Pathophysiology of trauma

Transcript

1. PATHO-PHYSIOLOGY (& MX) OF TRAUMA Dr Aoibhin Hutchinson 27th September

   2013 Monday, 21 October 13

2. THE REAL TRAUMA INTERFACE Monday, 21 October 13

3. TRAUMA LOGISTICS Monday, 21 October 13

4. MAJOR TRAUMA CENTRE • 24 hours a day, fully staffed

   ED • Consultant led trauma team • Dedicated trauma theatres & operating lists • All major specialties: • Ortho, general, vascular, neuro, plastics, cardiothoracic, head & neck, urology • Interventional radiology • Anaesthesia & Critical care Monday, 21 October 13

5. •High volume trauma centres reduce mortality from major injury by

   50%. 1 • (high volume > 20 cases per week) •Time from trauma to definitive surgery / intervention is the primary determinant of outcome in major trauma (not time to ED). 2 1. Relationship Between Trauma Center Volume and Outcomes. Nathens A et al, JAMA. 2001;285:1164-1171 2. Resources for Optimal Care of the Injured Patient. American College of Surgeons, 1999 • Monday, 21 October 13

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7. Jim McGuigan Thoracic Surgeon Royal Victoria Hospital Belfast Monday, 21

   October 13

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10. ATLS Monday, 21 October 13

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12. No  springing  pelvis Binder  on  early Pan  scan Use  of

     focused   ECHO  /  US No  major  changes   to  thoracic Though  role  of  US   Monday, 21 October 13

13. SURVIVING TRAUMA •Early patho-physiology: •Immediate threat to life •ABC •Longer

    term patho-physiology: •Surviving critical care (prolonged care phase) •MOF / Sepsis ATLS: Trimodal death distribution Monday, 21 October 13

14. AIMS 1.What’s important in the early resuscitative phase? 2.What important

    in the critical care in recovery phase? Monday, 21 October 13

15. BASIC TRAUMA PATHO-PHYSIOLOGY in a word - bleeding Monday, 21

    October 13

16. •Define shock ....an abnormality of the circulatory system that results

    in inadequate organ perfusion and delivery of oxygen •Classify shock •Haemorrhagic / hypovolaemic •Cardiogenic •Obstructive •Distributive •Septic •Neurogenic Monday, 21 October 13

17. CO = HR x SV BP = CO x SVR

    Monday, 21 October 13

18. BLEEDING... Clinically: •Tachycardic •Hypotensive •Narrow pulse pressure •Cold peripheries /

    shut down Blood%loss% Decreased%IV%volume% Reduced%venous%return% (preload)% Decreased%stroke%volume% Lowered%CO% Reduced%BP%% Hypoperfusion%of%Assues% Tissue%hypoxia% MODs% Compensatory • Increase SVR • Increase HR To preserve CO / BP Monday, 21 October 13

19. Control the bleeding Restore IV volume Correct coagulopathy Preserve organ

    perfusion MANAGEMENT AIMS Monday, 21 October 13

20. WHAT’S NEW? Monday, 21 October 13

21. Triad of Death 1.Coagulopathy 2.Acidosis 3.Hypothermia Vicious circle rather than

    a triangle Acute Traumatic Coagulopathy 25% trauma pts have established coagulopathy (ATC) on presentation - 4 fold increase in mortality Brohi K, Singh J, Heron M, Coats T. Acute traumatic coagulopathy. J Trauma 2003;54:1127-30. MacLeod JB, Lynn M, McKenney MG, Cohn SM, Murtha M. Early coagulopathy predicts mortality in trauma. J Trauma 2003;55:39-44. Maegele M, Lefering R, Yucel N, Tjardes T, Rixen D, Paffrath T, et al. Early coagulopathy in multiple injury: an analysis from the German Trauma Registry on 8724 patients. Injury 2007;38:298-304. SIRS CARS Monday, 21 October 13

22. WHAT’S ‘RELATIVELY’ NEW? •Fluid resuscitation •Permissive hypotension •Haemostatic resuscitation •Blood

    product administration ratios •Military approach: Damage control resuscitation •Tranexamic acid •Damage control Sx •Interventional radiology Monday, 21 October 13

