Shock

1. Shock Mod I 2013 ECRN CE Condell Medical Center EMS System Site Code: 107200E-1213 Prepared by: Sharon Hopkins, RN, BSN, EMT-P

2. Objectives Upon successful completion of the program the ECRN will be able to: • 1. Review the circulatory system. • 2. Describe the pathophysiology, signs and symptoms of different mechanisms of shock. • 3. Describe the stages of shock and the signs and symptoms of the stages as the patient progresses from compensated shock through decompensated shock to irreversible shock.

3. Objectives cont’d • 4. Describe unique elements of shock in special populations (i.e.: pregnancy, elderly, children). • 5. Discuss appropriate interventions and treatment of • the various mechanisms of shock. • 6. Review case scenarios presented. • 7. Identify the pre-tibial and humeral sites and insertion of an IO needle. • 8. Review process of removing an IO needle • 9. Review process of removing the King airway • 10.Successfully complete the post quiz with a score of • 80% or better.

4. Circulatory System • Closed system for transport of oxygen and nutrients dissolved in blood and for the removal of waste material • Comprised of 3 components • The pump = heart • The fluid = blood • The container = blood vessels • Any one of these functioning poorly will affect the whole system

5. The Pump • The heart is the pump • Functions under 2 systems • High power system • Arterial side • Lower power system • Venous side • Body’s function dependent on an adequate stroke volume • Amount of blood pumped with each contraction • Approximately 70 ml for the average adult

6. Influences on Stroke Volume • Preload • Amount of blood returning to the heart • Dependent on venous return • Venous system functions as a storage container • Cardiac contractile force • The greater the stretch (i.e.: volume) the greater the recoil the better the strength of contraction • Influenced by circulating catecholamine's • Epinephrine and norepinephrine • Controlled by sympathetic nervous system

7. Stroke Volume cont’d • Afterload • Resistance against which ventricles have to contract • Determined by degree of peripheral vascular resistance met • Dictated by degree of vasoconstriction present • The greater the resistance (degree of vasoconstriction) the smaller the volume of blood (i.e.: stroke volume) able to be pumped out of the heart due to higher pressures met in the vascular system

8. Cardiac Output • Amount of blood pumped out of the heart in one minute is the cardiac output • Calculated on a formula • Stroke volume x heart rate = cardiac output Ex: 70ml x 80 bpm = 5600 ml blood/minute A change (reduction or increase) in stroke volume and/or heart rate will impact cardiac output

9. Blood Pressure • Dependent on cardiac output and degree of vascular resistance • Calculation of B/P: • B/P = cardiac output (CO) x peripheral vascular resistance (PVR) • To increase B/P •  cardiac output or peripheral vascular resistance • To decrease B/P •  cardiac output or peripheral vascular resistance

10. Perfusion • All body cells require constant supply oxygen and nutrients • Waste products must be removed • Build-up is harmful to the functioning of the body • Multi-system coordination needed to supply oxygen & nutrients and remove waste • Circulatory system • Respiratory system • Gastrointestinal system

11. Hypoperfusion • This is shock! • Inadequate delivery of oxygen and essential nutrients to all tissues • Inadequate removal of wastes from tissue • Most critical tissues in the body • Brain • Heart • Kidneys

12. Pathophysiology of Hypoperfusion • Usually a result of inadequate cardiac output • Factors that could affect cardiac output • Inadequate pumping •  preload •  cardiac contractile strength •  heart rate • Excessive afterload (high resistance in arterial system decreasing stroke volume that gets pumped out) • Inadequate fluid level • Inadequate container • Dilated vessels (poor systemic vascular resistance) • Leaking vessels

13. Pathophysiology of Shock • A very complex process • Causes can vary • Signs and symptoms can vary BUT… • Basic definition holds across the span Shock = inadequate tissue perfusion! • Ultimate outcome = impaired cellular metabolism

14. Pathophysiology - Impaired Cellular Metabolism • All cells dependent on adequate supplies of oxygen and glucose to function • In any type of shock, there is a disconnect in the use of oxygen and glucose • Aerobic metabolism changes to anaerobic • In the absence of oxygen, breakdown of glucose hindered • Primary source of energy, glucose, not available to the cell • Glucose does not provide energy until it is broken down inside the cell

15. Impaired Use of Oxygen • Harmful by-products produced • Lactic acid & other metabolic acids accumulate • Acidic condition of blood not favorable to normal bodily function • Hemoglobin not able to bind with and carry oxygen • Cellular stores of ATP used up and not replaced • Energy production, essential for metabolism of cells, decreases • Sludging of blood develops • Slowed blood flow due to  pumping of heart and vasodilation of vessels

16. Impaired Use of Glucose • Glucose must be transported into the cell • Step necessary for a process where glucose produces energy • Glucose remaining in blood results in hyperglycemia • Alternative sources used to produce energy • Breakdown of fats (lipolysis) • Amino acids from protein • Depletion of proteins in the system leads to organ failure

