Hyperbaric Oxygen Therapy for Wound Healing and Limb Salvage: A Systematic Review

Diabetic foot ulcer: an evidence-based treatment update

BACKGROUND

Diabetic foot ulcers (DFUs) are extremely debilitating and difficult to treat. Multidisciplinary management, patient education, glucose control, debridement, offloading, infection control, and adequate perfusion are the mainstays of standard care endorsed by most practice guidelines. Adjunctive therapies represent new treatment modalities endorsed in recent years, though many lack significant high-powered studies to support their use as standard of care.

OBJECTIVE

This update intends to identify recent, exclusively high level, evidence-based evaluations of DFU therapies. Furthermore, it suggests a direction for future research.

METHODS

PubMed, Embase, Ovid Technologies, CINAHL, Cochrane, and Web of Science databases were systematically searched for recent systematic reviews published after 2004, and randomized controlled trials published in 2012-2013 that evaluated treatment modalities for DFUs. These papers are reviewed and the quality of available evidence is discussed.

RESULTS

A total of 34 studies met inclusion criteria. Studied therapies include debridement, off-loading, negative pressure therapy, dressings, topical therapies, hyperbaric oxygen therapy, growth factors, bioengineered skin substitutes, electrophysical therapy, and alternative therapy. Good-quality evidence is lacking to justify the use of many of these therapies, with the exception of standard care (offloading, debridement) and possibly negative pressure wound therapy.

LIMITATIONS

There is an overall lack of high-level evidence in new adjunctive management of DFU. Comparison of different treatment modalities is difficult, since existing studies are not standardized.

CONCLUSIONS

Many therapeutic modalities are available to treat DFU. Quality high-level evidence exists for standard care such as off-loading. Evidence for adjunctive therapies such as negative pressure wound therapy, skin substitutes, and platelet-derived growth factor can help guide adjunctive care but limitations exist in terms of evidence quality.

CD34+/CD45-dim stem cell mobilization by hyperbaric oxygen - changes with oxygen dosage

Because hyperbaric oxygen treatment mobilizes bone marrow derived-stem/progenitor cells by a free radical mediated mechanism, we hypothesized that there may be differences in mobilization efficiency based on exposure to different oxygen partial pressures. Blood from twenty consecutive patients was obtained before and after the 1st, 10th and 20th treatment at two clinical centers using protocols involving exposures to oxygen at either 2.0 or 2.5 atmospheres absolute (ATA). Post-treatment values of CD34+, CD45-dim leukocytes were always 2-fold greater than the pre-treatment values for both protocols. Values for those treated at 2.5 ATA were significantly greater than those treated at 2.0 ATA by factors of 1.9 to 3-fold after the 10th and before and after the 20th treatments. Intracellular content of hypoxia inducible factors -1, -2, and -3, thioredoxin-1 and poly-ADP-ribose polymerase assessed in permeabilized CD34+ cells with fluorophore-conjugated antibodies were twice as high in all post- versus pre-treatment samples with no significant differences between 2.0 and 2.5 ATA protocols. We conclude that putative progenitor cell mobilization is higher with 2.5 versus 2.0 ATA treatments, and all newly mobilized cells exhibit higher concentrations of an array of regulatory proteins.

Hyperbaric oxygen therapy for diabetic ulcers: systematic review and meta-analysis

OBJECTIVES

Approximately 10-15 percent of individuals with diabetes mellitus develop foot ulcers, which precede 85 percent of amputations. Increased oxygen, through the use of hyperbaric oxygen therapy (HBOT), has been suggested to encourage ulcer healing thus reducing the risk of amputation. The objective of this systematic review is to evaluate the efficacy of systemic HBOT for nonhealing ulcers of the lower limb in diabetes patients.

METHODS

A systematic search, using controlled and keyword terms focusing on "HBOT" and "lower limb diabetic ulcers," was conducted. Databases searched included Medline, EMBASE, CINAHL, PubMed, Wiley's Cochrane Library, and Biosis. Randomized controlled trials (RCTs) and observational studies were included. Pooled estimates of outcomes were determined when appropriate.

RESULTS

Of the 654 citations identified, 157 articles underwent full-text review. Data were abstracted from twelve publications (six RCTs and six comparative observational studies). Pooled analysis of the RCT and observational data showed that treatment with HBOT reduced the risk of major amputation by 60 percent (p = .29) and 61 percent (p = .003) compared with standard wound care, respectively. The RCT data revealed that the relative risk of having an unhealed wound following HBOT was 0.54 (p = .10) and 0.24 (p < .0001) based on observational data.

CONCLUSIONS

Due to the limited RCT evidence, it is not possible to conclusively establish the benefits and harms of treating diabetic lower limb ulcers with HBOT. No significant effects on amputation rates were found in the RCT evidence and in the high quality studies, no difference was found.

