Prognostic Burn Index Research Articles

Tazobactam/ceftolozane and tobramycin combination therapy in extensively drug-resistant Pseudomonas aeruginosa infections in severe burn injury: a case report

BackgroundCombination therapy with tazobactam/ceftolozane (TAZ/CTLZ) and high-dose aminoglycosides has been reported to be efficacious in extensively drug-resistant (XDR)-Pseudomonas aeruginosa infection. However, there are no reports of efficacy in XDR-P. aeruginosa infection for combination therapy with low-dose aminoglycosides and TAZ/CTLZ. Herein, we describe a rare case of severe burn injury patients with persistent bacteremia due to XDR-P. aeruginosa, which was successfully treated with TAZ/CTLZ and low-dose tobramycin (TOB).Case presentationA 31-year-old man was admitted to the intensive care unit with severe burn injury involving 52% of the total body surface area and a prognostic burn index of 79.5. The patient had recurrent bacterial infections since admission, and blood cultures collected on the 37th day of admission revealed the presence of P. aeruginosa strains that were resistant to all β-lactams and amikacin (AMK). The results of the antimicrobial synergistic study showed no synergistic effect of low-dose meropenem (MEPM) and AMK combination therapy. The patient had acute renal failure, and it was difficult to increase the dose of MEPM and AMK, respectively. Thus, we initiated TAZ/CTLZ 1.5 g/8 h instead of the AMK and MEPM combination therapy on the 43rd day of hospitalization. Low-dose TAZ/CTLZ was continued because of prolonged renal dysfunction and resulted in a transient clinical improvement. However, the dosage of TAZ/CTLZ could be increased as the renal function improved, but despite an increased TAZ/CTLZ dose, bacteremia persisted, and the blood cultures remained positive. Thus, TOB was added to TAZ/CTLZ at low doses for synergistic effect against Gram-negative bacteria. Blood cultures collected after initiation of combination therapy with TAZ/CTLZ and low-dose TOB were negative on two consecutive follow-up evaluations. Thereafter, although the patient had several episodes of fever and increased inflammatory response, blood cultures consistently tested negative, and all of the wounds healed. On the 93rd day, due to the good healing progress, the patient was transferred to another hospital.ConclusionsTAZ/CTLZ and low-dose TOB combination therapy showed the potential for synergistic effects. Our present report suggests a novel synergistic treatment strategy for rare cases that are refractory to the treatment of infections, such as XDR-P. aeruginosa infection.

The Revised Baux Score as a Predictor of Burn Mortality: A Systematic Review and Meta-Analysis.

Mortality following a severe burn is influenced by both patient- and injury-factors, and a number of predictive models have been developed or applied. As there is no consensus on the optimal formula to use, we aimed to investigate the predictive value of the revised Baux score in comparison to other models when determining mortality risk in patients with burn injuries. A systematic review was performed following the PRISMA statement. The review yielded 21 relevant studies. The PROBAST quality appraisal checklist was used with many studies classified as "high" quality. All studies assessed the utility of the revised Baux score in comparison to other scoring systems such as the original Baux, BOBI, ABSI, APACHE II, SOFA, Boston Group/Ryan scores, the FLAMES model, the Prognostic Burn Index. There was a range of 48 to 15975 participants per study, with a mean age range of 16 to 52 years old. The AUC values of the rBaux score ranged from 0.682 to 0.99, with a summary AUC of 0.93 for all included studies (CI 0.91-0.95). This summary value demonstrates that the rBaux equation is a reliable predictor for mortality risk in heterogeneous populations. However, this study also identified that the rBaux equation has a diminished ability to predict mortality risk when applied to patients at both extremes of age, highlighting an important area for future research. Overall, the rBaux equation offers a relatively easy means to quickly assess the mortality risk from burn injury in a broad range of patient populations.

503 The Accuracy of the Revised Baux Score in Predicting Burn Mortality: A Systematic Review

Abstract Introduction Osler et al. revised the Baux score in 2010 to include inhalation injury, attempting to improve upon the original 1961 model given the significant advances in modern burn care. Other predictive models of burn mortality have similarly been developed using use an assortment of other variables, however there is no consensus on the preferred formula to use. This systematic review aims to investigate the accuracy of the revised Baux (rBaux) score in comparison to other models when determining mortality risk in patients with burn injuries. Methods A systematic review was performed by two independent reviewers using electronic databases (PubMed, EMBASE, Scopus) from March 1, 2010 to May 22, 2022. The majority of studies were classified as “high” quality and no studies were excluded due to risk of bias. Articles were included if they were published in English and assessed risk of mortality from burns using the rBaux model and an alternative model. The PRISMA statement was followed, and all the PROBAST quality appraisal checklist was used during data extraction. Results The search identified 79 non-duplicate citations, of which 33 underwent full-text review, and 21 met inclusion criteria. They assessed the predictive ability of the rBaux score in comparison to the original Baux score, Belgian Outcome for Burn Injury, Abbreviated Burn Severity Index, APACHE II, Sequential Organ Failure Assessment score, Boston Group/Ryan scores, the FLAMES model, the Prognostic Burn Index, and several other equations that have not been externally validated. The accuracy of mortality prediction (area under ROC curves) for the rBaux score ranged from 0.68 to 0.99 and 14 studies found a value greater than 0.90. These ROC values were found to be lowest in the two studies with subgroupings for age, demonstrating an ROC of 0.01 in children, and 0.68 and 0.92 in the elderly. Eleven studies described sensitivity, specificity, or both, with sensitivity ranging from 12% to 96%, and specificity ranging from 80% to 100%. Conclusions The rBaux score offers a relatively easy method to rapidly assess the mortality risk from burn injury in a broad range of patient populations based on age, percent total body surface area burned, and presence/absence of an inhalation injury. This tool remains valid despite the exclusion of patient comorbidities and other injury-related factors. However, this study also identified the rBaux’s ability to predict mortality risk was limited when applied to patients at the extremes of age, highlighting an important area for future research. At present, given its relative simplicity and generalizability, the rBaux score remains a useful clinical tool for predicting mortality. Applicability of Research to Practice The rBaux score remains a simple yet powerful predictor of mortality in burn patients, which can be applied at the bedside on initial presentation across diverse patient populations.

