Presented by: Angela Novak, BSN, RN, CCRN Mercy Hospital St. Louis

Transcription

1 Presented by: Angela Novak, BSN, RN, CCRN Mercy Hospital St. Louis

2 Objectives Review the history of induced hypothermia use post cardiac arrest, discuss evidence and rationales. Discuss the most recent studies about therapeutic hypothermia and how they change the standard of care. Discuss the methods for hypothermia induction, with side effects and complications of each method.

3 What is Therapeutic Hypothermia? The use of internal or external cooling devices to keep a patient s core body temperature between 32 to 36 Goal: Save the brain!

4 Hypothermic State Core temperature <35 C (95 F) Metabolic rate falls Subcategories: Mild: 32 C-35 C Moderate: 28 C-32 C Severe: <28 C

5 Therapeutic Hypothermia Has become a standard of care for patients who are comatose after cardiac arrest How it all began Benson DW, Williams GR, Spencer FC, et al: The use of hypothermia after cardiac arrest. Anesth Analg 1959; 38:

6 Journey to present day Bernard SA, Jones BM, Horne MK: Clinical trial of induced hypothermia in comatose survivors of out-of-hospital cardiac arrest. Ann Emerg Med 1997; 30: Hypothermia After Cardiac Arrest Study Group. Mild therapeutic hypothermia to improve the neurologic outcome after cardiac arrest [published correction appears in N Engl J Med. 2002;346(22):1756]. N Engl J Med. 2002;346(8);

7 HACA Study Group

8 Save the Brain Hypoxia leading to ischemia Secondary injury Reperfusion Injury

9 Beneficial Effects of Cooling Decreases brain s metabolic rate Decreases neurotransmitter excitement Inhibits release of inflammatory cytokines Decreases production of free radicals

10 Purpose of Therapeutic Hypothermia Increase survival Improve neurologic outcome

11 What to call it??? Therapeutic Hypothermia Targeted Temperature Management Induced Hypothermia Therapeutic Temperature Management Therapeutic Temperature Modulation Cardio-cerebral Resuscitation Therapy

12 2015 American Heart Association Guidelines TTM should be initiated for any comatose post arrest patient regardless of initial rhythm Target temperature may be between 32 to 36. But consistent temperature should be maintained for 12 to 24 hours. There is no harm in fever prevention after patient is re-warmed. Wait 72 hours after patient returns to normothermia before prognosticating Don t cool patients with chilled IV fluids pre-hospital, no benefit Guidelines-Highlights-English.pdf

13 33 C versus 36 C Nielsen N, Wetterslev J, Cronberg, T, et al. Targeted Temperature Management at 33 C versus 36 C after Cardiac Arrest. N Engl J Med Trial compared two active management of temperature arms. Control was 36 degrees. No differences in benefit or harm. 74% of patients received bystander CPR, and may have had good outcome with or without TTM.

14 33 C versus 36 C International Liaison Committee on Resuscitation This trial found similar good outcomes with a new regimen targeting 36ºC, and a formal evidence review will need to consider whether this new TTM regimen should be part of future treatment recommendations. Pending formal consensus on the optimal temperature, we suggest that clinicians provide post resuscitation care based on the current treatment recommendations. We accept that some clinicians may make a local decision to use a target temperature of 36 C pending this further guidance.

15 Keys to Success: Duration of cooling Speed of induction Speed of rewarming Prevention of side effects

16 How do we cool patients? FAST! External surface cooling system Computer controlled, water-cooled pads Cools skin and vessels in chest, abdomen, thighs Internal Cooling System Computer controlled, saline-cooled central line catheter Cools blood by direct contact Traditional Cooling Ice packs, ambient temp, chilled NS boluses, cooling blanket Can be used in addition to external/internal system

17 External Surface Cooling System Pros Precise cooling to set temperature Pads have various sizes, can be customized for patient shape Cons Cannot be used on burned or open skin Water flow into pads can affect patient temperature

18 Internal Cooling System Pros Cools blood directly Precise cooling to direct temperature Less risk of device related skin alterations Cons Requires placement of specialized catheter in jugular, subclavian, or femoral site Different catheters can stay in patient for differing amount of days

19 Cooling blanket Pros Least expensive Cons Not as much skin contact, making it less precise hard to access patient without lifting blanket Temperature must be manually adjusted during rewarming

