Correlation of procalcitonin and cytokine expression with dehiscence of wartime extremity wounds

Development of a cellular assay as a personalized model for testing chronic wound therapeutics

Exudates of non-healing wounds contain drivers of pathogenicity. We utilized >800 exudates from non-healing and healing wounds of diverse etiologies, collected by three different methods, to develop a wound-specific, cell-based functional biomarker assay. Human dermal fibroblast proliferation served as readout to a) to differentiate between healing and non-healing wounds, b) follow the healing process of individual patients, and c) assess the effects of therapeutics for chronic wounds ex vivo. We observed a strong correlation between wound chronicity and inhibitory effects of individual exudates on fibroblast proliferation, with good diagnostic sensitivity (76-90%, depending on the sample collection method). Transition of a clinically non-healing to a healing phenotype restored fibroblast proliferation and extracellular matrix formation while reducing inflammatory cytokine production. Transcriptional analysis of fibroblasts exposed to ex vivo non-healing wound exudates revealed an induction of inflammatory cytokine- and chemokine pathways and the unfolded protein response, indicating that these changes may contribute to the pathology of non-healing wounds. Testing the wound therapeutics platelet derived growth factor and silver sulfadiazine yielded responses in line with clinical experience and indicate the usefulness of the assay to search for and profile new therapeutics.

Procalcitonin as an Endogenous Biomarker for Mastitis in Cows

Mastitis is one of the most common diseases of dairy cows. Procalcitonin (PCT) has been described as an endogenous inflammatory biomarker for bacterial infections. The aim of this study was to find possible correlations between PCT concentrations in the serum and milk of cows with mastitis and their clinical signs and disease progression. In total, 88 dairy cows were examined, of which 30 animals were diagnosed with clinical mastitis, 30 had subclinical mastitis, and 28 were designated as a healthy control group. The diseased animals were re-examined after 12 days. All PCT levels in this study were determined by a species-specific ELISA. All three groups could be differentiated from each other based on serum and milk PCT levels. The animals with clinical mastitis showed the highest mean concentrations of PCT (serum: 2641 pg/mL; milk: 1326 pg/mL), and the lowest PCT concentrations were found in the healthy control group (serum: 1166 pg/mL; milk: 176 pg/m). Over the course of the disease, results from the kinetics study showed that PCT levels remained high for the entire observation period. The results from this study showed that the PCT concentration could be used to differentiate between clinical mastitis, subclinical mastitis, and healthy cows.

Advanced Wound Diagnostics: Toward Transforming Wound Care into Precision Medicine

Significance: Nonhealing wounds are an ever-growing global pandemic, with mortality rates and management costs exceeding many common cancers. Although our understanding of the molecular and cellular factors driving wound healing continues to grow, standards for diagnosing and evaluating wounds remain largely subjective and experiential, whereas therapeutic strategies fail to consistently achieve closure and clinicians are challenged to deliver individualized care protocols. There is a need to apply precision medicine practices to wound care by developing evidence-based approaches, which are predictive, prescriptive, and personalized. Recent Advances: Recent developments in "advanced" wound diagnostics, namely biomarkers (proteases, acute phase reactants, volatile emissions, and more) and imaging systems (ultrasound, autofluorescence, spectral imaging, and optical coherence tomography), have begun to revolutionize our understanding of the molecular wound landscape and usher in a modern age of therapeutic strategies. Herein, biomarkers and imaging systems with the greatest evidence to support their potential clinical utility are reviewed. Critical Issues: Although many potential biomarkers have been identified and several imaging systems have been or are being developed, more high-quality randomized controlled trials are necessary to elucidate the currently questionable role that these tools are playing in altering healing dynamics or predicting wound closure within the clinical setting. Future Directions: The literature supports the need for the development of effective point-of-care wound assessment tools, such as a platform diagnostic array that is capable of measuring multiple biomarkers at once. These, along with advances in telemedicine, synthetic biology, and "smart" wearables, will pave the way for the transformation of wound care into a precision medicine. Clinical Trial Registration number: NCT03148977.

Wound fluid sampling methods for proteomic studies: A scoping review

Understanding why some wounds are hard to heal is important for improving care and developing more effective treatments. The method of sample collection used is an integral step in the research process and thus may affect the results obtained. The primary objective of this study was to summarise and map the methods currently used to sample wound fluid for protein profiling and analysis. Eligible studies were those that used a sampling method to collect wound fluid from any human wound for analysis of proteins. A search for eligible studies was performed using MEDLINE, Embase and CINAHL Plus in May 2020. All references were screened for eligibility by one reviewer, followed by discussion and consensus with a second reviewer. Quantitative data were mapped and visualised using appropriate software and summarised via a narrative summary. After screening, 280 studies were included in this review. The most commonly used group of wound fluid collection methods were vacuum, drainage or use of other external devices, with surgical wounds being the most common sample source. Other frequently used collection methods were extraction from absorbent materials, collection beneath an occlusive dressing and direct collection of wound fluid. This scoping review highlights the variety of methods used for wound fluid collection. Many studies had small sample sizes and short sample collection periods; these weaknesses have hampered the discovery and validation of novel biomarkers. Future research should aim to assess the reproducibility and feasibility of sampling and analytical methods for use in larger longitudinal studies.

Do Battlefield Injury-acquired Indwelling Metal Fragments Induce Metal Immunogenicity?

BACKGROUND

A battlefield-related injury results in increased local and systemic innate immune inflammatory responses, resulting in wound-specific complications and an increased incidence of osteoarthritis. However, little is known about whether severe injuries affect long-term systemic homeostasis, for example, immune function. Moreover, it also remains unknown whether battlefield-acquired metal fragments retained over the long term result in residual systemic effects such as altered immune reactivity to metals.

QUESTIONS/PURPOSES

Does a retained metal fragment from a battlefield injury contribute to increased (1) adaptive metal-specific immune responses, (2) systemically elevated metal ion serum levels, and (3) serum immunoglobulin levels compared with combat injuries that did not result in a retained metal fragment?

METHODS

In this pilot study, we analyzed metal-immunogenicity in injured military personnel and noninjured control participants using lymphocyte transformation testing (LTT, lymphocyte proliferation responses to cobalt, chromium and nickel challenge at 0.001, 0.01 and 0.1-mM concentrations in triplicate for each participant), serum metal ion analysis (ICP-mass spectroscopy), and serum immunoglobulin analysis (IgE, IgG, IgA, and IgM ). Military personnel with a battlefield-sustained injury self-recruited without any exclusion for sex, age, degree of injury. Those with battlefield injury resulting in retained metal fragments (INJ-FRAG, n = 20 male, mean time since injury ± SD was 12 ± 10 years) were compared with those with a battlefield injury but without retained metal fragments (INJ-NO-FRAG, n = 12 male, mean time since injury ± SD was 13 ± 12 years). A control group comprised of male noninjured participants was used to compare measured immunogenicity metrics (n = 11, males were selected to match battlefield injury group demographics).

RESULTS

Military participants with sustained metal fragments had increased levels of metal-induced lymphocyte responses. The lymphocyte stimulation index among military participants with metal fragments was higher than in those with nonretained metal fragments (stimulation index = 4.2 ± 6.0 versus stimulation index = 2.1 ± 1.2 (mean difference 2.1 ± 1.4 [95% confidence interval 5.1 to 0.8]; p = 0.07) and an average stimulation index = 2 ± 1 in noninjured controls. Four of 20 participants injured with retained fragments had a lymphocyte proliferation index greater than 2 to cobalt compared with 0 in the group without a retained metal fragment or 0 in the control participants. However, with the numbers available, military personnel with retained metal fragments did not have higher serum metal ion levels than military participants without retained metal fragment-related injuries or control participants. Military personnel with retained metal fragments had lower serum immunoglobulin levels (IgG, IgA, and IgM) than military personnel without retained metal fragments and noninjured controls, except for IgE. Individuals who were metal-reactive positive (that is, a stimulation index > 2) with retained metal fragments had higher median IgE serum levels than participants who metal-reactive with nonmetal injuries (1198 ± 383 IU/mL versus 171 ± 67 IU/mL, mean difference 1027 ± 477 IU/mL [95% CI 2029 to 25]; p = 0.02).