Neutrophil Count in Severe Burns Is Useful for Predicting Prognosis.

Burn injuries, particularly extensive severe burns, often have a fatal prognosis. However, many prognostic predictors are based on changes in the clinical course of treatment, and no prognostic predictors can be estimated in the early phases of injury. Using the Burn Index (BI) for evaluations requires familiarity with daily burn treatment, such as being able to evaluate the change from a second degree burn to a third degree burn appropriately. We sought to find a simpler and more quantitative prognostic prediction index. Compared to the Survivor group, neutrophil (P = 0.038) and white blood cell counts were increased significantly in the Non-survivor group (P = 0.004). Neutrophil counts and white blood cell counts correlated positively with the length of hospital stay, total body surface area, Prognostic Burn Index (PBI), and BI. The BI and PBI correlated with patient prognosis, as did neutrophil and white blood cell counts. These results suggested that neutrophil and white blood cell counts in the early phases of burn injuries might be another factor in the prognosis of burn patients in addition to the current predictors.

Epidemiology and risk prediction of patients with severe burns admitted to a burn intensive care unit in a burn center in beijing: A 5-year retrospective study

ObjectiveThis study was performed to describe the epidemiology of patients with severe burns hospitalized in a burn intensive care unit (BICU), explore the risk factors associated with the patients’ outcomes and evaluate the ability of prognostic scoring systems as risk prediction of mortality. MethodsThe data for this study were derived from patients with severe burns in the BICU of Beijing Jishuitan Hospital from 2015 to 2019. The following epidemiological information and outcomes were collected for retrospective analysis: sex, age, date of injury, etiology of burn, admission time after injury, extent of burn, inhalation injury, length of stay, and outcome. Abbreviated Burn Severity Index (ABSI), prognostic burn index (PBI), the burn index (BI), Belgian Outcome in Burn Injury (BOBI) scores and the revised Baux (rBaux) scores were calculated. ResultsOf the 243 patients included in this study, the median age was 41.00 (22.00) years and the male: female ratio was 4.28:1.00. Most of the burns had occurred from March to July. Flame was the main cause of the burns (77.37%), followed by electricity (14.40%). In total, 78.19% of all patients sustained third-degree burns, and the median burn area and third-degree burn area of patients were 40% (53%) and 15.0% (43.0%) of the total body surface area, respectively. The incidence of inhalation injury was 69.14%. Tracheotomy was performed in 53.89% of the patients with inhalation injuries, and the rate of tracheostomy showing a rising trend. The median length of stay was 37 (40) days, and the case fatality rate was 8.64%. Multivariable logistic regression model indicated that age and third-degree burn area were risk factors for death, and the area under the receiver operating characteristic curve for the full prediction model was 0.921 (95% CI = 0.874–0.967). ConclusionsThe majority of severe burns are flame-related accidents in middle-aged men. Risk prediction model combining age and third-degree burn area has better mortality predictive value.

Comparison of prognostic models for severe burn patients in an Indonesian tertiary hospital: retrospective study

Background: Despite the high burn-related mortality rate, few studies investigate the discriminating power of various mortality prognostic models for burn patients in the Indonesian setting. Thus, the objective of our study is to describe and compare the discriminating power of several prognostic models for burn patients, including the Prognostic Burn Index (PBI), Belgian Outcome of Burn In-jury (BOBI), Revised Baux Score (rBaux), and Abbreviated Burn Severity Index (ABSI). Patients and methods: We conducted a retrospective study using medical records data with analysis including patients with severe burn (>20% Total Body Surface Area (TBSA), >10% for children and elderly), excluding those with known chronic conditions. Statistical analyses were performed on IBM SPSS 23.0 and included ROC curve and diagnostic values calculation, including sensitivity, specificity, positive, and negative predictive values with 95%CI. Results: Final analysis included 117 subjects with a 38.9% mortality rate. All prognostic models were statistically significant discriminating power with Area Under the Curve (AUC) values of 0.817, 0.849, 0.929, and 0.859, respectively. Comparing diagnostic values identified rBaux to have the strongest discriminating power with the highest specificity, PPV, and NPV. PBI score was identified with the highest sensitivity score. Conclusion: Discrepancy of results between our study and another Indonesian study with a similar design pointed to the need for a multi-centered study with a larger sample size to improve generalizability and statistical power of analysis.