23. AKI Mortality Monday, 21 October 13

24. FLUIDS  Increasing evidence for crystalloid  Hyperoncotic Colloid: Increased

    risk AKI Increased mortality CHEST STUDY 6S STUDY Monday, 21 October 13

25. • June 20th 2013: Joint position statement from FICM, RCOA,

    ICS, College of EM following on from European Medicines Agency suspending marketing authorisation for HES due to risks outweighing any perceived benefits • Applies equally to pts with hypovolaemia, hypovolaemic shock, critically ill patients including those with sepsis, burns, trauma and those undergoing surgery Monday, 21 October 13

26. EMA DECISION BASIS •1. Perner A, Haase N, Guttormsen AB,

    et al. Hydroxyethyl starch 130/0.42 versus Ringer's acetate in severe sepsis. N Engl J Med 2012;367:124-34. (6S Study) •2. Brunkhorst FM, Engel C, Bloos F, et al. Intensive insulin therapy and pentastarch resuscitation in severe sepsis. N Engl J Med 2008;358:125-39. (VISEP study) •3. Myburgh JA, Finfer S, Bellomo R, et al. Hydroxyethyl starch or saline for fluid resuscitation in intensive care. N Engl J Med 2012;367:1901-11. (CHEST Study) Monday, 21 October 13

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28. PERMISSIVE HYPOTENSION • Fluid resuscitating • a patient who is

    no longer bleeding is easy • a patient with ongoing bleeding is much more complicated: huge potential to make the patient worse - your endpoints are much more important • Increasingly accepted view that moderate hypotension (Systolic <90mmHg) in trauma patients without TBI is sufficient to maintain critical organ perfusion (but pressure = flow) • Resuscitating to >90mmHg runs the risk of clot dislodgment & vicious circle formation Monday, 21 October 13

29. NOT SO NEW? Monday, 21 October 13

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32. NICE 2004 : PRE HOSPITAL Monday, 21 October 13

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34. RESUSCITATION OF THE BLEEDING PATIENT • Rather than aggressive fluid

    replacement, the ability to control ongoing blood loss is one of the most important determinants in the outcome of a seriously injured patient. Hess JR, Holcomb JB, Hoyt DB: Damage control resuscitation: The need for specific blood products to treat the coagulopathy of trauma. Transfusion 2006;46:685-6. Don’t obsess about fluid resuscitation ....control the source of bleeding Monday, 21 October 13

35. RESUSCITATION • Coapulopathy (ATC) occurs much earlier than we thought

    & is a major driver • Haemorrhage control is the priority • Do not delay transfer to place of definitive control transfer but use with caution • Permissive hypotension - arguable for - really relevant to prehospital • Clinical end points of resuscitation are uncertain - we are stuck with BP (Sys 100; Hb 7-8; plts100; INR<1.5; fibrinogen>1) Monday, 21 October 13

36. BLOOD -HAEMOSTATIC RESUS -MASSIVE TRANSFUSION -BLOOD PRODUCT RATIOS Monday, 21

    October 13

37. MASSIVE TRANSFUSION • emerging opinion that massive transfusion of red

    cells and clotting factors in trauma patients should be given in broadly similar proportions from the outset Borgman MA, Spinella PC, Perkins JG, Grathwohl KW, Repine T, Beekley AC, et al. The ratio of blood products transfused affects mortality in patients receiving massive transfusions at a combat support hospital. J Trauma 2007;63:805-13. Monday, 21 October 13

38. PRBC : FFP : PLTS: CRYO Borgman MA, Spinella PC,

    Perkins JG, Grathwohl KW, Repine T, Beekley AC, et al. The ratio of blood products transfused affects mortality in patients receiving massive transfusions at a combat support hospital. J Trauma 2007;63:805-13. Monday, 21 October 13

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40. DILUTIONAL COAGULOPATHY Monday, 21 October 13

41. ACUTE TRAUMATIC COAGULOPATHY (ATC) & TRAUMA INDUCED COAGULOPATHY (TIC) Monday,

    21 October 13

42. DIAGNOSING ATC •It is a nightmare.....blind •PT & APTT -

    only describe isolated fragments of the haemostatic process •Always delays •Next set sent before first set back •If it were easy & quick - decisions about blood product ratios would not have to be pre- emptive Typical example of time to receiving PT result Monday, 21 October 13

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48. TRANEXAMIC ACID Monday, 21 October 13