CONCLUSIONS

We found that males with retained metal fragments after a battlefield-related injury had altered adaptive immune responses compared with battlefield-injured military personnel without indwelling metal fragments. Military participants with a retained metal fragment had an increased proportion of group members and increased average lymphocyte reactivity to common implant metals such as nickel and cobalt. Further studies are needed to determine a causal association between exposure to amounts of retained metal fragments, type of injury, personnel demographics and general immune function/reactivity that may affect personal health or future metal implant performance.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Postoperative Spine Infection: Diagnosis and Management

STUDY DESIGN

Review article.

OBJECTIVES

A review of the literature on postoperative spinal infections, their diagnosis, and management.

METHODS

A systematic computerized Medline literature search was performed using PubMed, Cochrane Database of Systematic Reviews, and EMBASE. The electronic databases were searched for publication dates from the last 10 years. The searches were performed from Medical Subject Headings (MeSH) used by the National Library of Medicine. Specifically, MeSH terms "spine," "infections," "management," and "diagnosis" were used.

RESULTS

Currently, the gold standard for diagnosis of postoperative spine infection is positive deep wound culture. Many of the current radiologic and laboratory tests can assist with the initial diagnosis and monitoring treatment response. Currently erythrocyte sedimentation rate, C-reactive protein, computed tomography scan, and magnetic resonance imaging with and without contrast are used in combination to establish diagnosis. Management of postoperative spine infection involves thorough surgical debridement and targeted antibiotic therapy.

CONCLUSIONS

Postoperative spine infection is a not uncommon complication following surgery that may have devastating consequences for a patient's short- and long-term health. A high index of suspicion is needed to make an early diagnosis.

Preclosure spectroscopic differences between healed and dehisced traumatic wounds

BACKGROUND

The complexity and severity of traumatic wounds in military and civilian trauma demands improved wound assessment, before, during, and after treatment. Here, we explore the potential of 3 charge-coupled device (3CCD) imaging values to distinguish between traumatic wounds that heal following closure and those that fail. Previous studies demonstrate that normalized 3CCD imaging values exhibit a high correlation with oxygen saturation and allow for comparison of values between diverse clinical settings, including utilizing different equipment and lighting.

METHODS

We screened 119 patients at Walter Reed National Military Medical Center and at Grady Memorial Hospital with at least one traumatic extremity wound of ≥ 75 cm2. We collected images of each wound during each débridement surgery for a total of 66 patients. An in-house written computer application selected a region of interest in the images, separated the pixel color values, calculated relative values, and normalized them. We followed patients until the enrolled wounds were surgically closed, quantifying the number of wounds that dehisced (defined as wound failure or infection requiring return to the operating room after closure) or healed.

RESULTS

Wound failure occurred in 20% (19 of 96) of traumatic wounds. Normalized intensity values for patients with wounds that healed successfully were, on average, significantly different from values for patients with wounds that failed (p ≤ 0.05). Simple thresholding models and partial least squares discriminant analysis models performed poorly. However, a hierarchical cluster analysis model created with 17 variables including 3CCD data, wound surface area, and time from injury predicts wound failure with 76.9% sensitivity, 76.5% specificity, 76.6% accuracy, and a diagnostic odds ratio of 10.8 (95% confidence interval: 2.6-45.9).

CONCLUSIONS

Imaging using 3CCD technology may provide a non-invasive and cost-effective method of aiding surgeons in deciding if wounds are ready for closure and could potentially decrease the number of required débridements and hospital days. The process may be automated to provide real-time feedback in the operating room and clinic. The low cost and small size of the cameras makes this technology attractive for austere and shipboard environments where space and weight are at a premium.

Perceived Stress and Surgical Wound Cytokine Patterns

This was a pilot study to examine pre- and postoperative stress experienced by women who were undergoing autologous breast reconstruction and how stress might impact wound healing, specifically examining cytokines and other chemical mediators in the wound environment. A nonexperimental descriptive design over time was utilized. Participants were women who were undergoing autologous abdominal breast reconstruction for breast cancer (N = 20). Data were collected preoperatively and at 24, 48, 72, and 96 hr postsurgery. Complications were monitored intraoperatively and up to 30 days postsurgery. Psychological stress was measured with the 10-item Perceived Stress Scale (PSS), the Impact of Events Scale-Revised (IES-R), and a 100-mm Visual Analog Scale (VAS). Cytokines were assayed using the 27-plex kit with a Bio-Plex Plus. Although breast cancer is considered a stressor, in this sample of women, scores of the PSS, IES-R, and VAS showed that in fact these participants experienced low levels of psychological stress. All measured biochemical mediators in serum and wound fluid were detected and trends were identified. IL-1ra, IL-6, IL-8, G-CSF, IP-10, MCP-1, MIP-1β, RANTES, and VEGF were present in the highest concentrations. Significant changes in levels of cytokines in wound fluid were observed in IL-1β, IL-2, IL-5, IL-6, IL-8, IL-9, IL-10, IL-17, FGF-basic, G-CSF, MIP-1α, PDGF-bb, MIP-1β, RANTES, and TNF-α. The remaining cytokine concentrations stayed stable over time. These findings suggest that although these women were not experiencing high levels of stress, meaningful cytokine patterns were detected.

Defining the Balance between Regeneration and Pathological Ossification in Skeletal Muscle Following Traumatic Injury

Heterotopic ossification (HO) is characterized by the formation of bone at atypical sites. This type of ectopic bone formation is most prominent in skeletal muscle, most frequently resulting as a consequence of physical trauma and associated with aberrant tissue regeneration. The condition is debilitating, reducing a patient's range of motion and potentially causing severe pathologies resulting from nerve and vascular compression. Despite efforts to understand the pathological processes governing HO, there remains a lack of consensus regarding the micro-environmental conditions conducive to its formation, and attempting to define the balance between muscle regeneration and pathological ossification remains complex. The development of HO is thought to be related to a complex interplay between factors released both locally and systemically in response to trauma. It develops as skeletal muscle undergoes significant repair and regeneration, and is likely to result from the misdirected differentiation of endogenous or systemically derived progenitors in response to biochemical and/or environmental cues. The process can be sequentially delineated by the presence of inflammation, tissue breakdown, adipogenesis, hypoxia, neo-vasculogenesis, chondrogenesis and ossification. However, exactly how each of these stages contributes to the formation of HO is at present not well understood. Our previous review examined the cellular contribution to HO. Therefore, the principal aim of this review will be to comprehensively outline changes in the local tissue micro-environment following trauma, and identify how these changes can alter the balance between skeletal muscle regeneration and ectopic ossification. An understanding of the mechanisms governing this condition is required for the development and advancement of HO prophylaxis and treatment, and may even hold the key to unlocking novel methods for engineering hard tissues.

Nonsteroidal anti-inflammatory drugs may affect cytokine response and benefit healing of combat-related extremity wounds

BACKGROUND

After adequate operative debridement and antimicrobial therapies, combat-related extremity wounds that either heal or fail are both associated with a distinct inflammatory response. Short-term use of nonsteroidal anti-inflammatory drugs in postoperative pain management may affect this response and, by consequence, the healing potential of these wounds. We investigated whether patients treated with nonsteroidal anti-inflammatory drugs had a distinct inflammatory response; different rates of critical colonization, defined as >10⁵ colony forming units on quantitative bacteriology; and healing potential.