Survey on the current status of self-immolation attempts in Akita Prefecture: A cross-sectional survey

ObjectiveGiven the up to 70% fatality rate of self-immolation, with tragic consequences for survivors, proposals have been made for a global task force to prevent self-immolation. However, little research has recently been conducted on the actual situation of patients who attempt self-immolation in Japan. The current study aimed to investigate the actual situation of patients who attempt self-immolation in Akita Prefecture. ResultWithin Akita Prefecture, 13 individuals had attempted self-immolation in the past 5 years, with a predominance of a history of psychiatric disorders (46%). The following three novel findings were also revealed. First, patients with low a prognostic burn index tended to commit arson, while those with a high prognostic burn index tended to self-immolate. Second, patients attempting suicide tended to have a higher incidence of carbon monoxide poisoning. Third, those whose clothes caught on fire tended have more severe burns, regardless of whether suicide was attempted. ConclusionSelf-immolation tends to be serious, and prevention is imperative. In Akita Prefecture, the percentage of patients with a history of psychiatric disorders may be higher than commonly believed, and a more detailed understanding of the mental state of self-immolation is necessary in the future to develop effective prevention measures.

Effect of acute coagulopathy before fluid administration in mortality for burned patients

BackgroundThe presence of acute coagulopathy and its effect on prognosis in burn patients are unclear. No studies are extant verifying early coagulopathy before fluid administration in burn patients. The current study focused on arrival coagulopathy before volume resuscitation was begun in earnest. MethodsData from 137 burn patients transported directly to the hospital without fluid administration from January 2006 to December 2019 were analyzed retrospectively. ResultsThe non-survival group had significantly increased age, total burn surface area (TBSA) burned, various scoring systems, prothrombin time-international normalized ratio (PT-INR), activated partial thromboplastin time (APTT), the presence of coagulopathy, and lactate levels compared to the survival group. In the logistic regression analysis, the incidence of coagulopathy was independently associated with mortality. The coagulopathy group had significant increases in TBSA burned, various scoring systems, PT-INR, APTT, lactate levels, and the mortality than the noncoagulopathy group. The prognostic burn index (PBI) was significantly correlated with PT-INR and APTT. We also found a significant correlation between the serum lactate and the PT-INR, APTT, and PBI. ConclusionsAcute coagulopathy of burn patients might be present on arrival to the hospital before fluid replacement which is an independent risk factor for in-hospital mortality.

Reevaluation for prognostic value of prognostic burn index in severe burn patients.

AimThe prognostic burn index (PBI), which consists of half partial‐thickness burn surface area plus full‐thickness burn surface area and age, has been widely used to predict mortality in Japan. However, the prognostic value of PBI has not been investigated sufficiently. The purpose of the present study is to clinically reevaluate the PBI in severe burn patients.MethodsData of 69 severe burn patients admitted to the burn center at Kyorin University Hospital (Tokyo, Japan) from January 2008 to December 2017 were analyzed retrospectively. The primary outcome in this study was in‐hospital mortality.ResultsThe overall in‐hospital mortality rate was 34.8%. There were significant differences in age, the presence of inhalation injury, total burned surface area, full‐thickness burn area, burn index, and PBI between survivors and non‐survivors. In logistic regression analysis, PBI was independently associated with mortality, while the presence of inhalation injury was not. A PBI above the threshold of 105 was significantly associated with in‐hospital mortality. The area under the receiver operating characteristic curve for PBI was 0.85 (95% confidence interval, 0.73–0.93).ConclusionThe PBI could be a good prognostic indicator. A PBI above the threshold of 105 was associated with mortality among severe burn patients treated in burn‐care facilities.

Volume-outcome relationship on survival and cost benefits in severe burn injury: a retrospective analysis of a Japanese nationwide administrative database

BackgroundAlthough it has been reported that high hospital patient volume results in survival and cost benefits for several diseases, it is uncertain whether this association is applicable in burn care.MethodsWe conducted a retrospective observational study on severe burn patients, defined by a burn index ≥ 10, using 2010–2015 data from a Japanese national administrative claim database. A generalized additive mixed-effect model (GAMM) was used to evaluate the nonlinear associations between patient volume and the outcomes (in-hospital mortality, healthcare costs per admission, and hospital-free days at 90 days). Generalized linear mixed-effect regression models (GLMMs) in which patient volume was incorporated as a continuous or categorical variable (≤ 5 or > 5) were also performed. Patient severity was adjusted using the prognostic burn index (PBI) or the risk adjustment model developed in this study, simultaneously controlling for hospital-level clustering. Sensitivity analyses evaluating patients who were directly transported, those with PBI ≤ 120 and those excluding patients who died within 2 days of admission, were also performed.ResultsWe analyzed 5250 eligible severe burn patients from 737 hospitals. The PBI and the developed risk adjustment model had good discriminative ability with areas under the receiver operating characteristic curves of 0.86 and 0.89, respectively. The GAMM plots showed that in-hospital mortality and healthcare costs increased according to the increase in patient volumes; then, they reached a plateau. Fewer hospital-free days were observed in the higher volume hospitals. The GLMM model showed that patient volume (incorporated as a continuous variable) was significantly associated with increased in-hospital mortality (adjusted odds ratio [95% confidence interval (CI)] = 1.14 [1.09–1.19]), high healthcare costs (adjusted difference [95% CI] = $4876 [4436–5316]), and few hospital-free days (adjusted difference [95% CI] = − 3.1 days [− 3.4 to − 2.8]). Similar trends were observed in the analyses in which patient volume was incorporated as a categorical variable. The results of sensitivity analyses showed comparable results.ConclusionsAnalysis of Japanese nationwide administrative database demonstrated that high burn patient volume was significantly associated with increased in-hospital mortality, high healthcare costs, and few hospital-free days. Further studies are needed to validate our results.

