1. As part of Lady Minto Hospital Emergency Rounds and All Day Emergency Simulation Workshop Saturday November 14, 2016 Prepared by Shane Barclay UNDIFFERENTIATED SHOCK DIAGNOSIS AND MANAGEMENT

2. 1. Review the types of shock. 2. Review the clinical approach to diagnosis of undifferentiated shock. 3. Review the management of undifferentiated shock 4. Practice clinical scenarios for shock. GOALS AND OBJECTIVES

3. Patients presenting with shock often have obvious causes of their shock – multiple fractures etc. However patients can present with shock and no obvious cause. The approach to these patients must be a simultaneous resuscitation along with diagnosis. We typically equate shock with hypotension – this is NOT always the case initially. Failure to recognize shock states early increase the chance of bad outcomes. OVERVIEW

4. Even transient or a single episode of hypotension (systolic below 100 mg Hg) is associated with increased mortality. Remember, shock is a time-dependent disorder. These patients need continual monitoring and repeated clinical assessment. OVERVIEW

5. We will cover the initial assessment and stabilization as this is the most critical. We will then cover actual fluid management. OVERVIEW

6. Standard history and physical. However all undifferentiated shock patients should also have: - Blood glucose - Pregnancy test in females of child bearing age. - ECG to look for arrhythmias - Assessment of feet and hands for abnormal vasodilation. - Examine neck veins for paradoxical increased CVP. - Rectal exam for melena - CXR (+/- EDE) for pneumonia, pneumothorax or pulmonary edema. INITIAL ASSESSMENT OF SHOCK

7. Ensure patent airway and oxygenation. Use devices as required to maintain O2Sats > 93%. Large bore IVs in antecubital fossa. Intraosseous device if needed, but tend to not allow same fluid volumes quickly like IV access. Remember to use pressure bag on IV. Give 1 – 2 liters of N/S in all but hemorrhagic shock patients. In hemorrhagic shock, the new ATLS guidelines recommend 1 liter of N/S and if fluid support still needed go immediately to Packed Red Blood cells. INITIAL STABILIZATION OF SHOCK

8. Goal of fluid resuscitation is to achieve Mean Arterial Pressure (MAP) of 65. Values higher than 65 mm Hg are not associated with better outcomes and can predispose the patient to complications. Trendelenburg position may have some transitory benefit for increasing BP but should not be uses as a resuscitation position. All critically ill patients should be placed with the head up 30 degrees (with the exception of anaphylaxis – supine with feet elevated) If the MAP is very low (35 – 40) then temporary use of vasopressors can be used while fluids are being administered. INITIAL STABILIZATION OF SHOCK

9.  1  1  1 DRUG  1 INOTR CHRON DROMO  2 V/C V/D Phenylephrine +++ Epinephrine ++ +++ ++ ++ ++ Norepinephrine +++ ++ ++ ++ + Dobutamine ++ ++ + Dopamine +/- + + VASOPRESSORS

10. Norepinephrine: start 0.5 -1 mcg/min (0.03 mcg/kg/min) titrate 1-2mcg/min. Max 30 mcg/min Phenylephrine:start 100 – 180 mcg/min titrate 100 mcg/min. Max 10 mcg/kg/min Epinephrine:start 1 mcg/min titrate 1 mcg/min. Max 10 mcg/min Dobutamine: 2.5 mcg/kg/min titrate 2.5 mcg/kg/min. Max 20 mcg/kg/min Vasopressin: start 0.01 units/min titrate 0.01 units. Max 0.04 units/min VASOPRESSORS

11. With a 5 ml syringe, draw 1 ml of 50mg/ml (1 vial) Phenylnephrine. Mix it in 100 cc minibag of normal saline Draw out 3 – 5 cc of solution. This is now Phenylephrine of 100 mcg/ml Put labels on both the minibag and the syringe Dose is 50 – 100 mcg/min ie give 0.5 – 1 ml q2-5 minutes. Action is within 1 minutes and lasts for 10-20 min. MIXING PUSH DOSE PHENYLEPHRINE

12. Take a 10 cc N/S syringe. Discard 1 cc. Take a preloaded syringe of Epi 1:10,000 from the cardiac drawer. Take the bottom stopper off the syringe. With the 9 cc Saline syringe, draw out 1 cc Epi (1:10,000) You now have 10 mls of Epinephrine 10 mcg/ml Dose is 0.5 – 2 ml (5-20 mcg) q 2-5 min Onset 1 minute, duration 2-5 minutes. MIXING PUSH DOSE EPINEPHRINE

13. Calcium is a positive inotrope. When given IV will cause increase vasoconstriction and inotropy, especially in patients who are hypocalcemic. Dose: Calcium Gluconate 3 – 6 gm slowly IV through peripheral line (Calcium chloride 1 – 3 gm through central line) CALCIUM

14. DIFFERENTIAL DIAGNOSIS Shock can be viewed like a simple pump. The four components are: - a pump - reservoir - inflow pipes - outflow pipes

15. DIFFERENTIAL DIAGNOSIS

16. 1. Pump failure: Cardiogenic shock, arrhythmia, PE. 2. Reservoir: Hemorrhage, Hypovolemia. 3. Inflow pipes: Cardiac tamponade, tension pneumothorax. 4. Outflow pipes (vasodilation): Anaphylaxis, Sepsis, Neurogenic shock.

