Oxygenation, Airway Management, & BLS

Oxygen Delivery Systems

Oxygen therapy is a fundamental clinical intervention used to treat or prevent hypoxemia. Under DHA guidelines, nurses are responsible for selecting, setting up, and monitoring the appropriate oxygen delivery device, ensuring that the prescribed fraction of inspired oxygen (FiO2) is delivered safely. Oxygen delivery systems are divided into low-flow and high-flow systems.

1. Nasal Cannula

• Flow Rate: 1 to 6 L/min.
• FiO2 Range: 24% to 44% (increases by approximately 4% for every 1 L/min increase in flow).
• Clinical Guidance: It is comfortable, allows the patient to eat and speak, and is suitable for mild hypoxemia. Humidification (sterile water bottle) must be added for flow rates greater than 4 L/min to prevent mucosal dryness, irritation, and epistaxis.

2. Simple Face Mask

• Flow Rate: 5 to 8 L/min.
• FiO2 Range: 40% to 60%.
• Clinical Guidance: It is used for short-term oxygen therapy.

[!IMPORTANT] The flow rate must be set to at least 5 L/min at all times. If the flow rate is lower than 5 L/min, the patient may rebreath carbon dioxide (CO2) that accumulates inside the mask, causing carbon dioxide retention.

3. Venturi Mask

• Flow Rate: 4 to 12 L/min (varies based on the specific colored adaptor dial).
• FiO2 Range: 24% to 50% (highly precise).
• Clinical Guidance: The Venturi mask is the device of choice for patients with chronic obstructive pulmonary disease (COPD). COPD patients rely on a hypoxic drive (low oxygen levels) to breathe. Administering uncontrolled high-flow oxygen can abolish this drive, leading to respiratory arrest. The Venturi mask allows precise titration of low-concentration oxygen.

4. Non-Rebreather Mask

• Flow Rate: 10 to 15 L/min.
• FiO2 Range: 60% to 90% (delivers the highest oxygen concentration of low-flow devices).
• Clinical Guidance: It is equipped with a reservoir bag and one-way valves that prevent exhaled air from entering the bag.

[!WARNING] The reservoir bag must be pre-inflated to at least two-thirds full before placing the mask on the patient, and it must remain inflated during inspiration. If the bag deflates completely during inhalation, the patient can suffocate or receive inadequate oxygenation.

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Airway Management and Suctioning Guidelines

Suctioning is performed to clear secretions from the airway when a patient is unable to clear them through coughing. It can be performed in the oropharynx, nasopharynx, or directly within an artificial airway (endotracheal or tracheostomy tube).

Standard Suctioning Protocol and Safety Rules

Nurses must adhere to strict clinical protocols to prevent trauma, infection, and severe hypoxia during suctioning:

1. Preparation and Aseptics: Oropharyngeal suctioning (using a Yankauer catheter) requires clean technique. In contrast, nasotracheal, endotracheal, and tracheostomy suctioning are invasive and require strict sterile technique.
2. Hyperoxygenation: Prior to suctioning, hyperoxygenate the patient with 100% oxygen for 30 to 60 seconds (using a manual resuscitation bag or the ventilator's suction-oxygenation function). Hyperoxygenate again after the procedure.
3. Catheter Insertion: Insert the catheter gently without applying suction. In endotracheal suctioning, insert the catheter until resistance is met (or the patient coughs), then pull back 1 to 2 cm before applying suction.
4. Suction Application: Apply suction only during withdrawal of the catheter. Rotate the catheter gently using a twisting motion as it is being withdrawn.
5. Time and Frequency Limits: Limit suction application to 10 to 15 seconds per pass. Limit the number of suction passes to a maximum of 3 per session. Allow the patient to rest for 1 to 2 minutes between passes, providing hyperoxygenation.
6. Monitoring: Monitor the patient's heart rate, rhythm, and oxygen saturation (SpO2) throughout the procedure. Suctioning stimulates the vagus nerve, which can trigger profound bradycardia, bronchospasm, and cardiac arrhythmias. If the heart rate drops or the rhythm changes, stop suctioning immediately and administer oxygen.

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Tracheostomy Care & Emergency Preparedness

Tracheostomy care is performed to maintain airway patency, promote skin integrity around the stoma, and prevent infection. Typically, tracheostomy care is performed at least once every 8 to 12 hours, or more frequently if indicated.