METHODS

We retrospectively reviewed the records of 73 patients with combat-related extremity wounds. Patients were separated into 2 groups: those who received nonsteroidal anti-inflammatory drugs during the debridement period (nonsteroidal anti-inflammatory drugs group, N = 17) and those who did not (control group; N = 56). Serum and wound tissue samples collected during each operative debridement were measured for 32 known cytokines and tested for quantitative bacteriology, respectively. We compared cytokine concentrations between groups and then designed a logistic regression model to identify variables associated with successful wound healing, while controlling for known confounders.

RESULTS

Despite similar demographics and wound characteristics, the nonsteroidal anti-inflammatory drugs group had significant lesser concentrations of inflammatory cytokines, interleukin-2, interleukin-6, interleukin-8, and monocyte chemoattractant protein-1. On multivariate analysis, nonsteroidal anti-inflammatory drug treatment emerged as a predictor of successful wound healing after controlling for known confounders such as wound size, tobacco use, Acute Physiology and Chronic Health Evaluation II score, and critical colonization.

CONCLUSION

Treatment with nonsteroidal anti-inflammatory drugs for postoperative pain management after major combat-related extremity trauma is associated with lesser concentrations of inflammatory cytokines and may contribute to a more favorable inflammatory response leading to successful wound healing.

LL-37 but Not 25-Hydroxy-Vitamin D Serum Level Correlates with Healing of Venous Leg Ulcers

Human cathelicidin, LL-37, is small antimicrobial peptide, which reveals also some immunomodulatory and proangiogenic properties and, therefore, may promote wound healing. The expression of LL-37 is controlled by various factors, including vitamin D. Thus, any disturbances in vitamin D level may influence LL-37 production and, possibly, affect wound healing. Since deficiency of vitamin D was identified as a common problem in the population, this proof of concept study aimed to verify the relationship between serum levels of LL-37, vitamin D, and healing rate of venous leg ulcers. The study involved small group (n = 19) of patients with venous leg ulcers. Apart from non-venous ulcer aethiology, compression intolerance, active vein thrombosis, and wound infection, the exclusion criteria concerned also kidney insufficiency. The results of the analysis of wound healing rates were correlated with patients' serum levels of 25(OH) vitamin D and LL-37. In addition, serum levels of pro-inflammatory cytokines (IL-6, IL-8, and TNF) were analyzed. We have found strong association between serum concentrations of LL-37 and the healing rates in patients with leg ulcers. Despite the fact that 25(OH) vitamin D levels in all patients were below the normal range, they did not show any correlation with healing rates. Furthermore, no association was observed between serum levels of 25(OH) vitamin D and LL-37. No significant correlation between tested pro-inflammatory cytokines and healing rate, LL-37, or 25(OH) vitamin D levels was also observed. Regardless of small study group, our results suggest that the assessment of serum concentration of LL-37, but not 25-hydroxy vitamin D, may help in predicting the wound healing efficacy. Moreover, this assessment may be useful in pre-selection of patients, which could benefit from local treatment with exogenous LL-37.

Pleural fluid procalcitonin to distinguish infectious from noninfectious etiologies of pleural effusions

In this study we investigate the diagnostic value of pleural fluid procalcitonin (PCT) in distinguishing infectious and noninfectious etiologies of pleural effusion. We reviewed the medical records of 75 hospitalized patients who underwent thoracentesis between 2011 and 2012. Data on pleural fluid lactate dehydrogenase (LDH), protein, albumin, cell count and differential, pH, Gram stain and culture, cytology, triglyceride, cholesterol, amylase, and PCT were collected. Data on serum LDH, protein, albumin, prothrombin time, normalized, and blood culture were also collected. Pleural effusions were classified into 2 groups, infectious and noninfectious. There were 18 infectious pleural effusions (IPE) and 57 noninfectious pleural effusions (NIPE). Median pleural fluid PCT was 1.088 ng/mL (0.312-2.940 ng/mL) in IPE and 0.123 ng/mL (0.05-0.263 ng/mL) in NIPE, with a P value < 0.0001. Pleural fluid PCT > 0.25 ng/mL had a sensitivity of 77.78% and specificity of 74.14% for diagnosing an IPE. A subgroup analysis of PCT in exudative infectious effusions versus exudative noninfectious malignant/paramalignant effusions showed higher levels in the former. PCT is a novel biomarker for diagnosing infectious pleural effusion, and it would be worthwhile to investigate the role of pleural PCT in assessing severity of illness, risk stratification, and antibiotic stewardship in hospitalized patients with pleural effusions. Journal of Hospital Medicine 2016;11:363-365. 2016 Society of Hospital Medicine.

Biomarkers for wound healing and their evaluation

A biological marker (biomarker) is a substance used as an indicator of biological state. Advances in genomics, proteomics and molecular pathology have generated many candidate biomarkers with potential clinical value. Research has identified several cellular events and mediators associated with wound healing that can serve as biomarkers. Macrophages, neutrophils, fibroblasts and platelets release cytokines molecules including TNF-α, interleukins (ILs) and growth factors, of which platelet-derived growth factor (PDGF) holds the greatest importance. As a result, various white cells and connective tissue cells release both matrix metalloproteinases (MMPs) and the tissue inhibitors of metalloproteinases (TIMPs). Studies have demonstrated that IL-1, IL-6, and MMPs, levels above normal, and an abnormally high MMP/TIMP ratio are often present in non-healing wounds. Clinical examination of wounds for these mediators could predict which wounds will heal and which will not, suggesting use of these chemicals as biomarkers of wound healing. There is also evidence that the application of growth factors like PDGF will alleviate the recuperating process of chronic, non-healing wounds. Finding a specific biomarker for wound healing status would be a breakthrough in this field and helping treat impaired wound healing.

Analysis of Orthopaedic Research Produced During the Wars in Iraq and Afghanistan

BACKGROUND

Military orthopaedic surgeons have published a substantial amount of original research based on our care of combat-wounded service members and related studies during the wars in Iraq and Afghanistan. However, to our knowledge, the influence of this body of work has not been evaluated bibliometrically, and doing so is important to determine the modern impact of combat casualty research in the wider medical community.

QUESTIONS/PURPOSES

We sought to identify the 20 most commonly cited works from military surgeons published during the Iraq and Afghanistan conflicts and analyze them to answer the following questions: (1) What were the subject areas of these 20 articles and what was the 2013 Impact Factor of each journal that published them? (2) How many citations did they receive and what were the characteristics of the journals that cited them? (3) Do the citation analysis results obtained from Google Scholar mirror the results obtained from Thompson-Reuters' Web of Science?

METHODS

We searched the Web of Science Citation Index Expanded for relevant original research performed by US military orthopaedic surgeons related to Operation Iraqi Freedom and Operation Enduring Freedom between 2001 and 2014. Articles citing these studies were reviewed using both Web of Science and Google Scholar data. The 20 most cited articles meeting inclusion criteria were identified and analyzed by content domain, frequency of citation, and sources in which they were cited.

RESULTS

Nine of these studies examined the epidemiology and outcome of combat injury. Six studies dealt with wound management, wound dehiscence, and formation of heterotopic ossification. Five studies examined infectious complications of combat trauma. The median number of citations garnered by these 20 articles was 41 (range, 28-264) in Web of Science. Other research citing these studies has appeared in 279 different journals, covering 26 different medical and surgical subspecialties, from authors in 31 different countries. Google Scholar contained 97% of the Web of Science citations, but also had 31 duplicate entries and 29 citations with defective links.

