1. Upper Airway Anatomy.
1.1. The Oral Cavity: The cheeks, hard and soft palates, and the tongue.
1.1.1. The Pharynx: A muscular tube that extends vertically from the back of the soft palate to the superior aspect of the esophagus.
1.1.1.1. The Larynx: The complex structure that joins the pharynx with the trachea.
1.1.1.1.1. Circothyroid Membrane: Connects the inferior border of the thyroid cartilage with the superior aspect of the cricoid cartilage.
2. Airway Sounds.
2.1. Snoring: Results from partial obstruction of the upper airway by the tongue.
2.1.1. Gurgling: Results from the accumulation of blood, vomitus, or other secretions in the upper airway.
2.1.1.1. Stridor: A harsh, high-pitched sound heard on inhalation, associated with laryngeal edema or constriction.
2.1.1.1.1. Wheezing A musical, squeaking, or whistling sound heard in inspiration and/or expiration, associated with bronchiolar constriction.
3. Oxygen Delivery Devices
3.1. Nasal Cannula: The nasal cannula is a catheter placed at the nares. It provides an optimal oxygen supplementation of up to 40 percent when set at 6 L/min flow.
3.1.1. Venturi Mask: The venture mask is a high- flow face mask that uses a Venturi system to deliver relatively precise oxygen concentrations, regardless of the patients rate and depth of breathing. This mask can deliver concentration of 24, 28, 35, or 40 percent oxygen. The liter flow depends on the oxygen concentration desired.
3.1.1.1. Simple Face Mask: The simple face mask is indicated for patients requiring moderate oxygen concentration. Flow rates generally range from about 6 to 10 L/min, providing 40 to 60 percent oxygen at the maximum rate, depending on the patient's respiratory rate and depth.
3.1.1.1.1. Partial Rebreather Mask: This mask is indicated for patients requiring moderate-to-high oxygen concentration when satisfactory clinical results are not obtained with the simple face mask. Maximum flow rate is 10 L/min.
4. Manual Airway Maneuvers.
4.1. Head-Tilt/Chin-Lift: This is performed in the absence of cervical spine trauma. 1.) Place the patient supine and position yourself at the side of the patient's head. 2.) Place one hand on the patient's forehead and, using firm downward pressure with your palm, tilt the head back. 3.) Put two fingers of the other hand under the bony part of the chin and lift the jaw anteriorly to open the airway
4.1.1. Jaw-Thrust Maneuver: This is acceptable for any unresponsive patient and recommended for any patient at risk for cervical spine injury who cannot protect his airway. 1.) Lift the jaw using fingers behind the mandibular angles; do not tilt the head. It usually helps to prop the thumbs on the cheekbones to provide some counter-force.
5. Subjective Verification of Proper Tube Placement
5.1. Direct Visualization: While seeing the tube pass through the cords should be considered the gold standard, this method of tube confirmation has failed.
5.1.1. Tube Misting: Observing mist or condensation in the tube, or a "vapor trail", has long been held out as a means of confirming the tracheal placement of the tube, but is not reliable.
5.1.1.1. Auscultation: After intubation, breath sounds should be checked bilaterally and compared to preintubation breath sounds, unless ambient noise makes this impossible. Sounds should be present bilaterally if they were present bilaterally before intubation.
6. Objective Verification of Proper Tube Placement.
6.1. Capnography: Detection of end-tidal CO2 is the gold standard for tube confirmation if the patient is producing enough CO2 to detect. There are 2 types of end tidal CO2 detection: Qualitative (indicating only if CO2 is present or absent) and quantitative ( providing a measure, usually with a waveform for analysis, of how much CO2 is present.)
6.1.1. Esophageal Detector Device: A syring device or bulb is placed on the end of the endotracheal tube to create suction. If the tube is correctly placed in the trachea, the cartilaginous rings keep the trachea patent when suction is applied, so there is rapid air return into the device.
6.1.1.1. Endotracheal Tube Introducer: A bougie may be used to confirm tube placement. When a well-lubricated introducer is passed through an ETT that is correctly placed in the trachea, you should be able to feel it "hold up" in the smaller airways within approximately 40 cm of the teeth or about 50 cm from the tube end.
