An Overview of Rapid Sequence Intubation (RSI)


Author: Colleen M Hayes, MBA, RN, EMT-P

What is it?

The first thing that is taught in medic school is that control of airway and ventilation is the key to patient stabilization. Until recently, if the airway could not be controlled the patient could succumb to respiratory or cardiopulmonary arrest and die. Maintaining control of a patient’s airway is one the most basic things that paramedics can do to prevent deterioration into cardiac or respiratory arrest because of severe hypoxemia. That patient with a life-threatening emergency and an inadequate airway and ventilation because of a clenched jaw, persistent seizures, or a combative conscious patient with an intact gag reflex often cannot be safely intubated either nasally or orally intubated leaving the paramedic helpless to gain adequate control of the airway and ventilation. Rapid Sequence Intubation (RSI) involves the rapid administration of a sedative and a paralytic agent that extinguishes the patient’s ability to breathe on their own. Once paralysis has occurred the paramedic can successfully intubate and quickly attain control of a patient’s airway. The potential serious danger is that the patient will not be able to be intubated, or ventilated and will require a surgical cricothyroidotomy to secure the airway.

There are a several different medications that can be used. Hospitals and EMS services have many different guidelines for the use of RSI. While you read this paper please become familiar with your local guidelines, medications and rationale for the use of each medication. This paper is meant to review the common medications and present an overview of the rapid sequence of events involved in RSI to promptly sedate, paralyze, and intubate a patient.

When to use RSI

The primary indication of the use of RSI is the need for immediate control of a patient’s airway when it cannot be controlled by other means and intubation and airway control is imperative. RSI should not be used routinely and should be implemented only when the patient cannot be intubated because of clenched jaw (trismus), persistent seizures, combativeness in a conscious patient with an intact gag reflex, etc. If safe to do so an attempt at nasal intubation should be tried prior to choosing to use RSI.

Anticipate the Difficult Airway and Avoid RSI When...

If there is any reason that the patient may not be able to intubated or ventilated after paralysis RSI is contraindicated. There are several obvious anatomic findings that can assist the paramedic in anticipating a difficult intubation. The patient with a short neck may provide for only limited cord visualization that will probably not be overcome by changes in positioning. Prominent upper incisors will effectively contribute to a smaller oral opening to maneuver the laryngoscope blade and endotracheal tube. A receding mandible also lends to a potentially difficult intubation since the angles between the mouth, oropharynx and larynx become altered. In addition, manipulating the tongue out of the visual field of the cords in these patients may be more technically difficult. Limited jaw opening, as a result of TMJ dysfunction (i.e. arthritis), or limited cervical spine mobility from arthritis or prior surgery can also pose significant obstacles in trying to visualize the cords. Additionally, a history of difficult intubation, or more than three fingers between the chin to the thyroid cartilage should be suspected to be at high risk for a difficult intubation. Avoid using RSI in any medical condition that may result in narrowing of the glottis, as in croup, epiglottitis, anaphylaxis, burns or incomplete airway obstruction. In this case the patient may not be easily intubated even after paralysis.

Equipment Preparation

Do not attempt RSI without having the right equipment prepared, organized and ready for use. If you are using RSI, make sure your partner knows how to assist you. When an RSI program is implemented have your BLS staff go through the same training and have them perform their role in the RSI procedure so they are well prepared. Prepare your regular intubation equipment. Draw up all medications and assemble them near the patient’s IV so that they may be administered quickly and in sequence. Have suction turned on and ready to go. Any and all alternative airway devices used in case of f ailed RSI must be prepared and ready for use. Alternative airway devices may include: laryngeal mask airway (LMA), light-guided intubation stylet (Trachlight), or a double lumen airway (CombiTube, PTL). Surgical airway back-up must be available. Have all equipment prepared and within easy reach. The approach to RSI must be organized, rapid and smooth.

Medications

Rapid Sequence Intubation uses several different medications. These may include: neuromuscular blockers, defasciculation agents, sedatives, and premedication agents such as Lidocaine and Atropine that are administered in specific situations. Please see Tracy Evan's article, "Neuromuscular Blockade: How Depolarizing and Non-depolarizing Agents Work. A comparison of succinylcholine and rapacuronium bromide (Raplon)." Next month we will take close look at sedative agents.

The Procedure

Following an organized and simple step-by-step process will help organize and facilitate a smooth and rapid procedure. Prior to initiating the procedure select the appropriate agents for premedication and paralysis based on the patient’s presenting condition, calculate the doses and prepare medications for the proper sequence of administration of neuromuscular blockers. This procedure will reflect the use of a defasciculating (a non-depolarizing agent used to prevent painful muscle contractions and twitching) agent and succinylcholine as the paralyzing agent. Know your local operating guidelines, as there are several methods and different medications that can be used for RSI.

Sequence

  1. Prepare, Preoxygenate & Get Assistance
  2. Premedication
  3. Sedation
  4. Cricoid Pressure
  5. Neuromuscular blockade
  6. Intubation

1. Prepare, Preoxygenate & Get Assistance

It is essential that your partner is knowledgeable about the RSI procedure. In order to prevent complications and insure a smooth process with minimal difficulty make sure everyone understands what is about to be done. Adequate preoxygenation with 100% O2 delivered by a BVM, suctioning, cervical-spine stabilization and application of cricoid pressure are essential skills everyone needs to be proficient with. Ensure that a baseline neurological assessment has been completed prior to paralysis, especially in the head injured patient.

