Cardiopulmonary Resuscitation (CPR)

Cardiopulmonary Resuscitation (CPR)
SCIENCE • Form 4 • Chapter 2: Emergency Help

2.1 Cardiopulmonary Resuscitation (CPR)

Cardiopulmonary resuscitation (CPR) is an essential emergency life-saving aid that does not require any equipment. It combines chest compressions and mouth-to-mouth breathing to restore heartbeat and breathing in an unconscious individual, maintaining vital blood circulation and oxygen supply to prevent irreversible brain damage before paramedics arrive.

Learning Objectives

  • State the definition of cardiopulmonary resuscitation (CPR).
  • Identify the situations and causes that require CPR.
  • Explain and demonstrate the correct sequence of steps in the CPR procedure for an adult.
  • Describe the importance of chest compressions and mouth-to-mouth resuscitation.

Steps of the Adult CPR Procedure

Follow the five emergency actions in the correct order to keep blood and oxygen moving.

Five-step adult CPR procedure flowchart A five-stage flowchart showing the adult CPR procedure: check response and call 999, open the airway and check breathing, perform 30 chest compressions at 5 to 6 cm depth and 100 to 120 compressions per minute, give 2 mouth-to-mouth breaths with the nose pinched, then repeat the 30 to 2 cycle or place the victim on their side if breathing resumes. Step 1 Check response and call 999 Tap shoulder, ask "Are you OK?" Step 2 Open airway and check breathing Tilt head back, lift chin Step 3 30 chest compressions 5–6 cm depth 100–120/min Step 4 2 rescue breaths Pinch nose, blow 1 second Step 5 Repeat 30:2 cycle, or turn victim on their side if breathing resumes

Short Explanation

Definition of CPR

Cardiopulmonary resuscitation (CPR) is an emergency aid involving a combination of chest compressions and breathing into the mouth of the victim to restore their heartbeat and breathing. It is a simple procedure that does not require any equipment.

Situations that Require CPR

CPR is needed when an individual:

  • does not respond to stimulus.
  • is not breathing.
  • has no heartbeat or pulse.

Causes of Situations Requiring CPR

Heart attack

The heart stops functioning, so blood stops flowing to the brain and body.

Electric shock

An electric current can disrupt the normal rhythm of the heart.

Drowning

Water prevents oxygen from entering the lungs, causing breathing to stop.

Lightning strike

A lightning strike can stop the heart and breathing suddenly.

Importance of CPR

Chest compressions

Produce artificial blood circulation by pumping blood through the heart to sustain continuous blood flow, especially during a heart attack where the heart stops functioning.

Mouth-to-mouth resuscitation

Delivers oxygenated air into the lungs, allowing oxygen to reach the brain and body. This prevents brain damage, which occurs if oxygen fails to reach the brain within a certain period.

Science Gallery Note. According to the American Heart Association (2016), hands-only chest compressions can still help save a victim's life if a rescuer is uncomfortable performing mouth-to-mouth resuscitation.

Risks of Incorrect Technique

  • Ribs may be fractured if compressions are improper.
  • Air blown into the victim's mouth may not reach the lungs if the airway is not opened correctly.

Steps in the CPR Procedure for an Adult

Perform each step in order until the ambulance arrives or the victim regains consciousness.

1

Check the victim's responses. Attend to the victim and make sure the surrounding area is safe. Check responses by tapping the victim's shoulder and asking, "Are you OK?". If there is no response, shout "Help" and ask a bystander to call the 999 emergency helpline.

2

Open the airway. Place the victim lying down on a flat surface with the chest facing upwards. Tilt the head back and lift the chin to open up the airway. Check breathing: listen for breathing sounds from the mouth/nose and observe the movement of the chest.

3

Chest compressions. Performed if no pulse or breath is detected to restore blood circulation. Place the heel of one hand on the centre of the victim's chest. Straighten arms, cover the first hand with the other hand, and interlock fingers. Lean body slightly forward with shoulders vertically above the victim's chest. Press down at least 5 cm and not more than 6 cm. Release compression while keeping hands on the chest, allowing the chest to return to its normal position. Rate: 100 to 120 compressions per minute.

4

Mouth-to-mouth resuscitation. If there is still no breath, pinch the victim's nose and blow air into the mouth for 1 second. This enables oxygenated air to enter the trachea and reach the lungs.