17. DIFFERENTIAL DIAGNOSIS Some clues to the diagnosis mentioned at the beginning in the clinical exam: Warm extremities in a hypotensive patient point to abnormal vasodilation from such things as sepsis, anaphylaxis, overdose or poisoning. Cold extremities and hypotension can indicate hypovolemia, hemorrhage and cardiogenic causes. Clear lungs nearly always exclude cardiogenic shock unless right ventricular infarction is the cause of hypotension.

18. DIFFERENTIAL DIAGNOSIS Some clues to the diagnosis mentioned at the beginning in the clinical exam: Females of child bearing age with undifferentiated shock should be assumed to be an ectopic pregnancy until proven otherwise. Jugular vein distention with hypotension, one should consider PE, Tension Pneumothorax, Pericardial Tamponade or Pump Failure.

19. There are many protocols (eFAST, RUSH) for examining hypotensive patients. EDE 1 ‘graduates’ have covered most but not all of the views used. The EDE 2 course covers the remaining cardiac views. EDE AND POINT OF CARE ULTRASOUND (POCUS)

21. FLUID RESUSCITATION IN SHOCK

22. Shock is defined a state of inadequate tissue perfusion. This does not equal ‘perfusion pressure’ Thus blood pressure is not a reliable indicator of adequate oxygen delivery to tissues, nor perfusion. Shock can occur in patients with normal or even elevated blood pressure. Inadequate tissue perfusion in the setting of normotension is called ‘compensated shock’. SHOCK

23. Decompensated shock on the other hand is a late sign of shock. MAP of < 65 or a Systolic < 90 mm Hg should raise concerns of hypotension even in the absence of overt clinical hypotension. Brief, self limited episodes of hypotension represent depletion of CV compensation and are the first signs of decompensated shock. Remember, automated BP cuffs can overestimate BP in low flow states. As well, direct auscultation can underestimate SBP by as much as 30 mm Hg in low flow states. SHOCK

24. SHOCK – CLASSES I - IV % blood loss blood loss Signs I < 15%<750 mls none, + HR II15 – 30 %750 – 1500 ml HR, RR, no syst. change III30 – 40 %1500 – 2000 ml HR, RR, Syst BP, PPres IV> 40 %> 2000 ml HR, RR PPres Syst BP, + no Dias BP Importance of serial vital monitoring.

25. This is covered in the Power Point “Fluid Resuscitation in the ER” Points to remember: - flow is related to diameter and length of the IV - doubling the catheter size increases flow by 16 fold, whereas doubling cannula length decreases flow by half. - use large short IV in the antecubital veins, with pressure bags. IV ACCESS AND CHOICE OF FLUIDS

26. Traditionally restoration of systolic BP or a MAP of 60-65 was considered an end point. Recent data suggests such end points don’t necessarily guarantee optimal organ perfusion. Serum lactate helps predict morbidity and mortality independent of hemodynamics. Lactate clearance can be reassuring that resuscitation efforts are being successful. However no optimal end point of resuscitation is currently available. END POINT OF RESUSCITATION

27. Historically the rule of 3:1 (3 units of volume for every 1 unit lost in hemorrhage) was taught. However experimental models of severe hemorrhage/hypotension show that the 3:1 rule is often quite inadequate. Also, CVP measurement is an unreliable predictor of fluid status, preload or response to fluid therapy. Although not exact, respiratory collapse of the inferior vena cava greater than 50% can be a helpful and easily identified sign in the rural setting with ultrasound, that the patient is volume depleted. END POINT OF RESUSCITATION

28. Passive leg raising. Volume responsive patients respond to passive leg raising of 3 minutes, with a temporary improvement in stroke volume greater than 15%. However such monitoring is not available to us so not of value. END POINT OF RESUSCITATION

29. Even a transient drop in BP can signal significant hypotension and is associated with poorer outcomes. Be systematic in examination and the approach to shock. IV Normal Saline should be provided to virtually all ER critically ill patients. Be familiar with pressor agents. Goal is to achieve a MAP of 65 mm Hg. However a MAP of 65 does not ensure adequate organ perfusion. Lactate clearance is one marker of favorable resuscitation. SUMMARY

30. 78 year old woman is found collapsed on the floor at home by her neighbor. ‘Down time’ unknown. EHS bring her in saying patient responding to pain, spontaneous respirations. BP 90/44 RR 20, HR 110. Unknown medication or medical history. CLINICAL SCENARIO 1

31. What are you going to do? CLINICAL SCENARIO 1

32. 40 year old woman is found outside her house by her car by her sister who came over from Victoria to visit for the weekend. EHS brings her saying at scene she was moaning incoherently, diaphoretic, BP 100/45 HR 150 RR 22, Sats 90%, glucose at scene 8.5 Past Med Hx: Diabetes – diet controlled HTN – on hydrochlorothiazide 25 mg od CLINICAL SCENARIO 2

33. What are you going to do? CLINICAL SCENARIO 2