Hand in hand with determining the depth of a burn wound, determining the total body surface area (henceforth TBSA) involved is critical in describing an injury, determining its severity, and is a key factor in determining immediate treatment and disposition. In this post, we’ll discuss how to rapidly determine TBSA (in the era of the smartphone and apps).
A 30-year-old male is brought in by ambulance to the ED with multiple burn wounds. He states he was extracting essential plant oils in his basement when an explosion occurred. Flash burns occurred to his chest, arm, scalp, and face, as pictured. Additionally, he had non-circumferential burns of both of his legs (not pictured). He opted to stay home and clean his basement before seeking help. Thus, he presents four hours after his injury occurred.
You determine that most of the burn wounds are partial thickness (second degree).
Clinical question for consideration:
How extensive is the surface area of this wound, and how do you use that information to guide fluid resuscitation and transfer considerations?
Burn Total Body Surface Area Assessment (TBSA)
In burn wound TBSA calculation, any wound that is graded as second degree (partial thickness, whether superficial or deep) or greater is included in TBSA assessment. This percentage burn is then used to describe the severity of the wound to consultants, calculate fluid resuscitation requirements, and determine if transfer for inpatient management at a specialty center is warranted.
Were I writing this post 10 years ago, I would spend more time talking about wound size estimation using the rule of nines, the rule of palms, or Lund-Browder diagrams. Suffice it to say that in austere situations, it pays to remember the basics of these rules. For example, the rule of nines dictates that, in adults: each arm and the head are 9% TBSA, respectively; the anterior and posterior trunk are each 18%; each leg is 18%; and the final 1% is the genital region. A cartoon schematic known as a Lund-Browder diagram allows for more accurate estimation of TBSA adjusted for different age ranges. For smaller burns, the rule of palms states that the patient’s own palm is 1% of his/her TBSA.
The next step is to take the %TBSA and plug it in to a formula for determining the patient’s 24 hour fluid requirement. IV fluids are essential in the major burn injury to augment the patient’s cardiac output and compensate for insensible losses. This in turn increases perfusion to the zone of stasis (benefiting the wounds) and maintains the patient’s hemodynamic stability. Any one of a number of similar formulas will work (in the absence of definitive evidence that one is the best), but the most widely used and generally accepted is the formula from Parkland Memorial Hospital, created by Dr. Charles Baxter and colleagues:
4 ml/kg Lactated Ringer’s (LR) per %TBSA burn
½ over 1st 8 hrs, ½ over next 16 hrs
So, that’s how it’s done, traditionally: a careful exam followed by a few minutes with a calculator. But realistically, we live in an age where we carry around little computers in our pockets! Smartphone apps can accurately and rapidly perform these estimations. Furthermore, many apps can do the math of the Parkland formula (or other resuscitation calculations) to guide resuscitation for you. While burn apps have been around for a few years, the utility of these applications is starting to receive some backing in the medical literature just this past year.
So, the rest of this post will simply be a review of the best burn-related apps out there. Disclaimer: My search was performed using the Apple US App store in December 2014, using the latest OS on an iPhone 5; thus it is very possible that some great apps are missed in this discussion, including on the Android platform. Please feel free to comment on the post if there is a worthwhile app I have missed!
Here is a sample of some of the burn-related applications I found in my App store search. I played with all of the apps mentioned above, and I’d like to discuss in more detail my three favorites.
BurnCase 3D is an impressive effort by its creators. This app allows manipulation of a 3D model in space. The model can be marked with an arrow directed by your fingertip with 1st, 2nd (superficial and partial thickness are separate), 3rd, and 4th degree burns (the final not used in all grading systems, this describes a burn penetrating connective tissue, muscle, and bone). Several human models are available, including infants & children and adults of “corpulent” builds. It took a few minutes for me to understand how to use the marker, but once I did, it worked pretty seamlessly. Once the burns are marked, a calculations page gives exhaustive data including the fluid requirements by Parkland (although not broken down in to hourly rates) and caloric intake requirements.
BurnCase 3D is clearly aimed at burn specialists and those providing care within burn units. The app allows patient profiles to be saved with identifying information. Patient photographs of the burns can be added to a file. All data can be exported via email. While impressive, these tools are a bit more than the emergency physician needs. Thus, the bells and whistles actually start to clutter the app, making it a little difficult to use practically in an environment such as the emergency department. But, the (current) price is right–free! It appears to be in a development phase, after a previous paid version floundered with multiple bugs.
Johns Hopkins BurnMed Lite/Pro
BurnMed shares some similar features to BurnCase 3D: a 3D model which can be rotated in space, and marked with burned skin areas. This app does not allow separate marking of 1st/2nd/3rd degree burns, but rather makes the assumption that all burns worth marking are 2nd degree or greater. The use of your finger as a marker made it a little bit difficult to finely demarcate wounds compared with BurnCase 3D, but it is probably sufficient. The unpaid “lite” version marks the burns, and simultaneously spits out TBSA, but doesn’t allow any further calculation of treatment recommendations without upgrading to the paid version ($4.99).
