19.1 Basic Life Support (BLS), CPR Concepts & Emergency Response in Radiology

19.1 Basic Life Support (BLS), CPR Concepts & Emergency Response in Radiology

Radiologic technologists frequently encounter patients suffering from severe trauma, acute systemic illnesses, or severe adverse contrast media reactions. Recognizing acute deterioration and rapidly instituting life-saving interventions is a core professional competency. In diagnostic imaging and interventional suites, radiographers must serve as competent first responders in Basic Life Support (BLS), CPR execution, and acute medical emergency management.

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1. Basic Life Support (BLS) & CPR Principles

Basic Life Support comprises non-invasive emergency procedures designed to maintain adequate ventilation and blood circulation in patients experiencing cardiac or respiratory arrest. The American Heart Association (AHA) guidelines emphasize high-quality chest compressions to maintain coronary and cerebral perfusion pressure.

The C-A-B Sequence

In cardiac arrest, chest compressions take precedence over rescue breathing. The standard sequence is C-A-B:

1. Compressions (C): Immediate initiation of high-quality manual chest compressions to maintain central arterial pressure.
2. Airway (A): Opening the airway using the head-tilt/chin-lift maneuver (or jaw-thrust maneuver if cervical spine injury is suspected).
3. Breathing (B): Delivering rescue breaths via bag-valve-mask (BVM) or barrier device after 30 compressions.

Key Metrics for High-Quality Adult CPR

• Chest Compression Rate: 100 to 120 compressions per minute (bpm). Rates below 100/min lead to inadequate perfusion, while rates exceeding 120/min prevent full cardiac filling.
• Chest Compression Depth: 2 to 2.4 inches (5 to 6 cm) in adults. Compressions must allow complete chest recoil after each downstroke to enable ventricular refilling.
• Compression-to-Ventilation Ratio: 30:2 for single-rescuer and two-rescuer adult CPR. Each rescue breath should be delivered over 1 second, producing visible chest rise.
• Minimizing Interruptions: Limit pauses in chest compressions to less than 10 seconds (e.g., during AED rhythm analysis or pulse checks).
• Chest Compression Fraction (CCF): Target a CCF of at least 60% (ideally >80%), representing the percentage of total resuscitation time spent delivering compressions.

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2. Respiratory Arrest & Airway Obstruction

Respiratory arrest occurs when breathing ceases while cardiac activity persists. If uncorrected, it rapidly progresses to cardiac arrest and irreversible brain damage within 4 to 6 minutes.

Foreign Body Airway Obstruction (FBAO) Management

Airway obstruction may be partial or complete:

• Partial Obstruction: Patient can cough forcefully and speak. Intervention: Encourage spontaneous coughing; do not interfere with physical maneuvers.
• Complete Obstruction: Patient cannot speak, cough, or breathe, and displays the universal distress signal (clutching the neck with both hands). Cyanosis rapidly ensues.

Relief Maneuvers by Patient Condition

• Conscious Adult/Child: Perform abdominal thrusts (Heimlich maneuver). Position yourself behind the patient, place a fist just above the navel and below the xiphoid process, and deliver quick inward and upward thrusts until the object is expelled or the patient becomes unconscious.
• Pregnant or Markedly Obese Patients: Perform chest thrusts instead of abdominal thrusts. Position hands over the middle of the sternum (lower half of sternum, avoiding xiphoid process) and deliver backward, horizontal thrusts.
• Unconscious Choking Patient: Carefully lower the patient to the floor, call for immediate emergency help (activate Code Blue), and begin CPR starting with 30 chest compressions. Every time the airway is opened to deliver rescue breaths, look inside the oral cavity for the obstructing object. If visible, perform a single finger sweep to remove it. Never perform blind finger sweeps as this can push foreign objects deeper into the pharynx.

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3. Cardiac Arrest & Automated External Defibrillator (AED)

Defibrillation is the electrical termination of cardiac dysrhythmias by delivering a controlled shock across the myocardium, allowing the heart's natural pacemaker (SA node) to re-establish an organized rhythm.

