Taking the Fear Out of RSI/DSI

With this article we begin a new series by our regulars Kelly Grayson and Gene Gandy, joined by a new coauthor, Jason Kodat, MD, EMT-P. Jason is a paramedic and an emergency physician practicing in Pennsylvania.

It is 0245, the EMS witching hour when the bars have all closed and drunks start driving into immovable objects and each other. The tones drop, and you are dispatched to a one-vehicle collision. As you near the scene, Engine 34 radios there’s a car into a tree and they’re beginning extrication of the male passenger.

You observe massive damage to the front and driver’s side of the car. The fire lieutenant reports the driver is deceased and there is a male in his 20s trapped in the passenger side. You confirm his evaluation of the driver, who has massive head injuries incompatible with life.

Soon you are able to extricate a male patient, also with head and chest injuries. You determine to load and go. A firefighter offers to drive, and you and your partner load the patient and signal to begin transport to the Level II trauma center.

As you expose your patient, you note blood in his airway, which your partner immediately suctions, but obvious bleeding there continues. You see a large abrasion to the mid chest. Your patient is awake but not alert. He is restless and moaning and thrashing about. You realize you need to protect his airway, but he gags when you attempt to place an oral airway. His nose is mashed, so you know you need to intubate, but you will have to paralyze him to do it.

A surge of adrenaline and fear shoots through you. It’s been years since you practiced RSI. You break into a cold sweat as you start to think about what you must do.

You draw up 100 mg of succinylcholine and push it. Thirty seconds later your patient is paralyzed and not breathing. You are scrambling to find your laryngoscope and the blade you want. You grab a 7.5 ET tube and open it but can’t find a syringe to check the cuff, so you just decide to go ahead without checking the cuff. You advance your blade but can’t see anything. You withdraw and try again. Nothing! Now you’re panicked. You decide to try a different blade, but you can’t find the one you want. You think about the pulse oximeter and ask your partner to put it on and let you know what the sats are. Your partner says, “Where is it? I can’t find it.”

You try again to intubate, but the airway is full of blood, so you try to find the suction catheter, which is on the floor now. You suction and try again—still can’t see the cords. Now your partner has found the pulse oximeter and says the sats are 60%. You try once more to intubate and see nothing but blood. Now you notice your patient is turning blue and purple. You start CPR.

It doesn’t have to be this way. Through careful education, training, planning and practice, you can avoid disasters like this one.

Gene: Rapid sequence intubation, or rapid sequence induction and intubation (RSI), and delayed sequence induction and intubation (DSI) are techniques that can be lifesaving. When your patient cannot protect his airway, endotracheal intubation is the preferred method for airway management, but if there is a gag reflex, you will have to sedate and paralyze him to accomplish that. Not all EMTs are allowed to practice RSI. Some states prohibit it, others restrict it, and many medical director physicians do not trust their medics to do it and therefore do not allow it.

Jason: There’s a reason for that. Many airway studies have been done in systems that, like the paramedic above, aren’t really prepared to do RSI well. As a result, many of them showed harm, particularly in patients who would have done well, such as those with head injuries. The medicine isn’t different out there in the field, so if these are patients we would intubate in the hospital without harm, there’s clearly something at play besides the mere location of intubation. Fortunately, newer data from New Zealand shows that a good system can not only match hospital outcomes, but exceed them.¹

Kelly: Fun fact: Louisiana added RSI to the paramedic scope of practice based in large part on a proposal I drafted for our EMS certification commission in 1999. I wrote it following a call in 1997 that threatened to spiral out of control much like this one. I was 12 minutes from a rural hospital with a nonbreathing patient in a “can’t intubate, can’t ventilate” situation. As I prepared to do a surgical cricothyroidotomy—not in our scope of practice at the time—I distinctly remember thinking, Boy, it sure was fun being a paramedic. I wonder what I’m going to do next.

Fortunately, with a little creativity and a lot of luck, I managed to nasally intubate the patient instead, and a week later I had an RSI protocol on our medical director’s desk. It took two years to percolate through the EMS bureaucracy, but eventually RSI was added to the Louisiana paramedic scope of practice.

In researching that proposal, I encountered a few eye-openers. First, relatively few EMS agencies that had RSI had an increased airway training requirement, and second, my own agency’s intubation success rates sucked. Companywide, our first-pass success rate was 74%, but when you eliminated two medics, it jumped to 96%. Those two medics missed over half their intubation attempts and were the first medics we targeted for remedial training.

And therein lies the problem with RSI: While it may make intubation easier in certain instances, the person wielding the laryngoscope has to have some serious airway chops before you even consider the procedure.

You must consider the potential efficacy of the procedure based not upon the airway skills of your best medic, but those of your worst medic. I factored that consideration into my proposal to the state, and when we implemented RSI we had a yearly live intubation quota to meet, 24 hours of additional airway management training, and a clinical contract with a local teaching hospital to get our medics the additional live intubation attempts as needed.