A baseline neurological examination must include at minimum: initial survey information, disability exam (AVPU), pupils, extremity movement, and a Glasgow Coma Score.

2. Premedication

Primarily Atropine and Lidocaine are used depending on the clinical situation. The dosages and recommended clinical guidelines are described below:

Atropine: Atropine’s parasympatholytic / anticholinergic effects help prevent bradycardia due to acetylcholine and succinylcholine stimulation of muscarinic receptors of the heart. Atropine does not affect nicotinic receptors, so it will not interfere with neuromuscular blockade.

Administer the adult dose of : 0.6-0.8 mg rapid IV push or pediatric dose: 0.02 mg/kg rapid IVP before succinylcholine, if indicated. Atropine is administered when there is preexisting bradycardia, or in children less than one year of age. Atropine must always be administered prior to a repeat dose of succinylcholine.

Lidocaine: Given to suppress the cough reflex and reduce the risk of increased intracranial pressure. Administer it before intubating patients with the potential for increased intracranial pressure. The dose is 1.5 mg/kg IV push. Some guidelines recommend 1 mg/kg.

3. Sedation

Sedation is mandatory! It is essential to adequately sedate the patient because Paralytics have absolutely no effect on consciousness or pain perception. Administering adequate sedation is ethically correct and physiologically it reduces panic, helps to reduce intracranial pressure and induces amnesia.

The sedative of choice is diazepam (Valium) or midazolam (Versed). Valium will outlast most paralytics but Versed has a faster onset of action. Sedation must be in adequate doses to maintain sedation of the patient post-intubation. Always administer benzodiazepine agents at a minimum of 60 seconds before paralyzing the patient.

Valium: adult: 5-10 mg IV; peds: 0.1 mg/kg IV

Versed: adult dose only: 2-5 mg IV push

4. Cricoid pressure

Sellick’s maneuver improves visualization of glottis and occludes the esophagus to inhibit aspiration of gastric contents. It must be maintained until placement of the ET tube is confirmed and the cuff inflated.

5. Paralyze

In this sample guideline we recommend giving a small dose of a non-depolarizing paralytic agent to prevent fasciculations caused by succinylcholine that are painful and potentially a cause of increased intracranial pressure. A common approach is to administer vecuronium at 1/10th the paralyzing dose to prevent fasciculations. The defasciculating dose of vecuronium is 0.01 mg/kg IV push. We do not recommend using vecuronium as the initial paralyzing agent because it is long-acting (can last up to 45-90 minutes). If the patient is unable to be intubated, you will need to perform a surgical airway procedure. We encourage prehospital guidelines that use only short-acting agents in the field for initial paralysis. Not only is it better for the patient but it is good risk-management as well.

One the patient has received the defasciculating dose of vecuronium succinylcholine will be administered to achieve paralysis. The paralyzing dose of succinylcholine is 1.5 mg/kg rapid IV Push (same dose and volume as Lidocaine). Paralysis is confirmed when the patient’s jaw becomes slack, or they become flaccid, or the vocal cords release their spasm. Agent choice is based on your local guidelines. Rapacuronium is a new short-acting non-depolarizing paralytic that we recommend reading up on. For detailed information about neuromuscular blocking agents read Tracy Evan’s article, "Neuromuscular Blockade: How Depolarizing and Non-depolarizing Agents Work. A comparison of succinylcholine and rapacuronium bromide (Raplon)."

6. Post-paralysis

One paralysis is confirmed -GET AN AIRWAY! If the patient can’t be intubated by direct laryngoscopy or an alternative procedure such as the intubating laryngeal mask airway (ILMA) or by transillumination, you must perform a cricothyroidotomy. You might be able to adequately ventilate and oxygenate the patient until the succinylcholine wears off. If the patient’s airway and oxygenation are inadequate you must be prepared to perform a surgical cricothyroidotomy. Follow your local guidelines and know the alternative procedures your medical director has made available in your operating guidelines.

7. Confirm the endotracheal tube placement and secure it.

Summary

Ongoing case review and peer review must support the RSI program. 100% quality assurance is necessary to continually evaluate the program for strengths and weaknesses. Integration of field providers into the QA procedure will optimize the program’s success. Retrain and reeducate frequently. Expect skill deterioration and have practice sessions built into monthly training programs. Skill deterioration is a natural part of implementing any new program. Obtain feedback regularly from paramedics and EMTs. Find out what is working well and what doesn’t work well. Then improve it immediately. Training and continuing education are the key to making this program safe and successful. There are many prehospital services that are using various approaches to RSI and enjoying excellent results. Airway management is our best weapon and preventing death. In those patients who are suffering from an inadequate airway we must not tie the paramedic’s hands behind his back, but evaluate new procedures and guidelines that enable the paramedic. The most important thing is that the guideline be evidence-based, and implemented in a safe and progressive fashion. RSI is not the only approach to gaining an airway in the difficult patient, but we are seeing its implementation in more and more systems with success.