Shock and Resuscitation

1. Shock and Resuscitation Chapter 15

2. Objectives • Discuss etiologies of shock • What the common categories of shock are • Specific types of shock • What the body’s responses are to shock • Discuss shock assessment • Discuss age considerations • What the general goals are of pre-hospital management of shock • Pathophysiology of cardiac arrest • Discuss terms related to resuscitation • The points of resuscitation in cardiac arrest • Discuss AED and CPR • Discuss the recognition and treatment of cardiac arrest • Talk about the special considerations of the AED

3. Etiologies of Shock Shock is inadequate tissue perfusion (hypoperfusion) • Less oxygen is delivered to the cells than is needed for normal metabolism • The elimination of carbon diozide and other waste products is impaired

4. Etiologies of Shock Three Etiologies provide a foundation for general emergency care; • Inadequate Volume • Will have a decrease in preload, which will cause the stroke volume and cardiac output to fall • May result from a loss of whole blood from bleeding • May result from a loss of plasma volume from diarrhea, burns, excessive urination, increased capillary leakage, and excessive vomiting

5. Etiologies of Shock • Inadequate Pump Function • May result from an injury to the heart that reduces its ability to generate strong enough contractions • May result from weakening over time from disease, old age, or injury • May result from mechanical obstruction of the movement of blood into the heart

6. Etiologies of Shock • Inadequate Vessel Tone • Tone is related to the size of the vessel • The sympathetic nervous system regulates vessel size • Inadequate vessel tone may result from an injury to the spinal cord or released chemical mediators that cause a systemic dilation of vessels

7. Categories of Shock

8. Perfusion Triangle Blood Vessels (Container Function) If all the vessels dilate at once, the normal amount of blood volume is not enough to fill the system and provide adequate perfusion to the body. Heart (Pump Function) Damage to the heart by disease or injury. It cannot move blood adequately to support perfusion. Blood (Content Function) If blood or plasma is lost, the volume in the container is not enough to support the perfusion needs of the body.

9. Categories of Shock – Hypovolemic Shock • Caused by low blood volume • Most common type of shock • Generally caused by hemorrhage • Also be caused by burns and dehydration

10. Categories of Shock – Distributive Shock • Associated with a decrease in intravascular volume • Massive systemic vasodilation • Increase in capillary permeability • Reduction in systemic and peripheral vascular resistance • Reduction in systolic blood pressure

11. Categories of Shock – Cardiogenic Shock • Caused by ineffective pump function of the heart • Patient is prone to cardiogenic shock when more than 40% of the left ventricle is lost

12. Categories of Shock – Obstructive Shock • Results from a condition that obstructs forward blood flow • Possible causes: Blood clot, Tension pneumothorax, or Pericardial Tamponade

13. Categories of Shock – Metabolic or Respiratory Shock • Described as the fifth type of shock in some sources • Dysfunction in the ability of oxygen to diffuse into the blood, be carried by hemoglobin, off-load at the cell, or be used by the cell for metabolism

14. Specific Types of Shock Hemorrhagic Hypovolemic Shock • Results from the loss of whole blood from the intravascular space • Relates to whole blood loss that can occur from traumatic injury or medical illness • Reduction in pressure and a decrease in oxygen-carrying capability • Poor perfusion state from an inadequate intravascular volume • Bleeding must be stopped • Administration of whole blood or blood components

15. Specific Types of Shock Non-hemorrhagic Hypovolemic shock • Results from the loss of fluid from the intravascular space • Red blood cells and hemoglobin remain within the vessels • Water, plasma proteins, and electrolytes are lost • Blood volume, pressure and perfusion of cells are reduced • Administration of intravenous fluids may be beneficial

16. Specific Types of Shock Burn Shock • Non-hemorrhagic Hypovolemic shock resulting from a burn injury • Burns may interrupt the integrity of the capillaries and vessels • “Pull” effect draws fluid into the interstitial space, causing edema • Establish and maintain adequate airway, ventilation, and oxygenation

17. Specific Types of Shock Anaphylactic Shock • This is a type of distributive shock • Chemical mediators in the anaphylactic reaction cause massive and systemic vasodilation • Capillaries become permeable and leak • Fluid is forced out into the interstitial space • Systemic vascular resistance is reduced • Blood pressure and perfusion are decreased • Epinephrine is the medication of choice

18. Specific Types of Shock Septic Shock • This is a type of distributive shock • Results from an infection that releases bacteria or toxins in the blood • Vessels dilate and become permeable • Fluid leaks into the interstitial space • Systemic vascular resistance, blood pressure, and perfusion are reduced • Intravascular volume, preload, stroke volume, cardiac output, systolic blood pressure and perfusion are decreased • Manage the airway, ventilation, and oxygenation • Administer intravenous fluids and medication to constrict the vessels