受傷初日に両下肢切断術を施行した高齢者の広範囲火焔熱傷の1救命例(A case of survival of elderly patient with extensive flame burn after amputation of bilateral lower limbs on the first day)

症例は81歳の男性で，田んぼでの野焼き中に衣服へ着火して受傷し，当院へ搬送された。腹部から両下肢にかけて皮膚の著明な炭化を認め，両膝より遠位では熱傷が筋層に達していた。深達性II度熱傷7%，III度熱傷46%で熱傷予後指数（prognostic burn index: PBI）は130.5であり，予測される死亡率は98%以上であった。検査所見では血清CPK値の上昇，急性腎傷害，高カリウム血症を認めた。受傷から約4時間後，股関節から10cmの部位での両下肢切断術を施行し，ICUへ入室した。4日目に昇圧剤を終了，7日目に抜管，人工呼吸器離脱に至った。分層植皮術を繰り返し，119日目の転院時には車椅子で自走可能な状態であった。高齢者の広範囲火焔熱傷に対する受傷初日の四肢切断術がその後の集中治療管理や手術戦略に寄与し，救命し得た。過去に熱損傷での両下肢切断術を受傷初日にしたとする症例報告はなく，その臨床経過について詳述した。 An 81–year–old man who suffered a flame burn during burning on the soil presented to our hospital. His skin from the abdomen to bilateral lower limbs seemed to be carbonized. The burn depth extended to the muscles on the distal area from the knees. Because 7% of his body surface area was covered in deep dermal burn (DDB) and 46% was covered in deep burn (DB), his prognostic burn index was 130.5, so mortality was estimated more than 98%. Laboratory test results were consistent with elevation of serum CPK and revealed acute kidney injury and hyperkalemia. Four hours after the accident, an emergency amputation of the bilateral limbs at an area 10cm distal from his hip was performed, and he was admitted to the intensive care unit. Vasopressor was discontinued on day 4, and he was extubated and weaned from the ventilator on day 7. After several split thickness skin graft and debridement, on day 119 he could use a wheelchair at the time of his transfer. In the case of an elderly patient with an extensive flame burn, performing amputation on day 1 may affect subsequent critical care and operative strategy, and in this case, the patient survived. This is a detailed first report of bilateral limb amputation for thermal injury on day 1. 熱傷患者の予後予測の手段として熱傷指数（burn index: BI）や熱傷予後指数（prognostic burn index: PBI）がある。PBI 85以上では有意に死亡率が上昇し 1，とくにPBI 130以上では死亡率98%を超え，救命困難とされる 2。また，熱傷では四肢の切断に至ることがあるが，その適応や時期について未だ議論が残る。今回我々は，受傷初日の両下肢切断術が救命に寄与したと考えられる高齢者の広範囲火焔熱傷の1例を経験したため報告する。 なお倫理委員会の承認を要する内容はなく，本人の同意を得たうえで匿名化した。 患 者：81歳の男性 主 訴：腹部・腰部より尾側の熱傷 既往歴：高血圧症 現病歴：田んぼの野焼きをしていたところ着衣に火がつき，受傷から約1時間後に当院へ救急搬送された。 入院時現症：呼吸数40/分，SpO2 97%（酸素15L/min，リザーバーマスク），脈拍121/分・整，血圧175/131mmHg，意識 Glasgow coma scale 14点（E3V5M6）であった。血液検査所見ではCPK 22,221IU/L，AST 396IU/Lと筋原性酵素の上昇を認め，Cre 1.23mg/dL，K 6.6mEq/L，base excess –6.9mmol/Lと急性腎傷害，高カリウム血症，代謝性アシドーシスを呈した（Table 1）。鼻腔の煤と鼻毛の焦げを認め，腹部から両下肢にかけて皮膚が炭化しており，両足背動脈は触知不能であった。深達性II度熱傷7%，III度熱傷46%，熱傷面積（total body surface area， %TBSA）53，BI 49.5，PBI 130.5であった（Fig. 1）。 Physical examination on the first day. 7% of his body surface area was covered in DDB and 46% was covered in DB. DDB: deep dermal burn, DB: deep burn 入院後経過：両膝より遠位では炭化が筋層にまで達していたため，今後歩行などの荷重に耐えられるまでの機能回復は見込めないと予想された。また，PBI 130.5から予測される救命率は1%程度と推定されるものの上半身の損傷が比較的軽微であり，下肢切断による大幅な熱傷面積の減少が達成できれば予測値よりも救命率を向上できる可能性も考えられた。以上をふまえ，本人・家族に対して一般的な熱傷治療戦略では救命の可能性が極めて低いこと，下肢機能の回復が望めず遅かれ早かれ切断術に至る可能性が極めて高いこと，緊急での両下肢切断により救命率が向上する可能性があること，長期の集中治療管理や人工肛門造設術を要して日常生活動作の著しい低下を伴うこと，緩和医療への移行という選択肢もあることを説明し，両者ともに積極的治療を望まれた。 術式決定に際しては機能的予後の見込めない患肢救済よりも救命を最優先とし，熱傷面積を可能な限り軽減できるよう大腿近位での切断を想定した。また，軟骨面などに感染が生じた際に治療に難渋することが予想され，股関節離断は回避する方針とした。 気管支鏡検査で気道熱傷を否定した後に気管挿管を実施し，Parklandの公式に則った大量輸液（4×62.4kg×53%：13.2×103mL/day）と高カリウム血症の是正を行いながら，受傷から約4時間後に緊急で両下肢切断術を施行した。 