Everyone talks about airway all the time, and I was at first reluctant to give this talk. However, I believe it is time to talk about this important subject in a slightly different way. The last time we talked about airway management in regards to intubation was with Kris Maday (from the PAINE Podcast) in Podcast #18 where we went over the basics (a great review to listen to first if needed). There we talked mostly about rapid sequence intubation (RSI). Although commonly used, this is not for every patient. Today, we talk about RTI, which is what we need in most patients.
Some of this will sound similar to other talks out there such as resuscitative sequence intubation. REBEL EM covered this and EmCrit has discussed HOp (hemodynamics, oxygenation, and pH – meaning acidosis) killers. This post is all about explaining why and how to take these steps in a safe and effective manner.
The first step in RTI is to plan! This needs forethought and careful consideration. The first step is planning your intubation. Think about what will kill this patient or what is currently trying to kill them. Is this a hypotensive septic shock patient? Then bring that blood pressure up! The crashing asthmatic that quit moving air is no longer oxygenation and needs this replaced before intubation attempts. What about the aspirin overdose who is now unresponsive? Have you considered how his pH may affect the safety of that intubation? Recognizing HOp killers is the first step to success.
Hypotension can lead to death and has been associated with increased mortality. We must carefully consider how we approach this patient. Unless this is a trauma patient, IV fluids are the first step. In trauma, try to give blood as this is what actually needs to be replaced in the patient. Remember, saline is not blood and may make your numbers look pretty but not actually fix the underlying problem. That and you are diluting the blood, which also means that hard-earned oxygenation is going to be the next problem without more red blood cells.
Patients who are hypotensive can often have a safe delay of intubation. Fluid (or blood) resuscitation is important as the actual intubation can cause transient hypotension. In an already hypotensive patient, this is poor form. A profoundly hypotensive patient does not need only fluids, but most likely vasopressor support. Do not delay this care and go ahead with getting it to the bedside and in the patient. If they need it less after the intubation and being fluid resuscitated, you can back it down or turn it off entirely. It is better to be slightly hypertensive in these patients than lead to an arrest. Remember, peripheral vasopressors are safe and effective. Norepinephrine in most patients can be the safest and tends to work the best. If not available quickly, start with push-dose epinephrine which can be made at the bedside.
Blood pressure correction is not the end of hypotension. Medications in hypotensive patients need to adjust. Be light on your sedative dosing but use higher paralytic dosing. Physiologically, these patients usually respond strongly to the sedatives but paralytics have a harder time reaching the rest of the body and performing the needed relaxing of the muscles. Ketamine is very safe in these patients and usually the best option. In addition, ketamine is probably the one that it is least important to drop the dose given that it is very cardiac stable. Other medications like etomidate are commonly used but are associated with hypotension. When it comes to paralytics, try to use rocuronium versus succinylcholine since the former will provide a longer safe apnea time and does not have the contraindications to monitor in an already stressful situation.
Although it can be performed in many cases, awake intubation is probably the hardest to do given the time and resource constraints. It can be the ace in the hole needed since keeping the patient awake helps maintain the patient’s endogenous catecholamines. Scott Weingart has perfected a technique that is worth the listen.
Prior to any intubation, pre-oxygenation is a necessary step. In the case of the patient who already has hypoxemia, this step is more vital. Not only are we trying to push out the nitrogen but also we now need to get more oxygen. This is to help with providing a safer peri-intubation period by providing alonger period of safe apnea.
The first step is to deliver oxygen. In patients this sick, high oxygen delivery is important and safe. Every patient about to undergo intubation should have at least a nasal cannula since this also used for apneic oxygenation. Many will crank it to 15 L/min and call it good but push this to the highest setting possible (flush and sounding like a rocket). Patients will tolerate it for the most part and gets that much more oxygen in them. Even in the prehospital environment, the oxygen tanks should be able to handle this, especially in brief periods prior to intubation. Slapping on a non-rebreather is not a bad idea either and further helps with oxygen delivery.
Inpatients with shunt physiology using a PEEP valve is vital to act as recruitment. This should be available in most departments or easily obtained for working BVMs. Set the PEEP valve to 5-15 cm/H2O. If the patient simply will not tolerate this, the next step is delayed sequence intubation (DSI).
DSI is great for the uncooperative or combative patient. Give the patient ketamine at a dissociative dose and this will facilitate pre-oxygenation basically by procedural sedation. Ketamine also has broncho-dilatory effects which is a bonus as most of these patients will need bronchodilation. Once the patient has reached satisfactory oxygen saturation levels, it is time to paralyze the patient. Continue with apneic oxygenation using the nasal cannula throughout the intubation.
One other important part is to optimize your positioning of the patient. This is important for any intubation, but even more in the hypoxemic patients. Back Up Head Elevation (BUHE) has demonstrated fewer complications. Essentially, ramp the patient to allow for a more natural airway position and anatomy. Use this as much as possible given its safety and effectiveness for intubation. Do not just reserve this for HOp killers.