19. Specific Types of Shock Neurogenic Shock • This is also a type of distributive shock, also known as vasogenic shock • May be caused by a spinal injury • May damage the sympathetic nerve fibers that control vessel tone • Vessels dilate • Systemic vascular resistance, blood pressure, and perfusion may drop • Blood will pool in the peripheral vessels • Preload, stroke volume, cardiac output, and systolic BP will decrease • Emergency care focuses on spinal immobilization and management of the airway, ventilation, and oxygenation • Patient may also benefit from intravenous fluids and medication to constrict the vessels

20. Specific Types of Shock Cardiogenic Shock • Most common causes; • Myocardial Infarction • Congestive heart failure • Abnormal cardiac rhythm • Overdose on drugs that depress the pumping function of the heart • Emergency care focuses on management of airway, ventilation, and oxygenation

21. The Body’s Responses to Shock The body attempts to compensate for a disturbance and returns perfusion and tissue function to a normal state Compensatory mechanisms; • Direct Nerve Stimulation • Increase in heart rate • Increase in force of ventricular contraction • Vasoconstriction • Stimulation of the release of epinephrine and norepinephrine

22. The Body’s Responses to Shock Release of Hormones • Epinephrine stimulates alpha and beta receptors • Norepinephrine stimulates alpha receptors • Other hormones decrease urine output, cause further vasoconstriction, cause an increase in glucose in the blood

24. Stages of Shock Compensatory Shock • Near normal BP and perfusion of the vital organs is maintained • Etiology of shock is reversed at this stage, the compensatory mechanisms will continue to maintain the BP and perfusion • A narrow pulse pressure should be noted in the early stages of shock

25. Stages of Shock Decompensatory Shock • Advanced stage in which the compensatory mechanisms are no longer able to maintain BP and perfusion to vital organs • If state continues, the compensatory mechanisms become exhausted • Cells, tissues, and organs become ischemic • Heart function depresses • Blood in capillaries begins to sludge and form microemboli • Blood leaks out of the vessels into the interstitial spaces • The vasomotor in the medulla becomes hypoxic, sympathetic nervous system stimulation is reduced • Aggressive shock management may or may not reverse the process

26. Stages of Shock Irreversible Shock • Stage where the patient outcome is death • Cell, tissue, and organ failure is so severe that it cannot be reversed • Microemboli block capillaries throughout the body • Fibinolysis leads to widespread uncontrolled bleeding

27. Shock Assessment History • Pay attention to chief complaint • Identify signs/symptoms that might provide clues to the etiology of the shock • Gather SAMPLE history

28. Shock Assessment Physical Exam • Assess for signs of shock • Obtain vital signs – BP, Heart rate, pulse character, respiratory rate and tidal volume, skin color, temperature, and condition, SpO2 • Note signs of poor perfusion; • Altered mental status • Pale, cool, clammy skin • Delayed capillary refill • Decreased urine output • Weak or absent peripheral pulses

29. Age Consideration in Shock • Elderly and infants deteriorate rapidly • Children/young adults exhibit minor signs over a long period of time and then decompensate suddenly • Medications in the elderly may prevent some signs/symptoms from appearing • Altered mental status and tachypnea may be most profound signs of shock in the elderly

30. General Goals of Prehospital Management of Shock Management of shock is geared to improving oxygenation of the blood and delivery of oxygen and glucose to the cells General goals; • Secure and maintain a patent airway • Establish and maintain adequate ventilation and oxygenation • Do not hyperventilate • Stop the bleeding using direct pressure • Splint fractures • Do not remove impaled objects • Maintain the body temperature • Keep the patient in a supine position

31. General Goals of Prehospital Management of Shock • Apply PASG • Refer to Whatcom County Protocol’s page 17 • A pelvic fracture is suspected • Systolic BP less than 90 mmHg • Profound hypertension is present • Intra-abdominal hemorrhage is suspected with severe hypotension • Retroperitoneal hemorrhage is suspected with hypotension • Rapidly transport patient • Consider ALS

32. Pathophysiology of Cardiac Arrest Resuscitation is bringing a patient back from a potential or apparent death Cardiac arrest occurs when the ventricles are not contracting or when the cardiac output is completely ineffective Sudden death occurs when the patient dies within one hour of the onset of signs/symptoms

33. Pathophysiology of Cardiac Arrest Three phases the patient goes through following cardiac arrest that lead to biological death; • Electrical phase • Begins immediately upon cardiac arrest and ends four minutes afterwards • Heart is in good condition for resuscitation • Restore an effective electrical rhythm

