Ch 20. The EMS Airway
The EMS airway follows the same basic principles as in the hospital; however, it comes with its own unique challenges and limitations. In the emergency department there is greater staffing, better lighting, more supplies, as well as physical space.
EMS personnel may be providing airway management on the bathroom floor, on a crowded sidewalk with multiple onlookers, in a wrecked vehicle, or in the back of the ambulance. The key to a successful EMS airway is to remember one’s training while be- ing flexible and able to improvise.
You will find that the tools available for the EMS personnel vary greatly by level of training as well as by system and company. Most EMS personnel do not have access to RSI, so intubation and some adjuncts can be done mainly on patients who no longer have a gag reflex. This leaves a large group of patients who require oxygenation and ventilation yet who cannot be intubated in the field. An airway adjunct often will be used and breaths assisted with a bag-valve-mask (BVM) until arrival at the hospital or the patient either improves or loses his or her gag reflex to allow for intubation. There is the possibility of a conscious, nasal intubation mainly in the setting of a very cooperative patient with flash pulmonary edema; however, as many systems are now pro- viding CPAP to their paramedics, nasal intubations have become increasingly rare.
Below you will see what is available to EMS personnel. Remember, you will not find all options in every ambulance, so familiarize yourself with what is available at the start of your field shift.
The Airway Bag
- Suction: There is often a portable suction in the airway bag or a separate bag in addition to a standing unit in the ambulance. This is a wonderful invention allowing suction for airway management anywhere a patient may be found: on the sidewalk, the edge of a mountain, or in the living room.
- Various sized ET tubes: Paramedics are equipped to intubate neonates to 100-year-old patients. Each ambulance should be equipped with all tube sizes.
- Nasal cannula (NC): Available to all EMS providers.
- Nonrebreather (NRB): Available to all EMS providers.
- Neb Mask: Who can use nebulizers varies greatly depending on the EMS system you are in. Some places, EMTs can give albuterol nebulizers to known asthmatics only. There are other systems where EMTs cannot give any nebulizers, or saline only for a croup patient.
- In-line Nebulizer: To provide nebs to intubated patients. May be limited to critical care / flight crews.
- Mac and Miller blades of various sizes.
- Colormetric CO2 detector: This helps verify placement after intubation. The detector should turn from purple to gold if ET tube is in the trachea. This is only used initially after intubation. Less reliable than capnography.
- End-tidal CO2 monitor: Used for confirmation of initial tube placement and to monitor CO2 values throughout the transport. Waveform capnography is generally preferred to value-only capnometry.
- Oropharyngeal Airway (OPA): Inserted through the mouth to help prevent the tongue from falling back. These adjuncts only work with patients without a gag reflex. Sometimes you will see a paramedic use an OPA to “test” if the patient has a gag reflex prior to attempting intubation. Available to all levels of training. For a cardiac arrest patient, this is the primary airway management for an EMT.
- Nasopharyngeal Airway (NPA): Inserted through the nose
- great for obtunded patients. These should not stimulate a gag reflex. Available to all levels of training.
- Endotracheal Tube (ET Tube)
- Nasotracheal Tube: These are for awake and breathing patients who require advanced airways. They are exceedingly rare, especially with CPAP becoming more common on ALS ambulances.
- Laryngeal Mask Airway (LMA): You may be familiar with these in the OR. The LMA has an airway tube that connects to an elliptical mask with a cuff. When the cuff is inflated, the mask conforms to the anatomy with oxygen delivering portion of the mask facing the space between the vocal cords. After correct insertion, the tip of the LMA laryngeal mask sits in the throat against the muscular valve that is located at the upper portion of the esophagus.
- Combitube: Also known as the double-lumen airway, this is a blind insertion airway device. It consists of a cuffed, double-lumen tube that is inserted into the patient’s airway, facilitating ventilation. Inflation of the cuff allows the device to function similarly to an ET tube and usually closes off the esophagus, allowing ventilation and preventing aspiration of gastric contents.
- King LT: Also known as the laryngeal tube. Comes as either a single lumen or double lumen, with the second lumen allowing access for an OG tube to aspirate gastric contents. This is also a blind insertion airway device. With balloon inflated, the esophagus is closed off protecting the airway from aspiration.
CPAP: This is becoming more common to find on ALS ambulances. Usually used for CHF exacerbations and flash pulmonary edema, but also used in some asthmatics or COPD exacerba- tions.
Ventilators: These are typically found on ALS transport ambulances. They have limited settings (typically only rate and tidal volume), but are quite small and compact. Great for inter-facility transports.
The Difficult Airway
- Bougie: You may be familiar with these from the ED. A bougie is a long, flexible plastic stylet with an angle at the end used to facilitate difficult intubations. It can be placed into the trachea when only the epiglottis may be seen. By placing the angled end of the device in first, the tip can be felt “bouncing” over the tracheal rings, and then an ET tube can be advanced into the trachea over it.
- Needle Cricothyrotomy: Not all paramedics are authorized to use this skill; however, it is more common as a backup airway than a surgical cricothyrotomy. This protocol varies widely from system to system. The procedure itself varies greatly as well, depending on the system and the supplies available.
- Surgical Cricothyrotomy: This tends to be found in more advanced EMS systems, and requires advanced training for paramedics. This procedure is typically found in systems that also allow RSI.
- RSI: Rapid sequence intubation is only found in more advanced systems. It requires advanced training and medical oversight, and its use in the field is controversial, with mixed outcomes. The indications, medications, and protocols for RSI will be different in each system.
- Needle Decompression: All paramedics receive training in needle decompression. This procedure is allowed in most systems for suspected tension pneumothorax.