CONCLUSIONS

Modern combat casualty research by military orthopaedic surgeons is widely cited by researchers in a diverse range of subspecialties and geographic locales. This suggests that the military continues to be a source of innovation that is broadly applicable to civilian medical and surgical practice and should encourage expansion of military-civilian collaboration to maximize the utility of the knowledge gained in the treatment of war trauma.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Lessons of War: Turning Data Into Decisions

Background

Recent conflicts in Afghanistan and Iraq produced a substantial number of critically wounded service-members. We collected biomarker and clinical information from 73 patients who sustained 116 life-threatening combat wounds, and sought to determine if the data could be used to predict the likelihood of wound failure.

Methods

From each patient, we collected clinical information, serum, wound effluent, and tissue prior to and at each surgical débridement. Inflammatory cytokines were quantified in both the serum and effluent, as were gene expression targets. The primary outcome was successful wound healing. Computer intensive methods were used to derive prognostic models that were internally validated using target shuffling and cross-validation methods. A second cohort of eighteen critically injured civilian patients was evaluated to determine if similar inflammatory responses were observed.

Findings

The best-performing models enhanced clinical observation with biomarker data from the serum and wound effluent, an indicator that systemic inflammatory conditions contribute to local wound failure. A Random Forest model containing ten variables demonstrated the highest accuracy (AUC 0.79). Decision Curve Analysis indicated that the use of this model would improve clinical outcomes and reduce unnecessary surgical procedures. Civilian trauma patients demonstrated similar inflammatory responses and an equivalent wound failure rate, indicating that the model may be generalizable to civilian settings.

Interpretation

Using advanced analytics, we successfully codified clinical and biomarker data from combat patients into a potentially generalizable decision support tool. Analysis of inflammatory data from critically ill patients with acute injury may inform decision-making to improve clinical outcomes and reduce healthcare costs.

Funding

United States Department of Defense Health Programs.

•

We analyzed biomarker and clinical data to predict the likelihood of wound failure.

•

We found that systematic inflammatory conditions contribute to local wound failure.

•

This response is comparable between combat wounded and civilian patients.

•

This response can be measured and translated into clinical decision support tools.

•

These predictive models will benefit both military and civilian health systems.

Antifungal wound penetration of amphotericin and voriconazole in combat-related injuries: case report

Background

Survivors of combat trauma can have long and challenging recoveries, which may be complicated by infection. Invasive fungal infections are a rare but serious complication with limited treatment options. Currently, aggressive surgical debridement is the standard of care, with antifungal agents used adjunctively with uncertain efficacy. Anecdotal evidence suggests that antifungal agents may be ineffective in the absence of surgical debridement, and studies have yet to correlate antifungal concentrations in plasma and wounds.

Case presentation

Here we report the systemic pharmacokinetics and wound effluent antifungal concentrations of five wounds from two male patients, aged 28 and 30 years old who sustained combat-related blast injuries in southern Afghanistan, with proven or possible invasive fungal infection. Our data demonstrate that while voriconazole sufficiently penetrated the wound resulting in detectable effluent levels, free amphotericin B (unbound to plasma) was not present in wound effluent despite sufficient concentrations in circulating plasma. In addition, considerable between-patient and within-patient variability was observed in antifungal pharmacokinetic parameters.

Conclusion

These data highlight the need for further studies evaluating wound penetration of commonly used antifungals and the role for therapeutic drug monitoring in providing optimal care for critically ill and injured war fighters.

Host response biomarkers in sepsis: the role of procalcitonin

Procalcitonin is the prohormone of calcitonin and present in minute quantities in health. However, during infection, its levels rise considerably and are correlated with the severity of the infection. Several assays have been developed for measurement of procalcitonin levels; in this article, we will briefly present the PCT-sensitive Kryptor(®) test (Brahms, Hennigsdorf, Germany), one of the most widely used assays for procalcitonin in recent studies. Many studies have demonstrated the value of procalcitonin levels for diagnosing sepsis and assessing disease severity. Procalcitonin levels have also been successfully used to guide antibiotic administration. However, procalcitonin is not specific for sepsis, and values need to be interpreted in the context of a full clinical examination and the presence of other signs and symptoms of sepsis.

Fluid collections in amputations are not indicative or predictive of infection

BACKGROUND

In the acute postoperative period, fluid collections are common in lower extremity amputations. Whether these fluid collections increase the risk of infection is unknown.

QUESTIONS/PURPOSES

The purposes of this study were to determine (1) the percentage of patients who develop postoperative fluid collections in posttraumatic amputations and the natural course of the collection; (2) whether patients who develop these collections are at increased risk for infection; and to ask (3) are there objective clinical or radiologic signs that are associated with likelihood of infection when a fluid collection is present?

METHODS

We performed a review of all 300 patients injured in combat operations who sustained at least one major lower extremity amputation (at or proximal to the tibiotalar joint) and were treated definitively at our institution between March 2005 and April 2009. We segregated the groups based on whether cross-sectional imaging was performed less than 3 months (early group) after closure, greater than 3 months (late group) after closure, or not at all (control group, baseline frequency of infection). Our primary study cohort where those patients with a fluid collection in the first three months. The clinical course was reviewed and the primary outcome was a return to the operating room for irrigation and débridement with positive cultures. For those patients with cross-sectional imaging, we also collected objective clinical parameters within 24 hours of the scan (white blood cell count, maximum temperature, presence of bacteremia, tachycardia, oxygen desaturation), extremity examination (presence of erythema, warmth, and/or drainage), and characteristics of the fluid collections seen (size of the fluid collection, enhancement, complexity (simple versus loculated), surrounding edema, skin changes, tract formation, presence of air, and changes within the bone itself). The presence of a fluid collection on imaging was analyzed to determine whether it was associated with infection. We further analyzed clinical parameters, objective physical examination findings at the extremity, and characteristics of the fluid collection to determine if there were other parameters associated with infection.

RESULTS

Over half (55%) of the limbs demonstrated fluid collection in the early postoperative period and the prevalence decreased in the late group (11%; p = 0.001). There was no association between the presence of a fluid collection and infection. However, there was an association between objective clinical signs at the extremity (erythema and/or drainage) and infection (p < 0.001) in our primary study cohort.

CONCLUSIONS

Fluid collections are common in combat-related amputations in the immediate postoperative period and become smaller and less frequent over time. In the absence of extremity erythema and wound drainage, imaging of a residual limb to evaluate for the presence of a fluid collection appears to be of little clinical use.

Do inflammatory markers portend heterotopic ossification and wound failure in combat wounds?

BACKGROUND

After a decade of war in Iraq and Afghanistan, we have observed an increase in combat-related injury survival and a paradoxical increase in injury severity, mainly because of the effects of blasts. These severe injuries have a devastating effect on each patient's immune system resulting in massive upregulation of the systemic inflammatory response. By examining inflammatory mediators, preliminary data suggest that it may be possible to correlate complications such as wound failure and heterotopic ossification (HO) with distinct systemic and local inflammatory profiles, but this is a relatively new topic.

QUESTIONS/PURPOSES

We asked whether systemic or local markers of inflammation could be used as an objective means, independent of demographic and subjective factors, to estimate the likelihood of (1) HO and/or (2) wound failure (defined as wounds requiring surgical débridement after definitive closure, or wounds that were not closed or covered within 21 days of injury) in patients sustaining combat wounds.

METHODS

Two hundred combat wounded active-duty service members who sustained high-energy extremity injuries were prospectively enrolled between 2008 and 2012. Of these 200 patients, 189 had adequate followups to determine the presence or absence of HO, and 191 had adequate followups to determine the presence or absence of wound failure. In addition to injury-specific and demographic data, we quantified 24 cytokines and chemokines during each débridement. Patients were followed clinically for 6 weeks, and radiographs were obtained 3 months after definitive wound closure. Associations were investigated between these markers and wound failure or HO, while controlling for known confounders.