Management of open wounds: lessons from orthopedic oncology

The management of complex wounds remains a challenge, and although there have been many promising advances, patients often undergo a morbid and lengthy process to obtain sufficient, satisfactory healing. Sarcoma patients are especially vulnerable to soft tissue wound-healing complications. These patients are often treated with neoadjuvant radiation and/or chemotherapy and have compromised local vascularity to healing tissue. The advent and refinement of wound vacuum-assisted closure technology have been shown to have a tremendous impact. This article reviews the benefits of some novel technologies currently undergoing investigation in orthopedic oncology that will likely have applications in wound management from other causes.

Hyperbaric oxygen therapy for treating acute surgical and traumatic wounds

BACKGROUND

Hyperbaric oxygen therapy (HBOT) is used as a treatment for acute wounds (such as those arising from surgery and trauma). However, the effects of HBOT on wound healing are unclear. 

OBJECTIVES

To determine the effects of HBOT on the healing of acute surgical and traumatic wounds.

SEARCH METHODS

We searched the Cochrane Wounds Group Specialised Register (searched 9 August 2013); the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 12); Ovid MEDLINE (2010 to July Week 5 2013); Ovid MEDLINE (In-Process & Other Non-Indexed Citations, August 08, 2013); Ovid EMBASE (2010 to 2013 Week 31); EBSCO CINAHL (2010 to 8 August 2013).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing HBOT with other interventions such as dressings, steroids, or sham HOBT or comparisons between alternative HBOT regimens.

DATA COLLECTION AND ANALYSIS

Two review authors conducted selection of trials, risk of bias assessment, data extraction and data synthesis independently. Any disagreements were referred to a third review author. 

MAIN RESULTS

Four trials involving 229 participants were included. The studies were clinically heterogeneous, which precluded a meta-analysis.One trial (48 participants with burn wounds undergoing split skin grafts) compared HBOT with usual care and reported a significantly higher complete graft survival associated with HBOT (95% healthy graft area risk ratio (RR) 3.50; 95% confidence interval (CI) 1.35 to 9.11). A second trial (10 participants in free flap surgery) reported no significant difference between graft survival (no data available). A third trial (36 participants with crush injuries) reported significantly more wounds healed (RR 1.70; 95% CI 1.11 to 2.61), and significantly less tissue necrosis (RR 0.13; 95% CI 0.02 to 0.90) with HBOT compared to sham HBOT. The fourth trial (135 people undergoing flap grafting) reported no significant differences in complete graft survival with HBOT compared with dexamethasone (RR 1.14; 95% CI 0.95 to 1.38) or heparin (RR 1.21; 95% CI 0.99 to 1.49).Many of the predefined secondary outcomes of the review were not reported. All four trials were at unclear or high risk of bias.

AUTHORS' CONCLUSIONS

There is a lack of high quality, valid research evidence regarding the effects of HBOT on wound healing. Whilst two small trials suggested that HBOT may improve the outcomes of skin grafting and trauma, these trials were at risk of bias. Further evaluation by means of high quality RCTs is needed.

The medical use of oxygen: a time for critical reappraisal

Oxygen treatment has been a cornerstone of acute medical care for numerous pathological states. Initially, this was supported by the assumed need to avoid hypoxaemia and tissue hypoxia. Most acute treatment algorithms, therefore, recommended the liberal use of a high fraction of inspired oxygen, often without first confirming the presence of a hypoxic insult. However, recent physiological research has underlined the vasoconstrictor effects of hyperoxia on normal vasculature and, consequently, the risk of significant blood flow reduction to the at-risk tissue. Positive effects may be claimed simply by relief of an assumed local tissue hypoxia, such as in acute cardiovascular disease, brain ischaemia due to, for example, stroke or shock or carbon monoxide intoxication. However, in most situations, a generalized hypoxia is not the problem and a risk of negative hyperoxaemia-induced local vasoconstriction effects may instead be the reality. In preclinical studies, many important positive anti-inflammatory effects of both normobaric and hyperbaric oxygen have been repeatedly shown, often as surrogate end-points such as increases in gluthatione levels, reduced lipid peroxidation and neutrophil activation thus modifying ischaemia-reperfusion injury and also causing anti-apoptotic effects. However, in parallel, toxic effects of oxygen are also well known, including induced mucosal inflammation, pneumonitis and retrolental fibroplasia. Examining the available 'strong' clinical evidence, such as usually claimed for randomized controlled trials, few positive studies stand up to scrutiny and a number of trials have shown no effect or even been terminated early due to worse outcomes in the oxygen treatment arm. Recently, this has led to less aggressive approaches, even to not providing any supplemental oxygen, in several acute care settings, such as resuscitation of asphyxiated newborns, during acute myocardial infarction or after stroke or cardiac arrest. The safety of more advanced attempts to deliver increased oxygen levels to hypoxic or ischaemic tissues, such as with hyperbaric oxygen therapy, is therefore also being questioned. Here, we provide an overview of the present knowledge of the physiological effects of oxygen in relation to its therapeutic potential for different medical conditions, as well as considering the potential for harm. We conclude that the medical use of oxygen needs to be further examined in search of solid evidence of benefit in many of the current clinical settings in which it is routinely used.

