Cardiac arrest and its management

Cardiac arrest is a medical emergency where identification of the condition and immediate action is critical for the patient's survival. There are many causes and types of cardiac arrest.

Let us discuss these and their management in brief. Please follow these simple rules:

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Cardiac Arrest
Defination:
- sudden and complete loss of cardiac function.
- Patient will loss consciousness and respiration ceases immediately, pulse will be absent as well.
- death is inevitable unless effective treatment is given.
- accounts for 25% - 30% of people who die for cardiovascular disease.

Common causes:
- coronary artery disease (85%)

• myocardial ischaemia
• myocardial infarction

- structural heart disease (10%)

• aortic stenosis
• hypertrophic cardiomyopathy
• congenital heart disease

- no structural heart disease (5%)

• Long QT syndrome
• Woff-Parkinson-White syndrome
• adverse drug reactions
• severe electrolyte abnormalities

Types:
4 cardiac arrest rhythms
-Ventricular asystole
-Pulseless electrical activity
-Ventricular fibrillation
-Pulseless ventricular tachycardia

Management of cardiac arrest:
Basic life support(BSL)

1. Check responsiveness
2. open airway
3. check breathing
4. 2 effective breaths
5. assess signs of circulation
6. CPR - 100 per minute, ratio of 15 compressions to 2 breaths

Advance life support(ALS)

1. attach defibrillator/monitor
2. assess rhythm, check pulse

• If ventricular fibrillation or pulseless ventricular tachycardia - defibrillate 3 times as necessary, then do CPR 1 min.
• If ventricular asystole or pulseless electrical activity - ventilate with high oxygen concentration, then do CPR for 3 minutes.

-during CPR, administer adrenaline every 3 minutes. Consider anti-arrhythmics, atropine/pacing, buffers. Check monitor as well.
- during CPR, correct reversible causes e.g hypoxia, hyper/hypo-kalemia.

Defination:

A cardiac arrest, also known as cardiorespiratory arrest, cardiopulmonary arrest or circulatory arrest, is the abrupt cessation of normal circulation of the blood due to failure of the heart to contract effectively during systole.



It is a medical emergency.


When unexpected cardiac arrest leads to death this is called sudden cardiac death (SCD)
The out-of-hospital cardiac arrest (OHCA) has a worse survival rate (2-8% at discharge and 8-22% on admission), than an in-hospital cardiac arrest (15% at discharge).

2 main mechanisms of sudden unexpected cardiac arrest:
-Ventricular fibrillation/ Ventricular tachycardia
- Non-VF/VT (asystole and pulseless electrical activity ie electromechanical dissociation)

Management:
Basic Life support
-Shout for help
-Assess resposiveness of victim by shouting or shaking
-Check airway, breathing, circulation
- Airway- Head tilt + Chin lift + clear mouth
- Breathing- Look for chest movement, listen to breath sound, feel for expired air
- Circulation- carotid pulse
- Start cardiopulmonary resuscitaion
- Give 2 effective breaths
- Assess carotid pulse in 10sec
- Circulation present- continue rescue breathing, check circulation every minute
- No circulation- chest compression 100/min in 15:2 ratio

Advanced cardiac life support
- ECG monitoring, endotracheal intubation, IV infusion

In VF/VT, defribillation without delay, defribillation x 3 then CPR 1 min then assess rhhythm
In non- VF/VT, CPR upto 3min then reassess

Correct REVERSIBLE causes during performing CPR such as hypoxia, hypovolemia, hyper/hypokalemia, hypothermia, tension pneumothorax, cardiac tampone etc

Simultaneously, give epinephrine 1mg every 3min. Consider amiodarone, atropine/pacing buffer. antiarrthymics

Maximize prognosis by:
1. Early assess
2. Early CPR
3. Early defribillition
4. Early hospital care

Management of cardiac arrest.
1) Confirm the diagnosis, check the time, start CPR and call for help.
2) Maintain the airway, breathing, circulation.
3) When the help arrives, give 100% oxygen via ambu-bag, set up IV line and infuse normal saline.
4) Place ECG leads.
5) Carry on CPR except during intubation and defibrillation.
6) Subsequent management will depend on ECG rhythm. (specific cardiac sequences)
7) Prepare the following drugs: 1ml 1:1,000 adrenaline, lignocaine 100mg IV, 50ml bicarbonate 8.4%, isoprenaline 2mg in 500ml 5% dextrose to be used when necessary.
8) If cardiac arrest has persisted for > 30 minutes, resuscitation is unlikely to be successful, look for signs of brain death.
9) If resuscitation successful, it is very important to maintain the vital signs. Fluid balance, ABG, CVP, urine output and electrolytes need to be monitored closely and treated appropriately.
10) The further management depends on specific cardiac sequences.

