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Exudate consists of fluid and leukocytes that move to the site of injury from the circulatory system in response to local inflammation. This inflammatory response leads to blood vessel dilatation and increased permeability, resulting in increased production of exudate. The nature and quantity of exudate depend on the nature and severity of the tissue damage. The exact amount of wound exudate and moisture to promote moist wound healing is unknown. This moisture balance is essential to promote healing and is oftentimes a major challenge to the wound care provider. This article will explore the benefits of wound fluid as well as the detrimental impact on wound healing. Assessment and management will also be briefly discussed.

Greater understanding of the role of moisture in wound healing has shown that proper management is essential.

Transparent film dressings have many of the attributes of the ideal wound dressing. However, currently available film dressings are deficient in their ability to handle varying levels of wound exudate. The permeability of polymeric films to water vapor is discussed and techniques are described to produce films in which the moisture vapor permeability is a function of the moisture in the environment. Illustrations are provided showing the variation of permeability with relative humidity and water contact. The unique properties of coextruded films are illustrated and the responsiveness of such a film dressing to varying conditions at the wound are discussed.

Objective: To compare the effects of green foam with black foam and gauze during negative pressure wound therapy (NPWT), with regard to wound bed appearance and granulation tissue formation, and monitoring of wound exudate. Method: Wounds on the backs of eight pigs underwent 72 hours of NPWT plus either green polyurethane foam with an open pore structure, black polyurethane foam with an open pore structure or saline-moistened AMD gauze. Sections of biopsies from the wound bed, including the overlying dressing, were examined histologically with regard to microdeformation of the wound bed and granulation tissue formation. The force required to remove the wound fillers was measured. Results:Wound exudate and bleeding could be easily seen when using gauze and green foam, but were not visible under the black foam. Such visibility facilitates monitoring of the wound status. No difference was found in the quantity or characteristics of the granulation tissue formed under the green foam or black foam. Both green foam and black foam resulted in more pronounced granulation tissue formation than gauze under negative pressure. There was also more leucocyte infiltration and tissue disorganisation under green foam and black foam than under gauze. All three wound fillers created microdeformation within the wound bed surface. Similar forces were required to remove green foam and black foam (5.0 ± 0.6 N for green foam and 4.0 ± 0.4 N for black foam), while less force was needed for gauze (2.1 ± 0.2 N). This may be a result of tissue ingrowth into the foam (357 ± 12pm for green foam and 362 ± 14pm for black foam), but not into gauze (0pm), as shown by examination of biopsy sections from the wound bed. Conclusion: Green foam and black foam have similar biological effects on the wound bed. Bleeding and exudate can be more easily monitored when using green foam or gauze. Differences in the wound bed tissue morphology when using foam or gauze plus NPWT support clinical observations that granulation tissue under foam is thick but fragile, whereas that under foam is thinner but denser. Conflict of interest: The study was supported by Molnlycke Health Care AB.

Wound malodour is rapidly becoming a critical issue, particularly with patients suffering with chronic illness that often result in wounds such as; venous leg ulcers, diabetic ulcers, pressure ulcers and fungating (malignant cancerous) lesions. The malodour is usually just part of the whole chronic situation but it can affect the patient in numerous social and psychological ways. There are specific wound dressings on ‘Drug Tariff to treat malodour. These contain a layer of activated charcoal which facilitates the adsorbing of wound malodour. Although activated charcoal is efficient in the adsorption of volatile odorous molecules, there are some issues with its use in wound dressings and these are: a) Activated charcoal cloth is black in colour; b) it is relatively weak in nature and can be easily ruptured and presents a risk of the broken fragments of carbon fibre contaminating the wound, if exposed; c) the efficiency of the ability to adsorb odorous volatile molecules is compromised if saturated with the molecular rich wound exudate; and d) activated charcoal cloth is relatively expensive to produce and this is often reflected in the cost of the final products. In order to address the above limitations, a research programme is in progress at the University of Bolton one of the objectives of this research is to investigate and develop a viable test method for evaluating the efficiency of odour adsorption, whilst researching and developing novel odour/volatile adsorbent materials, to possibly replace the use of activated charcoal. To date there appears to be a dearth of quantitative comparable data on these specific wound dressings particularly on their odour adsorption efficiency; this may be due to the limitation of realistic test methods of evaluating this characteristic. Further research work has been carried out on a novel test method for odour adsorption that has combined the efficiency of odour adsorption together with the assessment of fluid handling capabilities. Although there are still some criticisms with this method it appears to be the nearest, to date that simulates some of the physical conditions that the product would experience in use. A selection of currently available activated charcoal wound dressing products have been tested, evaluated and quantitative comparable data collected. Some natural polymeric antimicrobial agents have also been tested and evaluated for their potential odour adsorption efficiency. These results will enable us to develop, engineer and characterise a range of novel odour adsorbent materials by using innovative fibres/polymers, fabric structures and composites incorporating adsorptive and antimicrobial properties.

