SHOCK

1. SHOCK Dr.raed Al-Asmi

2. To develop an understanding of the definition and pathophysiology of shock To develop an understanding and overview of the different types of shock To develop a systematic approach to the detection and management of shock Objectives: Part 1

3. Objectives: Part 2 • To develop a deeper understanding of sepsis and septic shock • To discuss cost effective and high impact interventions to decrease mortality in shock

4. PART 1

5. Definition of Shock Inadequate perfusion and oxygenation of cells

6. Definition of Shock Inadequate perfusion and oxygenation of cells leads to: Cellular dysfunction and damage Organ dysfunction and damage

7. Why should you care? High mortality - 20-90% Early on the effects of O2 deprivation on the cell are REVERSIBLE Early intervention reduces mortality

8. Pathophysiology 4 types of shock Cardiogenic Obstructive Hypovolemic Distributive

9. Pathophysiology: Overview Tissue perfusion is determined by Mean Arterial Pressure (MAP) MAP = CO x SVR Heart rate Stroke Volume

10. Cardiogenic Shock: Pathophysiology Heart fails to pump blood out MAP = CO x SVR HR Stroke Volume

11. Cardiogenic Shock: Pathophysiology Normal MAP = CO x SVR Cardiogenic MAP = ↓CO x SVR MAP = ↓CO x ↑SVR ↓MAP = ↓↓CO x ↑SVR

12. Cardiogenic Shock: Causes ↓MAP =↓CO (HR x Stroke Volume) x ↑SVR Decreased Contractility (Myocardial Infarction, myocarditis, cardiomypothy, Post resuscitation syndrome following cardiac arrest) Mechanical Dysfunction – (Papillary muscle rupture post-MI, Severe Aortic Stenosis, rupture of ventricular aneurysms etc) Arrhythmia – (Heart block, ventricular tachycardia, SVT, atrial fibrillation etc.) Cardiotoxicity (B blocker and Calcium Channel Blocker Overdose)

13. Obstructive Shock: Pathophysiology Heart pumps well, but the output is decreased due to an obstruction (in or out of the heart) MAP = CO x SVR HR x Stroke volume

14. Obstructive Shock:Pathophysiology Normal MAP = CO x SVR Obstructive MAP = ↓CO x SVR MAP = ↓CO x ↑SVR ↓MAP = ↓↓CO x ↑SVR

15. Obstructive Shock: Causes ↓MAP =↓CO (HR x Stroke Volume) x ↑SVR Heart is working but there is a block to the outflow Massive pulmonary embolism Aortic dissection Cardiac tamponade Tension pneumothorax Obstruction of venous return to heart Vena cava syndrome - eg. neoplasms, granulomatous disease Sickle cell splenic sequestration

16. Hypovolemic Shock: Pathophysiology Heart pumps well, but not enough blood volume to pump MAP = CO x SVR HR x Stroke volume

17. Hypovolemic Shock:Pathophysiology Normal MAP = CO x SVR Hypovolemic MAP = ↓CO x SVR MAP = ↓CO x ↑SVR ↓MAP = ↓↓CO x ↑SVR

18. Hypovolemic Shock: Causes ↓MAP =↓CO (HR x Stroke Volume) x ↑SVR Decreased Intravascular volume (Preload) leads to Decreased Stroke Volume Hemorrhagic - trauma, GI bleed, AAA rupture, ectopic pregnancy Hypovolemic - burns, GI losses, dehydration, third spacing (e.g. pancreatitis, bowel obstruction), Adesonian crisis, Diabetic Ketoacidosis

19. Distributive Shock: Pathophysiology Heart pumps well, but there is peripheral vasodilation due to loss of vessel tone MAP = CO x SVR HR x Stroke volume

20. Distributive Shock:Pathophysiology Normal MAP = CO x SVR Distributive MAP = co x ↓SVR MAP = ↑co x ↓SVR ↓MAP = ↑co x ↓↓SVR

21. Distributive Shock: Causes ↓MAP = ↑CO (HR x SV) x↓SVR • Loss of Vessel tone • Inflammatory cascade • Sepsis and Toxic Shock Syndrome • Anaphylaxis • Post resuscitation syndrome following cardiac arrest • Decreased sympathetic nervous system function • Neurogenic - C spine or upper thoracic cord injuries • Toxins • Due to cellular poisons -Carbon monoxide, methemoglobinemia, cyanide • Drug overdose (a1 antagonists)

