Resuscitation tables: a useful tool in calculating pre-burns unit fluid requirements

Prise en charge des brûlures en préhospitalier et aux urgences

Une brûlure est une lésion de la peau ou d’un autre tissu organique principalement causée par la chaleur ou les rayonnements, la radioactivité, l’électricité, la friction ou le contact avec des produits chimiques. Les plus fréquentes, les brûlures thermiques (dues à la chaleur), surviennent lorsque certaines cellules ou toutes les cellules de la peau ou d’autres tissus sont détruites par des liquides bouillants, des solides chauds (brûlures de contact), ou des flammes. En France, l’incidence des brûlures prises en charge à l’hôpital est environ de 13 pour 100 000 habitants. La prise en charge en urgence du brûlé grave par lésion thermique est bien décrite, une recommandation de pratique professionnelle a été publiée en 2019 par la Société française d’anesthésie et de réanimation, en association avec la Société francophone de brûlologie, la Société française de médecine d’urgence et l’Association des anesthésistes-réanimateurs pédiatriques d’expression française. Pourtant, l’urgentiste va être confronté à de nombreuses brûlures de gravité et de nature différentes. Nous faisons ici une mise au point sur les données connues en termes d’épidémiologie, de manifestations cliniques et des différentes thérapeutiques qui peuvent être proposées dans la prise en charge des brûlures. Nous faisons aussi le point sur les localisations à risque particulier que l’urgentiste doit connaître, ainsi que sur les intoxications qui peuvent être associées aux brûlures. Nous détaillons aussi certains contaminants qui sont à connaître.

Should early amputation impact initial fluid therapy algorithms in burns resuscitation? A retrospective analysis using 3D modelling

AIMS

While the epidemiology of amputations in patients with burns has been investigated previously, the effect of an amputation on burn size and its impact on fluid management have not been considered in the literature. Fluid resuscitation volumes are based on the percentage of the total body surface area (%TBSA) burned calculated during the primary survey. There is currently no consensus as to whether the fluid volumes should be recalculated after an amputation to compensate for the new body surface area. The aim of this study was to model the impact of an amputation on burn size and predicted fluid requirement.

METHODS

A retrospective search was performed of the database at the Queen Elizabeth Hospital Birmingham Regional Burns Centre to identify all patients who had required an early amputation as a result of their burn injury. The search identified 10 patients over a 3-year period. Burn injuries were then mapped using 3D modelling software. BurnCase3D is a computer program that allows accurate plotting of burn injuries on a digital mannequin adjusted for height and weight. Theoretical fluid requirements were then calculated using the Parkland formula for the first 24 h, and Herndon formula for the second 24 h, taking into consideration the effects of the amputation on residual burn size.

RESULTS AND CONCLUSIONS

This study demonstrated that amputation can have an unpredictable effect on burn size that results in a significant deviation from predicted fluid resuscitation volumes. This discrepancy in fluid estimation may cause iatrogenic complications due to over-resuscitation in burn-injured casualties. Combining a more accurate estimation of postamputation burn size with goal-directed fluid therapy during the resuscitation phase should enable burn care teams to optimise patient outcomes.

Evaluation of 2 novel devices for calculation of fluid requirements in pediatric burns

OBJECTIVES

The Parkland formula for maintenance and resuscitation fluid requirements in the first 24 hours after pediatric burns is widely used, but calculation errors frequently occur. Two different novel aids to calculation, a dedicated electronic device and a mechanical disc calculator, are described and compared with the conventional method of calculation (pen and paper, assisted by a general purpose calculator).

METHODS

In a blinded randomized volunteer study, 21 participants performed a total of 189 calculations using simulated patient data to compare the accuracy and speed of 3 different methods for calculating resuscitation fluid requirements based on the pediatric Parkland formula. Bespoke software generated the simulated patient data and recorded accuracy and speed of all participant responses.

RESULTS

Sixty-five percent of calculations with the electronic device, 35% using the disc and 44% using the pen/paper methods were within ±5% of the correct value and considered "correct" for clinical purposes. The method used strongly affected the tendency to make errors (logistic regression). With thresholds of error magnitude classed as very small (>5%), small (>25%), medium (>50%) and large (>100%) of the correct value respectively, the electronic method produced fewer errors than both disc and pen/paper methods at all error thresholds. Disc produced more errors than pen/paper at the greater than 5% threshold but fewer at the greater than 25%, greater than 50%, and greater than 100% thresholds.