20 patients who all had two pathological nail conditions underwent two avulsions with phenolization identical in technique except that one was irrigated with alcohol following the application of phenol and the other was not. Following the procedures all patients were seen at short and regular intervals at which time wound exudate was tested for the presence of phenol. Phenol was shown to remain in the tissues for a wide range of time in both groups. When the results were subjected to statistical analysis no significant difference was found between the two methods. These findings indicate that irrigation with alcohol can have only a superficial effect in flushing phenol from the tissues and has no proven value.

This real-life, observational evaluation shows that, by absorbing and retaining within its structure the corrosive enzymes found in chronic exudate, this dressing both reduces the likelihood of peri-wound maceration and promotes healing

In this chapter, we have reviewed the technological advances in the development of interactive wound dressings. Since the time when the value of a moist wound environment in wound healing process was recognised, the primary purpose of dressings has changed from reducing moisture to maintaining moisture. The balance of moisture is critical to healing and this principle has been the driving force in the development of products that are currently available, such as hydrogels, hydrocolloids, alginates, and foams and films. Many interactive dressings work actively with wound properties, such as wound exudate, tissues, cells and some growth factors and, in addition to maintaining moisture, enhance healing process. We have provided suggestions on how to select the most appropriate interactive dressing product and discussed the latest studies and reviews on the effectiveness of selected products in wound management.

Fruits of squash (Cucurbita pepo) cv, ‘Delica' were challenged by surface cuts at 2-weekly intervals to investigate the relationship between exudation and rotting. Those fruits that stopped exuding within 2 months after harvest were more susceptible to fungal invasion than fruits that retained the ability to exude. However, the statistical relationship linking exudation and fungal resistance did not apply to individual fruits, some of which exuded whilst rotting.

Various parameters were monitored during growth and storage of fruit of buttercup squash (Cucurbita maxima D. hybrid ‘Delica’) in an attempt to identify a physiological basis for the marked influence of maturity at harvest on the susceptibility of fruit to rot in storage. Protease inhibitor levels in the exudate from artificial wounds were consistently higher in the more resistant fruit, harvested within 14 days after completion of expansion, than in the less resistant fruit, harvested about 21 days later. Enzymes capable of cleaving the agluconic bond in the artificial substrates p-nitrophenyl-N-acetyl-β-D-glucosamide and p-nitrophenyl-β-D-N, N'- diacetylchitobiose, possibly functioning as exochitinases in vivo, were found in the juice of the fruit tissue, but not in the wound exudate. The late-harvested, less resistant fruit consistently exhibited higher levels of these activities than did the early-harvested fruit. Other distinguishing factors which were also higher in late-harvested than in e...

