Method for Predicting the Outcome of Burn Injury Based on a Mathematical Model

The choice of treatment tactics for a patient with burns should be based on individual prediction of injury outcome. Known models for predicting the outcome of burn injury are inaccurate and do not allow us to determine the probability of different outcomes for a particular patient.

AIM OF THE STUDY. To develop a method for individual prediction of the outcome of burn injury based on a mathematical model using the revised Frank index.

MATERIAL AND METHODS. 399 patients: men 283 (71%), women 116 (29%); age — 50 (36; 66) years; total burn area — 25 (15; 40) % TBSA, I–II degree — 20 (10; 30) % TBSA, III degree — 8 (3; 20) % TBSA. In 140 (35%) patients, inhalation injury was detected.

Based on the number of revised Frank Index (RFI) scores (in increments of 10), frequency diagrams of different outcomes were constructed. The mathematical model of individual prognosis is based on a regression equation that was derived from an approximated curve of the proportions of a favorable outcome in the optimal RFI range.

RESULTS. Patient survival probability (%) depending on the number of RFI points was distributed as follows: with RFI<72 — ≥99.9%; for RFI ≥72 ≤189, the probability of survival is calculated using the formula obtained as a result of approximation by a 4th degree polynomial of the curve of the dependence of survival on the number of RFI points: 0.0049x⁴ – 0.1027x³ – 0.1624x² + 2.6794x + 96.54 ; where x= (RFI -35)/10; with RFI>189 — ≤0.1%. The probability of a lethal outcome is determined by subtracting the resulting probability of a survival from 100%.

CONCLUSION. The developed method for predicting the outcomes of a burn injury based on a mathematical model allows us to determine the probability of different outcomes for a particular patient.

1. Sheppard NN, Hemington-Gorse S, Shelley OP, Philp B, Dziewulski P. Prognostic scoring systems in burns: a review. Burns. 2011;37(8):1288–1295. PMID: 21940104 https://doi.org/10.1016/j.burns.2011.07.017

2. Ghanem AM, Sen S, Philp B, Dziewulski D, Shelley OP. Body Mass Index (BMI) and mortality in patients with severe burns: is there a “tilt point” at which obesity influences outcome? Burns. 2011;37(2):208–214. PMID: 21129850 https://doi.org/10.1016/j.burns.2010.08.010

3. Saadat DH, Toor R, Mazhar F, Bajani F, Tatebe L, Schlanser V, et al. Severe burn injury: Body Mass Index and the Baux score. Burns. 2021;47(1):72–77. PMID: 33234365 https://doi.org/10.1016/j.burns.2020.10.017

4. Lam NN, Duc NM, Hung NT. Influence of pre-existing medical condition and predicting value of modified Elixhauser comorbidity index on outcome of burn patients. Burns. 2020;46(2):333–339. PMID: 31859095 https://doi.org/10.1016/j.burns.2019.08.004

5. Knowlin L, Stanford L, Moore D, Cairns B, Charles A. The measured effect magnitude of co-morbidities on burn injury mortality. Burns. 2016;42(7):1433–1438. PMID: 27593340 https://doi.org/10.1016/j.burns.2016.03.007

6. Frank G. [The “prognostic index” in burns for a more exact characterization of their degree of severity and a more reliable statistical evaluation]. Zentralbl Chir. 1960;85:272–277. [Article in German]. PMID: 13824499

7. Osler T, Glance LG, Hosmer DW. Simplified estimates of the probability of death after burn injuries: extending and updating the baux score. J Trauma. 2010;68(3):690–697. PMID: 20038856 https://doi.org/10.1097/TA.0b013e3181c453b3

8. Tobiasen J, Hiebert JM, Edlich RF. The abbreviated burn severity index. Ann Emerg Med. 1982;11(5):260–262. PMID: 7073049 https://doi.org/10.1016/s0196-0644(82)80096-6

9. Tagami T, Matsui H, Fushimi K, Yasunaga H. Validation of the prognostic burn index: a nationwide retrospective study. Burns. 2015;41(6):1169–1175. PMID: 26120088 https://doi.org/10.1016/j.burns.2015.02.017

10. Ryan CM, Schoenfeld DA, Thorpe WP, Sheridan RL, Cassem EH, Tompkins RG. Objective estimates of the probability ofdeath from burn injuries. N Engl J Med. 1998;338(6):362–366. PMID: 9449729 https://doi.org/10.1056/NEJM199802053380604

11. Belgian Outcome in Burn Injury Study Group. Development and validation of a model for prediction of mortality in patients with acute burn injury. Br J Surg. 2009;96(1):111–117. PMID: 19109825 https://doi.org/10.1002/bjs.6329

12. Renz BM, Sherman R. The burn unit experience at Grady Memorial Hospital: 844 cases. J Burn Care Rehabil. 1992;13(4):426–436. PMID: 1429814 https://doi.org/10.1097/00004630-199207000-00008

13. Zavorotniy OO, Zinoviev EV, Kostyakov DV. Predicting for mortality rate using regression analysis in patient with burn injury. Grekov’s Bulletin of Surgery. 2020;179(5):21–29. (In Russ.) https://doi.org/10.24884/0042-4625-2020-179-5-21-29

14. Shlyk IV, Polushin YuS, Shirokov DM. Sposob prognozirovaniya iskhoda kombinirovannoy termicheskoy travmy. Patent 2185095 RF MPK51 A61B 5/107(2006.01); A61/02(2006.01); G01N 33/483(2006.01). No 2000128530/14; decl. 14.11.2000; publ. 20.07.2002. (In Russ.)

15. Sinev YuV, Skripal’ AYu, Gerasimova LI, Loginov LP, Prokhorov AYu. Fibrobronkhoskopiya pri termoingalyatsionnykh porazheniyakh dykhatel’nykh putey. Pirogov Russian Journal of Surgery. 1988;(8):100–104. (In Russ.)

16. Zhirkova EA, Spiridonova TG, Sachkov AV, Rebrova OYu, Petrikov SS. Revision of the Frank Index for Predicting Death in Thermal Injury. Russian Sklifosovsky Journal Emergency Medical Care. 2023;12(2):224–229. (In Russ.). https://doi.org/10.23934/2223-9022-2023-12-2-224-229

17. Rebrova OYu. Statisticheskiy analiz meditsinskikh dannykh. Primenenie paketa prikladnykh programm STATISTICA. Moscow: Media Sfera Publ.; 2003. (in Russ.)

18. Golubinskiy A.N. Metody approksimatsii eksperimental’nykh dannykh i postroeniya modeley. Vestnik of Voronezh Institute of the Ministry of Interior of Russia. 2007;(2):138–143. (In Russ.)

19. Ministerstvo zdravookhraneniya Rossiyskoy Federatsii; Ob”edinenie kombustiologov “Mir bez ozhogov”. Ozhogi termicheskie i khimicheskie. Ozhogi solnechnye. Ozhogi dykhatel’nykh putey: nats. klinicheskie rekomendatsii. Moscow; 2021. (In Russ.)

20. Matveenko AV, Plotnikov SA, Shindyapin SV. Model of Prognosis of Outcome of Burn Trauma on The Basis of Probit-Analysis. Grekov’s Bulletin of Surgery. 2006;165(4):50–53. (In Russ.)

21. Forster NA, Zingg M, Haile SR, Künzi W, Giovanoli P, Guggenheim M. 30 years later--does the ABSI need revision? Burns. 2011;37(6):958–963. PMID: 21493008 https://doi.org/10.1016/j.burns.2011.03.009