasty PE: intubated, 80/50, UOP 10mL/hr Echo: severe LV dysfunction What is the diagnosis? What is the plan?

Shock Case 2: Continued Dx: Post-myocardial infarction (cardiogenic) shock Plan: –ABC Pressor support as needed Placement of Swan-Ganz catheter +/- Intra-aortic balloon pump, cardiac assist device

Shock Case 4 55y M POD 0 s/p colectomy, w/epidural placed for post-op pain control Called by nurse for hypotension and bradycardia PE: AAOx3, abdomen ND, NT Recent post-op labs: HCT 35 What is your working diagnosis?

Shock Case 4: Continued DX: Neurogenic shock 2/2 epidural Treatment is: –IVF –Turn down or turn off epidural –If BP does not respond to IVF, initiate pressor support w/alpha-agonist such as phenylephrine

Shock Case 5 45y M p/w diffuse abdominal pain. PMHx PUD, chronic NSAID usage. PE: febrile, tachycardic, hypotensive, lethargic, rigid abdomen w/ involuntary guarding What is your working diagnosis? What is your plan?

Shock Case 5 Dx: septic shock 2/2 duodenal perforation Plan: –ABC –Broad-spectrum IV antibiotics –Emergent OR for ex-lap, washout & repair

Shock Shock: Take Home Points Shock = inadequate tissue perfusion Types of shock: hypovolemic, septic, cardiogenic, neurogenic, anaphylactic Signs of shock: altered MS, tachycardia, hypotension, tachypnea, low UOP Always start with ABCs Resuscitation begins with fluid