Hyperbaric oxygen for chronic wounds

Hyperbaric oxygen therapy (HBOT), the administration of pressurized 100% oxygen, is used as an adjunct to aid healing in selected chronic wounds. Though the therapy has had a controversial history, research is now elucidating the mechanisms by which HBOT helps to heal wounds. HBOT increases growth factors and local wound signaling, while also promoting a central stem cell release of endothelial progenitor cells from the bone marrow via nitric oxide pathways. The clinical data continue to accumulate in support of HBOT to help hasten wound healing, and reduce the amputation rate in diabetic ulcers. In appropriate patients, HBOT is an effective, noninvasive, adjunct modality that can be used to hasten chronic wound healing.

Using GRADE for evaluating the quality of evidence in hyperbaric oxygen therapy clarifies evidence limitations

OBJECTIVES

The current evidence rating for hyperbaric oxygen therapy indications uses the American Heart Association system, which mainly depends on the study design.

STUDY DESIGN AND SETTING

We systematically reviewed the literature and applied the Grading of Evidence, Assessment, Development and Evaluation (GRADE) approach to the main patient-important outcomes in each indication.

RESULTS

We included 17 systematic reviews that synthesized 44 randomized trials and 131 observational studies enrolling 8,145 participants. The quality of evidence for seven indications with category A was high (1), moderate (2), low (2), and very low (2); for 10 indications with category B, it was moderate (1), low (5), and very low (4); and for 1 indication with category C, it was high. The quality of evidence was rated down for the risk of bias and imprecision for most indications and rated up because of large effect size for some indications. Most discrepant ratings were in the indications of decompression illness (C, high), carbon monoxide poisoning (A, very low), and later presentations of idiopathic sudden hearing loss (A, very low).

CONCLUSION

The GRADE approach uncovered factors affecting the quality of evidence that were otherwise implicit. Knowing these factors can influence clinicians' confidence in applying hyperbaric oxygen therapy and orient the research agenda.

Hyperbaric oxygen therapy for primary sternal osteomyelitis: a case report

Introduction

Primary osteomyelitis of the sternum is a rare condition, which accounts for 0.3% of all cases of osteomyelitis reported in the literature. The diagnosis requires a high degree of suspicion and confirmation by percutaneous biopsy. The treatment consists of resection of the periosteum and affected bone. Despite reports of successful conservative treatment using antibiotics alone, early surgical intervention plus bacterial control is the definitive treatment; it reduces morbidity, and is the most cost-effective approach for the patient. We report a case of primary osteomyelitis surgically treated with debridement and antibiotics, followed by hyperbaric oxygen therapy.

Case presentation

A 39-year-old Brazilian man without a significant medical history presented with primary osteomyelitis. After a normal chest radiograph and normal laboratory test results, he was treated with 2 weeks of nonsteroidal anti-inflammatory drugs. One month later a presumptive diagnosis of Tietze syndrome was made and he was prescribed prednisolone (60mg/day) for 3 weeks. The following month he presented to our service with swelling, redness, and warmth in the area between his left third and fourth ribs. Subsequent magnetic resonance imaging revealed a large collection of liquid (8.8×6.8×20.2cm) in his chest wall, between the body and the manubrium of the sternum. An area of soft, friable tissue with a large amount of pus was found in his sternum during surgical debridement. Subsequent treatment consisted of antibiotic therapy using metronidazole and cefotaxime plus hyperbaric oxygen therapy. On postoperative day 10 the incision was sutured. The patient was discharged on postoperative day 15 on a regimen of oral ciprofloxacin, and completed hyperbaric oxygen therapy as an out-patient.

Conclusions

The satisfying outcome of this patient reflects the quick action to promote surgical debridement and use of antibiotics, which are both recommended treatments. The closure of the wound in 10 days after debridement suggests that the hyperbaric oxygen therapy might have indirectly, but not conclusively, aided in the premature closure of the wound, avoiding a longer healing by second intention or muscle flap rotation closure.

Prognostic factors predicting ischemic wound healing following hyperbaric oxygenation therapy

Identifying patients who benefit from hyperoxygenation therapy is important, because treatment is time-consuming and involves high costs and complications (minor). Our objective was to develop a model for predicting therapy outcome based on population of patients with and without diabetes. A retrospective cohort study was carried out in a major hospital in Israel. All 385 patients treated between 1/1/1998 and 1/1/2007 for ischemic nonhealing lower extremities wounds were included. Data on medical history, demographic, transcutaneous oximetry, wounds, treatment, and outcome characteristics were collected. Eight factors were identified to optimally predict wound healing: (1) number of hyperbaric oxygenation treatments (odds ratio [OR] = 1.034, p < 0.001), (2) transcutaneous oximetry values at hyperbaric conditions (OR = 1.001, p = 0.019), (3) wound duration (OR = 0.988, p = 0.022), (4) absence of heart disease (OR = 3.304, p < 0.001), (5) being employed (OR = 3.16, p = 0.008), (6) low socioeconomic status (OR = 2.50, p = 0.004), (7a) good/partial granulation wound appearance (OR = 2.73, p = 0.022), (7b) wounds covered with fibrin (OR = 3.16, p = 0.015), and (8) absence of anemia (OR = 2.13, p = 0.016). The model's sensitivity is 78.7%, specificity is 62.9%, and accuracy is 71.8%. We suggest using our model as an adjunct to patients' clinical evaluation. Also, we recommend initiating hyperoxygenation therapy no later than 2 months after wound appearance.