RESULTS

The presence of an amputation (p < 0.001; odds ratio [OR], 6.1; 95% CI. 1.63-27.2), Injury Severity Score (p = 0.002; OR, 33.2; 95% CI, 4.2-413), wound surface area (p = 0.001; OR, 1.01; 95% CI, 1.002-1.009), serum interleukin (IL)-3 (p = 0.002; OR, 2.41; 95% CI, 1.5-4.5), serum IL-12p70 (p = 0.01; OR, 0.49; 95% CI, 0.27-0.81), effluent IL-3 (p = 0.02; OR, 1.75; 95% CI, 1.2-2.9), and effluent IL-13 (p = 0.006; OR, 0.67; 95% CI, 0.50-0.87) were independently associated with HO formation. Injury Severity Score (p = 0.05; OR, 18; 95% CI, 5.1-87), wound surface area (p = 0.05; OR, 28.7; 95% CI, 1.5-1250), serum procalcitonin ([ProCT] (p = 0.03; OR, 1596; 95% CI, 5.1-1,758,613) and effluent IL-6 (p = 0.02; OR, 83; 95% CI, 2.5-5820) were independently associated with wound failure.

CONCLUSIONS

We identified associations between patients' systemic and local inflammatory responses and wound-specific complications such as HO and wound failure. However, future efforts to model these data must account for their complex, time dependent, and nonlinear nature.

LEVEL OF EVIDENCE

Level II, prognostic study. See the Instructions for Authors for a complete description of levels of evidence.

Microbial profiling of combat wound infection through detection microarray and next-generation sequencing

Combat wound healing and resolution are highly affected by the resident microbial flora. We therefore sought to achieve comprehensive detection of microbial populations in wounds using novel genomic technologies and bioinformatics analyses. We employed a microarray capable of detecting all sequenced pathogens for interrogation of 124 wound samples from extremity injuries in combat-injured U.S. service members. A subset of samples was also processed via next-generation sequencing and metagenomic analysis. Array analysis detected microbial targets in 51% of all wound samples, with Acinetobacter baumannii being the most frequently detected species. Multiple Pseudomonas species were also detected in tissue biopsy specimens. Detection of the Acinetobacter plasmid pRAY correlated significantly with wound failure, while detection of enteric-associated bacteria was associated significantly with successful healing. Whole-genome sequencing revealed broad microbial biodiversity between samples. The total wound bioburden did not associate significantly with wound outcome, although temporal shifts were observed over the course of treatment. Given that standard microbiological methods do not detect the full range of microbes in each wound, these data emphasize the importance of supplementation with molecular techniques for thorough characterization of wound-associated microbes. Future application of genomic protocols for assessing microbial content could allow application of specialized care through early and rapid identification and management of critical patterns in wound bioburden.

Proteomic sample preparation for blast wound characterization

Background

Blast wounds often involve diverse tissue types and require substantial time and treatment for appropriate healing. Some of these subsequent wounds become colonized with bacteria requiring a better understanding of how the host responds to these bacteria and what proteomic factors contribute wound healing outcome. In addition, using reliable and effective proteomic sample preparation procedures can lead to novel biomarkers for improved diagnosis and therapy.

Results

To address this need, suitable sample preparation for 2-D DIGE proteomic characterization of wound effluent and serum samples from combat-wounded patients was investigated. Initial evaluation of crude effluent and serum proved the necessity of high abundant protein depletion. Subsequently, both samples were successfully depleted using Agilent Multiple Affinity Removal system and showed greatly improved 2-D spot maps, comprising 1,800 and 1,200 protein spots, respectively.

Conclusion

High abundant protein removal was necessary for both wound effluent and serum. This is the first study to show a successful method for high abundant protein depletion from wound effluent which is compatible with downstream 2-D DIGE analysis. This development allows for improved biomarker discovery in wound effluent and serum samples.

Evidence-based medicine: pressure sores

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Cite risk factors for pressure sore development. 2. Detail the pathophysiology of pressure sores. 3. List the types and classification of pressure sores. 4. Consider the various nonsurgical conservative wound management strategies. 5. Describe the appropriate surgical interventions for each pressure sore type. 6. Understand the causes of recurrent pressure sores and methods of avoiding recurrence.

SUMMARY

Pressure sores are the result of unrelieved pressure, usually over a bony prominence. With an estimated 2.5 million pressure ulcers treated annually in the United States at a cost of $11 billion, pressure sores represent a costly and labor-intensive challenge to the health care system. A comprehensive team approach can address both prevention and treatment of these recalcitrant wounds. Consideration must be given to the patient's medical and socioeconomic condition, as these factors are significantly related to outcomes. Mechanical prophylaxis, nutritional optimization, treatment of underlying infection, and spasm control are essential in management. A variety of pressure sore patterns exist, with surgical approaches directed to maximize future coverage options. A comprehensive approach is detailed in this article to provide the reader with the range of treatment options available.

Computational approach to characterize causative factors and molecular indicators of chronic wound inflammation

Chronic inflammation is rapidly becoming recognized as a key contributor to numerous pathologies. Despite detailed investigations, understanding of the molecular mechanisms regulating inflammation is incomplete. Knowledge of such critical regulatory processes and informative indicators of chronic inflammation is necessary for efficacious therapeutic interventions and diagnostic support to clinicians. We used a computational modeling approach to elucidate the critical factors responsible for chronic inflammation and to identify robust molecular indicators of chronic inflammatory conditions. Our kinetic model successfully captured experimentally observed cell and cytokine dynamics for both acute and chronic inflammatory responses. Using sensitivity analysis, we identified macrophage influx and efflux rate modulation as the strongest inducing factor of chronic inflammation for a wide range of scenarios. Moreover, our model predicted that, among all major inflammatory mediators, IL-6, TGF-β, and PDGF may generally be considered the most sensitive and robust indicators of chronic inflammation, which is supported by existing, but limited, experimental evidence.

Immunoinflammatory response in critically ill patients: severe sepsis and/or trauma

Immunoinflammatory response in critically ill patients is very complex. This review explores some of the new elements of immunoinflammatory response in severe sepsis, tumor necrosis factor-alpha in severe acute pancreatitis as a clinical example of immune response in sepsis, immune response in severe trauma with or without secondary sepsis, and genetic aspects of host immuno-inflammatory response to various insults in critically ill patients.

Wound outcome in combat injuries is associated with a unique set of protein biomarkers

Background

The ability to forecast whether a wound will heal after closure without further debridement(s), would provide substantial benefits to patients with severe extremity trauma.

Methods

Wound effluent is a readily available material which can be collected without disturbing healthy tissue. For analysis of potential host response biomarkers, forty four serial combat wound effluent samples from 19 patients with either healing or failing traumatic- and other combat-related wounds were examined by 2-D DIGE. Spot map patterns were correlated to eventual wound outcome (healed or wound failure) and analyzed using DeCyder 7.0 and differential proteins identified via LC-MS/MS.

Results

This approach identified 52 protein spots that were differentially expressed and thus represent candidate biomarkers for this clinical application. Many of these proteins are intimately involved in inflammatory and immune responses. Furthermore, discriminate analysis further refined the 52 differential protein spots to a smaller subset of which successfully differentiate between wounds that will heal and those that will fail and require further surgical intervention with greater than 83% accuracy.

Conclusion

These results suggest candidates for a panel of protein biomarkers that may aid traumatic wound care prognosis and treatment. We recommend that this strategy be refined, and then externally validated, in future studies of traumatic wounds.

Bilateral lower-extremity amputation wounds are associated with distinct local and systemic cytokine response

BACKGROUND

Approximately 25% of U.S. military members sustaining extremity amputations in recent military conflicts have bilateral lower-extremity amputations (BLA). We investigated among combat-related extremity wounds whether BLA exhibit different bacterial burden, inflammatory response, and local complications.