17. Classifications of Shock • Generally classified based on cause • Cardiogenic • Impaired pumping of heart • Hypovolemic • Decrease in blood volume • Obstructive • Obstruction interferes with return of blood to heart (i.e.: tension pneumothorax, tamponade) • Distributive • Abnormal distribution and return of blood

18. Semantics of Shock • Alternative classifications of shock • Cardiogenic – pump problem • Hypovolemic – volume problem • Neurogenic – container/tank problem (distributive) • Anaphylactic - container/tank problem (distributive) • Septic - container/tank problem (distributive)

19. Identification of Shock • Need to identify the underlying cause of shock • Correcting the cause is key element in providing the right intervention for reversing the process • Many interventions can be universally applied to a variety of shock conditions • Some interventions have limited applications • Ex: fluid challenges given aggressively in hypovolemic shock could be harmful in the setting of cardiogenic shock

20. Stages of Shock • 3 stages • Based on ability of body to compensate at that point in time • Based on signs & symptoms present • Reflect what is happening internally • Stages are progressive and become more serious • Compensated • Decompensated • Irreversible

21. Stages of Shock - Compensation • Initial stage of shock; body compensating • Activated when a need triggered (i.e.: threat to cardiac output) • Patient can still maintain their blood pressure!!! • Sympathetic nervous system • Secretes epinephrine & norepinephrine •  heart rate (1st indicator to notice!) •  cardiac contractility • Vasoconstriction (seen as paleness)

22. Stages of Shock - Compensation • Renin-angiotensin system • Kidneys release renin • Triggers production of angiotensin II – a strong vasoconstrictor • Angiotensin II stimulates production of aldosterone • Kidneys reabsorb sodium and therefore water • Noticed as a decrease in urine output

23. Stages of Shock - Compensation • Antidiuretic hormone (ADH) secreted • Kidneys triggered to reabsorb more water • Spleen • Expels extra blood volume being stored • Approximately 200 ml of blood can be added to existing blood volume • Passive activity • Fluid shifts from interstitial spaces into the capillaries • Skin feels drier

24. Stages of Shock - Decompensation • Conditions causing shock are too serious or too rapidly progressing and compensatory measures can no longer maintain preload • Perfusion inadequate • Heart weakens • Cardiac output falls even more • Reduced blood flow to the brain and vital function stimulation ceases • Appropriate interventions may still correct condition if applied early enough and body can respond • KEY: Blood pressure cannot be maintained and begins to fall

25. Stages of Shock - Irreversible • Blood becomes even more acidic and hypoxic • Systemic acidosis develops • Further deterioration of cells & tissues • Sludging of blood occurs in capillaries • Minute blood clots formed • Capillaries leak fluid into interstitial space • Correction of the condition is no longer possible; cells beginning to die

26. Evaluating Signs and Symptoms • “Classic” shock • Altered mental status • 1st change to be noted • Anxiousness moving to lethargic • Skin pale, cool, clammy • Pulse moving from normal to increasingly faster and then slowing and disappearing • Cardiac dysrhythmias develop and deteriorate into asystole • Blood pressure maintained until it finally falls • When B/P falls, compensation is over!

27. Neurogenic/Distributive Shock • Injury to brain or spinal cord • Loss of sympathetic tone • Relative hypovolemia due to dilation of arteries • Warm, red, dry skin (vasodilation) • Low B/P and pulse (no catecholamine stimulation) • Key: hypotension, bradycardia, warm/dry skin

28. Anaphylactic/Distributive Shock • Response of immune system to foreign substance • Usually the faster the reaction the more severe the case • Skin flushed, itchy, hives, swelling • Respiratory distress • Coughing, wheezing, stridor • Vasodilation, heart rate,  B/P • Nausea/vomiting, cramping • Altered mental status

29. Septic/Distributive Shock • Infection of bloodstream • Signs and symptoms progressive • Toxins cause vasodilation • High fever • Often absent in elderly and very young • Skin flushed to pale to cyanotic • May have altered level of consciousness • May have respiratory distress and abnormal breath sounds

30. Elderly Population & Shock • Some body system changes over time can increase risk factors for the elderly who are traumatically injured • Influence on changes • Vulnerability increased for injury • Body response to injury not as effective or dramatic • Less tolerant of interventions received • Increased time of recovery of health status

31. Elderly System Changes • Altered mental status common • Poor historian • Hypertension common • What looks like a “normal” B/P may be hypotension in the person with hypertension • Atherosclerosis and arteriosclerosis more prevalent • Stiffer blood vessels less able to respond with adequate degree of vasoconstriction • Impaired swallowing increases risk for aspiration

32. Elderly Changes cont’d • Bones more brittle • Cough reflex diminished • Increased risk for aspiration • Less air and gas exchange in lungs • General decline in efficiency of renal system • Less ability to fight infection via immune system • Perspires less • Skin tears more easily; heals slower

33. Physiological Changes of Pregnancy • Respiratory system •  oxygen demand & consumption • Cardiovascular system • Cardiac output increases • Maternal blood volume increased • Due to changes patient has a relative anemia • May lose 30-35% of volume before signs & symptoms of shock are evident • Maternal heart rate  by 10 - 15 beats per minute • Maternal B/P  til end of 3rd trimester

