Implications for Burns Unit design following outbreak of multi-resistant Acinetobacter infection in ICU and Burns Unit

Burns and biofilms: priority pathogens and in vivo models

Burn wounds can create significant damage to human skin, compromising one of the key barriers to infection. The leading cause of death among burn wound patients is infection. Even in the patients that survive, infections can be notoriously difficult to treat and can cause lasting damage, with delayed healing and prolonged hospital stays. Biofilm formation in the burn wound site is a major contributing factor to the failure of burn treatment regimens and mortality as a result of burn wound infection. Bacteria forming a biofilm or a bacterial community encased in a polysaccharide matrix are more resistant to disinfection, the rigors of the host immune system, and critically, more tolerant to antibiotics. Burn wound-associated biofilms are also thought to act as a launchpad for bacteria to establish deeper, systemic infection and ultimately bacteremia and sepsis. In this review, we discuss some of the leading burn wound pathogens and outline how they regulate biofilm formation in the burn wound microenvironment. We also discuss the new and emerging models that are available to study burn wound biofilm formation in vivo.

Efficacy of Infection Control Measures in Managing Outbreaks of Multidrug-Resistant Organisms in Burn Units

BACKGROUND

Multidrug-resistant organisms (MDROs) pose a significant threat to severe burn victims and represents a clear epidemic hazard in burn units. Several infection control measures have been implemented to control and manage the outbreaks of MDRO. The efficiency of those measures, however, remains controversial and an area of debate. A systematic review was conducted to evaluate the efficacy of infection control measures and the necessity of closing burn units in dealing with MDRO outbreaks.

METHODS

Peer-reviewed articles were identified using PubMed, EMBASE, and Cochrane Central Register of Controlled Trials databases, focusing on infection control measures to manage MDRO outbreaks in burn units.

RESULTS

Twenty-one studies that reported MDRO outbreaks in burn units met the inclusion criteria. The outbreaks were successfully controlled with interventions in 17 units (81%), partially controlled in 1 unit (4.7%), and uncontrolled in 3 units (14.3%). Infection control measures were implemented by screening patient (19 units), screening health care worker (17 units), obtaining environmental cultures (16 units), providing ongoing staff education (13 units), cohort or isolation (17 units), preemptive barrier precautions (10 units), improving hand hygiene (15 units), and enhanced cleaning and environmental disinfection (17 units). Closure of burn units occurred in 8 units, with outbreaks controlled in 6 of the units (75%). The reasons for unit closure include decontamination (4 units; 50%), outbreak investigation (1 unit; 12.5%), and uncontrolled outbreaks (3 units; 37.5%). The incidence of infection was significantly decreased in 4 units after the closure but rose again after reopening in 1 of the units. In 3 units, the spread was halted by other control measures, including change of hydrotherapy facilities, identification of staff transmission, and unit structure remodeling.

CONCLUSIONS

Proper infection control measures play an important role in managing MDRO outbreaks in burn units. Temporary closure of burn units may be necessary to control the spread of nosocomial, and this option should be considered when other measures are ineffective.

Burn Unit Design-The Missing Link for Quality and Safety

The relationship between infrastructure, technology, model of care, and human resources influences patient outcomes and safety, staff productivity and satisfaction, retention of personnel, and treatment and social costs. This concept underpins the need for evidence-based design and has been widely adopted to inform hospital infrastructure planning. The aim of this review is to establish evidence-based, universally applicable key features of a burn unit that support function in a comprehensive patient-centered model of care. A literature search in medical, architectural, and engineering databases was conducted. Burn associations' guidelines and relevant articles published in English, between 1990 and 2020, were included, and the available evidence is summarized in the review. Few studies have been published on burn unit design in the past 30 years. Most of them focus on the role of design in infection control and prevention and consist primarily of descriptive or observational reports, opportunistic historical cohort studies, and reviews. The evidence available in the literature is not sufficient to create a definitive infrastructure guideline to inform burn unit design, and there are considerable difficulties in creating evidence that will be widely applicable. In the absence of a strong evidence base, consensus guidelines on burn unit infrastructure should be developed, to help healthcare providers, architects, and engineers make informed decisions, when designing new or renovated facilities.

Trauma intensive care in a terror-ravaged, resource-constrained setting: Are we prepared for the emerging challenge?