METHODS

A total of 75 patients with combat-related extremity wounds (19 BLA) were evaluated for age, tobacco use, body mass index, Injury Severity Score, Acute Physiology and Chronic Health Evaluation II, and delayed primary closure time. Blood, wound exudates, and muscle biopsies were obtained and analyzed for cytokine and quantitative bacteriology, excluding patients using nonsteroidal anti-inflammatory medications and corticosteroids, due to potential effects on their inflammatory profile.

RESULTS

BLA was not associated with differences in age, tobacco use, body mass index, and delayed primary closure time, but these patients had increased Injury Severity Score, Acute Physiology and Chronic Health Evaluation II, and rates of critical colonization. Proinflammatory cytokines including tumor necrosis factor-α (exudate), interleukin (IL)-1 (exudate) and IL-6 (serum) were increased in BLA patients. They also had serum and exudate increased IL-8 and decreased IL-13 and granulocyte-macrophage colony-stimulating factor. Both wound dehiscence (WD) and heterotopic ossification (HO) were more common in BLA patients.

CONCLUSION

BLA patients were more likely to exhibit critical bacterial colonization, a distinct inflammatory response, and develop WD and HO. Modulating this response represents an attractive target in an effort to prevent complications such as WD and HO.

Reconstructive challenges in war wounds

War wounds are devastating with extensive soft tissue and osseous destruction and heavy contamination. War casualties generally reach the reconstructive surgery centre after a delayed period due to additional injuries to the vital organs. This delay in their transfer to a tertiary care centre is responsible for progressive deterioration in wound conditions. In the prevailing circumstances, a majority of war wounds undergo delayed reconstruction, after a series of debridements. In the recent military conflicts, hydrosurgery jet debridement and negative pressure wound therapy have been successfully used in the preparation of war wounds. In war injuries, due to a heavy casualty load, a faster and reliable method of reconstruction is aimed at. Pedicle flaps in extremities provide rapid and reliable cover in extremity wounds. Large complex defects can be reconstructed using microvascular free flaps in a single stage. This article highlights the peculiarities and the challenges encountered in the reconstruction of these ghastly wounds.

Cellular events and biomarkers of wound healing

Researchers have identified several of the cellular events associated with wound healing. Platelets, neutrophils, macrophages, and fibroblasts primarily contribute to the process. They release cytokines including interleukins (ILs) and TNF-α, and growth factors, of which platelet-derived growth factor (PDGF) is perhaps the most important. The cytokines and growth factors manipulate the inflammatory phase of healing. Cytokines are chemotactic for white cells and fibroblasts, while the growth factors initiate fibroblast and keratinocyte proliferation. Inflammation is followed by the proliferation of fibroblasts, which lay down the extracellular matrix. Simultaneously, various white cells and other connective tissue cells release both the matrix metalloproteinases (MMPs) and the tissue inhibitors of these metalloproteinases (TIMPs). MMPs remove damaged structural proteins such as collagen, while the fibroblasts lay down fresh extracellular matrix proteins. Fluid collected from acute, healing wounds contains growth factors, and stimulates fibroblast proliferation, but fluid collected from chronic, nonhealing wounds does not. Fibroblasts from chronic wounds do not respond to chronic wound fluid, probably because the fibroblasts of these wounds have lost the receptors that respond to cytokines and growth factors. Nonhealing wounds contain high levels of IL1, IL6, and MMPs, and an abnormally high MMP/TIMP ratio. Clinical examination of wounds inconsistently predicts which wounds will heal when procedures like secondary closure are planned. Surgeons therefore hope that these chemicals can be used as biomarkers of wounds which have impaired ability to heal. There is also evidence that the application of growth factors like PDGF will help the healing of chronic, nonhealing wounds.

Inflammatory cytokine and chemokine expression is associated with heterotopic ossification in high-energy penetrating war injuries

OBJECTIVE

Heterotopic ossification (HO) develops frequently after modern high-energy penetrating war injuries. The purpose of this prospective study was to identify and characterize the unique cytokine and chemokine profile associated with the development of HO as it pertained to the systemic inflammatory response after penetrating combat-related trauma.

METHODS

Patients with high-energy penetrating extremity wounds were prospectively enrolled. Surgical debridement along with the use of a pulse lavage and vacuum-assisted-closure device was performed every 48-72 hours until definitive wound closure. Wound bed tissue biopsy, wound effluent, and serum were collected before each debridement. Effluent and serum were analyzed for 22 relevant cytokines and chemokines. Tissue was analyzed quantitatively for bacterial colonization. Correlations between specific wound and patient characteristics were also analyzed. The primary clinical outcome measure was the formation of HO as confirmed by radiographs at a minimum of 2 months of follow-up.

RESULTS

Thirty-six penetrating extremity war wounds in 24 patients were investigated. The observed rate of HO in the study population was 38%. Of the 36 wounds, 13 (36%) demonstrated HO at a minimum follow-up of 2 months. An elevated injury severity score was associated with the development of HO (P = 0.006). Wound characteristics that correlated with the development of HO included impaired healing (P = 0.005) and bacterial colonization (P < 0.001). Both serum (interleukin-6, interleukin-10, and MCP-1) and wound effluent (IP-10 and MIP-1α) cytokine and chemokine bioprofiles were individually associated and suggestive of the development of HO (P < 0.05).

CONCLUSIONS

A severe systemic and wound-specific inflammatory state as evident by elevated levels of inflammatory cytokines, elevated injury severity score, and bacterial wound colonization is associated with the development of HO. These findings suggest that the development of HO in traumatic combat-related wounds is associated with a hyper-inflammatory systemic response to injury.

LEVEL OF EVIDENCE

Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Axioms altered with research

The medical community is actively engaged in research to provide the highest level of evidence to support clinical practice. The care of wounded warriors creates unique challenges, and conducting research that provides evidence for clinical practice is important to outcomes in this patient population. When the current wars began, much debate centered on the best way to care for wounded warriors. To address these concerns, we use a MythBusters format, based on the popular television show, to describe how recent research has dispelled some earlier misconceptions and clarify how clinical practice has been changed. In addition, we assess the progress that has been made on addressing the original prioritized research objectives of the first Extremity War Injuries symposium.

Guidelines for the prevention of infections associated with combat-related injuries: 2011 update: endorsed by the Infectious Diseases Society of America and the Surgical Infection Society

Despite advances in resuscitation and surgical management of combat wounds, infection remains a concerning and potentially preventable complication of combat-related injuries. Interventions currently used to prevent these infections have not been either clearly defined or subjected to rigorous clinical trials. Current infection prevention measures and wound management practices are derived from retrospective review of wartime experiences, from civilian trauma data, and from in vitro and animal data. This update to the guidelines published in 2008 incorporates evidence that has become available since 2007. These guidelines focus on care provided within hours to days of injury, chiefly within the combat zone, to those combat-injured patients with open wounds or burns. New in this update are a consolidation of antimicrobial agent recommendations to a backbone of high-dose cefazolin with or without metronidazole for most postinjury indications, and recommendations for redosing of antimicrobial agents, for use of negative pressure wound therapy, and for oxygen supplementation in flight.

