Resuscitation: VT/VF vs PEA/Asystole

• Algorithm for pulseless electrical activity (PEA) and asystole is on page 134
• Start CPR for no pulse
• PEA and asystole are rhythms that cannot be shocked because there is nothing to jump-start the heart
• During VT or pVF rhythms, shocking stops the current rhythm, hoping it will change to another rhythm by shocking from one electrode to another
• Start CPR ASAP for PEA or asystole
• Medications take longer to perfuse if blood pressure and heart rate are slow
• CPR can transition a patient into v-tach or v-fib
• Epinephrine is administered for PEA and asystole
• Sedate awake patients before shocking
• Administer medications via IO if IV access is unavailable
• The time of death can be called with PEA
• How to approach asystole is on page 131

Pulseless Electrical Activity (PEA)

• The heart generates electrical activity, but there is no pulse
• The heart is not pumping enough blood to sustain cardiac perfusion
• You may see something on the monitor, but there is no pulse
• Use a Doppler (to listen) or an ultrasound (to visualize)
• Check carotid and femoral pulses; if no pulse for both, start CPR
• Any organized rhythm without a pulse is defined as PEA
• It excludes: VF & pVT
• Also known as electromechanical dissociation
• There is weak contractile function, but the cardiac function is too weak to produce a pulse or effective QT
• The most common initial condition present after successful defibrillation
• PEA can occur due to inadequate LV preload, hypovolemia, decreased venous return due to PE, cardiac tamponade, or tension pneumothorax
• Includes conditions where the left ventricle of the heart is empty due to the preload
• Administer Epinephrine 1mg every 3-5 minutes or every other pulse check for PEA
• Start fluids if the patient is hypovolemic in PEA
• If no IV access, administer via IO; if neither access is available, use ETT as a last resort
• Check rhythm and pulse every 2 minutes, switch between airway and chest compressions
• PEA can transition into pV-tach or V-fib

Asystole

• There is zero activity/no pulse, aka ‘''flat line'
• There is a lack of rhythm; no isoelectric EKG movement
• Administer Epinephrine 1mg every 3-5 minutes for asystole
• Represents final rhythm, including patients initially in VT or pVT
• Stop efforts if ETCO2 is 10 mmHg or less after 20 minutes of CPR
• Persistent asystole represents extensive myocardial ischemia and damage from prolonged periods of inadequate coronary perfusion

Cardiac Arrest Special Situations

• For accidental hypothermia, refer to page 138
• Rewarm the patient with a bear hugger, warm blankets, and warm fluids
• Administer a vasopressor while rewarming
• For cardiac arrest with severe (less than 30 Celsius) accidental hypothermia in the hospital, aim for ACLS treatment for rapid rewarming (warm them up faster)
• For cardiac arrest with moderate hypothermia (30-34 Celsius), start CPR, attempt to defibrillate, give medications, and then warm them up provide active core rewarming
• Hypothermia slows down the metabolic demands of the body
• Defibrillation of a cardiac patient in VF/pVT with severe accidental hypothermia is possible

Opiate Overdose (OD)

• Administer Naloxone AKA Narcan
• Rapidly reverses CNS and respiratory depression
• Treat the patient as a respiratory arrest and insert an oral airway if they come in with an OD but have a pulse
• Opiates can be given via IV, IM, Intranasally, subcutaneously, nebulized, or ETT
• Administer OPA first then ETT

Pregnancy

• There are concerns for 2 patients (mother & baby)
• In the event of an emergency C-section
• Place the patient on her left side to prevent cardiac arrest in pregnant women
• Move to L lateral decubitus if the mother is critically sick but not having to do CPR, which takes the pressure off the inferior vena cava; wedge something behind her
• Follow ACLS guidelines while using manual left uterine displacement (pushing belly over to the left side) if CPR is needed
• The gravid uterus compresses the inferior vena cava
• Push the belly over to the left side to perform compressions
• At 24-25 weeks the baby may survive outside the womb, consider emergency C-section
• Consider potential etiology and reversible causes of cardiac arrest
• Pre-existing medical conditions that complicate resuscitation
• Anesthetic complications (a reaction?), Bleeding, Cardiovascular, Embolic, Drugs, Fever, or hypertension are potential causes

ECMO

• ECMO oxygenates the blood by taking blood out to remove CO2 and replenish it; acts as the lungs
• ECMO helps replace the heart and the lungs when they are too damaged to function on their own
• There are two types:
• Veno-arterial: is used for respiratory and cardiac issues
• Veno-venous: is used for just respiratory issues
• LVAD (left ventricle assist device) allows blood to enter the device from the left ventricle and then pumps it to the central aortic circulation, helping the heart
• RVAD (right ventricular assist device)
• Inflow: right ventricle/atrium
• Outflow: main pulmonary artery, distal to the pulmonic valve