Introduction

Trauma in developing countries has been on the increase, a situation perpetuated by rising road traffic collisions, terrorism and firearms proliferation. Some of the victims of trauma are left with life threatening conditions requiring urgent surgical intervention and/or intensive care. The objectives of this study were to determine the pattern of major trauma needing intensive care in the region, and to determine the outcome of major trauma admitted to intensive care unit.

Methods

A six-year retrospective cohort study of trauma patients needing intensive care, set in the Intensive Care Unit of Ahmadu Bello University Teaching Hospital, Zaria, North-West Nigeria. Subjects were major trauma patients admitted into the intensive care unit of the institution, identified via an admission register kept in the unit. The main outcomes measured were length of stay and mortality.

Results

Trauma admissions represented 25.1% of the all intensive care admissions. Severe traumatic brain injury accounted for 32.1% of the trauma admissions, while burns accounted for 23.2%. Of the injuries, 15.5% were sustained in bomb blasts, and 8.3% were firearm injuries. The majority of the patients stayed for no more than seven days from admission. Burns patients had the worst outcomes, with 82.1% mortality.

Conclusion

Major trauma contributes significantly to local intensive care admissions, with terrorism- related trauma now an emerging challenging cause of major trauma in our region. The observed poor outcomes in this study are a reflection of the quality of available intensive care, and lends credence to the concept of appropriately resourced, specialised intensive care units for optimisation of care.

Multidrug-Resistant Bacterial Outbreaks in Burn Units: A Synthesis of the Literature According to the ORION Statement

The objective of this study is to review the literature on multidrug-resistant bacteria (MDRB) outbreaks in burn units according to the outbreak reports and intervention studies of nosocomial infection statement. A PubMed search engine was enlisted to identify reports, in English and French, on MDRB outbreaks in burn units, with no date restrictions, using the following key words: ("burn" OR "burns" OR "severe burn") AND ("unit" OR "critical care" OR "acute care" OR "intensive care" OR "center" OR "centre" OR "department") AND ("outbreak" OR "epidemic") AND ("resistant" OR "multidrug-resistant" OR "resistance" OR "MDR" OR "MDRO"). Twenty-nine articles on such outbreaks in burn units were analyzed. A wide variety of these outbreaks were studied in terms of the microbial agents involved, length of outbreak, and attack rate (1.9-66.7%). The most frequent bacteria were methicillin-resistant Staphylococcus aureus and Acinetobacter baumannii. Screening of staff revealed carrier rates of 0 to 20% in 16 studies. Environmental samples were taken in 21 studies and were positive in 14 of them. The mortality rate among infected patients varied from 0 to 33%. Implementation of isolation precautions did not always suffice, with unit closure being necessary in five outbreaks. The lack of consensus on how to manage such outbreak was highlighted. MDRB infections or colonizations are responsible for increased morbidity and mortality in vulnerable burn patients. Their management is problematic because of multifactorial transmission and limited therapeutic possibilities.

Next-Generation Sequencing and Comparative Analysis of Sequential Outbreaks Caused by Multidrug-Resistant Acinetobacter baumannii at a Large Academic Burn Center

Next-generation sequencing (NGS) analysis has emerged as a promising molecular epidemiological method for investigating health care-associated outbreaks. Here, we used NGS to investigate a 3-year outbreak of multidrug-resistant Acinetobacter baumannii (MDRAB) at a large academic burn center. A reference genome from the index case was generated using de novo assembly of PacBio reads. Forty-six MDRAB isolates were analyzed by pulsed-field gel electrophoresis (PFGE) and sequenced using an Illumina platform. After mapping to the index case reference genome, four samples were excluded due to low coverage, leaving 42 samples for further analysis. Multilocus sequence types (MLST) and the presence of acquired resistance genes were also determined from the sequencing data. A transmission network was inferred from genomic and epidemiological data using a Bayesian framework. Based on single-nucleotide variant (SNV) differences, this MDRAB outbreak represented three sequential outbreaks caused by distinct clones. The first and second outbreaks were caused by sequence type 2 (ST2), while the third outbreak was caused by ST79. For the second outbreak, the MLST and PFGE results were discordant. However, NGS-based SNV typing detected a recombination event and consequently enabled a more accurate phylogenetic analysis. The distribution of resistance genes varied among the three outbreaks. The first- and second-outbreak strains possessed a blaOXA-23-like group, while the third-outbreak strains harbored a blaOXA-40-like group. NGS-based analysis demonstrated the superior resolution of outbreak transmission networks for MDRAB and provided insight into the mechanisms of strain diversification between sequential outbreaks through recombination.

