Airway Management and Intubation Practice Flashcards

Airway Adjuncts: Oropharyngeal and Nasopharyngeal Airways

  • Oropharyngeal Airway (OPA)

    • Definition and Description: A non-invasive airway adjunct designed to maintain patency by displacing the tongue. OPAs range from "little itty bitty" sizes to "big, ginormous mamma jama" sizes and are color-coded for identification.
    • Primary Purpose: To prevent airway obstruction caused by the tongue, which is identified as the most common cause of airway obstruction.
    • Measurement Technique: Measured from the corner of the patient’s mouth to the tip of the earlobe.
    • Insertion Methods:
      • Sideways Method: Insert the OPA sideways into the mouth until resistance is felt, then rotate it 90 degrees downward and push it the rest of the way.
      • Upside Down Method: Insert the OPA completely upside down until resistance is met, followed by a 180-degree rotation.
      • Prohibition on Straight Insertion: The OPA should never be pushed straight back, as this will shove the tongue further into the back of the throat rather than lifting it.
    • Clinical Contraindications: The patient must not have an intact gag reflex. The uvula is the source of the gag reflex; stimulating it in an alert patient causes vomiting and potential aspiration. Consequently, OPAs are utilized almost exclusively on unconscious/unresponsive patients.

  • Nasopharyngeal Airway (NPA)

    • Definition and Description: Also referred to as a "nasal trumpet," these are soft, flexible, squishy tubes that vary in size from small to large "garden hose" diameters.
    • Measurement Technique: Measured from the nare (nostril) to the tip of the earlobe.
    • Insertion Technique:
      • Lubrication: Requires water-based lubricant. Oil-based lubricants are prohibited because they are flammable, and oxygen is combustible.
      • Aseptic Technique: Does not require sterile technique but should be a "clean technique" utilizing gloves.
      • Directionality: Insertion must go straight back and slightly down. Aiming upward can result in entry into the sinuses, causing significant trauma.
    • Clinical Advantages and Maintenance:
      • The NPA can remain in place for up to 48 hours.
      • It bypasses the uvula, meaning it does not trigger the gag reflex and can be used on awake or alert patients.
      • Infection Control: Risk of infection exists because the body treats the device as a foreign object. To mitigate risk, the device can be replaced with a new one in the opposite nare after 48 hours.
    • Special Considerations and Contraindications:
      • Skull/Facial Fractures: If a patient has suspected facial or skull fractures, NPAs can be accidentally inserted into the brain.
      • Deviated Septum: Anatomy where the bridge in the middle of the nose is off-center. Identified by looking for asymmetrical nares (one large, one small). In these cases, always use the larger nare.
    • Frequency of Use: Primarily used for patients requiring frequent nasotracheal suctioning to reduce trauma to the vascular sinuses.
    • Suctioning through NPA: Suctioning through a trumpet is a sterile procedure because the goal is to enter the trachea. Lubrication (water-based) is required for the suction catheter to prevent rubber-on-rubber friction.

Endotracheal Intubation: Process and Rapid Sequence Induction (RSI)

  • Overview and Risk Assessment

    • Intubation is a high-risk procedure performed only when other methods (like non-invasive ventilation) fail.
    • Primary Risk: Cardiac arrest. Other risks include lack of oxygen leading to organ damage and complications from positive pressure.

  • The Six Steps of Rapid Sequence Induction (RSI)

    1. Preparation: Gathering supplies and the intubation (tackle) box.
    2. Preoxygenation: Using 100% O2O_2 to build an oxygen reserve.
    3. Pretreatment: Including suctioning secretions/vomit and potentially using non-invasive ventilation.
    4. Sedation and Paralysis: Pharmacological induction.
    5. Placement and Protection: Inserting and securing the tube.
    6. Post-intubation Management: Ongoing care which can last hours, months, or years.

  • Preoxygenation and Physiology

    • Oxygen Dissociation Curve: The goal is to reach a high SpO2SpO_2 and PaO2PaO_2 before the attempt. A critical drop-off occurs at a PaO2PaO_2 of 60 mmHg60\,mmHg, which corresponds to an SpO2SpO_2 of approximately 90%90\%. Once saturation drops below 90%90\%, levels fall rapidly.
    • Monitoring: The SpO2SpO_2 monitor sound should be turned on; a steady beat above 90%90\% is healthy, while a lower, more aggressive, and obnoxious beep signals danger (85%85\%, 81%81\%, 75%75\%).
    • Bagging Technique: Bagging is the most effective way to oxygenate a patient. For a non-arrest adult, the rate is one breath every 55 to 66 seconds.
      • C-E Grip: "C" shape on the bridge of the nose, "E" shape under the chin for a head-tilt/chin-lift to displace the tongue.
      • PEEP Valve: A PEEP valve attached to the Ambu bag helps force oxygen in and facilitates lung recruitment.