手術所見：大腿部は熱傷の深達度が脂肪組織に留まっていたが，切断高位は両股関節から10cmの部位で離断し，その時点で残存する %TBSAは21，III度熱傷は14%となった。断端皮膚の著しい炭化により一期的な創閉鎖を見込めず骨を筋で被覆し，最後に下腹部から両大腿の断端まで焼痂切開を加えた。術中に血色素尿が出現し，ハプトグロビン製剤4,000単位を投与した。術中出血量は浸出液も含めて1,966mLであり，赤血球濃厚液8単位，新鮮凍結血漿10単位の投与，ノルアドレナリン0.09μg/kg/minの開始下にICUに入院となった。 超早期での手術侵襲もあり，受傷24時間での総輸液量は19.4×103mLに達した。受傷から22時間後より0.5mL/kg/hr，30時間後には1mL/kg/hrの尿量が安定して得られた。4日目に腹部，背部，陰茎，陰嚢に対する分層植皮術を行い，同日昇圧剤を終了して7日目に抜管，人工呼吸器離脱に至った（Fig. 2）。10日目に臀部，両大腿部背側，14日目に腹部，両大腿部腹側に対する分層植皮術，21日目に大腿断端の縫縮術をそれぞれ実施した。栄養療法に関しては，入院初日から乳性ペプチド含有の消化体栄養剤による経腸栄養と便失禁管理システムでの排便管理を行っていたが，プレアルブミン値の改善が得られず，低栄養状態による人工肛門の脱落が懸念された。さらに，本患者の最適人工肛門設置位置である左上腹部の健常皮膚領域は狭く，また同部位の上皮化遅延も重なり，人工肛門造設は53日目となった。その後59日目に会陰部，肛門部に分層植皮術を行った。119日目の転院時には車椅子で自走可能であり，熱傷創は全上皮化して完全創閉鎖を得た（Fig. 3）。受傷より301日経過した現在，精神的問題もなく家族の支えのもと自宅で生活している。 Clinical course from admission. Physical examination on day 89. 熱傷の四肢切断術は古くから行われており，1961年に膝上での両下肢切断術の救命例が報告 3されている。また，熱傷に対する四肢切断術が救命率の向上に寄与したとする報告 4, 5も散見される。熱傷における四肢切断術の頻度は1.5–5.8%と報告 6, 7, 8されているが，自験例のように火焔熱傷といった熱損傷での切断は電撃傷の場合よりも圧倒的に少ない 6。また，熱傷での四肢切断術の適応については，患肢の不可逆的な機能喪失，生命を脅かす感染症といった病態が挙げられ 5, 9，横紋筋融解に起因する全身性病態の併発や易出血性などの要素も加味して主観的に判断されている 5, 8。これらいずれの病態も基本的には入院後一定期間を経て判明するものである。しかし，自験例では少なくとも膝下は不可逆的な機能喪失が強く予想され，かつ急性腎傷害，高カリウム血症といった全身性病態も伴ったことから，初日の段階で四肢切断術の適応と判断した。その切断高位についてはリハビリテーションの見地からも判断されるべきである 8が，救命を第一目標とし，大腿部のうち可能な範囲で近位を選択した。 熱傷における四肢切断術の時期についても定まった見解はない。Parshleyら 10は，電撃傷に対する入院当日の四肢切断術は全身状態への忍容性も十分見込まれ，著明な改善が得られることがあるとしている。またYowlerら 4は，深達度の高い熱傷に対する度重なるデブリドマンが結果的に患肢を無機能にさせ，患肢の不適切な温存がかえって創感染のリスクを高めるとし，電撃傷以外の熱損傷での四肢切断術は受傷から平均18.4日と電撃傷よりも遅い傾向にあったと報告した。これは，電撃傷に比してそれ以外の熱損傷では受傷早期の組織損傷が浅い場合が多いことも関与していると思われる。このように，とくに電撃傷以外の熱損傷における受傷早期の四肢切断術は稀と考えられるが，自験例では患肢の筋を含めた深達度の経過を待たずに初日に施行した。Sotoら 8による原著論文の中で受傷初日に四肢切断術がなされた電撃傷以外の熱損傷症例を含んでいるものの年齢や熱傷面積，転帰などの情報は得ることができず，我々が渉猟した限りでは臨床経過について詳述した報告は見当たらなかった。当初のPBIから推定される死亡率98%以上の重症例に対し，入院後の治療経過で難渋しなかったことは特筆に値する。 Mackieら 11は，気道熱傷がなく人工呼吸管理を要した62例（平均42.2歳，%TBSA 47.4）での人工呼吸器離脱に平均18日を要したとし，受傷から3，7日目までの累積水分出納バランスについてもそれぞれ+23.1×103mL，+34.2×103mLであったとしている。自験例では受傷24時間での総輸液量はParklandの公式よりも多かったが，累積水分出納バランスは受傷から3日目で+16.8×103mL，7日目で+14.5×103mLと著明に少なく，人工呼吸器離脱も7日間と比較的短期間であった。これらの理由として，下肢の切断が炎症を来した異常な血管床を減少させ，利尿期を含めた輸液管理を容易にしたことが一因として考えられた。またその背景として，熱傷が広範囲であるほど炎症反応も強くなる 12が，近位かつ初日の切断が全身の炎症性サイトカインを軽減し，血管透過性亢進の制御に有利に作用した可能性が考えられる。さらに，四肢切断術を要した患者の受傷1，2日目の血清CPK値は要さなかった患者に比して有意に高かったとする報告 6や，切断によりミオグロビンによる急性腎傷害を軽減できるとした報告 10もある。自験例は来院時点で既に著明な筋原性酵素の上昇と急性腎傷害，代謝性アシドーシスといった横紋筋融解症様の病態を来していたが，受傷2日目にはCPK 6,382IU/Lと速やかに減少しており，これらのことからも受傷後数日経過した時期ではなく初日こそ四肢切断術のタイミングとして適切と考えられる。また，重症熱傷において壊死した開放創は容易に菌の侵入門戸となり 5，熱傷面積の増加に伴い感染の確率が上がるとする報告 13もあるが，自験例では昇圧剤を要するような重篤な感染は併発しなかった。この要因として，広範囲熱傷に対して早期手術といった迅速な創閉鎖が求められる 14ように，初日のより近位での切断が熱傷創を，ひいては創感染の機会を大幅に減少させたことが挙げられる。さらに，受傷早期の手術は入院後の手術戦略にも好影響をもたらしたと考えられる。高齢者では頭部をはじめとした採皮による出血が増加して全身状態の悪化を来すことがあるが，今回入院直後から32%にも及ぶ熱傷面積の減少が達成できたため，残る未上皮化創は21%に留まった。大小含め計7回の分層植皮術で一度も頭部からの採皮を行わずに済んでおり，この点においてもより早期かつ近位での切断は合理的と言える。 最後に，自験例は救肢の観点だけで考えれば皮弁を用いて膝下も含めて温存できたかもしれない。また自験例の転帰が良好であったことは受傷前の栄養状態や気道熱傷がなかったことも影響している可能性も否定できない。仮に自験例をふまえての提言をするのであれば，下肢を含む重症の広範囲熱傷の場合，例えばその指標として死亡率が50%を超えるとされる %TBSA 50以上，BI 40以上，PBI 100以上 2などの症例では，年齢，全身状態，上半身の熱傷の程度，下肢の機能的予後から総合判断して受傷初日の下肢切断術を考慮してもよいと思われる。現段階では %TBSA，PBIといった重症度と関連づけて四肢切断術を論じた報告は少なく，とくに重症の熱損傷について知見の蓄積が望まれる。 高齢者の広範囲火焔熱傷に対する受傷初日の四肢切断術がその後の集中治療管理や手術戦略に寄与し，救命し得たと考えられた。過去に熱損傷での両下肢切断術を受傷初日に行ったとする症例報告はないため，その臨床経過について詳述した。 本報告において利益相反はない。