Operating an Automated External Defibrillator (AED)

1. Power On: Turn on the AED immediately upon arrival.
2. Apply Pads: Attach self-adhesive electrode pads to the patient's bare, dry chest:
   • Sternum pad: Upper right chest, directly below the clavicle.
   • Apex pad: Lower left chest, anterior axillary line lateral to the left nipple.
3. Plug In: Connect the pad cable to the AED unit if not pre-connected.
4. Analyze Rhythm: Ensure no one is touching the patient while the AED analyzes the cardiac rhythm ("Clear the patient!").
5. Shock Delivery: If a shockable rhythm is identified, ensure everyone is clear of the patient and radiologic equipment/table, then press the shock button.
6. Immediate Resuscitation: Immediately resume chest compressions starting with 30 compressions; do not pause for pulse checks immediately post-shock.

Cardiac Dysrhythmia Classification

• Shockable Rhythms:
  • Ventricular Fibrillation (V-Fib): Chaotic, disorganized ventricular activity with no effective contraction or cardiac output.
  • Pulseless Ventricular Tachycardia (pVT): Rapid, regular ventricular rhythm without a detectable peripheral pulse.
• Non-Shockable Rhythms:
  • Asystole: Total absence of electrical ventricular activity ("flatline").
  • Pulseless Electrical Activity (PEA): Organized electrical rhythm present on ECG monitor but without corresponding mechanical ventricular contractions or palpable pulse.

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4. Shock Types, Clinical Recognition & Radiographic Management

Shock is a life-threatening failure of the circulatory system to maintain adequate tissue perfusion, resulting in cellular hypoxia and metabolic dysfunction.

Classification of Shock

Clinical Signs & Symptoms of Impending Shock

• Cardiovascular: Hypotension (systolic BP < 90 mmHg), tachycardia (HR > 100 bpm), weak thready pulse.
• Integumentary: Pale, cool, clammy skin, profuse diaphoresis, delayed capillary refill (>2 seconds).
• Respiratory: Rapid, shallow tachypnea; dyspnea.
• Neurological: Restlessness, anxiety, confusion, progressive lethargy, unresponsiveness.
• Renal: Oliguria (urine output < 30 mL/hr).

Emergency Patient Positioning for Shock

• Hypovolemic / Anaphylactic Shock: Place patient in Trendelenburg position (or modified Trendelenburg: supine with legs elevated 15–30 degrees above heart level) to promote venous return to the heart and vital organs. Contraindication: Suspected head or cervical spine injury.
• Respiratory Distress / Cardiogenic Shock: Place patient in Semi-Fowler's position (head of bed elevated 30 to 45 degrees) to decrease venous return, lower cardiac workload, and facilitate maximal diaphragm expansion.

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5. Medical Emergencies in the Radiology Department

Seizure Management

Seizures represent sudden abnormal electrical discharges within the brain.

• During Seizure Activity:
  • Protect the patient from physical trauma (move equipment, padded bed rails).
  • Do NOT attempt to forcibly restrain the patient's limbs.
  • Do NOT insert fingers, tongue depressors, or airway devices into the patient's mouth.
  • Call for immediate emergency assistance and note the duration/character of seizure activity.
• Post-Ictal Phase: Place the patient in the recovery position (lateral decubitus) to maintain airway patency and allow oral secretions or vomitus to drain safely, preventing aspiration pneumonitis.

Syncope (Fainting)

Syncope is a transient loss of consciousness caused by temporary cerebral ischemia resulting from vasovagal reaction, orthostatic hypotension, or emotional stress.

• Signs: Sudden pallor, diaphoresis, nausea, dizziness, dimming vision.
• Management: Immediately lower the patient to a supine position with feet elevated 8 to 12 inches, loosen restrictive clothing around the neck and waist, apply a cool damp cloth to the forehead, and monitor vital signs until fully recovered.

Diabetic Emergencies: Hypoglycemia vs. Hyperglycemia

Radiologic technologists must distinguish between acute low and high blood glucose states:

Emergency Conditions Management Guide