Podcast 125 - For Those Who Play With Fire
Before the July 4th weekend hits, I wanted to address two main questions whose answers may come in handy on a call you'll run very soon...
Should EMS use a burn formula?
What's the best way to manage pain for the burn patient?
For a sense of a well-rounded blog on burns, I've included some quick facts about burn care at the end that are unrelated to these questions. Also, Erik Rima (CFRN and former burn center RN) left us his perspective at the end in a peer review. Be sure to check those out before you leave! Alright, on to question number one... should EMS even bother with a burn formula?
Getting Burned on Fluids
As we all try to remember how a burn formula even works, you're probably recalling the Brooke Formula, the Parkland formula, and then the consensus formula.
Brooke: TBSA x 2 x kg.
Parkland: TBSA x 4 x kg. (no one uses this)
Consensus: TBSA x 2-4 x kg. (or this)
But, you shouldn't even memorize these things - just use a calculator like this one (but for the Brooke formula). However, I want to dismantle one of these formulas for a little experiment, so we'll look into an example. Let's say that we have a patient who weighs 80kg, and they have 20% TBSA burned. Let's use the Brooke method (I promise I'm going somewhere besides teaching you a burn formula).
20(%) x 2(mL) x 80k(kg) = 3,200 (mL)
Okay, now what do we do with that number (3,200)? That's the amount of fluid that the patient should receive over 24 hours. Do you remember what we do with this number next? We have to cut it in half.
3,200 / 2 = 1,600 (mL).
Now what? We would deliver half of that over the first 8 hours, and then the other half of it over the following 16 hours. To get our IV infusion rate of this fluid, we would divide by 8 hours.
1,600 / 8 = 200 mL/hour.
Seems kind of low, doesn't it? Especially considering you probably won't even be with this patient for a whole hour following their burn. Plus, we've probably over-estimated the TBSA burned. Let's assume you'll be with this patient for 30 minutes. If you're being all strict about it, that means you should infuse 100 mL over that time period. By the time you start your IV, hang the bag of LR to keep the vein open, push some medications and flush them, you're probably pretty close to catching up to that number without even trying. What if the patient had double the burns (40%)? Then our infusion rate would end up being doubled to 400 mL/hour, and in 30 minutes we would have needed 200mL. Again, I'm guessing that's lower than you thought it was going to be. My point in taking us through this math is to highlight that these formulas are probably not an emergent priority. In fact, I'll take this time to ask a favor of you. Here is what I ask:
If I show up as a burn patient in the back of your ambulance, please skip the burn formula. Manage my pain, assess my airway carefully, and dress my burns at some point after that.
Oh, and keep me warm - I'll probably be freezing.
Luckily, I'm not the only person who feels this way. Agencies are starting to default to an infusion rate of 500 mL/hour for adult burn patients in the prehospital setting - where did that number come from? The following is a direct quote from the Advanced Burn Life Support 2018 Provider Manual.
"In the pre-hospital and early hospital settings, before calculating the percent Total Body Surface Area (TBSA) burned, the following guidelines based on the patient’s age are recommended as the INITIAL FLUID RATE as a STARTING POINT:
• 5 years old and younger: 125 ml LR per hour
• 6 – 13 years old: 250 ml LR per hour • 14 years and older: 500 ml LR per hour
Once the patient’s weight in kg is obtained and the percent second and third-degree burn is determined in the secondary survey, the ABLS Fluid Resuscitation Calculations are used to calculate the ADJUSTED FLUID RATE."
Isn't that much easier? It's anxiety-reducing for me knowing that I don't have to be so exact with a formula, especially when the patient has other emergent needs. There probably won't be a very accurate measurement of both kilograms and exact TBSA burned until this patient reaches the ICU, so we're better off worrying about emergent needs, especially in prehospital and early ED care. However, there is one very important thing we need to keep in mind with this method of volume replacement - it's assuming the only volume loss is going to be from burns. If this patient has concurrent hypovolemia from fluid or blood loss, don't believe that you need to stick to these fluid rates. Concurrent trauma may need blood, and the dehydrated patient may need fluid. Take into account recent history and your assessment to assess the need for more volume. Keep in mind that the blood pressure and pulse might be elevated from pain, which can skew a couple of things that we usually use to assess the need for volume replacement.
Alright, we covered fluid replacement - it's likely much more simple than we thought, and we can focus on other important factors of the resuscitation. One of these very important points is going to be managing pain. What's the best way to provide analgesia?
Fentanyl Vs. Ketamine?
I used to believe that my experience with burn patients what that I only ever needed ketamine to manage their pain. However, after I really reflected on these transports, I realized I was wrong. Nearly all of my experience with burn patients has been in the IFT realm - bringing them from a rural facility to a burn center. During transport, all they generally needed was doses of ketamine, and they seemed to do great. However, what did they receive boatloads of before my arrival? Opioids. They always had fentanyl and hydromorphone in their system prior to my doses of ketamine, so their opioid receptors were already well saturated by the time ketamine came into their system - this is likely why I could get away with supplementing analgesia with ketamine (generally at 0.25 mg/kg SIVP if they were not intubated and 1mg/kg or more if they were intubated). So, is this really a question of one medication vs. the other?