A polyetherurethane (PEU) wound covering with non-interconnected micropores up to approximately 5 microns has been prepared by means of a phase inversion process. This highly elastic, very thin (15-20 microns), pliable wound covering showed good, immediate adherence to wet wound surfaces and high water vapor permeability, but was impermeable to bacteria. In guinea pigs epidermal wound healing of partial-thickness wounds under PEU wound coverings was accelerated compared with uncovered controls and an occlusive wound covering, OpSite. Water in liquid form or wound exudate could not leak through the PEU covering, but its high water vapor permeability induced concentration of the wound exudate into a jellylike clot layer, which apparently accelerated reepithelialization. The main conclusion from a clinical study on 20 donor sites was that the use of the PEU covering reduced pain, besides prevention of fluid retention. No differences in epithelialization were seen in comparison to tulle gras-treated wounds.

Disordered cell function within chronic wounds generates many parameters that can be measured to differentiate between healing and non healing status. Theoretically, these may form the basis of a wound assessment system to define disease severity and response to treatment. In a review of tissue, wound exudate and microbiology studies of venous leg ulcers, we identify many such parameters that are associated with healing status. These include cytokines, proteases and their inhibitors, senescence markers, oxidative stress markers and microbiological status defined by culture. Some of these, such as protease level in wound exudate, have been proposed as prognostic indicators of healing status and many more could be considered potential markers to incorporate into a wound assessment system. However, no published data are available that validate known wound components to accurately reflect wound progression on a single patient basis. Rather than further characterisation of the expression of known wound biomarkers, the development of an accurate and objective test for prediction of chronic wound outcome requires identification of an appropriate combination of novel molecules that vary coordinately with healing status.

Traditionally wet-to-dry gauze has been used to dress wounds. Dressings that create and maintain a moist environment, however, are now considered to provide the optimal conditions for wound healing. Moisture under occlusive dressings not only increases the rate of epithelialisation but also promotes healing through moisture itself and the presence initially of a low oxygen tension (promoting the inflammatory phase). Gauze does not exhibit these properties; it may be disruptive to the healing wound as it dries and cause tissue damage when it is removed. It is not now widely used in the United Kingdom.​Kingdom.​ Figure 1 Left: Healthy venous leg ulcer suitable for dressing with low adherent dressing. Right: Wound suitable for dressing with semipermeable film Table 1 Characteristics of the ideal dressing Occlusive dressings are thought to increase cell proliferation and activity by retaining an optimum level of wound exudate, which contains vital proteins and cytokines produced in response to injury. These facilitate autolytic debridement of the wound and promote healing. Concerns of increased risk of infection under occlusive dressings have not been substantiated in clinical trials. This article describes wound dressings currently available in the UK.​UK.​ Figure 2 Venous leg ulcer suitable for dressing with hydrocolloid Table 2 Low adherent dressings—suitable for use on flat, shallow wounds with low exudates

A model of infected skin ulceration could prove useful in assessing the clinical effectiveness of antimicrobial ointments and dressings. However, no such models have been previously established. Three types of wound were induced in rats: full-thickness wounds covered with gauze, burn wounds and wounds resulting from mechanical trauma. Wounds were inoculated with S. aureus or P. aeruginosa. Persistent infected wounds were observed only in full-thickness wounds covered with gauze. In a second experiment, colonies of P. aeruginosa or S. aureus were counted within 15 x 15 mm full-thickness wounds covered with gauze. Wounds were inoculated with 1.0 x 10(6) colony-forming units (CFU) of P. aeruginosa or S. aureus and then sealed to ensure an enclosed environment. Tissue bacterial counts exceeded 10(6) CFU/g from the next day until day 9 after infection. Bacterial counts exceeded 10(8) CFU/ml in wound exudate collected between days 1 and 7. We have developed a model of wound infection in which persistence of infection can be achieved for 9 days following ulceration due to the application of gauze to the base of a full-thickness wound.

Wound-bed preparation is “the management of a wound to accelerate endogenous healing or to facilitate the effectiveness of other therapeutic measures” [1]. Wound cleansing is a vital component of preparing the wound bed. It should be done initially and with each dressing change. Wound cleansing removes wound exudate, dressing residue, foreign materials, topical agents and metabolic wastes, which is necessary for getting the wound bed ready for healing to occur.

