Basic Life Support (BLS)

Learning Outcomes

• Describe the components of BLS.
• Define cardiopulmonary resuscitation (CPR).
• List steps for performing BLS.
• Describe how to help a person choking during BLS.

Key Components

• BLS includes CPR and defibrillation using automated external defibrillators (AED) when available.
• Keys to survival from sudden cardiac arrest (SCA):
  • Recognition and treatment.
  • Immediate initiation of excellent CPR.
  • Early defibrillation.

Cardiopulmonary Resuscitation (CPR)

• Emergency first-aid procedure to maintain respiration and blood circulation when breathing and heartbeats stop.
• Restores the flow of oxygenated blood to the brain and organs during SCA.

Chain of Survival

• Three basic vital functions: Breathing, Circulation, Consciousness.

Thoracic Pump Theory

• Chest compression increases intrathoracic pressure to propel blood out of the thorax.
• Equal time for compression and decompression.
• Pressure should be completely released.
• Hands should remain in contact with the chest.

Oxygen Content

• Atmospheric air: 21% O2.
• Alveoli: 14.5% O2.
• Expired air: 16–18% O2.
• Chest compressions provide about 30% of normal perfusion to brain and heart.

Timing

• Irreversible cerebral damage can occur 3-5 minutes after circulation failure.
• The chance of successful CPR (ROSC) decreases by 10% with each minute following SCA.

Conducting BLS

• Based on guidelines by:
  • International Liaison Committee on Resuscitation.
  • American Heart Association.
  • European Resuscitation Council.

Performance of Chest Compressions

• Most important element of CPR.
• CPR-ECC Guidelines: "Push hard and fast on the center of the chest."
• Optimal rescuer and patient position: firm surface, rescuer's chest above hands.
• Goals for excellent chest compressions:
  • 100 to 120 compressions per minute.
  • Compress at least 5 cm (2 inches) but no more than 6 cm (2.5 inches).
  • Allow full recoil of chest wall.
  • Change every 2 minutes if possible, minimize interruptions.
  • 30:2 ratio of compression to ventilation.

Ventilation

• Open airway using head tilt, chin lift, jaw thrust.
• Check for normal breathing (not agonal gasps).
• Perform ventilations in hospital with a bag/mask.
• Ventilation supersedes compressions over time.
• Give two ventilations after every 30 compressions.
• Avoid excessive ventilation, 6 to 8 breaths per minute are adequate.

Defibrillation

• Non-synchronized delivery of a shock during the cardiac cycle.
• Use AED or normal defibrillator.
• Assess cardiac rhythm and perform defibrillation quickly when indicated.
• BLS involves a single shock followed by chest compressions.

CPR Complications

• Possible injuries: rib and sternal fractures, cardiac and pulmonary contusions, pneumo- and hemothorax, intra-abdominal trauma.
• Risk of withholding treatment exceeds the risk of complications.

Choking

• Occurs when a foreign object lodges in airway.
• Common signs: inability to talk, difficulty or noisy breathing, blue skin/lips/nails, loss of consciousness.
• Provide first aid quickly to prevent oxygen cut-off to the brain.

Choking First Aid

• Five back blows:
  • Stand to the side and behind the person.
  • Bend person over at the waist, deliver five blows between shoulder blades.
• Five abdominal thrusts (Heimlich maneuver):
  • Stand behind person, arms around waist, fist above navel, perform upward thrusts.
• Alternate between five blows and five thrusts until blockage is dislodged.