While I am opposed to paying more than $0.99 for the average app, out of curiosity (and for the benefit of this audience), I bought the upgrade. I was pretty impressed with the features of BurnMed Pro. After marking the burned areas, “Eight Hour Treatment Guidelines” are provided. Basic advisement on management is given (administer oxygen, keep the patient warm) followed by IV fluid resuscitation recommendations. Interestingly, the app will only provide an IV fluid rate if the patient’s TBSA meets the American Burn Association (ABA) recommendations for providing IV fluids (otherwise, it recommends PO hydration). I thought this was a nice touch, as it means that some thought was put in to the algorithm for making treatment recommendations. Additionally, if any circumferential (or near circumferential) burns are marked, a link is provided to guidelines for when to perform an escharotomy, and an instructional video on the technique. Well done!
Bottom line, it’s a nice app and the target audience seems to be physicians who treat burns relatively infrequently, and could benefit from clear and concise information to guide treatment. According to the good people at imedicalapps.com (who reviewed this app more formally in 2012), this app was created by Johns Hopkins physicians who were inspired to create an assessment tool after an incident in Kenya where a gas tanker exploded, killing one hundred people and severely burning others. So, definitely good intentions behind this application. Still, the price tag is a little high if you don’t treat burn wounds often.
uBurn & uBurn Medic
The final apps I’ll discuss here are uBurn, uBurn lite and uBurn Medic. The same company, JAMB Innovations, produces these tools.
Rather than the detailed demarcation of burns that you perform with BurnCase 3D and BurnMed, in uBurn lite you just check off the burned areas with your finger’s touch, and a check mark appears. It’s similar to a Lund-Browder diagram, but interactive. In the paid uBurn program, you also have the option to look at body parts in detail, adjust a slider to set the percentage burned, and then bring this TBSA data to a separate calculation screen. You then plug in a weight for the patient and it provides you with: the fluid requirement in the first 8 hours, the first 24 hours, and the expected urine output for the patient’s weight. There is an option to factor in time since injury and fluid given prior to arrival, which is nice for real world application (also a feature of BurnMed, but less obvious to locate within the app).
Additional features include teaching tools for differentiating different burn depths, and an explanation of the rule of nines. There is also a child model available (which is actually an infant). The app is much simpler than the aforementioned BurnCase 3D and BurnMed, which in many ways I actually prefer. A tool like this is probably adequate for the average trained emergency physician, and the price is reasonable at $1.99. (The lite version is free, and is probably also sufficient).
Among the apps I’ve discussed, uBurn has the distinction of being validated in a randomized, blinded study as a tool for fluid calculation in burn resuscitation (versus a person with a calculator and another burn app not available in the US app store).
Along that vein, in some ways I liked uBurn Medic even more. As suggested by the name, this app is actually more geared towards pre-hospital care, and gives direction to the pre-hospital provider. After you check off the burned body areas, the app will instantly calculate an initial IV fluid rate further broken down in to an IV fluid hourly rate (further broken down in to a per minute, per 15 second, and per 10 second gtt). There is a clock icon which allows you to enter the time since the burn, which then recalculates the IV fluid rate to play “catch up” for the late presenting burn. There is a toggle between thermal and electrical burns (the latter which doubles the fluid requirement). The most beautiful part is that it’s all on one screen, with fewer clicks and distractions than the other apps. It’s a little more quick-and-dirty than the other apps, but what it does, it does pretty well.
From a technical standpoint, I did notice that both of these apps by JAMB seemed to freeze up and crash if I attempted to adjust data values too frequently/rapidly. Occasionally I had to close and restart the app to get it working again. I found this to be a reproducible problem on multiple uses; granted, I was changing parameters pretty frequently and pushing the app to its limit.
I imagine this app is perfect in the pre-hospital setting, but I think it would work pretty well for the emergency physician as well, who is simply trying to rapidly estimate a fluid resuscitation rate. It is not a thoughtful app, like BurnMed: it will give you an IV fluid rate for a 1% TBSA burn, and doesn’t advise you when escharotomies may be indicated. But, if you have a good grasp on basic principles of burn care and are simply looking for a rapid Parkland formula calculation, this may be the right choice. uBurn Medic is also priced at $1.99.
This patient has several patchy areas of superficial and deep partial thickness burns. Hoping to visually reproduce his burn injuries, you use BurnMed to create a schematic representation of his burn distribution:
You calculate 20.2% TBSA.
The app directs you to give IV fluid solution at 400 ml per hour for 7 hours. However, the patient was already given 1 liter of normal saline IV during EMS transport, and his burn occurred 4 hours ago, which affects calculations. You thus enter this additional data, and calculate an initial bolus of 600 ml, followed by a rate of 400 ml for the next 4 hours.
You are curious what the fluid rate will be beyond the initial 8 hour period, as you plan to transfer this patient to a burn center and anticipate a prolonged hospital course. As BurnMed does not perform this computation, you switch to UBurn and enter the same data.
You are then able to quickly order the fluid rate beyond the initial 8 hour period.
You initiate a transfer, and the Burn Surgeon at the accepting facility requests a visual schematic of the burn area. He is familiar with BurnCase 3D, which he uses to manage his patients on his ward. You reproduce your schematic using this app, then email him a copy of the data using the “Export” function.
Summary & Conclusions
As in many specialized fields in medicine, the nature of burn care is evolving–not so much in the basic principles of management, but rather, in the technology used to provide this care. Burn apps are rapidly gaining acceptance as a tool for assisting in the emergency management of the burn victim.
In the next part in this series, we’ll delve in to wound management for the minor burn injury that you would “treat & street” from an ED or office environment.