1. Leanna R. Miller, RN, MN, CCRN,-CMC, PCCN-CSC CEN, CNRN, CMSRN, NP Education Specialist LRM Consulting Nashville, TN

2. Definition  tissue perfusion that is inadequate to maintain normal metabolic and nutritional functions  potentially fatal if not identified & treated

3. Introduction  12% to 18% of patients presenting initially in severe shock have increased mortality or morbidity related to secondary organ failure

5. Clinical Signs of Shock Preterminal Stages  severe hypotension  agonal respirations  thready pulse  tachy or bradydysrhythmias

6. Shock Index HR / systolic blood pressure  HR / systolic blood pressure  inversely related to LVSW  abnormal > 0.9  application: persistently abnormal shock index in patient with normal VS suggests need for more invasive monitoring Rady (1992) Resuscitation 23:227 - 234

7.  most important feature to the care of a critically ill patient is delivery of oxygen to the cells

8. CO X CaO 2 X 10  CO X CaO 2 X 10  CaO 2 = Hgb x SaO 2 x 1.38  Normal 900 - 1100 mL/min  DO 2 I = 360 - 550 mL/min/m 2

9. oxygen consumption  CO x (SaO 2 - SvO 2 ) Hgb x 1.38 x 10  VO 2 = 220 - 290 mL/min  VO 2 I = 108 - 165 mL/min/m 2

10.  normally VO 2 is 25% of DO 2

11.  SvO 2 SaO 2 SaO 2 Hgb Hgb CO CO VO 2 VO 2

12.  amount of oxygen extracted from blood as it passes through the tissues  (CaO 2 - CvO 2 )/ CaO 2  values > 0.30 abnormal  > 0.35 serious  normal 22% to 27%

13.  > 0.35 increased VO 2 increased VO 2 decreased DO 2 decreased DO 2 both both

14.  CI 4.5 L/min/m 2  DO 2 I 600 L/min/m 2  VO 2 I 170 mL/min/m 2

15.  inadequate pulmonary gas exchange  inadequate oxygen carrying capacity  inadequate CO

17.  conditions and activities that alter demand and consumption

18. critically low DO 2  critically low DO 2  vasodilated state  vaso-obstructed state   diffusion distances   affinity of Hgb for O 2

19.  increased extraction  once extraction maximized – consumption is dependent on delivery  demand > consumption = O 2 debt

20.  may be  or normal in presence of hypoxia  not reliable reflection of tissue hypoxia  reliable indicator of tissue perfusion

21.  arterial more precise  normal < 1 mEq/L  > 3 - 4 mEq/L significant hypoperfusion  will decrease 5 - 10% / hr when appropriate therapy used

22.  pHi  early warning of inadequate splanchnic tissue oxygenation  low pH = poor prognosis (consistently < 7.3)

23. Lab Studies  Normal value: - 2 to + 2  reflects the extent to which the body buffers have been exhausted  rapidity of normalizing base deficit decreases morbidity & mortality

24. Most Reliable Perfusion Markers  Serum lactate  Base deficit

25. StO 2 n near infrared light illuminates tissue n light scatters and is absorbed differently by oxygenated and deoxygenated hemoglobin in the microcirculation n light returns to sensor and is analyzed and displayed as % StO 2

26. StO 2

27. .75 -.90

28.  volume  inotropes  vasodilators  assess peripheral circulation

29.  Identify potentially inadequate DO 2 states clinical evidence of shock clinical evidence of shock SvO 2 < 50% SvO 2 < 50% O 2 ER > 30% O 2 ER > 30%

30.  Identify pathological flow dependency state –  DO 2 with fluids or inotrope – recalculate VO 2 – VO 2  > 10-20 L/m 2

31.  ensure accurate parameters  index to body size  eliminate sources of error  use parameters with < 5-10% variance

32.  calculate actual VO 2  estimate potential VO 2 (look at factors that  demand)

33.  delivery needs to  by at least same by at least same percentage as demand percentage as demand

34.  O 2 demands are  30-50%  triggers systemic inflammatory response

35.  Hgb/Hct < 11/33 is associated with delivery- dependence   mortality if therapeutic targets reached < 12 - 24 hours

36.  CI > 4.5  DOI 2 700  VOI 2 170

37.  46 - year old male motor vehicle crash injuries: aortic disruption, severe bilateral pulmonary contusions, bilateral rib fractures, splenic fracture traumatic shock due to injuries

38. Which hemodynamic findings are abnormal? Which hemodynamic findings are abnormal?

39. HR 67 BP 122/64/82 RAP / PAOP 10/11 CI 4.6 PVRI / SVRI 143/317 RVSWI / LVSWI 17/61 PAP 46/22/32

40. EDV / EDVI237/107 EF 60% O 2 ER 26.8 SvO 2.74 DO 2 / DO 2 I 1603/722 VO 2 / VO 2 I 430/194

41. ABGs (.40 FiO 2 ) pH 7.31 pCO 2 42 pO 2 157 SaO 2.99 HCO 3 20.8 SvO 2 74% P/F ratio 314.0

42. Lab Values Hgb 12.1 Hct 31.0 Sodium 139 Chloride 112 Magnesium 1.7 Lactate 5.1 Base Deficit -5.1

43. What is the underlying pathophysiology? What is the underlying pathophysiology?

44. What is are the priority interventions? What is are the priority interventions?

45. n 33 yr with GSW to chest n 4 units of PRBC due to Hct of 27 n SVO 2 – 70 after blood administration n StO 2 – 80% n Lactate 1.2 n Does he need further treatment ? StO 2 and Hemodynamic Monitoring