CRACKCast E009 – Adult Resuscitation

This episode of CRACKCast cover’s Rosen’s Chapter 09, Adult Resuscitation. Here is some knowledge for the next time you are in the trauma bay with a patient with cardiac arrest.

Shownotes – PDF Link

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Rosen’s in Perspective: Cardiac Arrest

• out of hospital cardiac arrests: 3-16% survival rates
• <1/3 are due to VF
• those who achieve ROSC have a 19-50% survival
  • only 1/3 of those who survive to discharge return to near baseline pre-arrest function
• therapeutic hypothermia appeared to improve survival in comatose cardiac arrest survivors to near 50%

*But the key point is:

• all the highest survival rates occur within a comprehensive system of healthcare from pre-arrest, to intra-arrest, to post-arrest care*

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1) List 10 etiologies of non-traumatic cardiac arrest

Rosen’s breaks it down into broad categories:

• Cardiac
  • primarily a shockable rhythm: VF or VT (less likely)
  • 75% of the time due to CAD (30% due to acute MI)
  • other possible causes:
    • hypertrophic cardiomyopathy
    • structural disease (valves)
    • deterioration to PEA/asystole after defibrillation
• Respiratory
  • usually progresses: hypertension > tachychardia > hypotension > bradycadia > PEA/VT/asystole
  • foreign body / asthma / tension pneumothorax / PE / pneumosepsi
• Circulatory/Obstructive
  • tension pneumothorax / cardiac tamponade / PE
  • hemorrhage, sepsis, neurogenic shock
• Metabolic
  • hyperkalemia
  • hyper/hypoMg /hypokalemia – rare
• Toxic
  • Digoxin / CCB
  • TCAs
  • Cocaine / Heroin / CO / monoxide
• Environmental
  • electrocution
    • 100 mA = can cause VF if reach heart
    • >2000mA = asystole and apnea (*reverse triage at lightning strikes)
  • hypothermia:
    • requires external and internal rewarming
    • allow for prolonged resuscitation
  • drowning
    • results in bradycardic arrest

Alternatively you can just go through all the causes of shock.

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2) List the two most important determinants of good outcomes in cardiac arrest?

• TWO most important determinants of outcome:
  • time to defibrillation
  • quality CPR

Interestingly, there is:

• no evidence to support transporting someone in arrest to the ER, or using advanced life support if it interrupts CPR/defibrillation
  • patients should be pronounced dead at the scene if no ROSC
  • * recent trials and use of resuscitative ECMO may change this paradigm (CHEER trial)

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3) List the components of good quality CPR

According to the 2015 AHA guidelines the components of good quality CPR are:

1. place two hands on the lower half of the sternum
2. perform chest compressions at a rate of 100-120/min
3. compress to a depth of at least 2 inches (5 cm)
4. allow full recoil after each compression
5. minimize pauses in compressions (intubation/US)
6. ventilate adequately (2 breaths after 30 compressions, each breath delivered over 1 second, each causing chest rise)

So in summary, think about these P’s next time you do or see CPR: placement, pace, pressure, pauses, and puffs (don’t over ventilate)

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4) List 6 ways to monitor CPR

1. EtCO2 > 10 mmHg (minimum)
   • can be a reliable indicator of cardiac output in a cardiac arrest
   • levels greater than 10 indicate decent CPR, ideally around 20
   • helpful to detect ROSC when a pulse is too weak to be palpated (severe shock – in need of pressors)
   • don’t be misled by EtCO2, a rapid rise could come from:
     • new person doing CPR
     • a bolus of bicarb
     • response to treatment of tension pneumothorax; fluids; paracentesis etc.
     • ROSC

2. palpable carotid or femoral pulse
3. wave-form present on arterial line or pulse oximetry
4. diastolic pressure > 40
   • Need an arterial line to get this (check out emcrit.org for more!)
5. ScVO2 >40%
   • only really used in ICUs long ago
6. coronary perfusion pressure > 15 mmHg
   • minimum of 15 is needed to achieve ROSC

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5) What are 3 HARD indicators of adequate perfusion during CPR?

1. ET CO2 >10 mmHg
2. Diastolic pressure on intra-arterial monitoring > 40
3. SCVO2 > 40%

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6) What are your post cardiac-arrest care goals?