In my opinion, agencies that utilize RSI must have more rigorous CQI, alternative rescue airways and mandatory airway refresher training with a live intubation requirement. That becomes even more of a necessity given the low threshold for intubation proficiency in recent paramedic curricula. Five successful intubations does not make you competent, it makes you dangerous.

Gene: The key to successful RSI is planning, preparation and practice. Planning involves education and training beyond simply being familiar with the techniques. It involves having set routines that crews will practice.

The “pit crew” approach is excellent. If it works for NASCAR, why wouldn’t it work for EMS?

Kelly: The key to success in a successful resuscitation, like any complex EMS call, is scene choreography. The pit crew approach gives us a ready-made template to work out the intricate ballet of resuscitation.

In the pit crew approach to CPR, each rescuer has a designated position and task. That position and task may vary among agencies and with different crew configurations, but the point is that each rescuer has a role and place—no fumbling over each other and duplication of efforts. That same approach can work for other time-sensitive and intricate procedures, such as RSI/DSI.

Gene: Preparation requires that you set up your equipment for easy access, so you don’t have to dig through different bags to find all the items you’ll need. Most services keep drugs in one place and the airway kit in another. This requires the operator to open at least two bags or more to find the tools that will be needed and assemble them.

Instead, prepare an RSI/DSI kit to be used only for this procedure. It should be set up in a special way: First, pick a container that will allow you to place items in order of use. An airway “roll” may work, or a tool box. Whatever you use, configure it to make things easy to find and have everything that will be needed for the RSI in it.

Put your sedative in the first location. If you are using etomidate, tape a syringe to the vial and place it first in the kit. Next have your laryngoscope and blades. Then tubes, with syringes next to them, bougie and stylet, then your paralytic vial with syringe, long term-sedation vials with syringes, and if you use succinylcholine, your long-term paralytic with syringe. Have everything in the order you’ll need it.

Practice means exactly that. As a wise person once said, “Amateurs practice till they get it right; professionals practice till they can’t get it wrong.” When we are dealing with human lives, that should be our mantra. Unfortunately too few crews ever practice these procedures together. The time to perfect your techniques is before they’re needed. Every lead medic should practice the RSI/DSI procedures with all his partners until it is second nature.

Kelly: The purpose of preoxygenation is to establish a buffer to give us time to perform endotracheal intubation before desaturation occurs. For most, an oxygen mask applied for three minutes or so, or eight vital-capacity breaths via a BVM immediately before an intubation attempt, will do the job. This preoxygenation technique promotes maximum alveolar oxygenation and nitrogen washout, and in healthy, nonobese adults without significant pulmonary pathology, establishes a buffer of up to eight minutes before saturation falls below the critical 90% threshold. Even those with significant pulmonary pathology will still have a buffer of up to four minutes, giving us minutes to secure a tube, and not the arbitrary 30 seconds promoted by NREMT.²

In 2010 Dr. Richard Levitan described his technique of apneic oxygenation in Emergency Physicians Monthly.³ Simply put, add a nasal cannula at 15 lpm to your usual preoxygenation technique and keep it in place until an advanced airway is secured. The nasal cannula will allow you to reach oxygen delivery levels unobtainable with the BVM or nonrebreather alone, and it will provide a pressure gradient that will keep the alveolar capillaries suffused with oxygen for as long as you’ll need to secure an airway. In studies, researchers were able to maintain apneic patients’ oxygen saturation at 98% for up to 100 minutes.

That certainly dispels the fear of a crash intubation while the pulse oximeter alarm beeps urgently in your ear, doesn’t it?

All you need do is assign one team member—who can even be a BLS provider—the role of positioning the airway and beginning preoxygenation while you sedate the patient and prepare your equipment, and you have effectively performed DSI in the same time frame as it takes to perform RSI.

And one last thing: We’re talking about proper airway positioning, not what passes for a sniffing position with most providers. Keep the patient’s head elevated so the external auditory meatus is aligned with the sternal notch. The facial plane should be parallel with the ceiling and not tilted back.

Jason: Getting the sedative on board early makes preoxygenating a patient much easier. Of course, how much bang for your buck you get out of that time between sedative and paralytic depends on your medications. Benzodiazepines and narcotics (usually midazolam and fentanyl) depress the respiratory drive—exactly what you don’t want. Some people are also relatively resistant to those classes of medications, which might require you to give escalating doses to achieve adequate sedation. In general, these medications shouldn’t be used as your sole induction agents. (Having said that, the combination is useful to maintain sedation. It is also excellent for pain control, should your patient be an RSI candidate due to trauma.)