The role of oxygen during fracture healing

Oxygen affects the activity of multiple skeletogenic cells and is involved in many processes that are important for fracture healing. However, the role of oxygen in fracture healing has not been fully studied. Here we systematically examine the effects of oxygen tension on fracture healing and test the ability of hyperoxia to rescue healing defects in a mouse model of ischemic fracture healing. Mice with tibia fracture were housed in custom-built gas chambers and groups breathed a constant atmosphere of 13% oxygen (hypoxia), 21% oxygen (normoxia), or 50% oxygen (hyperoxia). The influx of inflammatory cells to the fracture site, stem cell differentiation, tissue vascularization, and fracture healing were analyzed. In addition, the efficacy of hyperoxia (50% oxygen) as a treatment regimen for fracture nonunion was tested. Hypoxic animals had decreased tissue vascularity, decreased bone formation, and delayed callus remodeling. Hyperoxia increased tissue vascularization, altered fracture healing in un-complicated fractures, and improved bone repair in ischemia-induced delayed fracture union. However, neither hypoxia nor hyperoxia significantly altered chondrogenesis or osteogenesis during early stages of fracture healing, and infiltration of macrophages and neutrophils was not affected by environmental oxygen after bone injury. In conclusion, our results indicate that environmental oxygen levels affect tissue vascularization and fracture healing, and that providing oxygen when fractures are accompanied by ischemia may be beneficial.

Factors That Impair Wound Healing

The body's response to tissue injury in a healthy individual is an intricate, sequential physiologic process that results in timely healing with full re-epithelialization, resolution of drainage, and return of function to the affected tissue. Chronic wounds, however, do not follow this sequence of events and can challenge the most experienced clinician if the underlying factors that are impairing wound healing are not identified. The purpose of this article is to present recent information about factors that impair wound healing with the underlying pathophysiological mechanism that interferes with the response to tissue injury. These factors include co-morbidities (diabetes, obesity, protein energy malnutrition), medications (steroids, non-steroidal anti-inflammatory drugs or NSAIDs, anti-rejection medications), oncology interventions (radiation, chemotherapy), and life style habits (smoking, alcohol abuse). Successful treatment of any chronic wound depends upon identification and management of the factors for each individual.

2012 Infectious Diseases Society of America clinical practice guideline for the diagnosis and treatment of diabetic foot infections

Foot infections are a common and serious problem in persons with diabetes. Diabetic foot infections (DFIs) typically begin in a wound, most often a neuropathic ulceration. While all wounds are colonized with microorganisms, the presence of infection is defined by ≥2 classic findings of inflammation or purulence. Infections are then classified into mild (superficial and limited in size and depth), moderate (deeper or more extensive), or severe (accompanied by systemic signs or metabolic perturbations). This classification system, along with a vascular assessment, helps determine which patients should be hospitalized, which may require special imaging procedures or surgical interventions, and which will require amputation. Most DFIs are polymicrobial, with aerobic gram-positive cocci (GPC), and especially staphylococci, the most common causative organisms. Aerobic gram-negative bacilli are frequently copathogens in infections that are chronic or follow antibiotic treatment, and obligate anaerobes may be copathogens in ischemic or necrotic wounds. Wounds without evidence of soft tissue or bone infection do not require antibiotic therapy. For infected wounds, obtain a post-debridement specimen (preferably of tissue) for aerobic and anaerobic culture. Empiric antibiotic therapy can be narrowly targeted at GPC in many acutely infected patients, but those at risk for infection with antibiotic-resistant organisms or with chronic, previously treated, or severe infections usually require broader spectrum regimens. Imaging is helpful in most DFIs; plain radiographs may be sufficient, but magnetic resonance imaging is far more sensitive and specific. Osteomyelitis occurs in many diabetic patients with a foot wound and can be difficult to diagnose (optimally defined by bone culture and histology) and treat (often requiring surgical debridement or resection, and/or prolonged antibiotic therapy). Most DFIs require some surgical intervention, ranging from minor (debridement) to major (resection, amputation). Wounds must also be properly dressed and off-loaded of pressure, and patients need regular follow-up. An ischemic foot may require revascularization, and some nonresponding patients may benefit from selected adjunctive measures. Employing multidisciplinary foot teams improves outcomes. Clinicians and healthcare organizations should attempt to monitor, and thereby improve, their outcomes and processes in caring for DFIs.