No. In the acute setting, a medication such as fentanyl is likely going to be our backbone of providing analgesia. Follow your institution's guidelines, but a usual dosing regimen might be 1-3 mcg/kg SIVP, following by a maintenance infusion of 1-3 mcg/kg/hour. The patient may require a larger dose than this, but it's a starting point. Also, keep in mind we are speaking about a spontaneously breathing patient. What if the patient requires bolus dose medications?
This is the point where I would reach for pain-dose ketamine, either at small, flat doses (10 -20 mg in the adult) or weight-based dosing (0.25 mg/kg). If the patient was intubated, then they would likely require disassociation doses with the ketamine maintenance infusion of 1mg/kg/hour, and I would keep the fentanyl going. I again want to stress that I'm just telling you what I would do - you should consult with your medical director, your own guidelines, and use your best clinical judgment.
There is not much about specific pain control guidelines in the ABLS provider manual, but it does offer this advice when it comes to pain control:
"In intubated patients, excessive doses of opioids and/or sedatives should be avoided. Their liberal use often exacerbates peripheral vasodilation and may cause hypotension, which then leads to the administration of more fluids. Other medications that can cause hemodynamic compromise include propofol and dexmedetomidine and should be used with caution. Whether they are intubated or not, the goal is for every burn patient to remain alert and cooperative with acceptable pain control."
Is this a use case for a ketamine add-on in the intubated patient? Perhaps. The take-home message here is likely that the patient should mostly be comfortable, but we might not aim for a pain level of zero in these patients, especially if we are trying to keep them spontaneously breathing. Having a conversation about what an acceptable pain level is to our patients may help us guide therapy (if they can communicate).
In searching for literature on this topic, much of the pain control literature surrounds dressing changes, since this is such a painful procedure in the burn patient. A study in pediatric burn patients by Tosun, Esmaoglu & Coruh (2008) evaluated a propofol-ketamine vs. a propofol-fentanyl mixture during dressing changes and concluded that both combinations provided adequate pain control, but the propofol-ketamine mixture was superior since it provided less restlessness. Another possible advantage of ketamine is that effective IM doses can be given if IV access is delayed (Kurdi, Theerth & Deva, 2014). There was a systematic review of adult burn patients by McGuinness et al (2011), however, it pooled a very wide variety of patients (including acute and chronic pain control). Owens et al (2006) essentially did a similar type of trial and concluded that ketamine was safe and effective in these patients as well. Again, these trials looked at a wide variety of patient acuities and situations, not just the acute pain burn patient.
By the way...
People often get a little confused about dosing ketamine when it comes to how much to draw up / administer. Test your knowledge in this quick quiz! And don't stress... no one will know what you scored.
Quick Points on Burns
Here are some quick points about burns you'll want to know before you see your next burn patient! Everything in these points is taken from the ABLS provider manual.
Destination
What if your patient meets trauma center AND burn center criteria? Go to the trauma center! The trauma center can provide initial burn care, but your burn center might not be able to offer high-level trauma care! Trauma trumps burns. Hopefully, your burn and trauma centers are the same facilities, but not everyone has that convenience.
Dressings
Dry, clean, and loose-fitting dressings are preferred. If the patient still has active burning going on, water can be used, but make sure it's neutral temperature. Burns of ~5% can be placed under running water for a few minutes prior to drying them and dressing them with dry dressings. Wet dressings can cause hypothermia.
Needles Through Burns
You can do IM administration and start an IV through a burn, but it's definitely not preferred.
Estimating Total Body Surface Area Burned
No one is really going to know until this patient hits the ICU and they get carefully evaluated. However, we can use the rule of 9s to quickly estimate the burn (only blistering burns and worse get counted). As a note, the palm rule is commonly misunderstood. Here is how it actually works according to the ABLS provider manual:
Were you taught that wrong too? You're not alone. Also, Google (especially Google Images) will mess you up on this as well. Just go with what ABLS recommends here for the rule of palms.
Fluids
LR is the preferred fluid, and if it's warm, that's even better (as long as your patient is not hyperthermic for some reason).
Keep them warm
Maintain a warm environment. If you've ever had a bad sunburn, you know how freezing cold you can get. Burn patients have a decreased ability to keep heat inside the body. Just like warmed fluid, the caveat to this would be the hyperthermic patient.
Irrigation of dry chemicals
Low pressure, prolonged irrigation is the correct method. High pressure can drive chemicals further into the skin (especially alkaline burns). Plus, you don't want to spray everyone with chemical water...
Dry chemicals
Brush everything off before you irrigate. Be especially careful with phenols, elemental metals, and dry lime (they react with water).