Etomidate has always been really popular for RSI because it’s a reliable medication that rarely changes a patient’s hemodynamics and generally leaves respiratory drive intact. Unfortunately, if you give it more than a minute in advance of the paralytic, you’re going to have to give another dose to ensure you’re not intubating an awake but paralyzed patient.

Propofol is nice in the setting of status epilepticus, because it tends to break seizures better than other induction agents. Again, because of the short duration of action, you may need to give more. It also tends to drop patients’ BP more than the other agents and suppresses respiratory drive at least as much as the benzo/opiate combo. I tend to avoid it in pretty much any intubating situation other than status epilepticus, especially in hypotensive patients.

Ketamine, like etomidate, leaves respiratory drive mostly intact. It has some useful side effects, including pain control, bronchodilation—nice for your respiratory patients—and a weak pressor effect, which is nice for your hypotensive patients. It has the benefit of being relatively long-acting, so there’s less redosing. I’m a huge fan of ketamine.

You’ll need to pair your sedative with a paralytic. Succinylcholine has always been popular because of its short duration of action (less than 4–6 mins.), as long as you avoid using it anytime you suspect hyperkalemia. Rocuronium doesn’t have that contraindication but lasts longer (30–40 mins.), so be sure to use a longer-acting sedative (yay for ketamine!) or rebolus a short-acting one.

Other medications that were traditionally used haven’t been shown to be as useful as once thought. Lidocaine was supposed to blunt sympathetic stimulation and ICP rise, but the effect isn’t reliable and has never been shown to be clinically meaningful. The same goes for “defasciculating” doses of paralytics.

[Table 1 goes here]

Gene: So here’s how it goes (vary as indicated depending on the capabilities of your crew members): Clear the airway and keep it clear as your partner gets a line. While that is going on, mentally figure your patient’s weight and the dose of sedation you’re going to use. You should know the doses by memory. As soon as the line is in, have your partner take over airway management and draw up and push your sedative.

As the sedative takes effect, your partner preoxygenates your patient to 98%. Preoxygenation techniques include a nonrebreather mask at 15 lpm if your patient is breathing on his own, together with a nasal cannula hooked to a separate oxygen regulator running at 15 lpm also. This will optimally preoxygenate your patient. If, after 3–5 minutes of this, your patient still does not have an oxygen saturation better than 90%, there is a shunt in place. It will be necessary to use CPAP or BiPAP or BVM ventilation to overcome this.

Check out your laryngoscope and tubes, leaving the syringes attached to the cuff inflators. Draw up your paralytic, long-term sedative and long-term paralytic. Check your patient’s oxygen saturation. If he is at 98% or above, push your paralytic, wait for paralysis and intubate. Take your time. You have far more than 30 seconds to intubate. If you encounter problems, see what needs to be done. What Cormack-Lehane view is seen? If it’s a grade 3 or 4, get your bougie and use your airway helper to facilitate visualization and try again. Have your partner monitor the patient’s oxygen saturation continually. As long as he’s above 90%, you are fine.

Kelly: Define the roles of your rescuer positions in the pit crew. For an example, see Table 2.

Once RSI/DSI is ready to be performed, all team members shift to their right. The airway assistant moves to patient’s right shoulder to assist with intubation by doing external laryngeal manipulation (ELM), lip retraction, holding the bougie, tube and suction, and so forth. The team lead moves to head and intubates. The IV starter moves to left shoulder and calls out EtCO₂ readings, heart rate and SaO₂ readings.

Airway management, and especially intubation, is a team sport, but over the years the role of those team members has evolved. Long ago the Sellick’s maneuver (posterior cricoid pressure) was applied by an assistant to limit gastric distention and facilitate visualization of the vocal cords, and that evolved into external laryngeal manipulation. The primary differences between Sellick’s and ELM are the structures manipulated and the presence of coaching by the laryngoscopist.

In Sellick’s maneuver, the assistant simply pressed down on the cricoid cartilage. In ELM, the assistant applied pressure to the thyroid cartilage itself, in response to coaching by the laryngoscopist on how much and where to apply pressure. This technique was widely known as BURP (backward, upward, rightward pressure). It was thought that BURP could improve the laryngoscopic view in difficult intubations by at least one Cormack-Lehane grade.

In more recent studies, BURP was found to worsen POGO (percentage of glottic opening) scores by 35%. In comparison, Sellick’s worsened those scores by 29%, and bimanual laryngeal manipulation worsened the visual POGO score by only 4%.⁴

In bimanual laryngoscopy, rather than coaching an assistant in applying the necessary external laryngeal manipulation, the laryngoscopist simply applies that pressure himself with his right hand until an optimal view of the glottis is achieved. The assistant then maintains pressure at that location, freeing the laryngoscopist’s right hand to place the tube. If the assistant applies lip retraction to the right corner of the patient’s mouth with his free hand, the procedure can be even more effective at achieving visualization.

