Infection control in the burn unit

The survival rates for burn patients have improved substantially in the past few decades due to advances in modern medical care in specialized burn centers. Burn wound infections are one of the most important and potentially serious complications that occur in the acute period following injury. In addition to the nature and extent of the thermal injury influencing infections, the type and quantity of microorganisms that colonize the burn wound appear to influence the future risk of invasive wound infection. The focus of medical care needs to be to prevent infection. The value of infection prevention has been acknowledged in organized burn care since its establishment and is of crucial importance. This review focuses on modern aspects of the epidemiology, diagnosis, management, and prevention of burn wound infections and sepsis.     

Excision of the burn wound in patients with large burns

The known major determinants of survival for patients with burn injury are age, burn size, inhalation injury, and infection. The clinical courses of 210 patients with burns of 30% of the body surface or greater treated from Jan 1, 1983, through Dec 31, 1985, were reviewed to determine whether excision of the burn wound could be identified as a factor in survival after massive burn injury. The predominant site of infection changed from the burn wound to the lung, with pneumonia being the most common bacterial infection in patients whose wounds were treated as described. Effective topical control of bacterial proliferation and excision of the burn wound have resulted in replacement of invasive bacterial wound infection by nonbacterial burn wound infection. The apparent advantages of excision, particularly in large burns, may reflect only patient selection, since only those patients who are considered to be physiologically stable and able to tolerate the physiologic stress of excision are considered for operation.     

从“PRIDE”五个方面谈提高严重烧伤救治水平的关键环节

The " PRIDE "-five combined measures,including "protection of cell function and anti-shock treatment to reduce ischemic-hypoxic injury"," rehabilitation from early postburn stage"," inhalation injury treatment"," deep burn wound repair",and " enterogenous infection control",are key measures to improve the levels of burn treatment.The progressive advances in combined measures denoted as " PRIDE" have raised the burn treatment to a higher level and greatly elevated the survival rate.The degree of attention has also been raised from improvement in survival rate only to higher survival rate and better life quality with improvement in rehabilitation.Clinically however,many problems remain to be solved in the treatment of severe burn patients.Further basic and translational studies on " PRIDE" will be helpful to further improve the level of burn treatment.     

The impact of inhalation injury in patients with small and moderate burns

BackgroundInhalation injury is an independent risk factor of mortality in burn patients. The burn index (BI), which includes burn depth and size, also plays a role in predicting mortality. We aimed to establish a relationship between survival rate, inhalation injury, and BI.MethodsFrom 1997 to 2010, 21,791 burn patients from 44 hospitals were retrospectively reviewed. Kaplan–Meier and log-rank assessments were used for survival curve analysis. Chi-square, Fishers-exact test and odds ratio evaluations were used to assess the relationship between mortality rate, inhalation injury, BI. Two population proportion Z test was used to analyze the causes of death and morbidity. The significance level was set at 0.01.ResultsThe overall mortality rate was 2.1%. Inhalation injuries were found in 7.9% of the patients. The mortality rate of inhalation and non-inhalation injury group was 17.9% and 0.7%, respectively. The survival rate of the inhalation injury group was significantly lower than that of the non-inhalation injury group at BI 0–50. The patients with both inhalation injury and BI less than 50 had significant higher rate to die of pneumonia, respiratory failure, sepsis and wound infection. There was no significant difference when BI was larger than 50.ConclusionsInhalation injuries significantly reduced the survival rate, especially when the BI was less than 50. The possibility of pulmonary dysfunction and complications arising from inhalation injury should be considered even in patients who have small cutaneous burns associated with inhalation injuries.     

Quantitation of rate of wound closure and the prediction of death following major burns

Data were obtained from 100 consecutive patients requiring hospitalization for 2 weeks or more for treatment of major burns. Age, total percentage burn, mechanism of injury, presence or absence of inhalation injury, and outcome were recorded. Serial weekly burn wound maps were used to calculate the wound closure index (WCI), previously defined as the slope of a straight line fitted to percentage burn as a function of time by linear regression analysis. Logistic regression analysis was used to construct an equation incorporating age, percentage burn and WCI. Addition of the WCI significantly improved the discriminant ability of the logistic regression model. The composite index correctly predicted survival in 97 percent of patients. Rapid wound closure, as measured by the WCI, correlated with survival.     