In the UK the so-called ‘foam’ dressings are currently the most widely used absorbent dressings. They can, in certain cases, be particularly useful for the management of exuding wounds. One type of foam dressing – the Tielle hydropolymer adhesive dressing family (by Johnson & Johnson Wound Management) – is a range of five types of hydropolymer dressings: Tielle Original dressing, Tielle Lite dressing, Tielle Plus dressing, Tielle Borderless dressing and Tielle Packing dressing. The Tielle range shares a common basic composition that gives each dressing bacterial barrier properties and the capability of managing exudate by the combined process of absorption and moisture vapour transmission. Each type except Packing can be used as either a primary or as a secondary dressing. The choice should be based on the characteristics of the primary dressing, if any, on the degree of exudate that the wound is producing and on the condition of the surrounding skin. This article aims to give an overview of the Tielle range and a review of research-based clinical and scientific evidence to support the management of differing levels of exuding wounds in everyday clinical practice.

Wound exudate is all too often perceived as a clinical management problem. While this can be the case, it should be recognized that exudate does fulfil an important function in the healing process. Gradual acceptance of the benefits of moist wound healing, combined with the current goals of the ‘ideal’ moist environment, focuses attention on the role of exudate. This review is intended to define the components and functions of ‘normal’ exudate and differentiate it from abnormal exudate.

Gel-forming dressings, which absorb the wound exudate to form a non-adherent gel, accelerate wound healing in a moist environment. The most commonly used of these dressings are calcium alginate and hydrocolloid membranes. This study was designed to evaluate the physical properties of these dressings, including fluid retaining ability, gel formation, and the dissolution process to clarify the mechanisms that promote healing. A simple immersion method was used for measurement. This technique was useful for the quantitative assessment of gel-forming dressings and may help to evaluate potential application of these dressings. A comparative analysis showed that alginate dressings remained gelled longer than hydrocolloid dressings. This result was consistent with previously reported clinical features of these dressings. The absence of calcium in wound fluid induced rapid resolution of alginate gel while the presence of a certain concentration of calcium prevented degradation of the gel for as long as one month.

This study explores the absorptive capacity of standard cotton wool-tipped swabs in vitro and in vivo. An alternative wound exudate sampling technique using small filter paper discs is also briefly examined. Results showed a poor uniformity of fluid absorption by swabs and a limited correlation of wound exudate quantities in relation to visual estimates and size of wound. It was found, however, that swabs reliably removed material from a wound surface. The filter paper technique appeared to offer no advantages.

There is a high need for rapid healing in the treatment of severe burns, trauma, diabetic, decubitus ulcers and other conditions where a great damage of the tissue is exist. In those cases, wound should be covered with a dressing which replaces the functions of the natural skin by protecting the loss of body fluid and proteins, preventing bacterial invasion, improving and stimulating the healing process by providing a support for the proliferating cells.

The issue of the care required by wounded patients infected with human immunodeficiency virus should be addressed by all nursing personnel. The virus can be transmitted through blood, blood products or wound exudate. Promotion of universal precautions should greatly minimise the risk. The patient's infection status is not always known and the problem may not be a major wound but an associated condition.

Many new discoveries have been made in the last decades in dermatology. The therapeutic use of corticosteroids, retinoids, and photochemotherapy has changed dermatology from an art, into a science in which basic research, controlled studies, and new etiopathogenetic insights prevail. With this approach, contentions and dogmas were checked and often found wanting. However, some traditional treatments have become, after some adaptation, important aids in treating skin diseases, e.g., psoralens and vitamin A and its derivatives.

The conventional open or nonocclusive treatment of split-thickness skin graft donor sites using wide-meshed, lattice tulle gras compresses impregnated with saline, paraffin or ointments requires frequent dressing changes, which are usually painful and often sanguineous. Even today, this complicates donor site treatment in children. Pediatric surgery practice therefore requires a type of wound dressing that: (a) provides a safe, immovable wound cover adhering tightly to healthy skin, even in mobile children, and (b) that can be changed without causing the patient pain.

