The King Laryngeal Tube: Failed Airway or Airway of Choice?

Your patient stops breathing! It is a fairly common occurrence in the cath lab. An acute patient suffering a myocardial infarction (MI) is brought into your lab emergently. Before the heart can be reperfused, the patient goes into cardiac arrest and subsequently stops breathing.  How do you manage respiratory depression or arrest in the cardiac cath lab?

Many would call a code and begin ventilating the patient with a bag valve mask (BVM) until a more experienced provider arrives to secure a more definitive airway. The problem with this is that in providing positive pressure, BVM ventilations ventilate not only the lungs, but also force air into the stomach, often leading to gastric inflation and subsequent emesis.¹ This greatly increases the chance of aspiration of stomach contents into the lungs, which can significantly compromise the patient’s prognosis. Additionally, at nighttime or in rural locations, advance airway providers may not be readily available.

Endotracheal intubation is the definitive answer for airway management.^1,2 This involves passing an endotrachial tube into the trachea under direct laryngoscopy. Once placed, tube placement must be verified. This can create a delay in chest compressions and radiographic imaging. While some nurses might receive additional training on intubation, it is not generally expected for this to be in the scope of practice of a registered nurse in the cath lab setting.  Intubation is a skill that requires much practice and experience to obtain proficiency. It is not feasible to provide and maintain the education and skill set needed for nurses to be proficient at intubations in the cath lab setting.

Supraglottic airways are devices that are generally designed to seat in the esophagus and provide a direct route for ventilation through the trachea. Currently, the three main supraglottic airways on the market are the King Laryngeal Tube (LT) (King Systems), the Laryngeal Mask Airway (Colgate Medical Ltd.), and the Combitube (Kendall-Sheridan Corporation). The King LT seems to be the best fit for use in the cath lab, as the other two devices have unique drawbacks that might create additional problems in this setting. The Combitube is a dual-lumen airway with a distal and proximal balloon that provides a direct route for ventilations. The drawbacks to this device are a more lengthy insertion technique and two ports available for ventilation that require a relatively high degree of assessment skill in order to ensure proper ventilations. The Laryngeal Mask Airway is a device used frequently in surgery to provide an airway. It has a higher incidence of aspiration, as it provides less occlusion of the esophagus. Its use is generally reserved for patients who have fasted.

The King Laryngeal Tube (King LT) allows practitioners to quickly and efficiently establish a secure airway without direct laryngoscopy. The device is a latex-free, single lumen tube with a distal and proximal balloon that occludes the esophagus and oropharynx, creating a direct route for ventilations through the larynx and trachea. Not only does this create a patent airway to ventilate through, but it also occludes the esophagus, preventing gastric inflation and aspiration. The insertion is a blind technique and requires pushing on only one syringe to inflate both balloons. Another cost-effective added benefit is that this device is reusable up to fifty times with autoclaving.⁴ The device has had FDA approval since 2003, but has mainly been used as a failed or backup airway after attempts at intubation have failed. The device has primarily been used in the field by paramedics and in surgery by anesthesia. Its use has been well studied in those settings, but more research is needed to determine its overall usefulness by nurses in the cath lab. One study found that ICU-trained nurses were able to deliver adequate ventilation on the first attempt in 100% of cases studied using this device. Additionally, no gastric inflation occurred.¹

While this device seems to have much potential for use in the cath lab setting, it is not without concerns. The device, of course, cannot be used on a patient with an intact gag reflex.  Additionally, it is not to be used on patients with known esophageal disease or patients who have ingested caustic substances, as it may cause further trauma to the patient’s airway.³ While highly unlikely, there is a small risk of the device seating in the trachea rather than the esophagus.² Breath sounds should be checked and end tidal capnography should be utilized to confirm proper tube placement. While the device is designed to minimize airway trauma, particular care should be taken with insertion due to the possibility of the patient being anticoagulated. 

Implementing the use of the King LT in the cath lab setting could potentially be met with some opposition. The anesthesia department is, many times, the department that may respond in a respiratory emergency. Since endotracheal intubation is the only definitive way to manage an airway, they may view the King LT as a failed airway, and decide to remove it and intubate the patient. There is the possibility of hospital politics between departments being a factor in implementation. This could easily be remedied by a strong education process and by always keeping the patient’s best interest in mind.

Respiratory compromise is a valid concern in the cath lab. While most patients scheduled for a procedure in the cath lab have been without food or drink for several hours, emergent patients may have recently eaten and are at risk for aspiration. Advanced airway providers may not always be readily available. The King LT could bridge the gap of time between when a patient stops breathing and an advance airway provider arrives. It could also help prevent aspiration.  For nurses in the cath lab, it should definitely be considered as the first-line airway of choice in a respiratory emergency.

Travis Mackey, RN, CCRN, RCIS, EMT-P, can be contacted at: travismackey_1@hotmail.com

This article received double-blind peer review from members of the Cath Lab Digest editorial board.

Disclosure: Travis Mackey reports no conflicts of interest regarding the content herein.

References

1. Dörges V, Wenzel V, Neubert E, Schmucker P. Emergency airway management by intensive care unit nurses with the intubating laryngeal mask airway and the laryngeal tube. Crit Care 2000;4(6):369-376.
2. Russi CS, Miller L, Hartley MJ. A comparison of the King-LT to endotracheal intubation and Combitube in a simulated difficult airway. Prehosp Emerg Care 2008 Jan-Mar;12(1):35-41.
3. King Systems Corresponds to the FDA Regarding KLT(S)D Labeling. January 22, 2010. Available online at https://www.kingsystems.com/news-releases/hello-world/. Accessed October 17, 2011.
4. KING LT®: Reusable Supraglottic Airways. Available online at https://www.kingsystems.com/medical-devices-supplies-products/airway-management/supraglottic-airways/reusable-supraglottic/. Accessed October 17, 2011.