Clinical significance of leukocyte infiltrative response in deep wound of patients with major burns

OBJECTIVE: To investigate the time course of infiltrated leukocytes and the subpopulations of infiltrated lymphocytes in deep wounds, and their relationship with injury severity in seriously burned patients. METHODS: Six patients with major burns were enrolled in the study. Specimens were taken from deep partial-thickness burn wounds of all patients at 3 days, 1 week, 2 weeks and 3 weeks after burn. The appearance time and cellular components of infiltrated leukocyte zone in the burn wound were evaluated by histological and immunohistochemistry examination with lymphocyte monoclonal antibodies. RESULTS: The infiltrated leukocyte zone of burn wound formed 1-2 weeks after burn. The more severe the degree of injury (including burn area, depth and combined injuries) was, the later the infiltrated leukocyte zone appeared. The infiltrated cells mainly consisted of polymorphonuclear leukocytes (PMN) during the early period after burn while macrophages and lymphocytes appeared later. There were some changes of the T lymphocyte subsets and their activation degree in the burn wound. CONCLUSION: The changes of infiltrated leukocyte zone of wound following burns were closely related to the injury severity, and represented alteration of the anti-infection ability and immune rejection of local wound. These results provide important evidence for appropriate wound treatment and prolonging the survival of skin allograft.     

An analysis of death in older burn patients

Between August 1976 and July 1986, 110 burn patients over the age of sixty-five were admitted to the Burn Unit of Ruijin Hospital. The average extent of burn was 19.9% TBSA (0.5-90%), with 14.7% full thickness (0.5-90%). There was a significant difference surface and full thickness area (P less than 0.001) of total burn between non-survival and survival patients. The analysis of causes of death in elderly burn patients suggested that the preexisting cardiopulmonary diseases and inhalation injury appeared particularly important since pneumonia was considered as a primary cause of death in 13 patients, myocardial infarction in 2, congestive heart failure in 2. The resuscitation, early excision of deep burn wound and grafting, prevention and treatment of other complications, and nutritional supplement can decrease the mortality of elderly burn patients.     

我国烧伤病理学研究的回顾与展望

A great achievement has been made on burn pathology research in China since 1958.These advances include: pathological changes in burn wound, the healing process of bum wound and its mechanism modulated by growth factors especially hFGF, intermingted transplantation of allo-skin or xenoskin with auto-skin for coverage of extensive third degree bums, characteristic postbum inflammatory reaction, pathological changes and evolution in various internal organs, multiple organ dysfunction syndrome (MODS),pathological changes in phosphorus burn, pathological changes in endotoxemia in burn, the role of vascular endothelial cell in pathogenesis of postburn visceral organ dysfunction as well as steam and smoke inhalation injury.     

Mortality in paediatric burns at the Women’s and Children’s Hospital (WCH), Adelaide,South Australia: 1960–2017

BackgroundBurn injuries are the third leading cause of preventable death in children worldwide, resulting in over 100 000 annual hospitalisations. In the paediatric population, scalds are the commonest mechanism and burn injuries of greater than 40% total burn surface area (TBSA) are associated with a high mortality and morbidity rate.AimsThe aim of this study was to review mortality in paediatric burns in a tertiary burns centre over a 60-year period, providing an understanding of local causes of mortality and directing future clinical research.MethodsWe reviewed data collected prospectively from patients treated for burn injuries at the WCH from 1960 to 2017. Data of age, gender, mechanism of injury and TBSA were collected. TBSA of 40% and greater were included in the study.ResultsAll patients with total burn surface area (TBSA) less than 40% survived. There were a total of 75 patients who sustained burns of or greater than 40% TBSA. Overall mortality was 34% (26 of 75) of which 24 occurred in the 1960s. Of the 21 patients who died of flame burn injuries, 12 of them were described as clothes catching alight from being in close proximity to the source of flame. Average length of stay for patients who did not survive was 7 days (1–26).ConclusionMortality has since declined and the prognosis for survival good, even in TBSA of greater than 90%. The investigations in fabric flammability led by Dr Thomas Pressley and Mr Murray Clarke prompted the rewriting of Australian standards for production of children’s clothing. This, in combination with advances in paediatric resuscitation, surgical techniques as well as wound care has improved survival rates and outcomes in extensive burn injuries. Future studies focus to see not only better survival rates, but also better aesthetic and functional outcomes in burn survivors.     

The relationship between interferon-gamma and keratinocyte alloantigen expression after burn injury.