Jason: Bimanual laryngoscopy is just one of many reasons to make airway management a team sport, not only in the performance phase but in the practice phase. The last place you want to be teaching an EMT bimanual laryngoscopy is when your favorite blade and ideal positioning aren’t quite giving you the view you need.

Even with a top-notch team in place, there are still things that can go wrong. Many of the complications of RSI aren’t specific to RSI alone, since they stem from the same places as other intubations: potential for tube dislodgement, insufficient sedation and so on. (On the other hand, some complications are less likely: a paralyzed stomach can’t regurgitate.) The worst thing that can happen is not getting an endotracheal tube in. You should be able to avoid this most of the time with excellent airway positioning, as Kelly mentioned, but if you do airways often enough, you’ll eventually end up with someone you just can’t tube. At that point you have to go to a backup—which could be either a supraglottic airway or a cricothyroidotomy. This is where your drug choice becomes extremely important.

Traditionally, the etomidate/succinylcholine combination was used because if you failed an airway, you could just bag the patient for a couple of minutes and be back to breathing. That’s fine for a semi-elective OR procedure but not really applicable to emergency medical practice; if you could just back off and try something different, you probably shouldn’t have done RSI in the first place. That’s why I recently switched almost all of my emergency airways to a ketamine/rocuronium combination, because the last thing you want while doing a cricothyroidotomy is the patient reaching up and grabbing your hand because everything wore off.

The rest of the potential things that can go wrong mostly center around the effects of the medications involved. Narcotics, benzos and (especially) propofol can give you hypotension. Succinylcholine can shift potassium out of the cells, causing lethal arrhythmias. Rocuronium can outlast your sedation, leaving you with an awake, paralyzed patient. People coming out of ketamine can develop frightening emergence reactions. There is also some concern that etomidate can increase mortality in septic patients, although some studies show no difference.

Above all, don’t forget sedation and pain control! Vecuronium isn’t a sedative, even though it will keep your patient from pulling at lines and tubes.

Gene: By using a controlled approach, being prepared and having practiced using a pit-crew procedure, you can successfully paralyze and intubate your patient in an orderly fashion.

Now let’s turn back the clock and assume your crew was prepared for RSI/DSI.

After recovering from the initial shock of realizing RSI has to be done, you implement the plan you’ve practiced with your team many times. You grab your RSI/DSI kit while the IV starter gets the line. Estimating your patient’s weight at 80 kg, you draw up 200 mg of ketamine while your partner secures the IV. Your airway assistant suctions the airway and applies the pulse oximeter. You push the ketamine, and in 30 seconds your patient is relaxed and breathing easily. Your airway assistant applies a NRB at 15 lpm and a nasal cannula at 15 lpm from the other regulator in your ambulance. You prepare your laryngoscope and tubes, draw up 100 mg of succinylcholine and push it.

Your airway assistant reports a sat of 99%. You take over and open the airway and take a look. There is some blood in the airway, so you suction and look again. Your patient has a short, thick neck, so you don’t see the cords and you know it’s going to be a difficult intubation, but since you have preoxygenated your patient adequately, you know you have plenty of time to accomplish it—far more than 30 seconds. After applying bimanual laryngeal manipulation (BLM), you ask your airway assistant to put her fingers on yours to maintain the view you’ve achieved. You insert your bougie, feel it bumping along the tracheal rings, advance it until it stops at 27 cm, and thread your 8.0 ET tube over it into place. You have already checked the cuff, and the syringe is still attached, so you inflate the cuff and ventilate. You see chest rise, hear good breath sounds bilaterally and attach the EtCO₂ monitor sensor. You see 40 torr of CO₂ registering with a nice, flat plateau in the waveform. You secure your tube and retake vital signs. Now you push your long-term sedatives and paralytic. The rest of your transport is routine.

Jason, Kelly and Gene: RSI/DSI does not have to be a panic situation. Through planning, preparation and practice, you can master this essential technique and, when the time comes, complete the procedure in a calm and orderly manner.

References

1. Bernard SA, Nguyen V, Cameron P, et al. Prehospital rapid sequence intubation improves functional outcome for patients with severe traumatic brain injury: a randomized controlled trial. Ann Surg, 2010 Dec; 252(6): 959–65.

2. Benumof J, Dagg R, Benumof R. Critical hemoglobin desaturation will occur before return to an unparalyzed state following 1 mg/kg intravenous succinylcholine. Anesthesiology, 1997 Oct; 87(4): 979–82.

3. Levitan R. No Desat! Emergency Physicians Monthly, www.epmonthly.com/archives/features/no-desat-/.

4. Levitan RM, Kinkle WC, Levin WJ, Everett WW. Laryngeal view during laryngoscopy: a randomized trial comparing cricoid pressure, backward-upward-rightward pressure, and bimanual laryngoscopy. Ann Emerg Med, 2006 Jun; 47: 548–55.