34. Pathophysiology of Cardiac Arrest 2. Circulatory Phase • Begins at 4 minutes and last through ten minutes following a cardiac arrest • Myocardial cells shift from aerobic to anaerobic metabolism • Myocardial cells become ischemic • Heart is not prepared for defibrillation and is not prone to restarting • CPR will provide oxygen and glucose to the heart, improving chances for defibrillation

35. Pathophysiology of Cardiac Arrest • Metabolic Phase • Begins at 10 minutes after cardiac arrest • Heart is starved of oxygen and glucose • Acid has built up in the heart • Tissues are very ischemic and may begin to die • Sodium/Potassium pump fails • Sodium that stays in the cells attracts water • Cells swell, rupture, and die • Resuscitation during this phase is typically unsuccessful

36. Terms Related to Resuscitation • Downtime – time the patient goes into cardiac arrest until CPR is being performed • Total downtime – Total time from when the patient goes into cardiac arrest until patient is delivered into the emergency department • Return of Spontaneous Circulation (ROSC) – Patient regains a spontaneous pulse during resuscitation • Survival – Patient who survives to be discharged from the hospital

37. Withholding a Resuscitation Attempt • DNR – Do Not Resuscitate • POLST – Physicians Orders for Life-Sustaining Treatment • MOLST – Medical Orders for Life-Sustaining Treatment • A patient with injuries that are not compatible to life • Obvious death in patients who are beyond the point of resuscitation

38. Chain of Survival • Early Access • Early recognition of cardiac event • Easy access to EMS system • Early CPR • Immediate CPR can double or triple chance of survival form VF SCA • Important to begin CPR within 2 minutes of cardiac arrest

39. Chain of Survival • Early defibrillation • Survival of VF SCA decreases approximately 7 – 10% for every minute that defibrillation is delayed • Defibrillation is the procedure of sending an electrical current through the chest • Early ALS • Paramedics who can provide advanced cardiac life support (ACLS) • Advanced EMT’s may be able to provide either all or certain components of ALS

40. Automated External Defibrillation & Cardiopulmonary Resuscitation Types of Defibrillators • Applied to the outside of the chest • Manual • Automated (AED) • Advantages of AED’s • Initial training and education • Speed to operation • Safer, more effective delivery • More efficient monitoring

41. Types of AED’sFully automated AED’s and Semiautomated AED’s

42. Analysis of Cardiac Rhythms • Ventricular Fibrillation (VF or VFib) • Disorganized cardiac rhythm • No pulse or cardiac output • Commonly associated with advanced coronary disease

43. Analysis of Cardiac Rhythms • Ventricular tachycardia (V-Tach) • Described as a very fast heart rate • Generated in the ventricle instead of the sinoatrial node in the atrium • Cardiac output is sharply reduced • Be aware that some V-Tach patients are not appropriate candidates for defibrillation • AED should only be used on patients who are pulseless, not breathing and unresponsive

44. Analysis of Cardiac Rhythms AED will detect rhythms for which no shock is indicated • Asystole – Electrical activity and pumping action in the heart is absent • Pulseless Electrical Activity (PEA) – Heart has an organized rhythm, but does not pump • The AED is very sensitive • No one should be touching the patient • Ambulance should be stopped with the motor off

45. When & When Not to Use the AED • Infants – Do not use AED on infants. This statement is in disagreement with Whatcom Co. Protocol page 4. • Patients between 1 – 8 – use AED with a does attenuating system to reduce defibrillation energy • Patients over 8 years of age • Within 5 minutes, apply AED • If over 5 minutes, immediate perform 2 minutes of CPR 30:2 and then apply AED • AED in not for trauma patients • Consult Med control and protocols if unsure about using AED

46. Recognizing and Treating Cardiac Arrest Scene size-up and Primary Assessment • Take appropriate Standard Precautions • Ensure scene is secure • Form a general impression • If a suspected cardiac patient is unresponsive, assess and care for cardiac-related emergencies

47. Recognizing and Treating Cardiac Arrest Unresponsive patients • Open airway • Assess breathing and pulse • No breathing/pulse, patient in cardiac arrest • One member of team start CPR • Deliver emergency care appropriate for age

48. Recognizing and Treating Cardiac Arrest Secondary Assessment • Gather the history from bystanders/relatives • Identify signs/symptoms of cardiac arrest • No breathing, pulse, unresponsive to stimuli Emergency Care • Follow steps to provide emergency care with AED • Use CPR/defibrillation as appropriate according to age and downtime Reassessment • Pulse is restored, continue to perform reassessment • Monitor patients pulse, breathing and mental status

49. Performing Defibrillation – Use of Semiautomated AED • BSI • Primary Assessment • Begin/resume CPR • Attach adhesive monitoring-defibrillation pads to cables • Turn on AED • Apply 2 pad to patients bared chest

50. Different Pad placements