5

Repetition / Cycle. Perform 30 chest compressions followed by 2 breaths of mouth-to-mouth resuscitation. Repeat continuously until the ambulance arrives or the victim regains consciousness. If the victim breathes but remains unconscious, position the body on his side (recovery position).

Try to Answer First

Answer in your mind, then press "Check Answer".

1

What is the recommended compression-to-breath ratio during CPR for an adult?

Answer: 30 chest compressions followed by 2 mouth-to-mouth breaths (30:2).
2

What is the correct depth and rate of chest compressions in adult CPR?

Answer: A depth of at least 5 cm and not more than 6 cm, at a rate of 100 to 120 compressions per minute.
3

What should you do if the victim starts breathing normally after CPR but is still unconscious?

Answer: Position the victim's body on his side.

Common Mistakes

  • !Pressing too shallowly (less than 5 cm) or too deeply (more than 6 cm), which either fails to circulate blood effectively or risks fracturing the ribs.
  • !Forgetting to pinch the victim's nose closed during mouth-to-mouth resuscitation, allowing blown air to escape rather than filling the lungs.
  • !Bending the elbows during compressions instead of keeping arms straight and positioning shoulders vertically over the victim's chest.
  • !Failing to tilt the head back and lift the chin, resulting in a blocked airway.

Concept Misunderstandings

Misconception

CPR restarts a completely dead heart instantly.

Correct Concept

CPR provides artificial blood circulation and oxygenation to keep the brain and vital organs alive until medical personnel arrive.

Misconception

If you are uncomfortable performing mouth-to-mouth breathing, you should do nothing.

Correct Concept

Hands-only chest compressions can still effectively pump blood and help save the victim's life.

Misconception

Compressions should be delivered as quickly as possible without letting the chest recoil.

Correct Concept

Compressions must be delivered at 100–120 per minute, and the chest must be allowed to return completely to its normal position between compressions.

Summary

  • Cardiopulmonary resuscitation (CPR) is an emergency procedure combining 30 chest compressions and 2 rescue breaths to restore breathing and blood circulation in victims of cardiac arrest, drowning, electric shock, or lightning strike.
  • Chest compressions sustain artificial blood flow, while breaths prevent brain damage by providing oxygen.
  • Compressions must be 5 to 6 cm deep at 100–120 compressions per minute.
  • CPR is needed when a victim does not respond to stimulus, is not breathing, or has no heartbeat or pulse.
  • If the victim breathes but remains unconscious, place the body on his side in the recovery position.

Short Activity

A. Objective Quiz

1 What is the correct compression depth when performing chest compressions on an adult?

2 Why is mouth-to-mouth resuscitation performed alongside chest compressions during CPR?

B. Fill in the Blanks

3 Chest compressions during CPR should be performed at a rate of compressions per minute.

 

4 During mouth-to-mouth resuscitation, the rescuer must pinch the victim's nose and blow air into the mouth for second(s).

 

C. Drag and Drop: Match Each CPR Step to Its Action

Drag each CPR step to the action it describes. On a phone, tap an answer first, then tap a matching box. Tap the Answer Choices area to return a selected item.

CPR Step
Step 1
Step 2
Step 3
Step 4
Action Performed
1 Tap the victim's shoulder, ask "Are you OK?", and shout for help to call 999.
2 Tilt the head back, lift the chin, and check for breathing sounds and chest movement.
3 Place interlocked hands on the centre of the chest and press down 5 to 6 cm.
4 Pinch the victim's nose and blow air into the mouth for 1 second.

C. Match Each CPR Step to Its Action

Write the correct CPR step next to each action.

Action Performed CPR Step
1. Tap the victim's shoulder, ask "Are you OK?", and shout for help to call 999.  
2. Tilt the head back, lift the chin, and check for breathing sounds and chest movement.  
3. Place interlocked hands on the centre of the chest and press down 5 to 6 cm.  
4. Pinch the victim's nose and blow air into the mouth for 1 second.  