The art of decorating the human body by painting, stigmatizing or tattooing has been practised for thousands of years. The earliest findings suggesting the practice of tattooing are bone needles from 6000 BC, on which pigments were found and which had apparently been used for tattooing [16].

While occlusive wound dressings help provide patients with moist wound healing to reduce pain and increase reepithelialization rate, the moisture vapor transmission rate (MVTR) of these dressings remains constant even though wound exudate levels may vary with time and from wound to wound. The clinician is therefore faced with exudate buildup in heavily exuding wounds and desiccation in lightly exuding wounds-a situation requiring frequent patient monitoring and dressing changes. Am "intelligent" wound dressing would have the ability to automatically respond to a wound's exudate level by self-adjusting its MVTR to maintain a constant moist wound environment. Such a dressing could help ensure that exudate buildup or wound desiccation is reduced or avoided. Three commercial wound dressings (hydrocolloid, thin film, and membrane laminate) were studied for their ability to alter their MVTR in response to varying moisture level. An efficient test methodology and experimental design was developed, which involved direct and indirect fluid contact with the dressings using two temperatures and two test methods. One dressing, a membrane laminate, was found to exhibit intelligent MVTR behavior. Data is presented which shows this dressing's ability to adjust its MVTR nearly eight-fold as a function of hydration level. Information regarding the mechanism of action of this intelligent dressing is also presented.

RATIONALE This patient was so debilitated that her heel ulcer was not expected to close. Her foot was cold, with poor capillary refill and an absent pedal pulse. Dressings were needed to prevent any infection from becoming systemic and to contain the wound exudate. Bordered polymeric membrane dressings conform well to heels and have a semipermeable membrane to protect wounds from contamination. They contain glycerol, a surfactant, and a super-absorbent starch. Polymeric membrane dressings’ ingredients draw and concentrate natural healing substances from the body into the wound bed to promote rapid healing while facilitating autolytic debridement directly by loosening the bonds between the slough and the wound bed. The liquefied slough is absorbed by the dressing, often eliminating the need for potentially damaging and painful manual wound bed cleansing during dressing changes. Together the dressing’s components reduce wound pain by inhibiting nociceptor activity at the wound site. In the absence of sufficient nutrients from the bloodstream, the glycerol in polymeric membrane dressings can be utilized by the body as an energy source and a component of new cells. The decision was made to use only silver or standard polymeric membrane dressings, depending upon the condition of the wound bed.

An ideal artificial skin should meet two opposing requirements. It should be sufficiently occlusive to prevent rapid wound dehydration and bacterial invasion, but it should also be permeable enough to allow passage of wound exudate.

Fibronectin concentration is much lower in wound exudate from the zone of operation for postoperational ventral hernia than in blood plasma. It gradually increases, reaching the plasma level before the end of exudation and wound healing.

Overgranulation in wounds causes a delay in wound healing and often produces an increase in wound exudate and is therefore difficult to dress. This article suggests non-traumatic methods of removal in order to preserve the granulation of tissue required for healing.

We have studied the cell population, neutrophil bactericidal activity, protein type and content of the exudate which accumulates on partial thickness wounds, on pigs, covered by an adhesive polyurethane film dressing (Op-Site∗) (Seymour et al., 1972), and compared the results obtained with those from a similar study in humans. Whilst there are some differences between the results from the two experiments, the pig wound exudate shows an antibacterial activity similar to that of human exudate, and we therefore conclude that the animal model described here is suitable for further studies on the bactericidal activity of wound exudate.