Step-by-Step Tracheostomy Care

• Step 1: Suction the Airway: Perform airway suctioning as described above to clear secretions before beginning care.
• Step 2: Clean the Inner Cannula: If the tracheostomy tube has a disposable inner cannula, replace it using sterile technique. If it is non-disposable, remove it, soak and clean it in sterile normal saline with a sterile brush, rinse with sterile saline, and reinsert it.
• Step 3: Clean the Stoma Site: Remove the soiled dressing. Clean the skin around the stoma and the outer flange using sterile cotton-tipped applicators saturated with sterile normal saline. Wipe in a circular motion from the stoma outward. Pat dry with sterile gauze.
• Step 4: Change Tracheostomy Ties/Collar: Change the soiled ties or Velcro collar.

[!IMPORTANT] To prevent accidental decannulation (dislodgement of the tube), always secure the new ties or collar before removing the old ones, or have a second nurse hold the tracheostomy tube securely in place during the exchange. Keep the ties loose enough to fit one to two fingers comfortably between the tie and the patient's neck.

• Step 5: Apply Sterile Dressing: Place a pre-cut, non-fraying sterile tracheostomy split-sponge dressing under the flange. Never cut a standard gauze sponge, as loose fibers can be aspirated into the trachea.

Emergency Bedside Supplies

Every patient with a tracheostomy must have the following emergency supplies kept at the bedside at all times:

• An emergency tracheostomy kit containing two spare tracheostomy tubes: one of the same size and one one size smaller (in case of stoma narrowing after accidental decannulation).
• The obturator (used to guide insertion of the outer cannula).
• A manual resuscitation bag (Ambu bag) with a face mask.
• Working suction equipment and sterile suction catheters.
• Tracheostomy dilator set.

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Basic Life Support (BLS) Guidelines

Basic Life Support (BLS) is the foundation of cardiopulmonary resuscitation (CPR) for patients in cardiac or respiratory arrest. Registered nurses must maintain BLS certification and follow the current American Heart Association (AHA) and international resuscitation guidelines.

Resuscitation Sequence (C-A-B)

Resuscitation follows the C-A-B sequence: Circulation (Compressions) -> Airway -> Breathing.

1. Verify Scene Safety: Ensure the environment is safe for the rescuer and the victim.
2. Assess Responsiveness & Breathing: Tap the victim's shoulder and shout, "Are you okay?" Simultaneously check for normal breathing or gasping (no more than 10 seconds).
3. Activate Emergency Response: Shout for help, activate the emergency system (e.g., call 999 in the UAE or activate the hospital code blue team), and obtain the Automated External Defibrillator (AED) or crash cart.
4. Pulse Check: Check the carotid pulse (in adults and children) or brachial pulse (in infants) for at least 5 but no more than 10 seconds. If no pulse is felt, or if you are unsure, initiate chest compressions immediately.

CPR Execution Parameters

To maximize survival rates, high-quality CPR must be performed:

• Compression Rate: 100 to 120 compressions per minute for all age groups.
• Compression Depth:
  • Adults: At least 2 inches (5 cm), but no more than 2.4 inches (6 cm).
  • Children (1 year to puberty): About 2 inches (5 cm) — approximately one-third of the chest depth.
  • Infants (< 1 year): About 1.5 inches (4 cm) — approximately one-third of the chest depth.
• Chest Recoil: Allow complete chest recoil after each compression. Do not lean on the patient's chest.
• Minimize Interruptions: Keep chest compression fraction (the proportion of total resuscitation time spent performing compressions) above 60%, ideally above 80%. Limit pauses (e.g., for pulse checks or rhythm analysis) to less than 10 seconds.
• Compression-to-Ventilation Ratio:
  • Adults: 30:2 for 1 or 2 rescuers.
  • Children & Infants: 30:2 for a single rescuer; 15:2 for two rescuers (reflecting the higher ventilation needs in pediatric arrests).
• Ventilation Delivery: Deliver each breath over 1 second, watching for visible chest rise. Avoid hyperventilation, which increases intrathoracic pressure and decreases venous return to the heart.
• AED/Defibrillator Use: Turn on the AED immediately upon arrival. Attach the pads, clear the patient during rhythm analysis and shock delivery, and resume chest compressions immediately after a shock is delivered (do not pause to check the pulse or rhythm after a shock).

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Summary of Oxygen Devices