Expert opinion on the management of infections in the diabetic foot

This update of the International Working Group on the Diabetic Foot incorporates some information from a related review of diabetic foot osteomyelitis (DFO) and a systematic review of the management of infection of the diabetic foot. The pathophysiology of these infections is now well understood, and there is a validated system for classifying the severity of infections based on their clinical findings. Diagnosing osteomyelitis remains difficult, but several recent publications have clarified the role of clinical, laboratory and imaging tests. Magnetic resonance imaging has emerged as the most accurate means of diagnosing bone infection, but bone biopsy for culture and histopathology remains the criterion standard. Determining the organisms responsible for a diabetic foot infection via culture of appropriately collected tissue specimens enables clinicians to make optimal antibiotic choices based on culture and sensitivity results. In addition to culture-directed antibiotic therapy, most infections require some surgical intervention, ranging from minor debridement to major resection, amputation or revascularization. Clinicians must also provide proper wound care to ensure healing of the wound. Various adjunctive therapies may benefit some patients, but the data supporting them are weak. If properly treated, most diabetic foot infections can be cured. Providers practising in developing countries, and their patients, face especially challenging situations.

Hyperbaric oxygen therapy as treatment of diabetic foot ulcers

Hyperbaric oxygen therapy (HBO) could be described as a short-term, high-dose oxygen inhalation and diffusion therapy, delivered systemically through airways and blood, achieved by having the patient breathing concentrated oxygen at a pressure higher than 1 absolute atmosphere. In clinical practice, monoplace or multiplace hyperbaric chambers are used to achieve this. Treatment is usually given as daily 90- to 120-min-long HBO sessions at pressures between 2.0 and 2.5 absolute atmosphere, aiming for 30-40 treatment sessions. The use of HBO as treatment of diabetic foot ulcers has been founded on weak scientific ground, although the outcomes from previous studies are in concert with the conclusions from preclinical studies and supports the theoretical framework of HBO reversing hypoxia-induced pathology. Two well-designed randomized double-blind trials have put HBO on firmer ground and may justify adjunctive HBO treatment to a selected group of patients with nonhealing diabetic foot ulcers. Some health economic studies suggest potential cost effectiveness, but these studies are limited by deficient primary clinical data and should be interpreted with caution. Several issues remain to be addressed, such as developing robust criteria to improve treatment protocols, determining which patients are likely to benefit, and when to start and stop treatment.

Distally based sural fasciomusculocutaneous flap for treatment of wounds of the distal third of the leg and ankle with exposed internal hardware

Soft tissue reconstruction of the distal third of the lower limb with exposure of the internal hardware is a challenging problem with several potential complications, such as exposure of the fracture line, fracture instability and bacterial contamination. The treatment of these lesions usually consists of substitution of the internal hardware with external fixation devices and further flap coverage. We propose a different reconstructive approach, characterized by harvesting a sural fasciomusculocutaneous flap on the exposed internal hardware once a sterile ground has been obtained. Four patients were retrospectively analyzed. Soft tissue reconstruction was achieved in all cases. In one case hardware removal was necessary for complete healing. The sural fasciomusculocutaneous flap is a safe alternative to other pedicled and free flaps. Moreover, it allows direct coverage of internal fixators, thus completing the reconstruction in less time. This flap fits best to the morphology of the wound and internal hardware, leaving the main vascular trunk of the leg intact and at the same time providing a reliable vascular supply.

Evaluation of the efficacy of hyperbaric oxygen therapy in the management of chronic nonhealing ulcer and role of periwound transcutaneous oximetry as a predictor of wound healing response: A randomized prospective controlled trial

BACKGROUND

Hyperbaric oxygen therapy (HBOT) is a treatment option for chronic nonhealing wounds. Transcutaneous oximetry (TCOM) is used for wound assessment. We undertook a randomized prospective controlled trial to evaluate the role of HBOT in healing of chronic nonhealing wounds and to determine whether TCOM predicts healing.

MATERIALS AND METHODS

This study was conducted in 30 consenting patients with nonhealing ulcer. The patients were randomized into group HT (receiving HBOT in addition to conventional treatment) and group CT (receiving only conventional treatment). Duration of treatment in both the groups was 30 days. Wound ulcer was analyzed based on size of the wound, exudates, presence of granulation tissue, and wound tissue scoring. Tissue oxygenation (TcPO(2)) was measured on 0, 10(th), 20(th), and 30(th) day.

RESULTS

There was 59% reduction in wound area in group HT and 26% increase in wound area in group CT. Ten patients in group HT showed improvement in wound score as compared to five patients in group CT. Complete healing was seen in three patients in group HT as compared to none in group CT. Surgical debridement was required in 6 patients in group HT and 10 patients in group CT. One patient in group HT required amputation as compared to five patients in group CT. A positive correlation was found between TcPO(2) value and various markers of wound healing.