Pharmacology for Intubation

  • Sedatives (Induction Agents)

    • Propofol: Known as "Milk of Amnesia." It is white, hypnotic, and the most common sedative in the hospital. It has a half-life of approximately 2.5 minutes2.5\,minutes. It can cause amnesia, respiratory depression, hypotension, and bradycardia. Warning: Cannot be used in patients with egg or soy allergies.
    • Etomidate (pronounced ah-tom-i-date): The NBRC gold standard sedative for intubation. It has a very short half-life and virtually no contraindications except sensitivity. It is given as a push, not as a drip.
    • Ketamine ("Special K"): A sedative with bronchodilatory effects, making it ideal for asthmatics. It does not cause respiratory depression.
      • Emergence Reactions: Patients wake up in the same emotional state they were in when they went under (e.g., if they were fighting, they come out swinging).
      • PCP Interaction: Interactions with PCP (Angel Dust) cause "superhuman strength" (e.g., bending metal medical tables) and synergistic effects.

  • Paralytics (Neuromuscular Blocking Agents)

    • Succinylcholine ("Sucks"): The gold standard paralytic due to its shortest half-life.
      • Contraindication: Hyperkalemia. Sucks causes a spike in potassium. Do not use in patients with high potassium or severe burns, as it can cause immediate cardiac arrest.
    • Rocuranium (and Vecuronium): Paralytics ending in "-ronium." These are used if potassium is high.
      • Warning: The half-life of Rocuranium is significantly longer than sedatives like Propofol. Clinicians must ensure the patient remains sedated until the paralytic wears off.

Anatomy and Features of Endotracheal (ET) Tubes

  • Sizing and Cuffs

    • Sizes range from 22 to 1010 (based on internal diameter, ID).
    • Neonatal Tubes: Often uncuffed. Because babies have soft, squishy cartilage, their airway narrows around the tube during negative pressure inspiration, creating a natural seal.

  • Markings and Safety Features

    • ID Size: Printed on the tube (e.g., 7.5,9.07.5, 9.0).
    • Centimeter Markings: Used to track depth. For most adults, the tube is secured at 23 cm23\,cm at the lip.
    • Radiopaque Line: A white or blue line that glows on a chest X-ray. It should be positioned 33 to 5 cm5\,cm above the carina.
    • Murphy’s Eye: A small hole near the tip that acts as a safety feature for ventilation if the distal tip becomes occluded by the carina or a mucus plug.
    • Stovepipe Adapter: A universal 15 mm15\,mm adapter that fits any ventilator or Ambu bag.

  • Cuff Management and Pressures

    • Cuff Monitoring: Pressures must be monitored to avoid tracheomalacia or fistulas caused by pinching off capillary blood flow.
    • Universal Safe Pressure Ranges:
      • 2020 to 25 mmHg25\,mmHg (Millimeters of Mercury).
      • 2020 to 30 cmH2O30\,cmH_2O (Centimeters of Water).
    • Integrity Check: To check if a cuff is intact, use a syringe to pull all air out of the pilot balloon until it collapses. If it stays collapsed, the cuff is intact; if it pops back up, there is a leak, and the tube should be discarded.
    • Subglottic Port: A specialized suction port located above the cuff to remove oral secretions. This drastically reduces Ventilator Associated Pneumonia (VAP) rates (e.g., Hartford Hospital saw a 47%47\% reduction in VAP rates within one year of switching to these tubes).

Intubation Equipment (The "Tackle Box")

  • Laryngoscopes

    • Handle: Contains batteries; must be tested for light brightness before use.
    • Macintosh (Mac): A curved blade. The tip is placed in the vallecula to indirectly lift the epiglottis.
    • Miller: A straight blade. Used to directly lift the epiglottis; often preferred for "squishy" neonatal airways.
    • Handedness: Regardless of the clinician's dominant hand, the laryngoscope is always held in the left hand because the light and tube guide are oriented for a right-side insertion.

  • Additional Tools

    • Yankauer: A rigid suction tip for cleaning the mouth and upper airway (blood, vomit, secretions).
    • McGill Forceps: Curved, grippy forceps used to remove foreign bodies (dentures, grapes, popcorn, mucus plugs) from the airway.
    • Stylet: A rigid wire inserted into the ET tube to provide shape (often a "hockey stick" bend) and rigidity. It is removed once the tube passes the vocal cords.
    • Colorimetric CO2CO_2 Detectors: A fast verification tool.
      • Yellow: Presence of exhaled CO2CO_2 (Tube is in the airway).
      • Purple: Absence of CO2CO_2 (Tube is in the esophagus/stomach).

Verification of Placement

  1. Fastest Methods: Chest rise, breath sounds, and colorimetric CO2CO_2 detectors.
  2. Most Accurate Method: Chest X-ray (CXR), which allows for precise measurement relative to the carina.