BACKGROUND: Cultured keratinocyte (CK) and cadaveric skin allografts have prolonged survival in patients with massive thermal injury. It is unclear if this delayed rejection is due to impaired host responsiveness or decreased graft immunogenicity. Although burn injury has been shown to decrease parameters of allograft response, no studies have examined the effect of burn injury on alloantigen expression. This study investigated the effect of burn size on class II antigen expression in CK allografts as well as on tissue levels of interferon-gamma (IFN-gamma), the principle regulator of alloantigen expression. METHODS: Anesthetized CBA mice (n = 64) received a 0%, 20% partial-thickness (PT), 20% full-thickness (FT), or 40% FT contact burn. Forty-eight hours later, wounds were partially excised and covered with CK allografts from C57BL/6 donors. Five days after burn injury, grafts were analyzed for donor-specific class II antigen. Protein expression was determined by Western immunoblotting and quantified with video densitometry. Wound, serum, and unburned skin levels of IFN-gamma were determined by enzyme-linked immunosorbent assay. Groups were compared by Fisher's analysis of variance. RESULTS: As burn size increased, class II antigen expression decreased (p < 0.001). This corresponded with decreased wound and skin levels of IFN-gamma after 40% burn (p < 0.05); however, wound IFN-gamma was significantly elevated after 20% PT and FT burns (p < 0.01). Serum IFN-gamma increased as burn size increased (p < 0.01). CONCLUSIONS: Burn injury decreases the antigenicity of CK allografts, which partly explains delayed allograft rejection after burn injury. Although wound IFN-gamma increases after minor thermal injury, the profound decrease in wound and skin IFN-gamma after a major burn corresponds with diminished class II antigen expression. The decreased availability of IFN-gamma after major thermal injury provides a mechanism for limited allograft tolerance.     

A review of the mortality in the burns units at the Victoria General Hospital and the Izaak Walton Killam Hospital, January, 1967, to April, 1977

We reviewed the mortality experience in Halifax burn units over the ten-year period January, 1967, to April, 1977. Major complications leading to death were examined and related to initial injury, length of survival, and preexisting disease. When possible, antemortem diagnoses were compared with postmortem pathological findings. Renal failure, sepsis, and pulmonary complications were the most frequent causes of death in burn patients. The patients who died from renal failure tended to expire soon after being burned, and tended to have been inadequately hydrated during the long journey to Halifax. Patients with sepsis did not die within the first 48 hours of being burned. Early excision of the burn wound with homograft replacement might have prevented some of these deaths. Pulmonary complications early in the postburn course appeared related to closed-space and possibly to inhalation injury. However, pneumonia tended to predominate later.     

我国烧伤免疫的研究

The electric burn is a kind of special injury, in which the injured areas are not big, but deep tissues and organs are often injured, resulting in higher rates of mortality and amputation than thermal injury. In the process of management, besides the treatment for systemic and pathologic changes, wound repair is also emphasized for restoration of function. In the past 50 years, ten thound patients with electric burn were cured in our country, including hundreds of severe electric burn patients with extensive injury. Lots of operative regimes for electric burn were developed, and the scope of experimental research was broadening. As aresult, six monographs concerning electric burns were published. However, clinical management of severe electric burn to give a satisfactory result is still difficult, therefore further indepth research is necessary, especially in the field of the use of artificial skin, vessels, nerves, muscular tendon, etc. from gene and tissue engineering to improve quality of wound repair.     

Wound excision to fascia in burn patients.

All charts of burn patients admitted to the US Army Institute of Surgical Research over a four-year period were reviewed to determine the efficacy of excision of the burn wound to fascia as a therapeutic modality. Of 1,013 burn patients, 72 underwent this procedure. The patients who had excisions had a mean total burn size of 52% of body surface area (BSA) and a mean third-degree burn of 33%. We correlated survival with burn size, associated injuries, day of excision, wound coverage, and sepsis. Survival in the group who had excisions (57%) did not differ substantially from that of the other patients (38%) when broken down by burn size. Careful selection of patients for this procedure and criteria for selection are stressed.     

烧伤创面愈合的理论探索与临床实践

The basic and clinical research in wound healing have made great progress in China in the past 50 years. The method of " intermingle skin transplantation" which was first advocated by surgeons of Ruijin Hospital in 1966 greatly reduced the amount of autologous donor skin, thus making the coverage of an extensive burn wound possible. This method is al so known as " Chinese therapy". In 1986,doctors of Jishuitan Hospital reported successful coverage of an extensive burn wound with mieroautografts and allogeneic skin. The basic research of wound healing has been carried out since 1992,a series of studies showed the characteristics of biological behaviours of cells in concern, extracellular matrix and growth factor, the mechanism underlying progressive injury in deep second burn wound, the effect of " skin island" and the local immune tolerance induced by it (which are the key factors of intermingle transplantation).The induction of local immune tolerance has now become the re search hot subject of skin transplantation immunology. Stem cell research in the field of wound healing has been extensively car ried out. The theory of " dermal template defection" has been proposed as one of the mechanisms of scar formation. On the other hand, great progress has been achieved in the treatment of bums on the basis of clinical researches. Doctors of PLA 304 hospital found that excision of eschar on patients with extensive deep burn injury at early shock stage greatly decreased the occurrence of complications and mortality. Doctors of Ruijin Hospital reported that healing of deep second burn wound could be improved by tangential excision of burn eschar within 24 hours after burn injury. Doctors of Xiang ya Hospital reported patients suffering from deep bums of the hands got satisfied functional restoration when treated with tangential excision of eschar while degraded dermal tissue could be retained with transplantation of autoskin grafts.     