Prevention of infections associated with combat-related extremity injuries

During combat operations, extremities continue to be the most common sites of injury with associated high rates of infectious complications. Overall, ∼ 15% of patients with extremity injuries develop osteomyelitis, and ∼ 17% of those infections relapse or recur. The bacteria infecting these wounds have included multidrug-resistant bacteria such as Acinetobacter baumannii, Pseudomonas aeruginosa, extended-spectrum β-lactamase-producing Klebsiella species and Escherichia coli, and methicillin-resistant Staphylococcus aureus. The goals of extremity injury care are to prevent infection, promote fracture healing, and restore function. In this review, we use a systematic assessment of military and civilian extremity trauma data to provide evidence-based recommendations for the varying management strategies to care for combat-related extremity injuries to decrease infection rates. We emphasize postinjury antimicrobial therapy, debridement and irrigation, and surgical wound management including addressing ongoing areas of controversy and needed research. In addition, we address adjuvants that are increasingly being examined, including local antimicrobial therapy, flap closure, oxygen therapy, negative pressure wound therapy, and wound effluent characterization. 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.

Biomarkers to predict wound healing: the future of complex war wound management

BACKGROUND

Currently, no biological assay exists to objectively assess wounds to aid in timing of wound closure and guide therapy. In this article, the authors review military investigations in biomarkers as a method of objectively determining acute traumatic wound physiology and their applicability in predicting healing of complex soft-tissue wounds.

METHODS

The civilian literature related to biomarkers and wound physiology related to chronic and acute wounds was reviewed as a basis for current research into acute traumatic soft-tissue wounds.

RESULTS

Analysis of serum and wound effluent from traumatic extremity soft-tissue combat wounds revealed changes in specific proinflammatory matrix metalloproteinases associated with impaired wound healing. Forsberg et al. analyzed serum and wound effluent for chemokines and cytokines. An increase in serum procalcitonin levels correlated with wound dehiscence. Lastly, serum, wound effluent, and wound bed tissue biopsy specimens were analyzed by Hawksworth et al. Consistent with previous studies, elevation in proinflammatory cytokines was associated with wound dehiscence.

CONCLUSIONS

Changes in levels of proteases, protease inhibitors, and inflammatory markers have been correlated with wound healing. These findings further support the idea that inflammatory dysregulation and a persistent inflammatory state leads to failure of wound healing in the acute setting. These findings highlight potential targets for the development of a biological assay to individualize management of complex soft-tissue wounds, based on patient physiology and response, that would be applicable to not only military trauma but also civilian trauma. Ultimately, this would result in earlier wound closure, reduction in the number of operating room trips, and reduced health care costs.

Diagnosis and management of chronic infection

High-energy penetrating extremity injuries are often associated with severe open fractures that have varying degrees of soft-tissue contamination and tenuous soft-tissue coverage. The result is a relatively high prevalence of chronic osteomyelitis compared with that in civilian trauma patients. Diagnosing chronic osteomyelitis requires a careful history and thorough physical and radiographic examinations. Cross-sectional imaging can help delineate the extent of bony involvement, and scintigraphy can be used as a diagnostic tool and to gauge response to treatment. Clinical staging also directs surgical management. Adequacy of débridement remains the most important clinical predictor of success; thus, adopting an oncologic approach to complete (ie, wide) excision is important. Reconstruction can be safely performed by a variety of methods; however, proper staging and patient selection remain critical to a successful outcome. Although systemic and depot delivery of antibiotics plays a supporting role in the treatment of chronic osteomyelitis, the ideal dosing regimens, and the duration of treatment, remain controversial.

Wound complications in thyroxine-supplemented patients following foot and ankle surgery

BACKGROUND

Our hypothesis was that thyroxine supplementation in patients undergoing foot and ankle surgery would be associated with increased postoperative wound complications and wound dehiscence compared to patients without thyroxine supplementation.

MATERIALS AND METHODS

A retrospective review of 48 patients supplemented with thyroxine that underwent foot and ankle surgery was conducted and analyzed for wound complications. All patients were non-diabetic. A total of 94 historical controls were used to compare the incidence of wound complications to the thyroxine sample. Patient demographics, medical comorbidities, principal diagnosis and procedure performed were recorded. The presence or absence of wound dehiscence, infection or other wound complications was recorded for all patients based on the followup clinical notes in the electronic record.

RESULTS

In the thyroxine group, the most common diagnosis was degenerative arthritis (31%, n=15), which also occurred in 28.7% of control patients (n=27). Wound dehiscence was reported in 36.2% (n=17) of thyroxine-supplemented patients compared to 10.8% of control patients (n=10). After adjusting for age, gender, hypertension diagnosis, and vascular disease diagnosis, the odds for wound dehiscence remained significantly greater for the thyroxine group compared to control patients (adjusted OR=3.7; 95% CI: (1.3, 11.4); p=0.01).

CONCLUSION

Overall, our results suggest increased wound dehiscence complications in the postoperative period for thyroxine-supplemented patients compared to control patients. This finding remained even after adjusting for the associated cardiovascular comorbidities seen in thyroxine-supplemented patients.

Traumatic and trauma-related amputations: part I: general principles and lower-extremity amputations

Deliberate attention to the management of soft tissue is imperative when performing an amputation. Identification and proper management of the nerves accompanied by the performance of a stable myodesis and ensuring robust soft-tissue coverage are measures that will improve patient outcomes. Limb length should be preserved when practicable; however, length preservation at the expense of creating a nonhealing or painful residual limb with poor soft-tissue coverage is contraindicated. While a large proportion of individuals with a trauma-related amputation remain severely disabled, a chronically painful residual limb is not inevitable and late revision amputations to improve soft-tissue coverage, stabilize the soft tissues (revision myodesis), or remove symptomatic neuromas can dramatically improve patient outcomes. Psychosocial issues may dramatically affect the outcomes after trauma-related amputations. A multidisciplinary team should be consulted or created to address the multiple complex physical, mental, and psychosocial issues facing patients with a recent amputation.

Biomarker use in tailored combat casualty care

Modern war wounds are complex and primarily involve extremities. They require multiple operative interventions to achieve wound closure and begin rehabilitation. Current assessment of the suitability of surgical wound closure is based upon subjective methods coupled with a semiquantitative determination of the wound bacterial burden. Measurement of the systemic and local response to injury using inflammatory biomarkers may allow for accelerated wound closure and treatment of other combat-related morbidity. This article presents the introduction of personalized medicine into combat casualty care.

Development of a Bayesian model to estimate health care outcomes in the severely wounded

BACKGROUND

Graphical probabilistic models have the ability to provide insights as to how clinical factors are conditionally related. These models can be used to help us understand factors influencing health care outcomes and resource utilization, and to estimate morbidity and clinical outcomes in trauma patient populations.

STUDY DESIGN

Thirty-two combat casualties with severe extremity injuries enrolled in a prospective observational study were analyzed using step-wise machine-learned Bayesian belief network (BBN) and step-wise logistic regression (LR). Models were evaluated using 10-fold cross-validation to calculate area-under-the-curve (AUC) from receiver operating characteristics (ROC) curves.

RESULTS

Our BBN showed important associations between various factors in our data set that could not be developed using standard regression methods. Cross-validated ROC curve analysis showed that our BBN model was a robust representation of our data domain and that LR models trained on these findings were also robust: hospital-acquired infection (AUC: LR, 0.81; BBN, 0.79), intensive care unit length of stay (AUC: LR, 0.97; BBN, 0.81), and wound healing (AUC: LR, 0.91; BBN, 0.72) showed strong AUC.

CONCLUSIONS

A BBN model can effectively represent clinical outcomes and biomarkers in patients hospitalized after severe wounding, and is confirmed by 10-fold cross-validation and further confirmed through logistic regression modeling. The method warrants further development and independent validation in other, more diverse patient populations.

Correlation of measurable serum markers of inflammation with lung levels following bilateral femur fracture in a rat model

Introduction

Evaluation of the systemic inflammatory status following major orthopedic trauma has become an important adjunct in basing post-injury clinical decisions. In the present study, we examined the correlation of serum and lung inflammatory marker levels following bilateral femur fracture.

