1 GSACEP core man LECTURE series: SCHOCK Brian Kitamura MD, CPT, USARNG Updated: 20APR2013

2 Disclaimer Views and opinions expressed do not necessarily reflect those of GS-ACEP, The Department of Defense, the U.S. Army, the U.S. Government, or any other governmental or nongovernmental organization unless explicitly stated.

3 Outline Shock Definition Types of Shock Cardiogenic Distributive Obstructive Hypovolemic 3

4 Definition of Shock “Shock is circulatory insufficiency that creates an imbalance between tissue oxygen supply (delivery) and oxygen demand (consumption).” Tintinalli’s Emergency Medicine, 7 th ed “In philosophic terms, shock [is the] transition between life and death” Rosen’s Emergency Medicine, 7 th ed 4

5 Definition of Shock In short, the tissues are not getting the oxygen they require Can often be qualified as a “fluids,” “pump,” or “pipes” problem It really is all plumbing Pulmonary and toxicologic causes of shock are outside the scope of the lecture 5

6 Definition of Shock Bedside determination of shock Systolic Blood Pressure < 90 Mean Arterial Pressure < 65 Shock index > 1 (Heart Rate/Systoilc BP) Elevated Lactate Decreased level of consciousness with brain injury All just general guidlelines Pulmonary and toxicologic causes of shock are outside the scope of the lecture 6

7 Cardiogenic Shock “Pump Problems” Essentially heart failure Caused by: Acute Myocardial Ischemia Cardiomyopathy Dysrhythmias Structural damage 7

8 Cardiogenic Shock Acute MI Heart Muscle is stunned or dead Blood flow is restricted to an area of muscle Muscle doesn’t contract properly Treatment Relieve the blockage: Aspirin, thrombolytics, stents/angioplasty, bypass 8

9 Cardiogenic Shock Congestive Heart Failure Heart muscle is globally weak Multiple heart attacks, high blood pressure, weakened ventricles, stiff ventricles Fluid overload stretches the heart Treatment Optimize the physiology Decrease blood pressure Decrease volume 9

10 Cardiogenic Shock Dysrhythmia Irregular rhythm prevents forward flow of blood Treatment Cardioversion/Defibrilation, antiarrhythmics 10

11 Cardiogenic Shock Structural Disturbances Penetrating trauma Valve disorders Treatment: Cold steel 11

12 Cardiogenic Shock Structural Disturbances Penetrating trauma Valve disorders Treatment: Cold steel 12

13 Distributive Shock “Pipe Problem” Leaky blood vessels (microscopic) Lack of vascular tone or “squeeze” “Warm Shock” Septic Shock Anaphylactic Shock Neurogenic Shock 13

14 Septic Shock Infection causes release of inflammatory signals Blood vessels “leak” to allow more blood flow, infection fighting cells out into the tissues System is overrun in shock Treatment Provide fluids first, then pressors 14

15 Anaphylactic Shock Massive, rapid, histamine release in response to a specific antigen Blood vessels dilate and leak Treatment EPINEPHRINE! Benadryl, Steroids 15

16 Neurogenic Shock Brain or spinal cord injury Neurologic system has constant control over vascular tone If input is lost, vessels dilate Treatment Vasopressors 16

17 Obstructive Shock Blockage prevents forward movement of blood Pulmonary Embolism Tension Pneumothorax Cardiac Tamponade 17

18 Pulmonary Embolism Blood clot from the venous system gets lodged in the lungs Common post traumatic patients Treatment: Difficult, but we use anticoagulants, lytics 18

19 Tension Pneumothorax Pressure builds up in the chest preventing return of venous blood Seen in chest trauma Treatment: Needle decompression, chest tube 19

20 Cardiac Tamponade Pressure builds up in the pericardial sac Seen in chest trauma Treatment: Pericardiocentesis 20

21 Hypovolemic Shock “Fluid Problem” Loss of fluid Loss of blood 21

22 Hypovolemia Non-blood losses decrease plasma volume Sweating GI Losses Inadequate Intake Treatment: Replace fluids - oral or IV 22

23 Hemorrhage Just like is sounds, someone is bleeding out Trauma GI Bleeding Stop the bleeding Resuscitate with crystalloids first, blood if needed. 23

24 In summary Shock is inadequate perfusion Treat underlying causes if possible Resuscitate based on cause 24

25 References Tintinalli’s Emergency Medicine 7th Edition Rosen’s Emergency Medicine 7 th Edition 25