Answer choices: Step 1 • Step 2 • Step 3 • Step 4

Keywords

Cardiopulmonary Resuscitation (CPR) Chest Compressions Mouth-to-Mouth Resuscitation Airway Artificial Blood Circulation Brain Damage

Cardiopulmonary Resuscitation (CPR)

Cardiopulmonary Resuscitation (CPR)
SCIENCE • Form 4 • Chapter 2: Emergency Help

2.1 Cardiopulmonary Resuscitation (CPR)

Cardiopulmonary resuscitation (CPR) is an essential emergency life-saving aid that does not require any equipment. It combines chest compressions and mouth-to-mouth breathing to restore heartbeat and breathing in an unconscious individual, maintaining vital blood circulation and oxygen supply to prevent irreversible brain damage before paramedics arrive.

Learning Objectives

  • State the definition of cardiopulmonary resuscitation (CPR).
  • Identify the situations and causes that require CPR.
  • Explain and demonstrate the correct sequence of steps in the CPR procedure for an adult.
  • Describe the importance of chest compressions and mouth-to-mouth resuscitation.

Steps of the Adult CPR Procedure

Follow the five emergency actions in the correct order to keep blood and oxygen moving.

Five-step adult CPR procedure flowchart A five-stage flowchart showing the adult CPR procedure: check response and call 999, open the airway and check breathing, perform 30 chest compressions at 5 to 6 cm depth and 100 to 120 compressions per minute, give 2 mouth-to-mouth breaths with the nose pinched, then repeat the 30 to 2 cycle or place the victim on their side if breathing resumes. Step 1 Check response and call 999 Tap shoulder, ask "Are you OK?" Step 2 Open airway and check breathing Tilt head back, lift chin Step 3 30 chest compressions 5–6 cm depth 100–120/min Step 4 2 rescue breaths Pinch nose, blow 1 second Step 5 Repeat 30:2 cycle, or turn victim on their side if breathing resumes

Short Explanation

Definition of CPR

Cardiopulmonary resuscitation (CPR) is an emergency aid involving a combination of chest compressions and breathing into the mouth of the victim to restore their heartbeat and breathing. It is a simple procedure that does not require any equipment.

Situations that Require CPR

CPR is needed when an individual:

  • does not respond to stimulus.
  • is not breathing.
  • has no heartbeat or pulse.

Causes of Situations Requiring CPR

Heart attack

The heart stops functioning, so blood stops flowing to the brain and body.

Electric shock

An electric current can disrupt the normal rhythm of the heart.

Drowning

Water prevents oxygen from entering the lungs, causing breathing to stop.

Lightning strike

A lightning strike can stop the heart and breathing suddenly.

Importance of CPR

Chest compressions

Produce artificial blood circulation by pumping blood through the heart to sustain continuous blood flow, especially during a heart attack where the heart stops functioning.

Mouth-to-mouth resuscitation

Delivers oxygenated air into the lungs, allowing oxygen to reach the brain and body. This prevents brain damage, which occurs if oxygen fails to reach the brain within a certain period.

Science Gallery Note. According to the American Heart Association (2016), hands-only chest compressions can still help save a victim's life if a rescuer is uncomfortable performing mouth-to-mouth resuscitation.

Risks of Incorrect Technique

  • Ribs may be fractured if compressions are improper.
  • Air blown into the victim's mouth may not reach the lungs if the airway is not opened correctly.

Steps in the CPR Procedure for an Adult

Perform each step in order until the ambulance arrives or the victim regains consciousness.

1

Check the victim's responses. Attend to the victim and make sure the surrounding area is safe. Check responses by tapping the victim's shoulder and asking, "Are you OK?". If there is no response, shout "Help" and ask a bystander to call the 999 emergency helpline.

2

Open the airway. Place the victim lying down on a flat surface with the chest facing upwards. Tilt the head back and lift the chin to open up the airway. Check breathing: listen for breathing sounds from the mouth/nose and observe the movement of the chest.

3

Chest compressions. Performed if no pulse or breath is detected to restore blood circulation. Place the heel of one hand on the centre of the victim's chest. Straighten arms, cover the first hand with the other hand, and interlock fingers. Lean body slightly forward with shoulders vertically above the victim's chest. Press down at least 5 cm and not more than 6 cm. Release compression while keeping hands on the chest, allowing the chest to return to its normal position. Rate: 100 to 120 compressions per minute.

4

Mouth-to-mouth resuscitation. If there is still no breath, pinch the victim's nose and blow air into the mouth for 1 second. This enables oxygenated air to enter the trachea and reach the lungs.