CONCLUSION

HBOT has a definitive adjunctive role in the management of chronic nonhealing ulcers. It decreases the amputation rate and improves patient outcome. Periwound TcPO(2) may be used as a predictor of response to HBOT and has a positive correlation with wound healing.

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.

Neuroprotective effects of hyperbaric oxygen treatment on traumatic brain injury in the rat

This study was designed to evaluate the potential benefits of hyperbaric oxygen (HBO) in the treatment of traumatic brain injury (TBI). The right cerebral cortex of rats was injured by the impact of a 20-g object dropped from a predetermined height. The rats received HBO treatment at 3 ATA for 60 min after TBI. Neurological behavior score, brain water content, neuronal loss in the hippocampus, and cell apoptosis in brain tissue surrounding the primary injury site were examined to determine brain damage severity. Three and six hours after TBI, HBO-treated rats displayed a significant reduction in brain damage. However, by 12 h after TBI, the efficacy of HBO treatment was considerably attenuated. Furthermore, at 24, 48, and 72 h after TBI, the HBO treatment did not show any notable effects. In contrast, multiple HBO treatments (three or five times in all), even when started 48 h after TBI, remarkably reduced neurology deficit scores and the loss of neuronal numbers in the hippocampus. Although multiple treatments started at 48 h significantly improved neurological behaviors and reduced brain injury, the overall beneficial effects were substantially weaker than those seen after a single treatment at 6 h. These results suggest that: (1) HBO treatment could alleviate brain damage after TBI; (2) a single treatment with HBO has a time limitation of 12 h post-TBI; and (3) multiple HBO treatments have the possibility to extend the post-TBI delivery time window. Therefore, our results clearly suggest the validity of HBO therapy for the treatment of TBI.

The pacific chapter annual meeting of the undersea & hyperbaric medical society

The following is the summary report on the UHMS Pacific Chapter Annual Meeting held in Long Beach in October 2010. The conference provided the latest updates on scientific, technical and organizational aspects of Hyperbaric and Diving Medicine. Invited speakers gave series of lectures dealing with current standards of clinical practice and presenting the results of laboratory investigations with particular emphasis on mechanisms of hyperbaric oxygen therapy. Scientific sessions were accompanied by vendor exhibits and social events.

Hyperbaric oxygen therapy: solution for difficult to heal acute wounds? Systematic review

Background

Hyperbaric oxygen therapy (HBOT) is used to treat various wound types. However, the possible beneficial and harmful effects of HBOT for acute wounds are unclear.

Methods

We undertook a systematic review to evaluate the effectiveness of HBOT compared to other interventions on wound healing and adverse effects in patients with acute wounds. To detect all available randomized controlled trials (RCTs) we searched five relevant databases up to March 2010. Trial selection, quality assessment, data extraction, and data synthesis were conducted by two of the authors independently.

Results

We included five trials, totaling 360 patients. These trials, with some methodologic flaws, included different kinds of wound and focused on different outcome parameters, which prohibited meta-analysis. A French trial (n = 36 patients) reported that significantly more crush wounds healed with HBOT than with sham HBOT [relative risk (RR) 1.70, 95% confidence interval (CI) 1.11–2.61]. Moreover, there were significantly fewer additional surgical procedures required with HBOT (RR 1.60, 95% CI 1.03–2.50), and there was significantly less tissue necrosis (RR 1.70, 95% CI 1.11–2.61). In one of two American trials (n = 141) burn wounds healed significantly quicker with HBOT (P < 0.005) than with routine burn care. A British trial (n = 48) compared HBOT with usual care. HBOT resulted in a significantly higher percentage of healthy graft area in split skin grafts (RR 3.50, 95% CI 1.35–9.11). In a Chinese trial (n = 145) HBOT did not significantly improve flap survival in patients with limb skin defects.

Conclusions

HBOT, if readily available, appears effective for the management of acute, difficult to heal wounds.

Correction of Hypoxia, a Critical Element for Wound Bed Preparation Guidelines: TIMEO2 Principle of Wound Bed Preparation

Wound bed preparation is an organized approach to create an optimal environment for wound healing by the use of the most cost-effective therapeutic options. It has become an essential part of wound management and seeks to use the latest findings from molecular and cellular research to maximize the benefits of today's advanced wound care products. The international advisory panel on wound bed preparation met in 2002 to develop a systemic approach to wound management. These principles of this approach are referred to by the mnemonic TIME, which stands for the management of nonviable or deficient tissue (T), infection or inflammation (I), prolonged moisture imbalance (M), and nonadvancing or undermined epidermal edge (E). One critical element of pathophysiology, understanding of the hypoxic nature of the wound and correction of hypoxia as a critical element of wound bed preparation, is not covered. This article proposes to add correction of hypoxia to the TIME principle (TIMEO2 principle) based on the evidence. The evidence that will support the reason and the need for modification of the wound bed preparation protocol is discussed.