Patients in acidosis can be some of the most difficult to intubate. They are a ticking time bomb easy to miss. Think of drug overdoses like aspirin, ethylene glycol, ethanol, and methanol. Diabetic ketoacidosis is another common cause. Avoid intubation if possible, but if needed make sure to get help and lots of it because this is the most important time to have the most experienced person as any time the patient is not breathing (whether spontaneously or on a ventilator) they are building up CO2 which is worsening the acidosis. The intubation must be rapid with the ventilator settings ready for the patient.
Sodium bicarbonate is controversial at best. Although theoretically it makes sense, sodium bicarbonate will convert to CO2 and if the patient is already maxing out the attempt to remove it adding more can cause problems such as dysrhythmias. Although the serum pH may improve, intracellular pH (the one we actually care about) does not improve nor does catecholamine response or hemodynamics. Given the current literature and lack of solid support, this dogma may be one to abandon for now and choose other options.
Unfortunately, other options are limited. However, Ventilator-Assisted Pre-OXygenation (VAPOX) is a great method and Scott Weingart on his site best explains the protocol best. REBEL EM does have a great synopsis though. Essentially, hyperventilation is the key as this patient needs to blow off as much CO2 as possible. Once the patient is inducted, adjust the settings to allow for continued respirations and immediately after the intubation increased the rate again. The other key point is using ETCO2 for monitoring both before and after intubation. Try to make sure levels are about the same and then work on the patient blowing off as much CO2 as possible. Respiratory rate will need to increase as a result.
Once you have considered and addressed the HOp killers, it is time to move on to the rest of the resuscitation. This patient needs close monitoring. Choose staff wisely and have someone designated to watch the monitor. Remember, the oxygen saturations on the monitor can be delayed by a minute in the critically ill patient. If the initial attempt fails, pull out quickly and do not rely on the monitor to get low. If the saturations are already low, you have most likely waited too long. Circulate the blood pressure frequently and make sure that there are good waveforms on the oxygen saturation as well as an accurate heart rate. Consider arterial line placement if feasible for continued monitoring.
Patients this sick need your absolute best attempt. Use a checklist like EmCrit's original one or his revised version. This is not the time to experiment or leave something out of the equation. Personally, video laryngoscopy is my preference for multiple reasons. However, if you are not used to such as device then choose what works well for you. Never forget the suction and know how to do theSALAD technique as Jim DuCanto explains! Pick a large ET tube (at least an 8.0 in most patients) as this can make the ventilation easier for the patient. Also, if a patient later needs a bronchoscope, your colleagues upstairs will thank you. Make sure to have difficult airway measures such as a bougie and a cricothyrotomy kit at the ready. A Cannot Intubate, Cannot Oxygenate (CICO) event requiring cricothyrotomy may not be avoidable and as the Vortex Approach mentions three attempts are not necessary in the correct circumstances. In addition to the above, if possible have ETCO2 available and use a portable ultrasound machine. Ultrasound and ETCO2 can very accurately predict the correct location and if mainstem intubation has occurred. Do not rely on lung sounds and a chest x-ray!
In addition to the right equipment, the right people need to be in the room. There should be at least one assistant at the head of the bed for maneuvers such as bagging the patient but also to give any pieces of equipment such as suction or the ET tube. The person at the head of the bed performing the intubation needs to be in total control for that time. They also should be the most competent person to perform this intubation. Sometimes a quick look at the airway is needed to judge what supplies could be used, but this must be done briefly and sparingly. Some argue this still counts as an attempt. Optimize your first pass success with the right personnel but if there are any failed attempts make sure to modify to guarantee success.
Clearly define roles in advance. This does not have to be led by the person performing the intubation. As discussed in previous podcasts, a resuscitationist should be able to lead the room. Furthermore, they should be able to discuss as much as possible in advance. Talk about this with staff prior to events. Run through scenarios before they even happen. In my shop, the RTs and nurses know what I want and how I want it because of previous experiences and discussions outside of the events.
In addition to the measures above, confirmation is key. Even the video laryngoscope can trick someone to thinking they went into the trachea when it was actually the esophagus. Not only is ETCO2 important (color change has been known to happen even in esophageal intubation so try to use quantitative if possible) but ultrasound can provide an immediate answer. Learn this skill and use if possible. Check lung sliding on both sides to assure that maintstem intubation has not occurred.
Never forget the analgesia! That is my most important tip when it comes to what happens after the intubation. A patient that pulls out their tube defeats the purpose of your hard-earned intubation. If you think it is a good idea to only use a paralytic because of concerns such as their blood pressure, this is poor form and harmful to patients. If blood pressure or compliance is that big of a concern, put them on vasopressors and make them comfortable. Paralytics are only harmful for patients.
This is extremely important for the team. Before you leave the room, make sure everyone is on the same page. Congratulate the team for their efforts and in the case of a complex situation where a more detailed debrief is not possible, find a time to have a discussion later. Staff appreciates this and you will become a better resuscitationist.
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