20 Temperature Measurement Use two sites to verify accurate temperature reading Provide both Celsius and Fahrenheit in policies/protocols Once a site and method have been selected, they must be used consistently to ensure accuracy and patient safety (Nursing times /Vol 108 No45/

21 Core Temperature Sites Pulmonary artery catheter Esophageal Rectal Bladder

22 Hypothermia Effects at 33 C Body Systems Side Effects Neuro: shivering (most common C, less common at 33 C) Cardio: sinus bradycardia, prolonged PR, widened QRS, increased QT, osbourne waves Resp: decreased metabolism causes decreased minute ventilation to maintain normal ph Renal: cold diuresis, potassium shift into cells, decreased phosphate ABG: increased gas solubility appear to have respiratory alkalosis on temperature corrected ABG GI: decreased motility, increased blood glucose concentration Skin: vasoconstriction Immunosuppression-increased risk of infection d/t number and function of WBCs decrease (fever noted by decrease in water temperature) Hypokalemia Electrolyte abnormalities(mag, phos) Mild coagulopathy, decreased number and function of platelets, prolonged clotting times

23 Shivering in Hypothermia anticipated consequence Major adverse effect Shivering: thermoregulatory defence to maintain body temperature at the hypothalamic set point

24 Shivering thresholds Peripheral Vasoconstriction 36.5 C Shivering 35.5 C Energy consumption Metabolic demand Shivering

25 Bedside Shivering Assessment Scale (BSAS) A simple, validated four-point scale that enables repeated quantification of shivering at the bedside. Critical Care 2012, 16(Suppl 2):A9 doi: /cc11267

26 SEIZURES? Occurrence: up to 30% of post-arrest patients. Often ONLY noticeable on EEG. DO NOT USE NEUROMUSCULAR BLOCKADE- Immediately notify Attending, neurology consult should be initiated. Initiate Hypothermia Achieve adequate sedation first: RASS -3 to -4, Q1h midazolam +/or fentanyl +/or propofol +/or precedex; or other medication as ordered Monitor and chart BSAS for shivering q1h; advance to q15m if shivering present. Notify Fellow of shivering, initiate counter-warming (wrap extremities and head in hot blankets), Give acetaminophen and buspirone PRN as ordered. Consider additional Mg++ bolus if serum Mg <4.0 mg/dl. If shivering continues after 30 minutes, escalate to level 2 (moderate) interventions Bedside Shivering Notify Fellow/Attending of shivering, attempt lower level interventions, Consider PRN IVP doses of midazolam, fentanyl, lorazepam. Consider lowering target temperature to 32.5 C. If shivering continues, escalate to level 3 (severe) interventions Assessment Scale 0 No shivering felt in masseter, neck, chest 1 (mild) Localized shivering in masseter, neck, chest 2 (moderate) Gross shivering of UE 3 (severe) Gross shivering of UE and LE 1 (mild) 2 (moderate) 3 (severe) Allow minutes posttreatment before escalation of interventions Notify Attending of shivering, attempt lower level interventions AND consider meperidine infusion and/or IVP Neuromuscular Blockade PRN pushes; maximum 3x, if fails THEN Notify Attending and supervisor, consider continuous neuromuscular blockade

27 Bedside Nursing Checklist TH/TTM is a complex process- steps get missed, 6 hour window delayed Time lost=brain lost Anecdotal article detailing RN checklist used at Brigham and Women s Hospital- Boston, MA (n=60) (Avery et al, 2015) Post implementation showed median time from code to target from 7:00h to 6:30h, ICU admission time to target from 5:47h to 4:00h.