Innovative designs for the smart ICU: part 1: from initial thoughts to occupancy

Designing a smart ICU is a time-consuming, complex, multiphased, political, and costly exercise. This process begins with two notions: First, all hospital parties agree that a new or renovated ICU is required, and second, the hospital has agreed to allocate space, personnel, and fiscal resources for the project. In this first of a three-part series on innovative designs for the smart ICU, we will explore the roles of the ICU design team in managing the design process. The team must be administratively empowered, knowledgeable, and forward thinking. The first charge of the design team is to develop a clear vision for the goals, look and feel, and functionality of the new ICU. This vision must be guided by the imperative to positively impact patients, staff, and visitors. The team must concentrate on innovative but practical ideas that are in compliance with building codes and design guidelines and address issues related to renovation vs new construction. Mock-ups, both physical and computer generated, and a simulation laboratory for advanced technologies should be used to test design assumptions and reveal problems well in advance of actual ICU construction and technology implementation. Technology platforms need to be standardized within the ICU and equipment purchases protected against early obsolescence. The ramifications and expectations of the new ICU must be thoughtfully considered and dealt with during the design process. Last, it is essential that the design group continue its involvement in the new ICU during construction, occupancy, and post occupancy.

Spatial and temporal analyses to investigate infectious disease transmission within healthcare settings

Background

Healthcare-associated infections (HCAIs) cause significant morbidity and mortality worldwide, and outbreaks are often only identified after they reach high levels. A wide range of data is collected within healthcare settings; however, the extent to which this information is used to understand HCAI dynamics has not been quantified.

Aim

To examine the use of spatiotemporal analyses to identify and prevent HCAI transmission in healthcare settings, and to provide recommendations for expanding the use of these techniques.

Methods

A systematic review of the literature was undertaken, focusing on spatiotemporal examination of infectious diseases in healthcare settings. Abstracts and full-text articles were reviewed independently by two authors to determine inclusion.

Findings

In total, 146 studies met the inclusion criteria. There was considerable variation in the use of data, with surprisingly few studies (N = 22) using spatiotemporal-specific analyses to extend knowledge of HCAI transmission dynamics. The remaining 124 studies were descriptive. A modest increase in the application of statistical analyses has occurred in recent years.

Conclusion

The incorporation of spatiotemporal analysis has been limited in healthcare settings, with only 15% of studies including any such analysis. Analytical studies provided greater data on transmission dynamics and effective control interventions than studies without spatiotemporal analyses. This indicates the need for greater integration of spatiotemporal techniques into HCAI investigations, as even simple analyses provide significant improvements in the understanding of prevention over simple descriptive summaries.

Reducing the spread of Acinetobacter baumannii and methicillin-resistant Staphylococcus aureus on a burns unit through the intervention of an infection control bundle

Methicillin-resistant Staphylococcus aureus (MRSA) and Acinetobacter baumannii are major nosocomial pathogens in burns units. We investigated the impact of an infection control bundle on the incidence of nosocomial MRSA and A. baumannii in our burns unit, comparing a pre-intervention period (December 2006-August 2008) with an intervention period (September 2008-December 2009). The bundle comprised regular hydrogen peroxide vapour (HPV) disinfection of the rooms following discharge of patients colonized or infected by multidrug-resistant bacteria, pre-emptive cohort isolation of newly admitted patients before being proven culture negative, cohorting of colonized or infected patients, installation of two air disinfection systems in the corridors of the unit and improvement of material storage. We also investigated the microbiological efficacy of HPV disinfection by sampling the environment before and after HPV treatments. HPV disinfection eliminated pathogens from the environment and significantly reduced total bacterial surface counts, and total fungal air and surface counts, on both a unit and room scale. The incidence of nosocomial MRSA infection or colonization fell by 89.3% from 7.22 to 0.77 cases/1000 patient days (p<0.0001) and A. baumannii fell by 88.8% from 6.92 to 0.77 cases/1000 patient days (p=0.002) in the intervention period with no further outbreaks of these organisms occurring in this period. The infection control bundle resulted in a significant reduction in the incidence of nosocomial MRSA and A. baumannii in our burns unit and prevented further outbreaks of these organisms.