CONCLUSIONS

Both novel devices provide safer and faster alternatives to conventional methods for calculation of fluid requirements in pediatric burns.

Comparison of three techniques for calculation of the Parkland formula to aid fluid resuscitation in paediatric burns

CONTEXT

Inadequate fluid resuscitation of acute burns may result in hypovolaemic shock. Excessive fluid resuscitation may result in fluid overload. A nomogram which uses the popular Parkland formula and '4-2-1' regime has been recently described to facilitate the calculation of fluid requirements in children during the first 24 h following burn injury.

OBJECTIVE

To compare the accuracy and speed of calculation of three different methods (pen and paper, electronic calculator and nomogram), which all use the Parkland formula and '4-2-1' regime to calculate maintenance and resuscitation fluid requirements for children in the first 24 h after burn injury.

DESIGN

A randomised volunteer study using computer-generated simulated patient data.

SETTING

Welsh Centre for Burns, ABM University Local Health Board, Swansea, UK. Data were collected between February 2011 and October 2011.

PARTICIPANTS

The group consisted of 36 volunteers including trainee and consultant surgeons and anaesthetists.

INTERVENTION

Thirty-six participants performed 318 calculations, using each of the three methods of calculation up to three times.

MAIN OUTCOME MEASURES

Accuracy, speed and acceptability of the different methods.

RESULTS

For nomogram, calculator and pen and paper: magnitude of error [low (≥25%), medium (≥50%) and high (≥75%)]: [5.7, 4.7 and 3.8%], [12.1, 12.1 and 7.5%], [28.6, 21.9 and 16.2%]; [P <0.001, P = 0.001 and P = 0.006]. Calculation time: [s; mean (SD)]: 121 (48), 109 (52) and 240 (140); P <0.001. The mean (SD) of the difficulty scores were 17.3 (13), 20.6 (13.4) and 62.2 (23.4); P <0.001.

CONCLUSION

The nomogram was the most accurate method of calculating fluid requirements using the Parkland formula, was only slightly slower than the electronic calculator and was deemed the easiest to use. The nomogram is also low cost, robust, and provides a rapid means of detecting and preventing the large errors that we have shown can occur when an electronic device is used as the primary method of resuscitation fluid calculation. We, therefore, suggest that the nomogram is a suitable method for the calculation of the Parkland formula to guide resuscitation and maintenance fluid requirements in the first 24 h of paediatric burns or for cross-checking the results obtained by other means of calculation.

A comparison of two smartphone applications and the validation of smartphone applications as tools for fluid calculation for burns resuscitation

We conducted a randomised, blinded study to compare the accuracy and perceived usability of two smartphone apps (uBurn(©) and MerseyBurns(©)) and a general purpose electronic calculator for calculating fluid requirements using the Parkland formula. Bespoke software randomly generated simulated clinical data; randomly allocated the sequence of calculation methods; recorded participants' responses and response times; and calculated error magnitude. Participants calculated fluid requirements for nine scenarios (three for each: calculator, uBurn(©), MerseyBurns(©)); then rated ease of use (VAS) and preference (ranking), and made written comments. Data were analysed using ANOVA and qualitative methods. The sample population consisted of 34 volunteers who performed a total of 306 calculations. The three methods showed no significant difference in incidence or magnitude of errors. Mean (SD) response time in seconds for the calculator was 86.7 (50.7), compared to 71.7 (42.9) for uBurn(©) and 69.0 (35.6) for MerseyBurns(©). Both apps were significantly faster than the calculator (p=0.013 and p=0.017 respectively, ANOVA: Tukey's HSD test). All methods showed a learning effect (p<0.001). The participants rated ease of use on a VAS scale with a higher score indicating greater ease of use. The calculator was easiest to use with a mean score (SD) of 12.3 (2.1), followed by MerseyBurns(©) with 11.8 (2.7) and then uBurn(©) with 11.3 (2.7). The differences were not found to be significant at the p=0.05 level after using paired samples t-test and a multiple correction was applied manually. Preference ranking followed a similar trend with mean rankings (SD) of 1.85 (0.17), 1.94 (0.74) and 2.18 (0.90) for the calculator, MerseyBurns(©) and uBurn(©) respectively. Again, none of these differences were significant at the p=0.05 level.