28 Phase I Phase II Phase III Phase IV Induction Phase (Goal: <6 h post-arrest) Maintenance Phase (for C) Rewarming Phase ( 12 h to reach 36.5 C) Normothermia Phase ( C for 48 h) Start date/time Start date/time Start date/time Start date/time Bedside Nursing Checklist Verify orders, call central (4444+2) for small and large pads, supplemental pad if >100kg. Check pt height/weight with chart on package to determine pad size Central line Arterial line Set machine target to 33 C, consider 32.5 C if shivering Call pharmacy for chilled Normal Saline, administer via pressure bag. Ice packs to groin, axilla VS, SO2, pt temp, water temp Q15 until stable and then Q1 hr. Target MAP >65, or higher if ordered. RASS Q1hr Maintenance same rate to match urine output (cold diuresis) if ordered POC glucose q1h: notify if <110 or >150 BSAS q1h, notify MD of shivering and see shivering flowchart Skin assessment q4h Initial Labs (CBC, CMP, temp adj ABG, PT/INR, PTT, Lactic Acid, CKMB, Troponin, D-Dimer, Fibrinogen, HCG quantitative (females) Administer IV electrolyte replacements PRN Hour 6: BMP, Mag+Phos, CBC w/dif, PTT, PT/INR, CKMB, Troponin, temp adjusted ABG, Lactic acid Hour 12: labs Hour 12:blood cultures Hour 18: labs Hour 24: labs w/o lactic acid POC glucose q1h VS, SO2, pt temp, water temp Q1 hr or more frequently per nursing judgment or provider order. RASS Q1hr BSAS q1h, follow shivering prevention flowchart Reasonable bradycardia OK If water temp <20 C, consider CXR for infection. Try Tylenol Order continuous EEG before start of Rewarming Phase. Order during the day before rewarming begins. Stop all potassiumcontaining infusions Set machine to rate of C/hour, Or 0.1C/hr for neuro injury patients. Monitor closely for dysrhythmias, shivering, hypotension VS, SO2, BSAS, patient temp, water temp, POC glucose q1h Hour 30: labs Hour 36: labs D/C Neuromuscular Blockade, if applies D/C q1h POC glucose Sedation vacation OK Discuss continued need for serial labs w/ MD Pads can stay on for 5 days, then check w/ MD regarding need Things to remember: Prognostication of neurological outcomes is inaccurate/unwise until AT LEAST 72 hours post arrest (euthermia is complete). High Magnesium levels are permissible during TTM. Potassium and other electrolytes can shift rapidly during cooling and rewarming Hypothermia can interfere with memory but can be very uncomfortable, suggested RASS goal -3 to -4 w/ sedation Seizures are a contraindication to therapeutic hypothermia and NMB, notify attending and neuro immediately and cooling should be stopped Most medications remain in the system longer and buildup d/t slowed metabolism Shivering may negate beneficial effects of TTM and should be treated quickly and aggressively. See shivering flowchart attachment Low flow warning on the Arctic Sun- check for kinks in the line, damaged/leaky pads, ensure all connections are tight, check when machine was last serviced/filter changed, try adding water to machine. Low flow OK so long as goal temperature maintained

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30 References Am J Crit Care 2013;22:76 doi: /ajcc American Association of Critical-Care Nurses Avery, K. R., O Brien, M, Pierce, C. D., Gazarian, P. K. (2015). Use of a nursing checklist to facilitate implementation of therapeutic hypothermia after cardiac arrest. Critical Care Nurse, 35(1), Badjatia, N., Strongilis, E., Prescutti, M., et al. (2009). Metabolic impact of shivering during therapeutic temperature modulation: the Bedside Shivering Assessment Scale. Stroke, 39(12): Bernard SA, Jones BM, Horne MK: Clinical trial of induced hypothermia in comatose survivors of out-of hospital cardiac arrest. Ann Emerg Med 1997; 30: Bernard SA, Gray T, Buist MD, et al. Treatment of comatose survivors of out-of-hospital cardiac arrest with induced hypothermia. N Engl J Med. 2002;346: Choi, H. A. et al, (2011) Prevention of shivering during therapeutic temperature modulation: The Columbia anti-shivering protocol. Neurocritical Care, 14, Hypothermia After Cardiac Arrest Study Group. Mild therapeutic hypothermia to improve the neurologic outcome after cardiac arrest [published correction appears in N Engl J Med. 2002;346(22):1756]. N Engl J Med. 2002;346(8); Nursing times /Vol 108 No 45/Measuring Body Temperature- Polderman KH. (2009). Mechanisms of action, physiological effects, and complications of hypothermia. Crit Care Med, 37 (7) (Suppl): S Yenari M, Wijman C, Steinberg G. Effect of hypothermia on cerebral metabolism, blood flow, and autoregulation. In: Mayer SA, Sessler DI, eds. Therapeutic Hypothermia. New York, NY: Marcel Dekker; 2005:

31 Special thanks to: John Luker, BSN, RN Kelly Ball, BSN, RN Critical Care Practice, Quality, and Research Shared Governance Council members Mercy Hospital St. Louis