The impact of the types of microorganisms isolated from blood and wounds on the results of treatment in burn patients with sepsis

Despite development of combustiology, infections continue to be the most important cause of death among patients with burns. Sepsis is the most severe clinical presentation of infection in patients after thermal injuries who require immediate treatment. Early diagnosis and proper treatment of sepsis are important in the clinical management that is often hampered for multiple reasons, e.g. impaired patient immunity, problems with microorganisms with multi-antibacterial drug resistance. The aim of the study was to assess effect of type of a microorganism isolated from blood and wound on results of treatment of sepsis in patients with burns.

MATERIAL AND METHODS

Effect of type of microorganisms isolated from blood and wound on the result of treatment of sepsis was studied in 338 patients hospitalized immediately after an injury in Centre for Burn Treatment in Siemianowice Śląskie in years 2003 - 2004 (at the age of 18 - 96 years, 66 women and 272 men). Clinical symptoms of generalized infection were found in all study subjects. The study group was divided into two subgroups: cured patients and patients who died of sepsis. The following parameters were assessed in both subgroups: type of microorganism isolated from blood, type of microorganism isolated from wound as well as occurrence of the same and different infections of blood and burn wound.

RESULTS

positive blood cultures were found in 165 patients (48.8%), 106 (64.2%) were cured, 59 (35.8%) died. The most commonly isolated microorganisms in cured patients were Gram(+) Staphylococcus epidermidis MRSE (19.81%) and Staphylococcus aureus MRSA (18.87%). Gram(-) intestinal rods were least commonly isolated from this group. The most commonly isolated microorganisms from blood of patients who were to die, included non-fermenting Gram(-) rods Acinetobacter baumannii (35.59%) and Pseudomonas aeruginosa (22.03%). Mixed bacterial flora was found in the blood of 22.03% patients. Among patients who were to die, the same microorganisms were found in the blood and in the wound in 32.2% of patients, while this rate was 17.92 in cured patients. The most commonly found bacteria in the blood and burn wound in the cured patients included Staphylococcus aureus MRSA (31.58%) and Staphylococcus aureus (21.05%). In the group of patients who were to die, the most common bacteria isolated simultaneously from the blood and burn wound included Acinetobacter baumannii (47.37%) and Pseudomonas aeruginosa (36.84%).

CONCLUSIONS

1. The patients with thermal injuries are at higher risk of death in the event of sepsis caused by Gram(-) bacteria versus Gram(+) bacteria. 2. Infection of blood and burn wound caused by the same bacteria Pseudomonas aeruginosa and Acinetobacter baumanni increases the risk of death due to sepsis in patients with burns following thermal injuries.

Prevention of infections associated with combat-related burn injuries

Burns are a very real component of combat-related injuries, and infections are the leading cause of mortality in burn casualties. The prevention of infection in the burn casualty transitioning from the battlefield to definitive care provided at the burn center is critical in reducing overall morbidity and mortality. This review highlights evidence-based medicine recommendations using military and civilian data to provide the most comprehensive, up-to-date management strategies for initial care of burned combat casualties. Areas of emphasis include antimicrobial prophylaxis, debridement of devitalized tissue, topical antimicrobial therapy, and optimal time to wound coverage. This evidence-based medicine review was produced to support the Guidelines for the Prevention of Infections Associated With Combat-Related Injuries: 2011 Update contained in this supplement of Journal of Trauma.

Accumulation and transport of microbial-size particles in a pressure protected model burn unit: CFD simulations and experimental evidence

BACKGROUND

Controlling airborne contamination is of major importance in burn units because of the high susceptibility of burned patients to infections and the unique environmental conditions that can accentuate the infection risk. In particular the required elevated temperatures in the patient room can create thermal convection flows which can transport airborne contaminates throughout the unit. In order to estimate this risk and optimize the design of an intensive care room intended to host severely burned patients, we have relied on a computational fluid dynamic methodology (CFD).