Three consecutive studies were performed in 58 patients evaluating the effect of occlusion on the healing of partial-thickness wounds. Mirror-image donor sites were covered with the occlusive hydrocolloid dressing (HCD) (DuoDerm) and compared to fine mesh gauze, and the HCD was subsequently compared to a semi-occlusive dressing of polyurethane film, (Op-site). In addition, partial-thickness burn wounds were covered with the HCD and the remaining burn wound was treated with silver sulfadiazine. The donor sites and burn wounds treated with HCD healed significantly faster than those covered with fine mesh gauze or silver sulfadiazine (p less than 0.001) and with less pain. The HCD and polyurethane film were equivalent. There were no clinical infections with the wounds that were occluded. The exudate collected beneath the DuoDerm and Op-site on donor sites was added to the tissue culture system and resulted in a modest increase in keratinocyte proliferation. However, the exudate from burn wounds under HCD resulted in a marked increase in cell proliferation (p less than 0.001).

The experimental poly(ether urethane) (PEU) wound covering with a high water vapour permeance was compared with tulle gras treatment on adjacent areas of the same 20 split-skin donor sites. All patients experienced little or no pain from the PEU-covered areas, while 70 per cent of the patients complained of more pain from the tulle gras-covered areas. The PEU covering did not absorb the wound exudate underneath, neither did it retain wound fluid, but turned the wound exudate into a jelly-like clot layer by allowing a high evaporative water loss from the wound. Tulle gras treatment also prevented wound desiccation, but the exudate was absorbed into the overlaying cotton pads, where it became dry at the outer surface. Microscopy revealed that re-epithelialization occurred at a similar rate under the PEU covering as under tulle gras. In conclusion, the high water vapour permeable PEU wound covering prevents fluid retention, induces clotting of the wound exudate and reduces pain in split-skin donor sites. Tulle gras dressed with gauzes and crepe bandage prevents wound desiccation, but causes more pain.

To assess the efficacy of laser therapy in the management of unresponding wounds and ulcers the method based on the estimation of chemiluminescence of tissue fluid in the presence of H2O2 was developed. It is suggested that laser radiation-induced decrease in chemiluminescence can be attributed to the activation of catalase in tissue fluid, which has an obvious positive therapeutic effect on reparative regeneration of wounds and ulcers.

Dextranomer is a hydrophilic dextran polymer advocated as a 'cleansing agent' for various types of exudating wounds or ulcers, including stasis (venous) ulcers and decubitus ulcers. It appears to exert its effect by a capillary action which absorbs wound exudate, as well as wound debris and micro-organisms, into the dextranomer beads or into the spaces between the beads, thus removing such products from the wound surface. Dextranomer is an aid to wound or ulcer management, and does not directly affect tissue repair in such ulcers, but as with other 'cleansing' agents or techniques, removal of debris (and possibly micro-organisms) from the wound could be expected to promote natural healing. Reports of its effectiveness in open studies, often in patients with seemingly resistant lesions, have been encouraging. Similarly, in comparative trials results have usually favoured dextranomer, but a clear indication of the relative efficacy and benefits as compared with other treatments used for exudating lesions has not yet emerged. Further well designed comparative studies are needed to provide such information.

Female screwworms, Cochliomyia hominivorax (Coquerel), responding to wounded hosts, began to feed immediately on the wound exudate, regardless of their stage of ovarian development. Vitellogenic parous females were more abundant than vitellogenic nulliparous females throughout the year. Twenty-eight and 45% of the early and late season females, respectively, completed at least one additional gonotrophic cycle. All parous females were mated. Virgin nulliparous females were 1st captured in Sept. and most (81%) were in the 1st stages of egg development.

The determination after high doses of penicillin of tissue concentrations from post-operative wound exudate byKolb andJaschek (1974) confirm the experimental results in animals ofChisholm and coworkers (1973) andWeinstein and coworkers (1974). The quotient tissue concentration/blood concentration rises steeply after the second hour with antibiotics such as penicillins which are rapidly eliminated, and is five times as high by the fourth hour. These results and those obtained by a group carrying out investigations between 1955 and 1965 demonstrate that a correlation between the blood level and the concentration at the site of infection will only be possible when more information becomes available. The claim ofNaumann (1974) that a concentration corresponding to the MIC of the pathogen which is attained in the middle of the dosage interval (τ/2) can be applied as a parameter for „clinical resistance“ is hereby rejected and pronounced dangerous.