34. Supine Hypotensive Syndrome • Usually occurs in 3rd trimester • Large weight of uterus compresses inferior vena cava when patient supine • Reduces return of blood flow to the heart • Goal – avoid decrease in return of blood to the heart • Transport patient tilted or turned to side • Preferably left side (Remember: “lay left”) • Especially important after 5th month • If patient must remain flat (i.e.: CPR), then manually displace uterus to side

35. Pediatric Population & Shock • Body systems less developed • Decreased capacities compared to the adult • Dehydration most common cause of hypovolemia • Pale, cool skin • Diminished peripheral pulses • Delayed capillary refill • Change in mental status • Decreased urination (i.e.: dry diapers, dark urine)

36. Pediatric Population • Average blood volume is by body size • Typical infant 80 ml/kg • Typical adult male 75 ml/kg • Typical adult female 65 ml/kg By formula then: • Infant = 300 ml total blood volume • 200# adult male = 6,800 ml total blood volume • 160# adult female = 4700 ml total blood volume

37. Average Blood Volume by Size • Infant Child Adult

38. Field Interventions for Shock • Frequent reassessments watching for changes/trends • Every 5 minutes (or sooner) for unstable patient • If not documented, then not done • Follow ABC’s (CAB’s if arrested) • Assess airway • Assess quality of breathing • Assess circulation / pulses / perfusion • Assess neurological function

39. Field Interventions for Shock • EMS to begin transport as soon as possible • EMS alerts receiving hospital as soon as possible • EMS rapid trauma assessment • Identification of immediate, obvious life threats • A quick head to toe examination • Vital signs and history obtained • Interventions begun as soon as possible • Transport should not be delayed to initiate additional interventions • IV/O2/monitor enroute in critical situation • Fluid challenge is at 200 ml increments

40. Field Interventions for Shock • Management of life threats in the field (usually same process in the ED) • Interventions performed if situation found • Airway opened • Ventilations supported • Via BVM – 1 breath every 5 – 6 seconds • Via ETT or King airway – 1 breath every 6 – 8 seconds • MUCH slower than usually practiced!!! • Needle decompression if tension pneumothorax • Sucking chest wound sealed • Major bleeding controlled

41. Field Interventions for Shock • If failure to secure peripheral IV access, IO is the backup • If failure to place an endotracheal tube, King airway is the backup • These are urgent skills and each paramedic must be capable of using these tools without delay if necessary

42. IO Access • Available when other alternatives are not • Sites provide non-collapsible space when peripheral veins have collapsed in shock • Sites can be rapidly accessed • Fluids and medications are rapidly absorbed into the bloodstream • Large amounts of fluid can be delivered quickly (i.e.: 125 ml/min) • Bony cortex provides stable base when securing inserted IO needle

43. Region SOP – IO Insertion Skill • Indications • Shock, arrest, impending arrest • Unconscious/unresponsive or conscious critical patient without IV access • 2 unsuccessful IV attempts or 90 second duration or no visible sites

44. IO Insertion Skill cont’d • Contraindication • Insertion into extremity with a fracture • Infection at insertion site • Previous orthopedic procedure (knee replacement, previous IO within 480) • Pre-existing medical condition (tumor near site, peripheral vascular disease) • Inability to locate landmarks (significant edema)

45. Primary Complication IO Insertion • Extravasation into soft tissue from infiltrated site • Could cause compartment syndrome • Reference June 2012 CE for review of compartment syndrome • Bone fracture during insertion – rare • Could occur with excessive force applied • Osteomyelitis – uncommon • Generally from poor technique • Leaving IO needle in >24 hours • Multiple attempts at same site

46. Equipment for IO Insertion • IV start pak • Pre-filled syringe • 10 ml 0.9 NS for adult insertion • 5 ml 0.9 NS for pediatric insertion • IO kit • Needle • Primed EZ connect tubing • Wristband • Drill • Cleansing material • Chloraprep ampule; alcohol wipe • Primed IV tubing inserted into IV bag • Pressure bag

47. IO Needle SizingNote: Gauge same for all sizes (15 G) • Pink for 3 – 39 kg (up to 88 pounds) • 15 mm; 15 G • Blue for >40 kg (>88 pounds) • 25 mm; 15 G • Yellow for excessive tissue over site & humeral head site • 45 mm; 15G

48. IO Needle Sizing Hint/Tip • Need to evaluate the site to determine the size needle to use • If you feel bone immediately under the site palpated, use the pink 15 mm needle • Ex: palpate over wrist at base of thumb • If you palpate tissue over the site and not bone, use the blue 25 mm needle • If there is excessive tissue over the site or use of the humeral site, use the 45 mm needle

49. Proximal Tibial IO Landmarks • Need to identify the tibial tuberosity – a rounded projection below knee cap • Sits approximately 2 finger widths below the patella

50. IO Site Identification – Proximal Tibia • Site must be viewed AND palpated • Locate tibial tuberosity - bump over shin 2 fingers below patella • 1 finger width medial (towards big toe) • In the very young, may not have a prominent tibial tuberosity