烧伤延迟复苏与细胞集落刺激因子

为探讨严重烧伤延迟复苏血清粒细胞集落刺激因子（Ｇ－ＣＳＦ）的变化规律及其与感染发生，发展，预后的关系，采用大鼠３０％ＴＢＳＡⅢ度烧伤模型，动态了观察了大鼠在立即复苏与延迟复苏两种条件下，外周血白细胞数量，血清（Ｇ－ＣＳＦ）和肿瘤坏死因子－α（ＴＮＦ－α）含量，中性粒细胞吞噬功能；采用大鼠３０％ＴＢＳＡⅡ度烧伤延迟复苏合并早期创面感染模型，动态观察应用重组粒细胞－巨噬细胞集落刺激因子（ｒｈＧＭ－ＣＳ     

Thirty-eight free fasciocutaneous flap transfers in acute burned-hand injuries

The benefits of free flap transfers in the acute burn injury are early wound closure, early mobility, reduced hospitalization, and possibly limb salvage. This retrospective study will attempt to provide principles to the use of free fasciocutaneous flap for the reconstruction of acute burned-hand injuries. Between 1995 and 2004, 5521 patients were admitted to the burn unit at Linkou Chang Gung Memorial Hospital. Of these, 38 patients (0.7%) patients received free fasciocutaneous flap transfers. Each patient's chart was reviewed the following data: age, gender, burn injury type, percentage of the burned area to total body surface area, flap type, operations prior to free flap coverage, the size and location of recipient area, timing of free flap coverage, operative time, duration of hospital stay, complications, flap survival and returning to work. All 38 free flaps survived and healed well. Three flaps with partial necrosis due to wound infections required subsequent debridement and skin grafting. Arterial thrombosis occurred in one patient and was salvaged successfully. Minimal donor-site morbidity with no intraoperative mortality was observed. Free fasciocutaneous flap transfer is a safe, efficacious one-stage reconstruction for acute burned-hands with satisfactory aesthetic and functional outcomes. Flap survival is not affected neither by the etiologies of burn nor the timing of free flap coverage.     

Development of a long-term ovine model of cutaneous burn and smoke inhalation injury and the effects of early excision and skin autografting

Smoke inhalation injury frequently increases the risk of pneumonia and mortality in burn patients. The pathophysiology of acute lung injury secondary to burn and smoke inhalation is well studied, but long-term pulmonary function, especially the process of lung tissue healing following burn and smoke inhalation, has not been fully investigated. By contrast, early burn excision has become the standard of care in the management of major burn injury. While many clinical studies and small-animal experiments support the concept of early burn wound excision, and show improved survival and infectious outcomes, we have developed a new chronic ovine model of burn and smoke inhalation injury with early excision and skin grafting that can be used to investigate lung pathophysiology over a period of 3 weeks.     

Recent advances in the management of severely burned patients]

With recent advances in the systemic care of burns, patients with burns covering 80% of their body surface can frequently survive. The percentage of total body surface area burn for an expected 50% mortality rate has improved to 98% for children and 72% for adults in one burn center in the USA. From the results of 11 burn units in Tokyo, the mortality rate of burn patients with a prognostic burn index of 90-100 was 51.4%. The improvement is attributable to advances in the understanding of the pathophysiology of severe burns as a systemic inflammatory response syndrome. Improved cardiopulmonary management of extensive burns and respiratory tract burns has also played a part in reducing the mortality rate. Individualized fluid resuscitation programs based on hemodynamic monitoring have reduced the incidence of burn shock and acute renal failure. Early eschar excision and wound closure by immediate grafting have further reduced the mortality rate from extensive full-thickness burns. The use of bilayer artificial skin has improved the survival and cosmetic results of early eschar excision in patients with massive full-thickness burns. Cultured autologous epidermal sheets hold promise if used on an appropriate dermal bed.     