6.1.1.1.1. Pulse Oximetry and Other Findings: An increase in the oxygen saturation will help confirm proper placement of the endotracheal tube. Similarly, a rise and fall of the chest indicates correct endotracheal intubation.
7. Lower Airway Anatomy.
7.1. The Trachea: The trachea is a 10 - 12 centimeter long tube that connects the larynx to the two mainstem bronchi.
7.1.1. The Bronchi: At the carina, the trachea divides, or bifurcates, into the right and left mainstem bronchi.
7.1.1.1. The Alveoli: The respiratory bronchioles divide into the alveolar ducts, which terminate in balloon like clusters of alveoli called alveolar sacs.
7.1.1.1.1. The Lung Parenchyma: The lung parenchyma is arranged in two pulmonary lobules that form the anatomic division of the lungs.
7.1.1.1.2. The Lung Parenchyma: The lung parenchyma is arranged in two pulmonary lobules that form the anatomic division of the lungs.
8. Orotracheal Intubation Technique.
8.1. Step 1.) Ventilate the patient.
8.1.1. Step 2.) Prepare the equipment.
8.1.1.1. Step 3.) Apply the cricoid pressure and insert laryngoscope.
8.1.1.1.1. Step 4.) Visualize the larynx and insert the ETT.
9. Advantages of Endotracheal Intubation.
9.1. It isolates the trachea and permits complete control of the airway.
9.1.1. It impedes gastric distention by channeling air directly into the trachea.
9.1.1.1. It eliminates the need to maintain a mask seal.
9.1.1.1.1. It offers a direct route for suctioning of the respiratory passages.
10. Disadvantages of Endotracheal Intubation.
10.1. The technique requires considerable training and experience.
10.1.1. It requires specialized equipment.
10.1.1.1. It requires direct visualization of the vocal cords.
10.1.1.1.1. It bypasses the upper airway's function of warming, filtering, and humidifying the inhaled air.
11. Oral Endotracheal Intubation Equipment.
11.1. Laryngoscope: The laryngoscope is an instrument for lifting the tongue and epiglottis out of the line-of-sight so that you can see the vocal cords. A laryngoscope consists of a handle and a blade. The handle houses batteries that power a light in the blade's distal tip. The blades may be divided into two types: curved and straight. The choice of straight or curved blade is often a matter of experience and provider preference.
11.1.1. Endotracheal Tubes: ETT is a flexible translucent tube open at both ends and available in lengths ranging from 12 to 32 cm, with centimeter markings along its length. Adult tubes come with an inflatable cuff at the distal end to provide a seal between the tube and the trachea. A thin inflation tube runs the length of the main tube from the distal cuff to a syringe. A one-way valve at the proximal end of the inflation tube permits the syringe to push air into the distal cuff or pull it out but prevents air from escaping the cuff when the syringe is removed.
11.1.1.1. Stylet: This is a plastic-covered metal wire that may be placed inside the ETT, stopping just short of the distal end, to allow the tube to be stiffened and maintained in the optimal shape for intubation.
11.1.1.1.1. Endotracheal Tube Introducer: This is commonly called a gumelastic bougie, is a 60- or 70-cm straight, semi-rigid, stylet-like device with a distal bent tip that is covered with a protective resin. It is used to facilitate endotracheal intubations when only the epiglottis may be visualized.
12. Complications of Endotracheal Intubation.
12.1. Equipment Malfunction: Equipment malfunctions consume valuable time when you are establishing an airway. Having a preassembled airway kit that is checked regularly will lessen the chances of this occurring.
12.1.1. Tooth Breakage and Soft-Tissue Laceration: Endotracheal intubation can easily injure the lips and teeth, but you can eliminate this hazard by carefully using the laryngoscope as in instrument, not a tool.
12.1.1.1. Aspiration: Aspiration is the entry of stomach contents, blood, or secretions into the lungs. A common cause of aspiration during non-medication facilitated airway management is placing a laryngoscope into the mouth of a patient who has just enough gag reflex to vomit but is too obtunded to fully protect his airway.
12.1.1.1.1. Elevated Intracranial Pressure: ICP can become elevated during intubation from the reflex response to stimulation of the airway with a laryngoscope and endotracheal tube, whether or not the patient is sedated and/or paralyzed.