5

Repetition / Cycle. Perform 30 chest compressions followed by 2 breaths of mouth-to-mouth resuscitation. Repeat continuously until the ambulance arrives or the victim regains consciousness. If the victim breathes but remains unconscious, position the body on his side (recovery position).

Try to Answer First

Answer in your mind, then press "Check Answer".

1

What is the recommended compression-to-breath ratio during CPR for an adult?

Answer: 30 chest compressions followed by 2 mouth-to-mouth breaths (30:2).
2

What is the correct depth and rate of chest compressions in adult CPR?

Answer: A depth of at least 5 cm and not more than 6 cm, at a rate of 100 to 120 compressions per minute.
3

What should you do if the victim starts breathing normally after CPR but is still unconscious?

Answer: Position the victim's body on his side.

Common Mistakes

  • !Pressing too shallowly (less than 5 cm) or too deeply (more than 6 cm), which either fails to circulate blood effectively or risks fracturing the ribs.
  • !Forgetting to pinch the victim's nose closed during mouth-to-mouth resuscitation, allowing blown air to escape rather than filling the lungs.
  • !Bending the elbows during compressions instead of keeping arms straight and positioning shoulders vertically over the victim's chest.
  • !Failing to tilt the head back and lift the chin, resulting in a blocked airway.

Concept Misunderstandings

Misconception

CPR restarts a completely dead heart instantly.

Correct Concept

CPR provides artificial blood circulation and oxygenation to keep the brain and vital organs alive until medical personnel arrive.

Misconception

If you are uncomfortable performing mouth-to-mouth breathing, you should do nothing.

Correct Concept

Hands-only chest compressions can still effectively pump blood and help save the victim's life.

Misconception

Compressions should be delivered as quickly as possible without letting the chest recoil.

Correct Concept

Compressions must be delivered at 100–120 per minute, and the chest must be allowed to return completely to its normal position between compressions.

Summary

  • Cardiopulmonary resuscitation (CPR) is an emergency procedure combining 30 chest compressions and 2 rescue breaths to restore breathing and blood circulation in victims of cardiac arrest, drowning, electric shock, or lightning strike.
  • Chest compressions sustain artificial blood flow, while breaths prevent brain damage by providing oxygen.
  • Compressions must be 5 to 6 cm deep at 100–120 compressions per minute.
  • CPR is needed when a victim does not respond to stimulus, is not breathing, or has no heartbeat or pulse.
  • If the victim breathes but remains unconscious, place the body on his side in the recovery position.

Short Activity

A. Objective Quiz

1 What is the correct compression depth when performing chest compressions on an adult?

2 Why is mouth-to-mouth resuscitation performed alongside chest compressions during CPR?

B. Fill in the Blanks

3 Chest compressions during CPR should be performed at a rate of compressions per minute.

 

4 During mouth-to-mouth resuscitation, the rescuer must pinch the victim's nose and blow air into the mouth for second(s).

 

C. Drag and Drop: Match Each CPR Step to Its Action

Drag each CPR step to the action it describes. On a phone, tap an answer first, then tap a matching box. Tap the Answer Choices area to return a selected item.

CPR Step
Step 1
Step 2
Step 3
Step 4
Action Performed
1 Tap the victim's shoulder, ask "Are you OK?", and shout for help to call 999.
2 Tilt the head back, lift the chin, and check for breathing sounds and chest movement.
3 Place interlocked hands on the centre of the chest and press down 5 to 6 cm.
4 Pinch the victim's nose and blow air into the mouth for 1 second.

C. Match Each CPR Step to Its Action

Write the correct CPR step next to each action.

Action Performed CPR Step
1. Tap the victim's shoulder, ask "Are you OK?", and shout for help to call 999.  
2. Tilt the head back, lift the chin, and check for breathing sounds and chest movement.  
3. Place interlocked hands on the centre of the chest and press down 5 to 6 cm.  
4. Pinch the victim's nose and blow air into the mouth for 1 second.  

Answer choices: Step 1 • Step 2 • Step 3 • Step 4

Keywords

Cardiopulmonary Resuscitation (CPR) Chest Compressions Mouth-to-Mouth Resuscitation Airway Artificial Blood Circulation Brain Damage