• CARDIAC ARREST MANAGEMENT

• Early recognition - Recognition of illness before the patient develops a cardiac arrest will allow the rescuer to prevent its occurrence.
• Early CPR- This buys time by keeping vital organs perfused with oxygen whilst waiting for equipment and trained personnel to reverse the arrest.
• Early defibrillation - This is the only effective for Ventricular fibrillation, and also has benefit in Ventricular tachycardia.
• Early post-resuscitation care - Treatment and rehabilitation in a hospital by specialist staff helps to prevent further complications.

• Treatment within a hospital usually follows advanced life support protocols. Various treatments are offered, ranging from defibrillation to surgery TO medication.

MANAGEMENT OF CARDIAC ARREST

Cardiac arrest means an abrupt loss of the heart’s ability to pump.
Three main causes of cardiac arrest:-

• Ventricular fibrillation
• Pulseless ventricular tachycardia
• Assystole – no electrical acivity
• Electrical and mechanical disassociation – no/less output despite good conduction

The management in cardiac arrest can be explained well based on these 4 steps:

• Call for help
• Early CPR
• Defibrillation
• Early Advance Life Support

There are 2 stages in the management, first is the Basic life support, which is aimed at maintaining a minimal circulation and breathing by doing CPR till definitive help arrives. Next is the Advance life support by defibrillation and it can also include intubation and IV drugs.
A summary of actions taken in the management:

• Call for help and initiate CPR
• When help arrives, give 100% oxygen and start IV line with normal saline infusion and continue CPR
• Take ECG at the same time.
• Stop CPR only when need to defibrillate or intubate.
• In ventricular tachycardia(VT) or ventricular fibrillation(VF) defibrillator is done for three times then continue CPR for 1 minute. In non ventricular fibrillation or tachycardia CPR for 3 minutes or for 1 minute after defibrillation.
• Emergency drugs, 1ml 1;1000 adrenaline, lignocaine 100mg, bicarbonate and isoprenaline. Given through IV
• If arrest persists more than 30 minutes then must look for signs of brain death
• If patient has been successfully resuscitated, then monitoring with intake output chart, ABG, CVP, urine analysis and antiarrhytmic drug and dopamine if required.

VF/VT
Precordial thump in witnessed arrest.
Defibrillation is initiated. (values correspond for the monophasic type)

• 200J, check pulse, recharged, give 15 chest compressions and check rhythm on monitor.
• 200-300J followed by the same.
• 360J at the third attempt
• If still unsuccessful, adrenaline injection is given and 1 minute of CPR is done before repeating the whole sequence again.

Electrical Mechanical Disassociation
It is treated with CPR, while identifying the cause and correcting it.
Asystole
Is treated with CPR and intravenous drug like atropine and adrenaline and if required transvenous pacemakers to produce the electrical current.

Basic cardiac life support
Basic cardiac life support aims to restore a circulation of oxygenated blood before professional help arrives. It comprises the basic skills of cardiopulmonary resuscitation (CPR) and combines closed chest compression with artificial ventilation of the lungs.
Principles
1. Diagnose cardiac arrest by checking the patient's response to sound and touch, absent respirations and impalpable carotid or femoral pulses.
2. If the arrest is witnessed, consider giving one or two precordial thumps.
3. Assess and clear the airway with the patient on their side. Then position the patient on their back. To prevent obstruction of the upper airway by the tongue, lift the jaw forwards and tilt the head backwards.
4. Occlude the patient's nose and give two breaths into the mouth, or, in small children, into the mouth and nose together. Each breath should last about 1.5 seconds. Do not exhale too vigorously to avoid inflating the stomach. Observe the chest wall rising and falling with each expired air ventilation.
5. Perform external chest compressions:
i. Locate the middle of the sternum by finding the point half-way between the suprasternal notch and the xiphisternum. Compress the chest at or just below this position.
ii. Perform chest compressions at a rate of 80-100 per minute in adults and at least 100 per minute in children and babies.
iii. With each compression, depress the chest wall to a depth of approximately 4-5 cm in adults, 3-4 cm in children and 2-3 cm in babies.
6. The single resuscitator performs 15 chest compressions followed by two exhaled air ventilations. With two operators, cycles comprise 5 chest compressions followed by a pause, during which the lungs are inflated once. These sequences are continued until help arrives.
Simultaneous chest compression and ventilation is no longer advocated.
Devices such as resuscitation bags and masks and oropharyngeal airways may improve the efficiency, hygiene and aesthetics of CPR.
Advanced cardiac life support
Basic life support maintains viability for only a few minutes. For successful resuscitation, additional advanced cardiac life support is usually required and comprises electrical defibrillation, endotracheal intubation and intravenous drugs and fluids. The principles of management are similar in adults and children.Unless there is immediate return of spontaneous cardiac output, certain `core' interventions are necessary in all cardiac arrests. Additional interventions depend on the specific circumstances of each arrest.