Validation of the prognostic burn index: A nationwide retrospective study

BackgroundThe burn index (BI=full thickness total burn surface area [TBSA]+1/2 partial thickness TBSA) and prognostic burn index (PBI=BI+age) are clinically used particularly in Japan. However, few studies evaluated the validation of PBI with large sample size. We retrospectively investigated the relationships between PBI and mortality among burn patients using data from a nationwide database. MethodsData of all burn patients with burn index ≥1 were extracted from the Japanese Diagnosis Procedure Combination (DPC) inpatient database from 1 July 2010 to 31 March 2013 (17,185 patients in 1044 hospitals). The primary endpoint was all-cause in-hospital mortality. ResultsOverall in-hospital mortality was 5.9% (1011/17,185). Mortality increased significantly as the PBI increased (Mantel-Haenszel trend test, P<0.001). The area under the receiver operating characteristic curve for PBI was 0.90 (95%CI, 0.90–0.91), and a PBI above a threshold of 85 showed the highest association with in-hospital mortality. Logistic regression analysis showed that PBI≥85 (odds ratio (OR), 14.6; 95%CI, 12.1–17.6), inhalation injury with mechanical ventilation (OR, 13.0; 95%CI, 10.8–15.7), Charlson Comorbidity Index≥2 (OR, 1.8; 95%CI, 1.5–2.3), and male gender (OR, 1.5; 95%CI, 1.3–1.8) were significant independent risk factors for death. ConclusionsOur study suggested that a PBI above a threshold of 85 was significantly associated with mortality. The PBI and mechanical ventilation were the most significant factors predicting in-hospital mortality, after adjustment for inhalation injury, comorbidity, and gender.