49. TRANEXAMIC ACID • Direct trauma causes activation of fibrinolysis •

    CRASH 2 June 2010, The Lancet • Over 20,000 pts; 274 hospitals, 40 countries • Admin <8hrs from injury:1gm over 10mins & then 1gm over 8hours • Administration of Tranexamic acid reduced the risk of death in bleeding trauma victims (14.5% vs 16%) • No increase in vascular occlusive events Monday, 21 October 13

50. June 2010 March 2011 Monday, 21 October 13

51. TRANEXAMIC TIMING • Early Rx <1hr from injury: • Mortality

    due to bleeding 5.3% (vs 7.7% placebo) • Rx 1-3hrs from injury: • Mortality due to bleeding 4.8% (vs 6.1% placebo) • Rx > 3hrs from injury: • Seemed to increase risk of death due to bleeding 4.4% (vs 3.1% placebo)......Unclear why Monday, 21 October 13

52. CRASH 2 - TIMING Monday, 21 October 13

53. TRANEXAMIC ACID • In bleeding trauma victims: Give it! •

    CRASH 2: 32% reduction in death if given <1hr • Give it ASAP (<3hrs) :1gm over 10mins (followed by 1gm over 8hrs) • Given early it effects ATC: prevents full activation of fibrinolysis which once started is difficult to abate • Pre hospital care may be where its role is best placed • Caution in those who present several hours after injury Monday, 21 October 13

54. •Transfusion policies •Liberal use of tourniquets •Joint theatre system •Critical

    care air transport team •Use of US & IO needles •Rx blast injury •Use of haemostatic dressings •PTSD LESSONS FROM CONTMEPORARY WAR Monday, 21 October 13

55. MILITARY APPROACH • Definitive care quickly • Permissive hypotension •

    Early administration of blood: • Haemostatic resus • High ratio PRBC : FFP : Plts • Tranexamic acid • Damage control resuscitation & surgery (DCR / DCS) Monday, 21 October 13

56. DIFFERENCES • Military & non military • Pre hospital &

    In hospital Mx • Penetrating / blunt / blast injuries • Patients- demographics Monday, 21 October 13

57. INCOMPLETELY ANSWERED QUESTIONS • Which patients would benefit most from

    haemostatic resus? • How do we identify them at the outset? • What is the optimal ratio PRBCs : FFP : Plts ? • Which pts will benefit most from permissive hypotension? • Precise indications for recombinant factor VII, tranexamic, cryo, calcium? • Does the storage age of the blood matter? Monday, 21 October 13

58. CONCLUSION • Trauma is a leading cause of death in

    young people: haemorrhagic shock is the leading cause of mortality • Control of bleeding is paramount: therefore rapid transfer is a priority • Permissive hypotension has a role in pre hospital care • Coagulopathy develops early & is an independent risk factor for death - aggressive Mx • Tranexamic acid should be given early - ideally pre hospital • Lessons to be learnt from Military approach - but be objective: different patients, injuries & situation • Haemostatic resus: high ratio of products needed; likely 1:2; who stands to benefit most? • Further Evidence base is required Monday, 21 October 13

59. AIMS 1.What’s important in the early resuscitative phase? 2.What important

    in the critical care in recovery phase? Monday, 21 October 13

60. • Trauma is a major cause of mortality in <50yrs

    in Western World • Mortality due to sustained injuries (early) • Subsequent immune reactions (late) & resultant MOF • About 5% trauma patients develop post traumatic MOF Monday, 21 October 13

61. TRAUMA & MOF Endogenous factors - susceptibility to MOF •genetics

    •physical condition Exogenous factors •Injuries themselves (1st hit: trauma load) •Resuscitation strategy & Surgery (2nd hit: intervention load) Organ damage & then failure is due to dysfunctional immune response Monday, 21 October 13

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63. SIRS • Fever >38 or <36 • HR >90 •

    RR >20 or PCO2 < 4.3kPa • WC >12 or <4 or > 10% immature bands Precipitants: •Tissue injury •Hypoxia •Hypovolamia •Hypercarbia •Infection Monday, 21 October 13

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68. PROPHYLAXIS • Address nutritional needs • Preventing stress bleeding, venous

    thrombosis & pressure ulceration • Assessing antimicrobial prophylaxis, tetanus status & preventing HCAIs • Consider LPV • FAST HUG Monday, 21 October 13

69. OTHER TOPICS TO MENTION • Hypothermia in trauma? • EPO

    in trauma? • Statins in trauma? Monday, 21 October 13