Wet Chemicals
Wet chemicals should be irrigated immediately (they're already wet). Be especially careful with hydrofluoric acid! The fluoride enters the system and causes toxicity (soaks up magnesium and calcium and causes absolute and relative hyperkalemia). These patients die of fatal arrhythmias due to a lack of recognition of toxicity. They need ECG monitoring, IV calcium, and possibly magnesium. The lowest TBSA burned with systemic toxicity leading to an arrest is only 2.5% TBSA!
Airway Burns / Need for Intubation
Alright, here's the thing. I talked to a few people about this, and it turns out this deserves its own blog/podcast. I have been made aware that there is an ongoing battle between emergency physicians and surgeons on when the correct time is to intubate these patients and what the indications actually are. I'm going to direct you to the ABLS manual for now, and we'll revisit this later. Click Here and check out pages 25-27 for what ABLS has to say about this. There is another article here that I found interesting as well. We'll be checking in with someone later on who has way more experience with burned airways than I do.
Conclusion
Fluid resuscitation and pain control are cornerstones in burn care that EMS plays a key role in. Simplifying our approach to fluids in the burn patient can free up our cognitive bandwidth for other aspects of the resuscitation, such as ensuring we are controlling the patient's pain. Pain control will likely include opioids as the baseline, and possibly other agents such as ketamine (or an anxiolytic or sedative). And, don't forget all the nuanced items mentioned above!
Be safe out there!
Peer Review
Erik Rima (CFRN, former Burn ICU Nurse)
My compliments to Sam for another excellent blog post. Burn injuries are an uncommon and often dramatic presentation that causes high stress to both the patient and providers. While the inpatient care of burn injuries is extremely specialized and nuanced, a few simple principles of burn care in the pre-hospital environment can not only benefit our patients but also provide a good foundation of care for the burn team that will eventually take over. Sam has done a wonderful job of laying out these principals but I will just add a few additional thoughts from my perspective as a former burn and current flight nurse.
Fluid Resuscitation: Sam absolutely nails this piece. The inherent issue with the use of any of these formulas is that they are predicated on getting an accurate BSA, and unless you are in the tub room of a burn center your odds of getting an accurate BSA are honestly next to zero. Our job in the pre-hospital realm in terms of calculating burn percentage is to know if it is a “big burn” or a “little burn” and then initiate fluid resuscitation in an appropriate manner. Dealing with a patient with a large burn BSA who is slightly under-resuscitated is far easier than dealing with the same patient who is massively fluid overloaded. Additionally, it is preferred to provide steady continuous fluid infusion (preferably LR) versus large boluses of fluid during burn resuscitation.
Pain Control: This can be a challenge with large burn injuries. Although, if the patient has mainly deep 3rd/4th degree burns, there may actually be very little pain involved. Ketamine in theory seems like a great choice, but in my past shop, it was really never our go-to for initial debridement or dressing changes for the adult burn population. My caveat here is that this is extremely center and physician dependent, but our center seemed to rely heavily on fentanyl and versed for most of our burn cares. Ketamine was frequently utilized for pediatric dressing changes. In terms of ongoing pain and sedation needs in the Burn ICU, this is actually a highly complex topic and really could have its own podcast, but suffice it say that there is no magic bullet for sedation and analgesia strategy for these extremely complex patients that can be in the ICU for months at a time.
Quick Points: Destination: Sam is spot on; trauma always kills before the burn so prioritize accordingly. Dressings: Sam also nails this; loose dry dressings are the way to go. No ointments or anything of that nature needs to be added either because the wrong ointments can form eschar and impede the healing process. In fact, an excellent charge RN that I used to work with would often tell referring ED’s to just loosely wrap a chux pad around the site because it was clean, would absorb the leaking fluid, and was easy for us to remove. This is another point, the burn team will absolutely 100% take your dressings off immediately once the patient hits the burn unit, so don’t spend crazy amounts of time doing pretty dressings.
Temperature control: Patients with large BSA’s cannot thermally regulate, I can’t emphasize that enough, keep them warm! If you are comfortable in your ambulance or helicopter, your burn patient is cold. Aside from being almost always fluid overloaded coming from the field, burn patients are almost always at least mildly hypothermic. In fact, the unit I previously worked on had special heating elements in the ceiling above the patient’s bed that would greatly increase the temperature in the area around the patient during dressing changes to prevent hypothermia during the dressing change that could take up to 4 hours on large burns.
Airway Burns: I’m going to leave this exactly where Sam left it, definitely needs its own podcast, but I will say that the presence of major facial burns does not correlate to airway burns nearly as often as I was lead to believe when I was in paramedic school, and that is where I’m going to leave that.
I thank Sam for the opportunity to review this blog and want to again commend his efforts in laying out how to simplify burn care in the pre-hospital realm. Following these simple steps will go a long way in improving the out-of-hospital care for burn patients not only in terms of their comfort but also in getting the continuum of their care started off on the right foot.