Materials and methods

45 Sprague Dawley rats underwent sham operation or bilateral femoral intramedullary pinning and mid-diaphyseal closed fracture via blunt guillotine. Animals were euthanized at specific time points after injury. Serum and lung tissue were collected, and 24 inflammatory markers were analyzed by immunoassay. Lung histology was evaluated by a blinded pathologist.

Results

Bilateral femur fracture significantly increased serum markers of inflammation including interleukin (IL)-2, IL-6, IL-10, GM-CSF, KC/GRO, MCP-1, and WBC. Femur fracture significantly increased serum and lung levels of IL-1a and KC/GRO at 6 hours. Lung levels of IL-6 demonstrated a trend towards significance. Histologic changes in pulmonary tissue after fracture included pulmonary edema and bone elements including cellular hematopoietic cells, bone fragments and marrow emboli.

Discussion and conclusion

Our results indicate that bilateral femur fracture with fixation in rats results in increases in serum markers of inflammation. Among the inflammatory markers measured, rise in the serum KC/GRO (CINC-1), a homolog to human IL-8, correlated with elevated levels of lung KC/GRO. Ultimately, analysis of serum levels of KC/GRO (CINC-1), or human IL-8, may be a useful adjunct to guide clinical decisions regarding surgical timing.

Inflammatory biomarkers in combat wound healing

BACKGROUND

Modern war ballistics and blast injuries inflict devastating extremity injuries, violating soft tissue, bone, and neurovascular structures. Despite advances in complex wound management, appropriate timing of war wound closure remains subjective. In addition, the pathophysiology of acute wound failure is poorly defined.

METHODS

Patients with penetrating extremity wounds sustained during combat were prospectively studied and followed for 30 days after definitive wound closure. The primary outcome was wound healing. Wound dehiscence was defined as spontaneous partial or complete wound disruption after closure. Serum, wound effluent, and wound bed tissue biopsy were collected at each surgical wound debridement. Serum and wound effluent were analyzed with a multiplex array of 22 cytokines and chemokines, and wound tissue for corresponding gene transcript expression.

RESULTS

Fifty-two penetrating extremity war wounds in 33 male patients were investigated. Nine (17%) wounds dehisced. Concomitant vascular injury, increased wound size, and higher injury severity score correlated with wound dehiscence. Both serum and wound effluent cytokine and chemokine protein profiles were statistically associated with healing outcome at various time points. Wound biopsy gene transcript expression demonstrated increased tissue inflammation associated with wound failure. Multiple protein and gene transcript biomarkers predictive of wound healing were identified.

CONCLUSIONS

The cytokine and chemokine protein and gene transcript expression patterns demonstrate a condition of inflammatory dysregulation associated with war wound failure. A molecular biomarker panel may predict combat wound healing outcome and warrants prospective validation.

Procalcitonin in sepsis and systemic inflammation: a harmful biomarker and a therapeutic target

The worldwide yearly mortality from sepsis is substantial, greater than that of cancer of the lung and breast combined. Moreover, its incidence is increasing, and its response to therapy has not appreciably improved. In this condition, the secretion of procalcitonin (ProCT), the prohormone of calcitonin, is augmented greatly, attaining levels up to thousands of fold of normal. This hypersecretion emanates from multiple tissues throughout the body that are not traditionally viewed as being endocrine. The serum values of ProCT correlate with the severity of sepsis; they recede with its improvement and worsen with exacerbation. Accordingly, as highlighted in this review, serum ProCT has become useful as a biomarker to assist in the diagnosis of sepsis, as well as related infectious or inflammatory conditions. It is also a useful monitor of the clinical course and prognosis, and sensitive and specific assays have been developed for its measurement. Moreover, it has been demonstrated that the administration of ProCT to septic animals greatly increases mortality, and several toxic effects of ProCT have been elucidated by in vitro experimental studies. Antibodies have been developed that neutralize the harmful effects of ProCT, and their use markedly decreases the symptomatology and mortality of animals that harbour a highly virulent sepsis analogous to that occurring in humans. This therapy is facilitated by the long duration of serum ProCT elevation, which allows for a broad window of therapeutic opportunity. An experimental groundwork has been established that suggests a potential applicability of such therapy in septic humans.

Perioperative blood transfusion in combat casualties: a pilot study

BACKGROUND

In recent studies, blood transfusion has been shown to increase the rate of wound healing disturbances in orthopedic patients. Furthermore, our group has determined a correlation between delayed wound healing and elevations in inflammatory mediators in combat casualties. Therefore, we sought to determine the effect of blood transfusion on wound healing and inflammatory mediator release in combat casualties.

METHODS

Prospective data were collected on 20 severely injured combat casualties sustaining extremity wounds. Patients were admitted to the National Naval Medical Center during a 13-month period from January 2007 to January 2008. Data variables included age, gender, Glasgow coma score (GCS), mechanism of injury, and transfusion history. Injury severity was assessed using the Injury Severity Score (ISS). Serum was collected initially and before each surgical wound debridement and analyzed using a panel of 21 cytokines and chemokines. The association between blood transfusion and wound healing, incidence of perioperative infection, intensive care unit (ICU) admission rate, and ICU and hospital length of stay was assessed. Differences were considered significant when p < 0.05.

RESULTS

The study cohort had a mean age of 22 +/- 1, a mean ISS of 15.8 +/- 2.6, and a mean GCS 13.9 +/- 0.6; all were men and suffered penetrating injuries (90% improvised explosive device [IED] and 10% gunshot wound [GSW]). The cohort was divided into two groups. Patients receiving <or=4 units of blood initially (group 1, n = 11) were compared with patients who received >4 units of blood initially (group 2, n = 9). There was no significant difference in age, ISS, GCS, or mortality between the two groups. However, group 2 patients had significant impairment in wound healing rate (54% vs. 9%, p < 0.05), higher ICU admission rate (78% vs. 9%, p < 0.01), perioperative infection rate (89% vs. 27%, p < 0.01), and a longer hospital length of stay (49.9 +/- 12.8 vs. 23.8 +/- 2.9, p < 0.05) compared with group 1 patients. In addition, there was a significant correlation between the initial mean serum cytokine/chemokine level of interleukin (IL)-10, IL-8, interferon inducible protein (IP)-10, IL-6, and IL-12p40 and the number of units of blood transfused (p < 0.05).

CONCLUSION

Allogeneic blood transfusions in combat casualties were associated with impaired wound healing, increased perioperative infection rate, and resource utilization. In addition, the extent of blood transfusion was associated with significant differences in inflammatory chemokine and cytokine release.

Salivary procalcitonin and periodontitis in diabetes

Periodontitis and type 2 diabetes are co-morbid conditions, both characterized by infectious susceptibility. We investigated procalcitonin (ProCT) levels in the serum and saliva of persons with periodontitis and type 2 diabetes (n = 20), to determine if these levels are altered by periodontitis activity or by hyperglycemia. Persons with severe periodontitis showed higher levels of salivary-ProCT than did those with moderate periodontitis (241 +/- 71 vs. 77 +/- 516 pg/mL, p = 0.02) and higher levels than did healthy control individuals (118 +/- 26 pg/mL, p = 0.05). Salivary-ProCT levels were correlated with bleeding-on-probing (r = 0.45, p = 0.05), as well as with HgbA(1c) (r = 0.49, p = 0.03). Salivary levels of ProCT were higher than serum levels for the periodontitis/diabetes group (152 +/- 37 vs. 78 +/- 17 pg/mL, p = 0.02) and the control group (118 +/- 146 vs. 48 +/- 17 pg/mL, p = 0.01). Persons with periodontitis and type 2 diabetes have salivary-ProCT levels that reflect their degree of periodontitis activity and hyperglycemia. This study demonstrates, for the first time, the presence of procalcitonin (ProCT), an established serum marker of infection, in saliva.