慢性难愈合创面住院患者回顾性调查

目的 了解慢性难愈合创面形成原因及患者相关情况,为该类创面的治疗、研究提供方向,为国家相关部门制定健康保障策略提供依据.方法收集2008年武汉市第三医院全院共12 161例次住院患者病历资料.以皮肤组织缺损经1个月治疗未愈合为判定标准,筛选出慢性难愈合创面患者病历,回顾性调查患者创面形成原因、性别、年龄、治疗情况、平均住院日.对数据行x2检验和方差分析.结果 12 161例次住院患者中,慢性难愈合创面患者397例次占3.3%.(1)创面的主要形成原因为烧伤占59.9%(238/397)、糖尿病占15.6%(62/397)、压疮占10.8%(43/397),其次为手术、感染、静脉曲张等.各种原因引起慢性难愈合创面患者例次比较,差异有统计学意义(x2=136.21,P=0.001).(2)慢性难愈合创面患者男、女比例为2.0∶1.0;年龄(44±23)岁,高发年龄段为大于或等于70岁,各年龄段创面患者例次比较,差异有统计学意义(x2=24.12,P=0.025).各种原因引起的慢性难愈合创面患者各年龄段例次比较,差异均有统计学意义(x2值为7.86～28.31,P值均小于0.05).(3)分别有60.5%(240/397)和86.4%(343/397)的慢性难愈合创面患者接受了手术与抗生素治疗,所有患者均采用传统敷料治疗.(4)慢性难愈合创面患者平均住院日为(38±27)d,较同期所有住院患者明显延长[(15±7)d,F=22.82,P=0.012].烧伤引起的慢性难愈合创面患者平均住院日[(47±27)d]最长,各种原因引起的慢性难愈合创面患者平均住院日比较,差异有统计学意义(F=24.06,P=0.036).结论烧伤及糖尿病引起的慢性难愈合创面较多,创面患者老龄化明显、住院时间明显长于其他疾病患者.有必要加大转化医学研究力度,促进国家相关政策制定,使慢性难愈合创面得到科学合理的治疗.

Abstract：

Objective To investigate cause of chronic wounds and related status of patients so as to provide strategy for study and treatment of chronic wounds and establish ment of health policy. Methods A total of twelve thousand one hundred and sixty-one cases hospitalized in our hospital in 2008 were enrolled in the study. A chronic wound was defined as skin tissue defect which could not heal after one month of treatment. Medical records were thus screened. Then a retrospective study was performed on patients with chronic wounds with analysis of age, gender, injury cause, therapy, and average length of hospital stay. Data were processed with chi-square test and one-way analysis of variance. Results Investigation showed:397 out of 12 161 cases ( accounting for 3.3% ) were recognized as having chronic wounds. ( 1 ) The main causes for chronic wound were burn, diabetes, and pressure ulcer, accounting for 59.9% (238/397),15.6% (62/397), 10.8% (43/397), respectively. The other causes were operative injury, infection,varicosity, etc. There was statistical difference among the numbers of patients with chronic wounds with regard to various causes of injury (x 2 = 136.21, P = 0. 001 ). (2) Among patients with chronic wound, the patients older than 70 years. There was significant difference in the numbers of patients with chronic wound among different age groups (x2 = 24.12, P =0. 025). There was statistical difference among the numbers of patients with chronic wound in different age groups with each cause of injury ( with x 2 values from 7.86 to 28.31, P values all below 0.05 ). ( 3 ) All patients with chronic wounds received traditional dressing. In 60. 5% (240/397) and 86.4% (343/397) of patients, operative treatment or antibiotics were given. (4)The average length of hospital stay in patients with chronic wound [( 38 ± 27 ) d] was longer as compared with that of all the inpatients in the same period [(15 ± 7) d, F = 22.82, P = 0. 012]. There was obvious difference in the average length of hospital stay among patients with chronic wound caused by different reasons ( F = 24.06, P = 0. 036) , in which burn injury resulted in the longest length of hospital stay [(47 ±27) d]. Conclusions Chronic wounds are mainly caused by diabetes and burn, and characterized by old age and longer length of hospital stay. It is necessary to strengthen translational research and related policy making, so that more rational treatment can be applied for patients with chronic wounds.     

Managing thermal injuries within WOCN practice.

WOC nurses may be asked to manage small burn wounds or to follow up with patients who have residual wound care issues after recovering from a major burn injury. Aspects of care include identifying patients who warrant a higher level of burn care expertise, managing small wounds, recognizing the common complications of burns, and determining the needs of patients undergoing burn rehabilitation. Persons managing burn wounds will incorporate a variety of techniques to facilitate wound cleansing and dressing, pain management, psychological support, and minimization of complications. In addition, depending on the setting, extent, and nature of the wounds, the patient's abilities and rehabilitation requirements will need to be determined. The patient and his or her family need to be educated about the normal changes that follow a burn injury and how to manage these issues.