METHODS

The study was carried out in 4 steps: i) patient room design, ii) CFD simulations of patient room design to model air flows throughout the patient room, adjacent anterooms and the corridor, iii) construction of a prototype room and subsequent experimental studies to characterize its performance iv) qualitative comparison of the tendencies between CFD prediction and experimental results. The Electricité De France (EDF) open-source software Code_Saturne® (http://www.code-saturne.org) was used and CFD simulations were conducted with an hexahedral mesh containing about 300 000 computational cells. The computational domain included the treatment room and two anterooms including equipment, staff and patient. Experiments with inert aerosol particles followed by time-resolved particle counting were conducted in the prototype room for comparison with the CFD observations.

RESULTS

We found that thermal convection can create contaminated zones near the ceiling of the room, which can subsequently lead to contaminate transfer in adjacent rooms. Experimental confirmation of these phenomena agreed well with CFD predictions and showed that particles greater than one micron (i.e. bacterial or fungal spore sizes) can be influenced by these thermally induced flows. When the temperature difference between rooms was 7°C, a significant contamination transfer was observed to enter into the positive pressure room when the access door was opened, while 2°C had little effect. Based on these findings the constructed burn unit was outfitted with supplemental air exhaust ducts over the doors to compensate for the thermal convective flows.

CONCLUSIONS

CFD simulations proved to be a particularly useful tool for the design and optimization of a burn unit treatment room. Our results, which have been confirmed qualitatively by experimental investigation, stressed that airborne transfer of microbial size particles via thermal convection flows are able to bypass the protective overpressure in the patient room, which can represent a potential risk of cross contamination between rooms in protected environments.

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.

Are topical antimicrobials effective against bacteria that are highly resistant to systemic antibiotics?

An increasing number of bacteria are resistant to multiple systemic antibiotics. The purpose of this study was to determine if topical antimicrobials are still effective against multi-drug resistant organisms (MDROs). MDROs, including Acinetobacter, Pseudomonas, Klebsiella, Staphylococcus, and Enterococcus, were collected from four burn hospitals. The sensitivity of 47 MDROs to 11 commonly used topical agents (mafenide acetate, nystatin, mafenide + nystatin, silver nitrate, Dakin's, polymyxin B, neomycin, polymyxin + neomycin, silver sulfadiazine, bacitracin, silver sulfadiazine + bacitracin) was tested using the agar well diffusion assay and compared with the sensitivity of 27 non-MDROs of similar genera. Overall 88% of the tests of the non-MDROs showed susceptibility to the topicals compared with 80% for the MDROs (P < .05). Specific findings included: all of the gram-positive non-MDROs were sensitive to bacitracin compared with only 67% of the MDROs (P < .05); 74% of the non-MDROs were sensitive to neomycin vs 26% of the MDROs (P < .01). Even for the susceptible isolates, the zones of inhibition were smaller for the MDROs than for the non-MDROs (P < .002), indicating decreased susceptibility of the MDROs. Specifically, while the MDRO Acinetobacter were sensitive to most of the topicals, the zones of inhibition for silvadene, silvadene + bacitracin, neomycin, and neomycin + polymyxin were significantly smaller (P < .001) for the Acinetobacter MDROs than the non-MDROs. Although many topicals are still effective against some MDROs, MDROs are more resistant to topicals than are non-MDROs. Some treatment assumptions based historically on the efficacy of topical antimicrobial agents against non-MDROs need to be re-evaluated for MDROs.

Prevention and management of infections associated with burns in the combat casualty

Burns complicate 5% to 10% of combat associated injuries with infections being the leading cause of mortality. Given the long term complications and rehabilitation needs after initial recovery from the acute burns, these patients are often cared for in dedicated burn units such as the Department of Defense referral burn center at the United States Army Institute of Surgical Research in San Antonio, TX. This review highlights the evidence-based recommendations using military and civilian data to provide the most comprehensive, up-to-date management strategies for burned casualties. Areas of emphasis include antimicrobial prophylaxis, debridement of devitalized tissue, topical antimicrobial therapy, and optimal time to wound coverage.

Infection in patients with severe burns: causes and prevention thereof

The better understanding of burn pathophysiology has resulted in effective fluid resuscitation in the acute stage, but the morbidity and mortality of burn patients are mostly linked to the burn wound consequences. Once the initial acute phase is over, the burn wound becomes the source of virtually all ill effects, local and systemic. The dysfunction of the immune system, a large cutaneous bacterial load, the possibility of gastrointestinal bacterial translocation, prolonged hospitalization, and invasive diagnostic and therapeutic procedures all contribute to infectious complications. Wound infection may lead to septicemia that may not only consume additional resources but is associated with significant morbidity and mortality despite the advances in burn care.