22. To Summarize

23. Ok…it’s really not THAT simple MAP = CO x SVR HR x Stroke volume Preload Afterload Contractility

25. Additional Compensatory Mechanisms Renin-Angiotensin-Aldosterone Mechanism AII components lead to vasoconstriction Aldosterone leads to water conservation ADH leads to water retention and thirst Inflammatory cascade

26. Case 1 24 year old male Previously healthy Lives in a malaria endemic area (PNG) Brought in by friends after a fight - he was kicked in the abdomen He is agitated, and won’t lie flat on the stretcher HR 92, BP 126/72, SaO2 95%, RR 26

27. Stages of Shock Timeline and progression will depend on: -Cause -Patient Characteristics -Intervention Insult Preshock (Compensation) Shock (Compensation Overwhelmed) End organ Damage Death

28. Case 1: Stages of Shock

29. Case 1: Stages of Shock

30. Case 1: Stages of Shock

31. Case 1: Stages of Shock

32. Is this Shock? Signs and symptoms Laboratory findings Hemodynamic measures

33. Symptoms and Signs of Shock Level of consciousness Initially may show few symptoms Continuum starts with Anxiety Agitation Confusion and Delirium Obtundation and Coma In infants Poor tone Unfocused gaze Weak cry Lethargy/Coma (Sunken or bulging fontanelle)

34. Symptoms and Signs of Shock Pulse Tachycardia HR > 100 - What are a few exceptions? Rapid, weak, thready distal pulses Respirations Tachypnea Shallow, irregular, labored

35. Symptoms and Signs of Shock • Blood Pressure • May be normal! • Definition of hypotension • Systolic < 90 mmHg • MAP < 65 mmHg • 40 mmHg drop systolic BP from from baseline • Children • Systolic BP < 1 month = < 60 mmHg • Systolic BP 1 month - 10 years = < 70 mmHg + (2 x age in years) • In children hypotension develops late, late, late • A pre-terminal event

36. Symptoms and Signs of Shock Skin Cold, clammy (Cardiogenic, Obstructive, Hemorrhagic) Warm (Distributive shock) Mottled appearance in children Look for petechia Dry Mucous membranes Low urine output <0.5 ml/kg/hr

38. Empiric Criteria for Shock 4 out of 6 criteria have to be met Ill appearance or altered mental status Heart rate >100 Respiratory rate > 22 (or PaCO2 < 32 mmHg) Urine output < 0.5 ml/kg/hr Arterial hypotension > 20 minutes duration Lactate > 4

39. Lactate Lactate is increased in Shock Predictor of Mortality Can be used as a guide to resuscitation However it is not necessary, or available in many settings

40. Management of Shock History Physical exam Labs Other investigations Treat the Shock - Start treatment as soon as you suspect Pre-shock or Shock Monitor

41. Historical Features Trauma? Pregnant? Acute abdominal pain? Vomiting or Diarrhea? Hematochezia or hematemesis? Fever? Focus of infection? Chest pain?

42. Physical Exam Vitals - HR, BP, Temperature, Respiratory rate, Oxygen Saturation Capillary blood sugar Weight in children

43. Physical Exam In a patient with normal level of consciousness - Physical exam can be directed to the history

44. Physical Exam In a patient with abnormal level of consciousness Primary survey Cardiovascular (murmers, JVP, muffled heart sounds) Respiratory exam (crackles, wheezes), Abdominal exam Rectal and vaginal exam Skin and mucous membranes Neurologic examination

45. Laboratory Tests CBC, Electrolytes, Creatinine/BUN, glucose +/- Lactate +/- Capillary blood sugar +/- Cardiac Enzymes Blood Cultures - from two different sites Beta HCG +/- Cross Match

46. Other investigations ECG Urinalysis CXR +/- Echo +/- FAST

47. Treatment Start treatment immediately

48. Stages of Shock Early Intervention can arrest or reduce the damage Insult Preshock (Compensation) Shock (Compensation Overwhelmed) End organ Damage Death

49. Treatment ABC’s “5 to 15” Airway Breathing Circulation Put the patient on a monitor if available Treat underlying cause

50. Treatment: Airway and Breathing Give oxygen