Generally speaking what’s good for the brain is good for the post-arrest patient. (Check out episode 8 for more info)

General Physiologic Parameters:

1. MAP 70-90 mmHg
2. CVP 10-15 mmHg
3. Hemoglobin >100
4. Lactate < 2
5. Temperature 32-24 degrees?* (36⁰C?)
6. Sa02 94-98%
7. ScVO2 >65%
8. D02 400-500 ml/min
9. VO2 > 90 ml/min

Rosen’s does flesh out the discussion around post-cardiac arrest by discussing the indications, contraindications, and controversies around hypothermia:

• some advocate the initiation of therapeutic hypothermia in cases of witnessed out of hospital VF arrest (some have expanded this to include PEA/asystole arguing the underlying cardiac rhythm does not influence the physiologic mechanism by which targeted temperature management should work)

There are some relative contraindications to therapeutic hypothermia to know about:

• severe cardiogenic shock
• uncontrolled bleeding (worsens coagulopathy)
• pregnancy
• coagulopathy / ESRD
• drug overdose / status epilepticus

However, the most controversial aspect is how low to go. See episode 8’s wisecracks essential evidence for discussion of the 33⁰C vs 36⁰C Targeted Temperature Management Trial¹

Ultimately it depends on your local centre, but if your centre is cool:

• cooling efforts:
  • ice packs to pits/folds
  • fan / misting
  • internal cooling if needed
  • commercial external cooling devices
• prevent shivering with:
  • sedation
  • NMBA’s
• consider continuous EEG monitoring
• gradual rewarming after 24 hrs

Bottom line, don’t let them go febrile.

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Wisecracks:

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Another Rosen’s in Perspective: Cardiopulmonary Arrest

• definition: “triad of unconsciousness, apnea, pulselessness”
• in VF loss of consciousness occurs in 15 seconds
  • brief seizures may occur for a few seconds due to decreased cerebral flow (hypoxic etiology)
• respiratory arrest often may progress to cardiac arrest

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1) List 4 contraindications to CPR

1. do not resuscitate (DNR) order
2. unwitnessed cardiopulmonary arrest in a patient who appears frozen/cold to touch or in rigor mortis (and no shockable rhythm)
3. traumatic arrest
4. unsafe to perform CPR due to an unsafe scene (bombs, hazardous chemicals, etc.)

Also, no CPR with an LVAD (some it may be ok if ABSOLUTELY necessary), but others you should use a hand-pump/crank and CPR should never be done according to the manufacturers (see www.mylvad.com)

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2) ACLS algorithms talk through – you must know these

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Ventricular Fibrillation / Pulseless Ventricular Tachycardia

• start CPR immediately
• single monophasic defibrillation at 360 Joules (biphasic at 200 Joules)
• if patient is on a monitor while in VT or VF may perform “cough CPR” to keep them alive for several seconds while defibrillator comes
• if unwitnessed arrest (>5 mins) then brief 90 secs of CPR prior to first shock increases chances of successful defibrillation
• immediately resume CPR after shock then pulse check at 2 mins
• refractory VF: (check out emcrit/emrap for more)
  • continued shocks
    • ?double pad shock at the same time
  • continue CPR
  • epinephrine q 3-5 mins
  • MgSO4 2g for torsades
  • amiodarone (little evidence)
  • lidocaine bolus
  • CaCl and sodium bicarbonate for hyperkalemia and TCA overdose
  • ?beta blockers (esmolol)
  • consider ECMO in ECMO capable center

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Pulseless Electrical Activity

There are at least three ways of approaching the PEA patient:

1. Using Rosen’s approach of pseudo-EMD or true-EMD
2. Use the QRS complex approach
3. Systematically go through the H’s and T’s

What is PEA?