Because of evidence that topical phenytoin (PHT) can promote wound healing, we undertook pilot clinical trials to evaluate its effectiveness in treating decubitus ulcers that resulted from war-related wounds at Basrah Teaching Hospital, Basrah, Iraq. Prompt pain relief, decreased wound exudate and bacterial contamination, enhanced granulation tissue formation, and more rapid healing characterized the PHT group. Fifteen PHT-treated decubitus ulcer patients healed in 1-3 weeks (one graft) versus 6-8 weeks (five grafts) in the control group. In addition, 20 patients with missile wounds were treated with PHT in an open trial. Further trials of PHT in war-related wounds are indicated.

Cellular patterns of healing subcutaneous connective tissue were studied histologically in 22 pediatric surgical patients using the CELLSTIC device. This wound drain, specially developed for this purpose, consists of a standardized, viscose cellulose sponge inside a thin silicone rubber tube. When left between the wound edges. wound exudate flows through the drain, allowing its cells to attach themselves to the sponge surface. The sponge serves as a framework within which the cells may migrate, divide and transform. During the first 12 h the cellular pattern in the sponge resembles that of peripheral blood, whereafter the number of polymorphonuclear leukocytes, almost exclusively neutrophils, gradually increases. Later on, monocytes, macrophages and lymphocytes invade. Fibro-blasts were usually seen at the end of the third day postoperatively, but in some cases the first fibroblasts appeared even earlier. CELLSTIC neither disturbs normal wound healing nor increases the rate of wound infections. CELLSTIC, as a cell culture in situ, provides a practical way to study human connective tissue regeneration under both physiological and pathological conditions.

CELLSTIC is a miniature wound drain composed of a thin silicone rubber tube and a pressed rectangular stick of viscose cellulose sponge (VCS) placed inside the inner end of the tube. When moistened and placed between wound edges two sides of the sponge expand in opposite directions leaving two free channels between the remaining sides and the tube wall for the flow of wound exudate. Most cells in the exudate become attached to the sponge, where they may further invade, multiply and be transformed. The first human fibroblasts in the CELLSTIC sponge are usually seen three or four days after implantation. CELLSTIC does not disturb normal wound healing in any way even in newborn babies, as has been proved in 155 pediatric surgical patients. As well as being a testing device for human connective tissue regeneration in general, CELLSTIC may also be used to control the local effects of various medicines and radiotherapy on human wound healing.

Operations of long duration, organ-transplants, and those where heterogenic material is implanted, all entail a particularly high risk of infection and consequent severe complications. The prophylactic use of antibiotics is therefore indicated in these situations.

The indecation and the efficacy of antibiotic prophylaxis in endoprosthetic operations are discussed with reference to prospective studies. After parenteral administration of 80 mg gentamicin the antibiotic concentrations in the serum and in the wound exudate were studied for 2 to 6 hrs after administration. During this observation period the gentamicin concentrations in the wound exudate were about equal to those in the serum. A comparison of the concentrations after parenteral and after local administration of gentamicin showed much higher concentrations in the wound exudate when gentamicin was administered with the bone cement.

As a temporary dressing on scald wounds in children Omiderm was tried in 10 consecutive patients. Omiderm is a thin, transparent, hydrophilic polyurethane membrane, permeable to water and oxygen. It was applied on the wound when exudation was declining, about 4-10 hours postburn. The dressing formed a crust with the wound exudate and was removed when the wound had reepithelialized or at day 14 postburn before split skin grafting of the wound if the wound had not yet healed. The dressing had no advantages nor disadvantages compared to conventional exposure treatment with regard to healing time, rate of bacterial contamination, need for split skin grafting, quality of scars on spontaneously healed areas nor comfort to the patients.

D-GLYCERO-D-GALACTO-HEPTITOL has been isolated from the semi-crystalline exudate of wounds in the bark of Persea americana Mill.