SHOCK

1. SHOCK

2. Case study • You are dispatched to a report of an overturned bulldozer, trapping a 39 y/o male. • On arrival, you find the patient CAO PPTE. His airway, respirations and pulse are normal. His pelvis and lower extremities are pinned under the side of the bulldozer. The FD tells you it will be at least 10 minutes before they can lift the bulldozer.

3. HMM?? • The pt. has O2 at 15 lpm/nrb. His BBS are =, clear and he complains that he can’t feel his feet. • Your DDX?

4. His BP is 110/68, HR 90, RR 24, and Sa02 99%. Because of the extended extrication time, you request Lifeflight response. You establish 2 IV’s w/NS; one at full flow. You check his vitals q 5 min. – they remain stable. • As the bulldozer is lifted, you realize that the pt. has pelvic, bilateral femur and L tibia Fx. • The pt. c/o increased pain, is restless and attempts to get up, then becomes lethargic. His Sa02 is now 94%; his HR is 130 and weak. You increase the IV flow rate, and his mentation improves, but his HR remains elevated.

5. The pt. is moved to the helicopter, and the IV’s are placed in pressure infuser bags. • At the hospital, his systolic BP is 90, and he is still tachycardic. • The pt. goes to surgery, tolerates the surgery well, and is in rehab for one year.

6. SHOCK • Inadequate Tissue Perfusion • Cells die>tissues die>organs die>patient dies • The transition between homeostasis and death

7. Causes • Trauma • spinal cord injury • fluid loss • Infection • Allergic reaction • etc

8. Perfusion • The pump • The fluid • The container

9. The pump • Stroke Volume = one beat = 70 mls • SV x HR = CO • 70 x 80 = 5,600 ml/min • Preload • Cardiac contractility • Afterload

10. Preload • Blood delivered to heart during diastole (between contractions) • Depends on venous return • The greater the preload, the greater the stroke volume

11. Contractile force • The greater the preload, the more the ventricles are stretched • The greater the stretch (to a point) the greater the contraction • Frank - Starling law • Contractile force is affected by catecholamines (controlled by sympathetic nervous system) – affect beta adrenergic receptors

12. Afterload • Arterial resistance (PVR) • Vasoconstriction/vasodilation

13. Afterload • Vasopressor drugs • Epinephrine • Dopamine • Norepinephrine

14. Blood pressure • BP • Baroreceptors • Nerve tissue in Carotids & Aorta • Adrenergic responses • Low B/P Releases Epi/Norepi • Rising B/P slows release of …

15. Adequate quantity Adequate quality Blood

16. The container • Closed system –Supposed 2B • Dynamic in nature

17. Capillaries – Still The Container • The Dam Pre-capillary sphincter • Responds to local needs • The Dam Post-capillary sphincter

18. Peripheral resistance • Length of vessel • Diameter of vessel • Viscosity of blood

19. Oxygen transport • Tidal volume 500-800 mls • 21% oxygen in air • Hemoglobin

20. The Fick Principle • Adequate concentration inspired • Appropriate diffusion into blood • More O2 in Stream than cells

21. The Fick Principle • Adequate RBCs • Adequate on-loading

22. The Fick Principle • Proper perfusion • Adequate off-loading

23. Brief Relation to SaO2 • Oxygen - Hemoglobin • Saturation

24. Decreased Perfusion • Pump • Container • Fluid

25. Decreased perfusion-Pump • Inadequate preload • Inadequate contraction • Excessive afterload • Inadequate rate

26. Inadequate fluid • Hypovolemia • Inadequate RBCs • Toxic – 3rd Spaced

27. Inadequate container • Dilated • Constricted • Leaking

28. Systemic response to shock • Early signs • Late signs

29. Compensated shock • Vasoconstriction • Increased cardiac output • Increased contractility

30. Compensated shock, cont. • Renin-angiotension system • Activated by hypotension • Renin released from kidneys into systemic circulation • Acts on special plasma protein angiotension to produce angiotension I and is converted to angiotension II by enzyme in lungs – angiotension converting enzyme (ACE). – a potent vasoconstrictor. • angiotension II stimulates production of aldosterone from adrenal gland – stimulates kidneys to readsorb sodium (water follows salt)

31. Compensated shock, cont. • Pituitary gland secretes ADH • Spleen (can store > 300 ml of blood – can expel up to 200 ml blood into venous circulation

32. Decompensated shock (Progressive shock) • BP begins to fall • Slow refill • Pre-capillary sphincters relax • Post-remain closed • No pressure to open • Rouleaux • Can’t limbo through capillaries

33. Bad news, baby • Cardiac depression – 2ndary to compensatory mechanisms – • Greatly increased demand for oxygen • Low arterial blood pressure = coronary blood flow too low to adequately perfuse the myocardium • Heart is weakened – CO falls • Vasomotor center of brain is depressed • Sympathetic activity slows, then stops

34. We ain’t done yet • Metabolic wastes are released into slower-flowing blood. Capillary beds become aciditic = microemboli • Generalized, systemic acidosis develops • Further deterioration of calls and tissues = increased permeability = shift into 3rd spaces

35. Irreversible shock • Death is inevitable • Short term save vs Long term save

36. Types of shock • Hypovolemic • Distributive • Obstructive • Cardiogenic • Respiratory • Neurogenic

37. Assessment • ABCDEs • Intervene early

38. Hypovolemic Shock • Internal or external hemorrhage • Traumatic injury • Long-bone or open fractures • Severe dehydration 2ndary to vomiting or diarrhea • Plasma loss – burns • Sweating • DKA with osmotic diuresis • 3rd spacing – • Bowel obstruction • Peritonitis, pancreatitis • Liver failure - ascites

39. Management - Hypovolemic • ABCs • C-spine • O2 • ECG • IVs • PASG?

40. Management - Distributive • ABCs • O2 • ECG • Ivs • Meds? • PASG?

41. Management - Obstructive • ABCs • O2 • ECG • IV • Correct obstruction?

42. Management - Cardiogenic • If BP is low, what is pulse? • Fluid challenge • If lungs are dry • Vasopressors? • Dopamine (Inotropin)

43. Management - Respiratory • ABCs • O2 • ECG • IV • Correct condition?

44. Usually spinal cord injury Spinal-immobilize IV fluids EKG Management - Neurogenic

45. Shock Assessment