Rosen’s defines it as:

• “coordinated/organized electrical activity of the heart without a palpable pulse”

The EMD approach

• may be pseudo-EMD (no pulse despite mechanical contractions) or true-EMD (no pulse and no mechanical)
• true electromechanical-dissociation (EMD) – asystole
  • primary cardiac disorder of myocytes due to global myocardial energy loss and acidosis
  • due to ischemia, toxins, hyperkalemia, hypothermia, etc.
• pseudo-EMD – severe shock
  • may occur with papillary muscle rupture or free wall rupture
  • hypovolemia / tamponade / PE / pneumothorax
  • treatment underlying causes

The QRS approach:

• Narrow QRS
  • Mechanical problem – fix the obstruction or flow
• Wide QRS
  • Cellular problem
    • Acidosis
    • Oxygen
    • Toxins / overdose
    • Potassium
    • Massive MI

The H’s and T’s approach:

• MUST know the 5 H’s and 5 T’s:
  • H’s
    • Hypovolemia
    • Hypoxia
    • Hydrogen ion (acidosis)
    • Hypothermia
    • Hypo/HyperK
  •  T’s
    • Thrombosis cardiac
    • Thrombosis pulmonary
    • Toxins
    • Tamponade
    • Tension pneumothorax

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Asystole

• “no organized cardiac activity”
• usually electric
• must be confirmed with at least TWO leads
  • you should confirm no pericardial effusion with echo (massive PCE can cause low voltage)
• does not respond to pacing
• does not respond to atropine
• epi is an option
• CPR and intubation
• very low (~0%) chance of survival

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Respiratory arrest//failure

You show up to a code and find that the person is not breathing adequately, but they have a pulse.
First: help them breath using a BVM and probably intubation (if you can’t reverse them quickly)
Second: figure out why they aren’t breathing

Many different approaches: this is a fairly intuitive one

1. Won’t breathe
   • CNS problem: tumour, stroke, bleed, toxin induced (benzo, opioids, sedatives, TCAs)
2. Can’t breathe
   • nerve problem (phrenic nerve, high C-Spine injury, GBS, myasthenia gravis, botulinum toxin)
   • muscle problem (electrolytes, drugs blocking muscle function (NMBAs), high doses of magnesium, environmental toxins, tick paralysis, etc.)
   • chest wall dysfunction (flail chest, tension pneumothorax, burns)
   • upper airway disorder (vocal cord, foreign body, anaphylaxis, angioedema)
3. Can’t breathe enough
   • diffusion problem at the level of the lungs: (shunt, VQ mismatch)
     • bad COPD
     • atelectasis
     • asthma

The best thing you can do is address any quickly treatable cause immediately:

• give naloxone (opioid overdose)
• decompress tension pneumothorax
• treat anaphylaxis
• control the airway

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Brain arrest / Cognitive arrest

You show up to a code or patient is wheeled in who is comatose, but breathing and a pulse…

(more in Episode 17 – Coma)

Bottom line you think of something affecting both hemispheres using an approach like DIMS:

• Drugs
• Infection
• Metabolic
• Structural

Approach this similarly to the post-ROSC patient and you won’t miss much.

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3) Describe your approach to the post-cardiac arrest patient

One great approach to the post arrest patient is from Dr. David Sweet (Emergency Physician/ Intensivist at Vancouver General Hospital)

His memory aid for the post arrest patient is:  1:2:2:3
1: one full set of vitals including glucose
2: two machines that you should call for ASAP – ECG and CXR
2: two bloods: full cardiac labs (CBC, troponin, lytes etc.) and an ABG
3: three basics: take a history, do a physical exam, and look at the old charts

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4) Sleuthing out why the patient arrested: an approach to the history and physical

History

• family, bystanders, EMS
• key questions
  • exact time of arrest – this is absolutely crucial!**
  • witnessed vs un-witnessed arrest
  • what was the patient doing at the time (exercise? eating? sitting?)
  • Bystander CPR
  • CPR duration – crucial
  • ECG rhythm – crucial (cath lab vs. no cath lab)
  • interventions by EMS providers
  • past medical/psychiatric history
  • drug ingestion or environmental exposures? do we need to give an antidote?
  • allergies

Physical Exam

• General exam
  • pallor or cyanosis
• Head to toe:
  • signs of trauma
  • airway secretions and ease of ventilation
  • abdominal exam
  • rectal exam (r/o massive GI bleed)
  • extremity exam – focal deficits
  • skin for track marks or signs of trauma

PEARLS:

• 1) ensure airway and ventilations
• 2) confirm dx of cardiac arrest
  • ***look with ultrasound***
    • is it severe shock (a beating heart with no BP)
    • or asystole (no organized beating heart)
• 3) confirm dx of cause

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This post was copyedited and uploaded by Sean Nugent (@sfnugent)

References