Comparison of three techniques using the Parkland Formula to aid fluid resuscitation in adult burns

We performed a randomised study to compare the accuracy and speed of three different techniques (pen and paper, electronic calculator and a novel graphic device: 'nomogram') for calculation of resuscitation fluid requirements for adults in the first 24 h of burn injury, based on the Parkland Formula. We also assessed acceptability of each technique using visual analogue scores and qualitative analysis of free text responses. 28 participants performed 252 calculations using a series of computer generated simulated patient data. For nomogram, electronic calculator, pen and paper: Magnitude of error [low (≥25%), medium (≥50%), high (≥75%)]: [6.0%, 1.2%, 0%], [17.9%, 14.3%, 8.3%], [25%, 16.7%, 9.5%]; p<0.002. Calculation time: [sec: mean (SD)]: 94(34), 73(31), 214(103); p<0.001. The mean (SD) of the difficulty scores for each method were 23(17), 17(14) and 70(21) out of 100. Of the 28 participants 15 preferred the calculator, 12 preferred the nomogram and 1 scored the calculator and nomogram equally (table 3). The nomogram was significantly more accurate at all levels, almost as fast as an electronic calculator, and deemed easy to use. It is low cost and robust, and provides a rapid means of detecting and preventing the large errors that we have shown can occur when an electronic device is used as the only method of calculation. We therefore suggest that the Parkland Formula nomogram is a suitable method for calculation of resuscitation fluid requirements in adult burns. Fluid requirement should, however, be reviewed frequently, and adjusted to ensure adequate organ perfusion.

Comparison of traditional burn wound mapping with a computerized program

Accurate burn estimation affects the use of burn resuscitation formulas and treatment strategies, and thus can affect patient outcomes. The objective of this process-improvement project was to compare the accuracy of a computer-based burn mapping program, WoundFlow (WF), with the widely used hand-mapped Lund-Browder (LB) diagram. Manikins with various burn representations (from 1% to more than 60% TBSA) were used for comparison of the WF system and LB diagrams. Burns were depicted on the manikins using red vinyl adhesive. Healthcare providers responsible for mapping of burn patients were asked to perform burn mapping of the manikins. Providers were randomized to either an LB or a WF group. Differences in the total map area between groups were analyzed. Also, direct measurements of the burn representations were taken and compared with LB and WF results. The results of 100 samples, compared using Bland-Altman analysis, showed no difference between the two methods. WF was as accurate as LB mapping for all burn surface areas. WF may be additionally beneficial in that it can track daily progress until complete wound closure, and can automatically calculate burn size, thus decreasing the chances of mathematical errors.

Graphic aids for calculation of fluid resuscitation requirements in pediatric burns

The Parkland formula is currently the most widely used protocol to guide fluid resuscitation of acute burns and has been adapted for pediatric use. We describe 3 novel graphic devices (a nomogram, slide rule, and disc calculator) based on this formula, which have significant advantages over existing graphic and electronic devices. The robust low-cost graphic devices would be particularly suited to developing countries and difficult locations, but could be used as the primary means of calculation in any environment. If a computer or calculator is used as the primary means of calculation, the graphic devices provide a simple and rapid means of checking and preventing errors that may arise because of inadvertent mis-keying of data or incorrect application of the pediatric Parkland formula.

Accuracy of burn size assessment prior to arrival in Dutch burn centres and its consequences in children: a nationwide evaluation

BACKGROUND

Total body surface area (TBSA) burned, expressed as percentage is one of the most important aspects of the initial care of a burn victim. It determines whether transfer to a burn centre is necessary as well as the need for, and amount of, intravenous fluid resuscitation. Numerous studies, however, have highlighted inaccuracies in TBSA assessment. Therefore, the differences in burn size estimates between referrers and burn centre's in children and its consequences in terms of transfer and intravenous fluid resuscitation were investigated.

METHODS

This study involved two time periods from January 2002 until March 2004 and January 2007 until August 2008. All referred children admitted to a Dutch Burn centre within 24h post burn were eligible. Data were obtained from patient records retrospectively and in part prospectively.

RESULTS

A total of 323 and 299 children were included in periods 1 and 2, respectively. Referring physicians overestimated burn size with a factor two (mean difference: 6% TBSA ± 5.5). About one in five children was referred to a burn centre without fulfilling the criteria for referral with regard to burn size (assessed by burn specialists) special localisation or inhalation trauma. Proportions of children receiving intravenous fluid resuscitation regardless of indication increased from 33% to 49% (p<0.01). The received volumes tended to be higher than necessary.

CONCLUSIONS

Referring physicians overestimate burn size in children admitted to Dutch burn centres. This has little negative consequences, however, in terms of unindicated transfers to a burn centre or unnecessary fluid resuscitation.