Impact of Acinetobacter Infection on the Mortality of Burn Patients

BACKGROUND

Acinetobacter calcoaceticus-baumannii complex (Acb) is recognized as an important cause of nosocomial infections. Although Acb can be associated with multidrug resistance, its impact on mortality in burn patients has not been fully elucidated.

STUDY DESIGN

In a retrospective cohort study assessing medical records and microbiology laboratory data at a US military tertiary care burn center, we evaluated all patients admitted to the burn center between January 2003 and November 2005. Data collected included age, severity of burn, comorbidities, length of stay, and survival to hospital discharge. In addition, microbiology data were reviewed to determine which patients were infected with Acb during this time frame. These data were then used to compare patients infected with Acb to patients not infected. Multivariate analysis using logistic regression was performed to determine which patient characteristics were associated with increased mortality.

RESULTS

There were 802 patients included in the study. Fifty-nine patients met the case definition for infection. An additional 52 patients were found to be colonized with Acb. Patients with Acb infection had more severe burns and comorbidities, and had longer lengths of stay compared with patients without Acb or those with Acb colonization. Mortality in infected patients was higher compared with those without infection (relative risk = 2.86, p = 0.001). On multivariate analysis, infection with Acb was not statistically associated with mortality.

CONCLUSIONS

Multidrug-resistant Acb is a common cause of nosocomial infection in the burn patient population. Despite this, it does not independently affect mortality.

Genotypic analysis of Acinetobacter bloodstream infection isolates in a Turkish university hospital

Acinetobacter baumannii is a significant pathogen of bloodstream infections in hospital patients that frequently causes single clone outbreaks. We aimed to evaluate the genetic relatedness and antimicrobial susceptibility of Acinetobacter spp. bloodstream isolates, in order to obtain insight into their cross-transmission. This prospective study was conducted at the Erciyes University Hospital. During a 1-y period, all patients with nosocomial BSI caused by Acinetobacter spp. were included in the study. All data with regard to the patients, underlying diseases and risk factors for BSI and the severity of disease were collected. Blood culture isolates of Acinetobacter spp. were identified according to their morphology and biochemical reactions. The antimicrobial susceptibility was determined using the Kirby-Bauer disk diffusion test according to the NCCLS; the genetic relatedness of isolates was determined by RAPD-PCR analysis and pulsed-field gel electrophoresis (PFGE). 41 patients acquired a nosocomial bloodstream infection caused by A. baumanii during this period. 88% of these infections (36 of 41) occurred while the patients were treated in the intensive care unit. Nearly 80% of the isolates belonged to 3 genotypes, suggesting cross-transmission in ICU settings where infection control practices are poor. All Acinetobacter isolates were multidrug-resistant and the crude mortality of patients infected with A. baumanii was 80.5%. We concluded that the genetic relatedness of Acinetobacter spp. causing BSI was very high, indicating cross-transmission within the ICU setting. Essential components of an infection control programme to prevent nosocomial transmission of A. baumannii are early detection of colonized patients, followed by strict attention to standard precautions and contact isolation.

Burn wound infections

Burns are one of the most common and devastating forms of trauma. Patients with serious thermal injury require immediate specialized care in order to minimize morbidity and mortality. Significant thermal injuries induce a state of immunosuppression that predisposes burn patients to infectious complications. A current summary of the classifications of burn wound infections, including their diagnosis, treatment, and prevention, is given. Early excision of the eschar has substantially decreased the incidence of invasive burn wound infection and secondary sepsis, but most deaths in severely burn-injured patients are still due to burn wound sepsis or complications due to inhalation injury. Burn patients are also at risk for developing sepsis secondary to pneumonia, catheter-related infections, and suppurative thrombophlebitis. The introduction of silver-impregnated devices (e.g., central lines and Foley urinary catheters) may reduce the incidence of nosocomial infections due to prolonged placement of these devices. Improved outcomes for severely burned patients have been attributed to medical advances in fluid resuscitation, nutritional support, pulmonary and burn wound care, and infection control practices.