Vasculogenic stem cell mobilization and wound recruitment in diabetic patients: increased cell number and intracellular regulatory protein content associated with hyperbaric oxygen therapy

Diabetic patients undergoing hyperbaric oxygen therapies (HBO(2)T) for refractory lower extremity neuropathic ulcers exhibit more than a twofold elevation (p=0.004) in circulating stem cells after treatments and the post-HBO(2)T CD34(+) cell population contains two- to threefold higher levels of hypoxia inducible factors-1, -2, and -3, as well as thioredoxin-1 (p<0.003), than cells present in blood before HBO(2)T. Skin margins obtained from 2-day-old abdominal wounds exhibit higher expression of CD133, CD34, hypoxia inducible factor-1, and Trx-1 vs. margins from refractory lower extremity wounds and expression of these proteins in all wounds is increased due to HBO(2)T (p<0.003). HBO(2)T is known to mobilize bone marrow stem cells by stimulating nitric oxide synthase. We found that nitric oxide synthase activity is acutely increased in patients' platelets following HBO(2)T and remains elevated for at least 20 hours. We conclude that HBO(2) T stimulates vasculogenic stem cell mobilization from bone marrow of diabetics and more cells are recruited to skin wounds.

Treating osteomyelitis: antibiotics and surgery

BACKGROUND

Osteomyelitis is an inflammatory disorder of bone caused by infection leading to necrosis and destruction. It can affect all ages and involve any bone. Osteomyelitis may become chronic and cause persistent morbidity. Despite new imaging techniques, diagnosis can be difficult and often delayed. Because infection can recur years after apparent "cure," "remission" is a more appropriate term.

METHODS

The study is a nonsystematic review of literature.

RESULTS

Osteomyelitis usually requires some antibiotic treatment, usually administered systemically but sometimes supplemented by antibiotic-containing beads or cement. Acute hematogenous osteomyelitis can be treated with antibiotics alone. Chronic osteomyelitis, often accompanied by necrotic bone, usually requires surgical therapy. Unfortunately, evidence for optimal treatment regimens or therapy durations largely based upon expert opinion, case series, and animal models. Antimicrobial therapy is now complicated by the increasing prevalence of antibiotic-resistant organisms, especially methicillin-resistant Staphylococcus aureus. Without surgical resection of infected bone, antibiotic treatment must be prolonged (≥4 to 6 weeks). Advances in surgical technique have increased the potential for bone (and often limb) salvage and infection remission.

CONCLUSIONS

Osteomyelitis is best managed by a multidisciplinary team. It requires accurate diagnosis and optimization of host defenses, appropriate anti-infective therapy, and often bone débridement and reconstructive surgery. The antibiotic regimen must target the likely (or optimally proven) causative pathogen, with few adverse effects and reasonable costs. The authors offer practical guidance to the medical and surgical aspects of treating osteomyelitis.

Wound care: the role of advanced wound-healing technologies

Wound repair and regeneration is a highly complex combination of matrix destruction and reorganization. Although major hurdles remain, advances during the past generation have improved the clinician's armamentarium in the medical and surgical management of this problem. The purpose of this article is to review the current literature regarding the pragmatic use of three of the most commonly used advanced therapies: bioengineered tissue, negative-pressure wound therapy, and hyperbaric oxygen therapy, with a focus on the near-term future of wound healing, including stem cell therapy.

Hyperbaric oxygen: its mechanisms and efficacy

BACKGROUND

This article outlines therapeutic mechanisms of hyperbaric oxygen therapy and reviews data on its efficacy for clinical problems seen by plastic and reconstructive surgeons.

METHODS

The information in this review was obtained from the peer-reviewed medical literature.

RESULTS

Principal mechanisms of hyperbaric oxygen are based on intracellular generation of reactive species of oxygen and nitrogen. Reactive species are recognized to play a central role in cell signal transduction cascades, and the discussion will focus on these pathways. Systematic reviews and randomized clinical trials support clinical use of hyperbaric oxygen for refractory diabetic wound-healing and radiation injuries; treatment of compromised flaps and grafts and ischemia-reperfusion disorders is supported by animal studies and a small number of clinical trials, but further studies are warranted.

CONCLUSIONS

Clinical and mechanistic data support use of hyperbaric oxygen for a variety of disorders. Further work is needed to clarify clinical utility for some disorders and to hone patient selection criteria to improve cost efficacy.

Hyperbaric oxygen therapy for treating acute surgical and traumatic wounds

BACKGROUND

Hyperbaric oxygen therapy (HBOT) is used as a treatment for acute wounds (such as those arising from surgery and trauma) however the effects of HBOT on wound healing are unclear. 

OBJECTIVES

To determine the effects of HBOT on the healing of acute surgical and traumatic wounds.

SEARCH STRATEGY

We searched the Cochrane Wounds Group Specialised Register (25 August 2010), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2010, Issue 3), Ovid MEDLINE (1950 to August Week 2 2010 ), Ovid MEDLINE (In-Process & Other Non-Indexed Citations August 24, 2010), Ovid EMBASE (1980 to 2010, Week 33) and EBSCO CINAHL (1982 to 20 August 2010).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing HBOT with other interventions or comparisons between alternative HBOT regimens.