Bradycardia

• Refer to pages 66-68
• Bradycardia is a rhythm with an HR less than 60 bpm unless it's their normal
• Atropine is the drug of choice for intervention
• Symptomatic Brady is HR less than 50 bpm:
• Pt may be weak, SOB, Hypotensive, weakness, syncope, or dizzy

Different Rhythms of Bradycardia

• Includes Sinus Brady, First-degree AV block, Second degree av Block, Mobitz type 1, Mobitz type 2, and Third-degree AV block

First-degree AV block: (picture A)

• Electrical conduction going through the AV node is a delayed impulse between atria and the ventricles; there is no interruption
• This is caused by a minor defect at or below AV node
• Characterized by:
• P wave for q QRS complex (p wave is present)
• Prolonged PR interval (greater than .20 sec)

Second Degree AV Block

• There is an interruption with some blocks
• Mobitz type 1 (picture B)
• Aka Wenckebach
• Occurs at AV node
• The PR interval gets gradually longer until a QRS is missing, and then the cycle begins again
• Mobitz Type 2 (picture C)
• Occurs below the AV node
• There is a consistent PR interval but randomly drops QRS complex

Third-degree AV Block

• Causes cardiovascular collapse; you need to pace
• It's worse when someone with a second-degree AV block develops a 3rd degree block
• A pacemaker is necessary in this block
• The pacing heart rate is too low; you need to give stimulation to pace the heart, which can be done with AED pads
• Third-degree AV requires immediate pacing because it is the most clinically significant block because it can cause cardiovascular collapse
• A pacemaker gives rhythm until the problem is fixed
• Think of PACE, not Atropine; do not use atropine, only PACE
• HR is usually closer to the 40s when there is a complete AV block (wide & narrow)
• Wide QRS complexes
• Complete AV Block with ventricular escape pacemaker
• Narrow QRS complexes
• 3rd-degree AV block with junctional escape pacemaker
• When you think of junctional, ask what area of the heart are we talking about? the AV node

Medications for Bradycardia:

• Atropine, 1st -1mg bolus (give at Rat call)
• Dopamine (infusion), 2nd -5-20mcg per min
• EPI (infusion) 3rd -2-10mcg per min
• Infusion is given through IV over time

Unstable Bradycardia:

• Refer to page 68
• Unstable bradycardia exists clinically when three criteria are present:
• HR is slow less than 60bpm
• Patient has symptoms
• Symptoms are due to slow HR

Signs and Symptoms of unstable bradycardia:

• Hypotension, dizziness, altered mental status, acute altered mental status, or chest pain
• Signs of shock such as clammy feeling and lethargy
• Ischemic chest discomfort or acute heart failure indicate an unstable bradycardia
• If you walk into a patient's room and HR is low, assess the patient
• Assess if they are responsive, have chest pain, or if they are normally asleep (is this their normal)

Manage Bradycardia

1. Identify and access appropriate for clinical conditions

• Assess patient if HR is less than 50 bpm

2. Identify and treat the underlying cause

• Identify: A, B, C, D, E,
• Monitor rhythm
• Place on 02
• Monitor BP, IV, access,
• EKG

3. Persistent Brady? OK, what could be causing it?

• Signs of shock or acute heart failure
• Hypotension

Further Bradycardia Treatment

4. Monitor patient with non-persistent bradycardia
5. Administer Atropine (if patient is persistently bradycardia) as a 1mg Bolus (repeat every 3-5 mins, max 3 mg)
6. If atropine is ineffective, then think dopamine or epi
7. 3rd degree heart block requires transcutaneous pacing

• Refer to page 69
• Know the causes of Bradycardia, such as MI or being Hypoxic

Transcutaneous Pacing:

• Giving support to the heart and delivering impulses to the heart, giving electrical activity to the heart
• Place AED pads on patients with pacemakers that aren’t working, or patients who do not have one
• Pacemaker is usually seen in the right upper chest
• Delivers pacing impulses to the heart through the skin via electrodes

Pacing Indications

• Include hemodynamically unstable or bradycardia with stable ventricular escape rhythm

Pacing Contraindications

• Severe hypothermia: HR is is going to be slow due to hypothermia
• Give sedation for discomfort for conscious patients
• Do not access the carotid pulse to confirm mechanical capture
• Stimulation from the pacer may mimic a carotid pulse; stimulation from the pacer can be felt, so check the femoral pulse instead
• Start at a pacing of 60-80bpm and start low, but if symptoms subside, increase the heart rate
• The goal of peacemaking: to stop the symptoms
• If you begin pacing a patient and their symptoms subside, stop on set rate, whether that is 65 or 70, just stop.
• If there is no IV access or if it is ineffective or delayed, start pacing; you can give medications such as atropine

Defibrillation halts arrhythmias in VT/VF but is ineffective in PEA/Asystole, where there's no rhythm to convert. Prompt medication perfusion is key in PEA/Asystole, but compromised by low BP/HR. Immediate CPR is crucial to maintain circulation. Intraosseous access should be considered if IV access is difficult.