Burn wound infections

Burns are one of the most common and devastating forms of trauma. Patients with serious thermal injury require immediate specialized care in order to minimize morbidity and mortality. Significant thermal injuries induce a state of immunosuppression that predisposes burn patients to infectious complications. A current summary of the classifications of burn wound infections, including their diagnosis, treatment, and prevention, is given. Early excision of the eschar has substantially decreased the incidence of invasive burn wound infection and secondary sepsis, but most deaths in severely burn-injured patients are still due to burn wound sepsis or complications due to inhalation injury. Burn patients are also at risk for developing sepsis secondary to pneumonia, catheter-related infections, and suppurative thrombophlebitis. The introduction of silver-impregnated devices (e.g., central lines and Foley urinary catheters) may reduce the incidence of nosocomial infections due to prolonged placement of these devices. Improved outcomes for severely burned patients have been attributed to medical advances in fluid resuscitation, nutritional support, pulmonary and burn wound care, and infection control practices.

The Bali burn disaster: implications and lessons learned

In October 2002, a terrorist attack on a nightclub in Bali resulted in an explosion and fire, causing the deaths of more than 200 people, including 88 Australian citizens. After first aid and primary care, the injured were repatriated to Darwin for triage and continued treatment and were then disseminated to various burn units throughout Australia. At the Repatriation General Hospital Concord Sydney, we received 12 patients with burns and a variety of blast injuries. Their treatment was complicated by infection with multiresistant organisms that were previously unseen in our unit and the presence of complex shrapnel wounds. There were no deaths and, with two exceptions, all patients were discharged within 6 weeks. This incident had profound effects on our unit, particularly related to the management of high-velocity shrapnel injuries, serious ongoing septic complications, and the psychological effects on both patients and staff, all of which are detailed and discussed.

A prevalent, multiresistant clone of Acinetobacter baumannii in Southeast England

A multiresistant clone of Acinetobacter baumannii was identified in 24 hospitals in the UK, predominantly in the London area, over a period of three years. Isolates were characterized by distinctive ApaI macrorestriction profiles, as resolved by pulsed-field gel electrophoresis (PFGE), which all clustered within 80% similarity using a 1% band position tolerance setting. The first isolates identified were received by the reference laboratories in April 2000, and by June 2003, a total of 375 isolates with similar PFGE profiles from 310 patients from 24 hospitals had been received. The isolates originated mainly from sputum and wound specimens, with the majority from patients in intensive care units. Amplified fragment length polymorphism analysis of a subset of isolates showed that they clustered closely, supporting the PFGE results. All the isolates tested were highly resistant to ampicillin, piperacillin, piperacillin/tazobactam, ceftazidime, cefotaxime, gentamicin and ciprofloxacin, and most isolates were carbapenem resistant. Amikacin sensitivity varied from susceptible [minimum inhibitory concentration (MIC) <or= 4 mg/L] to highly resistant (MIC >256 mg/L).

Epidemiology and control of antibiotic resistance in the intensive care unit

PURPOSE OF REVIEW

Resistance to antibiotics is very high in the intensive care units of many countries, although there are several exceptions. Some infections are becoming extremely difficult to treat. The risk of cross-transmission of those strains is very high. This review focuses on recent data (2003 to the present) that may help understanding and dealing with this serious public health problem.

RECENT FINDINGS

Intensive care units can be considered as 'factories' for creating, disseminating and amplifying resistance to antibiotics, for many reasons: importation of resistant microorganisms at admission, selection of resistant strains with an extensive use of broad-spectrum antibiotics, cross-transmission of resistant strains via the hands or the environment. Some national programs can be considered as failures, as in the UK and the USA. Other countries have been able to maintain a low level of resistance (Scandinavian countries, Netherlands, Switzerland, Germany, Canada). There is clearly an 'inoculum effect' above which preventive measures become poorly efficient. Several preventive measures have been proposed including preventive isolation, systematic screening at admission, local, national or international antibiotic guidelines, antibiotic prescriptions advice by infectious-disease teams, antibiotic prevention with selective digestive decontamination, antibiotic strategies such as 'cycling', or rather, for some authors, the use of an 'à la carte' antibiotic strategy which could be considered as a 'patient-to-patient antibiotic rotation'.

SUMMARY

There is obviously an international concern regarding the level of resistance to antibiotics in the intensive-care-unit setting. A strong program including prevention of cross-transmission and better usage of antibiotics seems to be needed in order to be successful. We do not know if this kind of program will enable countries with a very high endemic level of resistance to decrease the level in future years.