Characteristics of elderly Japanese patients with severe burns

In this study, we report the clinical characteristics of elderly Japanese patients with severe burns. We studied the clinical features of 76 adult patients with severe burns, 35 of whom (46.1%) were ≥65 years old. We evaluated the characteristics of patients with respect to each type of burn. In addition, we studied the rate of death and survival in the elderly and also between the elderly and non-elderly patients. The following parameters were either assessed or compared between the elderly and non-elderly: gender, average age, vital signs (Glasgow Coma Scale, systolic blood pressure, heart rate and respiratory rate) and PaO 2/FiO 2 (P/F) ratio at admission, cause of burn and a history of physical or psychiatric disease. Further, we investigated whether the burn was caused by attempting suicide and determined the percent total body surface area (%TBSA), second- and third-degree burn area, burn index (BI), prognostic burn index (PBI), presence of tracheal burns, presence of alcohol intoxication and overdose poisoning, presence of tracheal intubation, outcome and cause of death. The male:female ratio of the elderly patients was 17:18 (average age, 78.1 (8.2) years). Burns were mostly caused by flame (26/35), followed by scalding (8/35). Ten patients had attempted suicide. The %TBSA, second-degree burn area, third-degree burn area, BI and PBI, respectively were 46.6% (26.7%), 15.3% (19.0%), 35.6% (26.0%), 41.1 (25.2) and 119.2 (25.9). Of the 35 patients, 23 died. The notable characteristics of the elderly patients who died were flame as the cause of the burns: high %TBSA, BI and PBI, and a high rate of tracheal intubation. Elderly patients constituted approximately 45% of our study population. Most burns were caused by flames. The incidence of accidental bathtub-related burns was higher and that of suicide attempts was lower in the elderly patients, as compared with the non-elderly patients. Severe burns were fatal for elderly patients. Therefore, elderly Japanese people should be educated on how to prevent non-intentional burns.

Does inhalation injury increase the mortality rate in burn patients? Investigation of relationship between inhalation injury and severity of burn surface

Objective. Inhalation injury accounts for 20% to 80% of deaths in burn patients due to severe cardiopulmonary distress not seen in cutaneous injury alone.&nbsp;&nbsp;However, there are few comparative studies or retrospective analyses of the injury severity or deaths of patients with inhalation injury.&nbsp;Methods.&nbsp;We evaluated 59 patients (31 with inhalation injury and 27 without inhalation injury) who had sustained a severe burn injury and were treated in the intensive care unit at our medical center from 2004 through 2006.&nbsp;&nbsp;Of the 31 patients with inhalation injury, 14 (45.2%) died, and of the 27 without inhalation injury, 4 (16.7%) died.&nbsp;Results.&nbsp;We investigated specific aspects of the severity and mortality of burn patients.&nbsp;The median (mean) burn index in patients without and with inhalation injury were 45 and 50 points (17.9 and 34.4), and the median (mean) prognostic burn index scores between patients with and without inhalation injury were 88.5 and 55.5 points (86.8 and 69.4). The median (mean) prognostic burn index scores in surviving patients with and without inhalation injury were 49.5 and 67 points (60.0 and 70.0), which suggest that patients with inhalation injury sustained significantly more severe cutaneous burns than did patients without inhalation injury.&nbsp;Conclusions. We conclude that inhalation injury alone may be fatal, but many patients with inhalation injury also sustain more severe cutaneous burns, which can further increase the mortality rate.

Acute physiology, age, and chronic health evaluation (APACHE) III score is an alternative efficient predictor of mortality in burn patients

The present study was performed to evaluate the prognostic value of the acute physiology, age, chronic health evaluation (APACHE) III score in burn patients. We hypothesised that APACHE III score efficiently predicts mortality of burn patients as it reflects the physiological changes in the acute phase and the severity of the underlying illness. Data such as age, gender, inhalation injury, total burn surface area (TBSA), burn index (BI), prognostic burn index (PBI), APACHE III score and outcome of 105 hospitalised patients were analysed retrospectively. TBSA, BI, PBI, and APACHE III score in the mortality group were significantly higher than those of surviving group. The mean scores of surviving versus mortality groups were as follows: TBSA, 19.2 ± 17.8% versus 69.1 ± 28.4%, p < 0.0001; BI, 12.8 ± 13.1% versus 66.8 ± 28.6%, p < 0.0001; PBI, 68.8 ± 26.0% versus 124.4 ± 33.6%, p < 0.0001; APACHE III score, 28.4 ± 22.2% versus 71.3 ± 32.1%, p < 0.0001. PBI and APACHE III score showed marked associations between higher scores and higher mortality. APACHE III score showed a significant correlation with PBI ( p < 0.0001). The present study suggested that APACHE III score could be used as an alternative efficient predictor of mortality in burn patients.