DATA COLLECTION AND ANALYSIS

Two review authors conducted selection of trials, risk of bias assessment, data extraction and data synthesis independently. Any disagreements were referred to a third review author. 

MAIN RESULTS

Three trials involving 219 participants were included. The studies were clinically heterogeneous, therefore a meta-analysis was inappropriate.One trial (48 participants with burn wounds undergoing split skin grafts) compared HBOT with usual care and reported a significantly higher complete graft survival associated with HBOT (95% healthy graft area risk ratio (RR) 3.50; 95% confidence interval (CI) 1.35 to 9.11). A second trial (36 participants with crush injuries) reported significantly more wounds healed with HBOT than with sham HBOT (RR 1.70; 95% CI 1.11 to 2.61) and fewer additional surgical procedures required with HBOT: RR 0.25; 95% CI 0.06 to 1.02 and significantly less tissue necrosis: RR 0.13; 95% CI 0.02 to 0.90). A third trial (135 people undergoing flap grafting) reported no significant differences in complete graft survival with HBOT compared with dexamethasone (RR 1.14; 95% CI 0.95 to 1.38) or heparin (RR 1.21; 95% CI 0.99 to 1.49).Many of the predefined secondary outcomes of the review, including mortality, pain scores, quality of life, patient satisfaction, activities daily living, increase in transcutaneous oxygen pressure (TcpO(2)), amputation, length of hospital stay and costs, were not reported. All three trials were at unclear or high risk of bias.

AUTHORS' CONCLUSIONS

There is a lack of high quality, valid research evidence regarding the effects of HBOT on wound healing. Whilst two small trials suggested that HBOT may improve the outcomes of skin grafting and trauma these trials were at risk of bias. Further evaluation by means of high quality RCTs is needed.

Hyperbaric oxygen therapy for chronic wounds

Hyperbaric oxygen therapy continues to be discussed as another adjunctive therapy in the continuum of wound care. There is a dearth of evidence from randomized clinical trials on HBO therapy. For evidence-based practice, more randomized, controlled studies need to be conducted with HBO therapy to determine its efficacy in treating other chronic wounds besides those of patients with diabetes.

Hyperbaric oxygen therapy facilitates healing of chronic foot ulcers in patients with diabetes

OBJECTIVE

Chronic diabetic foot ulcers are a source of major concern for both patients and health care systems. The aim of this study was to evaluate the effect of hyperbaric oxygen therapy (HBOT) in the management of chronic diabetic foot ulcers.

RESEARCH DESIGN AND METHODS

The Hyperbaric Oxygen Therapy in Diabetics with Chronic Foot Ulcers (HODFU) study was a randomized, single-center, double-blinded, placebo-controlled clinical trial. The outcomes for the group receiving HBOT were compared with those of the group receiving treatment with hyperbaric air. Treatments were given in a multi-place hyperbaric chamber for 85-min daily (session duration 95 min), five days a week for eight weeks (40 treatment sessions). The study was performed in an ambulatory setting.

RESULTS

Ninety-four patients with Wagner grade 2, 3, or 4 ulcers, which had been present for >3 months, were studied. In the intention-to-treat analysis, complete healing of the index ulcer was achieved in 37 patients at 1-year of follow-up: 25/48 (52%) in the HBOT group and 12/42 (29%) in the placebo group (P = 0.03). In a sub-analysis of those patients completing >35 HBOT sessions, healing of the index ulcer occurred in 23/38 (61%) in the HBOT group and 10/37 (27%) in the placebo group (P = 0.009). The frequency of adverse events was low.

CONCLUSIONS

The HODFU study showed that adjunctive treatment with HBOT facilitates healing of chronic foot ulcers in selected patients with diabetes.

The treatment of diabetic foot infections: focus on ertapenem

Clinically, 3 distinct stages of diabetic foot infection may be recognized: localized infection, spreading infection and severe infection. Each of these presentations may be complicated by osteomyelitis. Infection can be caused by Gram-positive aerobic, and Gram-negative aerobic and anaerobic bacteria, singly or in combination. The underlying principles are to diagnose infection, culture the bacteria responsible and treat aggressively with antibiotic therapy. Localized infections with limited cellulitis can generally be treated with oral antibiotics on an outpatient basis. Spreading infection should be treated with systemic antibiotics. Severe deep infections need urgent admission to hospital for wide-spectrum intravenous antibiotics. Clinical and microbiological response rates have been similar in trials of various antibiotics and no single agent or combination has emerged as most effective. Recently, clinical and microbiological outcomes for patients treated with ertapenem were equivalent to those for patients treated with piperacillin/tazobactam. It is also important to judge the need for debridement and surgery, to assess the arterial supply to the foot and consider revascularization either by angioplasty or bypass if the foot is ischemic. It is also important to achieve metabolic control. Thus infection in the diabetic foot needs full multidisciplinary treatment.