Stenotrophomonas maltophilia bacteremia in burn patients

Stenotrophomonas maltophilia has been increasingly reported as a nosocomial opportunistic pathogen in debilitated patients, including burn patients. There is, however, only one published report in English that discusses S. maltophilia bacteremia in burns. We performed a retrospective chart review and statistical analysis of the incidence, the duration of hospital stays before a diagnosis of bacteremia, antimicrobial susceptibility, prognosis, and mortality risk factors in burn patients. From January 1996 to December 2004, 14 episodes of S. maltophilia bacteremia in 13 of 666 patients admitted to the burn center at our hospital were identified. The patients, nine males and four females, ranged in age from 1 to 76 years (mean: 42.9 ± 24.4 years). Eleven injuries were from flame burns and two were from scald burns. The mean total burned surface area (TBSA) was 47 ± 30.2% and mean prognostic burn index (PBI) was 81.7 ± 31.3. The average annual incidence was 2.3 episodes per 1000 admissions, and no outbreak cluster was noticed. The mean hospital stay before bacteremia was 19.8 ± 11.9 days. Most isolates were susceptible to ticarcillin-clavulanate (87.5%) and moxalactam (85.7%). The overall mortality was 30.7% (4/13) and correlated significantly with TBSA ( P < 0.01) and PBI ( P < 0.05). The incidence of S. maltophilia bacteremia was higher in hospitalized burn patients than in hospitalized non-burn patients. Different antimicrobial susceptibility patterns may exist, especially in different geographic regions. Awareness of the possibility of infection by this opportunistic pathogen and commencement of adequate antibiotics treatment, especially after 3 weeks of intensive care, should be incorporated into the strategy of treatment in major burn patients.

Differences in body temperature changes during dressing change in surviving and non-surviving burned patients.

Change in body temperature (delta BT) while dressings were being changed was measured in 52 extensively burned adults. The patients were divided into four groups based on outcome and the prognostic burn index (PBI; age + burn index): group I (15 survivors, PBI less than or equal to 80), group II (15 survivors, PBI between 80 and 120), group III (14 non-survivors, PBI between 80 and 120), and group IV (eight non-survivors, PBI greater than 120). The body temperature before the change of dressings was the same in the four groups. The mean(s.d.) delta BT in all patients was -0.5(0.8) degrees C. The magnitude of delta BT was not related to the time required for changing dressings (r = 0.04) or to the non-epithelialized area present at each change of dressings (r = -0.05). All groups showed a similar increase in delta BT during the early period after the burn, but in group I it began to decrease progressively after the 16th day after the burn (P < 0.05). A reduction in delta BT was noted in group II from day 25, whereas it was unchanged in groups III and IV (P < 0.05). It also significantly increased 2 days before the diagnosis of sepsis (P < 0.05). These results emphasize that delta BT may provide useful information about prognosis and the development of sepsis.

Correlation between QT dispersion and burn severity

QT dispersion, defined as the maximal-minus-minimal QT interval on a 12-lead electrocardiogram, has emerged as a non-invasive measurement for quantifying the spatial inhomogeneity of ventricular repolarization under various conditions, including acute stress. Because burn injuries elicit acute stress reactions, it was hypothesized that QT dispersion increases with the severity of the burn injury. To test the hypothesis, 13 burned patients (age range of 22–76 years, nine males, ranging from 4.0 to 75.0% of total body surface area burned) in whom a measurable 12-lead electrocardiogram had been obtained within 4h after arrival at the emergency department were identified retrospectively, and their QTc intervals, i.e. QT intervals corrected for heart rate by the standard Bazett formula, were measured. QTc dispersion (QTcd) was then calculated, and correlations were assessed with burn severity (burn index, BI; prognostic burn index, PBI). Of the 13 patients, nine patients had a prolonged QTcd (>40ms), and linear correlation analyses showed significant positive correlations between QTcd and both BI and PBI (r=0.61 and 0.62, respectively). In conclusion, QT dispersion was greater in the burned patients, and although the pathophysiology was unclear from the present study, the findings suggested that acute stress contributed to the spatial inhomogeneity of ventricular repolarization.

IGF-1, gut atrophy and bacterial translocation

Stenotrophomonas maltophilia has been increasingly reported as a nosocomial opportunistic pathogen in debilitated patients, including burn patients. There is, however, only one published report in English that discusses S. maltophilia bacteremia in burns. We performed a retrospective chart review and statistical analysis of the incidence, the duration of hospital stays before a diagnosis of bacteremia, antimicrobial susceptibility, prognosis, and mortality risk factors in burn patients. From January 1996 to December 2004, 14 episodes of S. maltophilia bacteremia in 13 of 666 patients admitted to the burn center at our hospital were identified. The patients, nine males and four females, ranged in age from 1 to 76 years (mean: 42.9 ± 24.4 years). Eleven injuries were from flame burns and two were from scald burns. The mean total burned surface area (TBSA) was 47 ± 30.2% and mean prognostic burn index (PBI) was 81.7 ± 31.3. The average annual incidence was 2.3 episodes per 1000 admissions, and no outbreak cluster was noticed. The mean hospital stay before bacteremia was 19.8 ± 11.9 days. Most isolates were susceptible to ticarcillin-clavulanate (87.5%) and moxalactam (85.7%). The overall mortality was 30.7% (4/13) and correlated significantly with TBSA (P < 0.01) and PBI (P < 0.05). The incidence of S. maltophilia bacteremia was higher in hospitalized burn patients than in hospitalized non-burn patients. Different antimicrobial susceptibility patterns may exist, especially in different geographic regions. Awareness of the possibility of infection by this opportunistic pathogen and commencement of adequate antibiotics treatment, especially after 3 weeks of intensive care, should be incorporated into the strategy of treatment in major burn patients.