ABSTRACT
Moist wound healing is one of the most frequently used, but least understood terms in wound care. Although no reliable operational definitions exist of too little or too much wound surface moisture, a low dressing water vapor transmission rate (WVTR) has proven to be a reliable measure of a dressing's capacity to retain moisture and provide an environment that supports healing. Dressing WVTR is a powerful linear predictor of both full- and partial-thickness healing of standardized acute wounds in vivo (alpha < 0.0001). Moreover, differences in the ability to produce an optimal moist wound environment within a dressing category, such as hydrocolloid dressings, are strongly correlated with dressing WVTR, suggesting that dressings in the same product categories may be associated with significantly different environments for healing. Even though the correlation between dressing WVTR and healing rates is more difficult to ascertain, clinical healing percentages during similar time-frames and healing times of similar wounds also follow patterns predicted by dressing moisture retention. These results suggest that, when other variables are held constant, use of more moisture-retentive dressings generally achieves environments supportive of earlier healing outcomes when compared to less moisture-retentive dressings. Maceration, an unwelcome occurrence with moisture-retentive dressing use on highly exuding wounds, is not consistently associated with increased adverse events. Evidence further suggests that greater dressing moisture retention is associated with fewer clinical infections, greater patient comfort, and reduced scarring.
Subject(s)
Bandages/standards , Humidity , Wound Healing , Wounds and Injuries/physiopathology , Wounds and Injuries/therapy , Absorption , Animals , Bandages/adverse effects , Chronic Disease , Disease Models, Animal , Exudates and Transudates , Humans , Treatment OutcomeABSTRACT
The epithelization of partial-thickness wounds (PTW) has been shown to be enhanced with the use of moisture-retentive dressings (MRD), and not with nonmoisture-retentive dressings (NMRD) like gauze. This study was designed to explore this effect using two different alginate products with and without MRDs. We evaluated these alginate dressings under a polyurethane film dressing (FMRD) and under an NMRD gauze. They were compared to hydrocolloid moisture-retentive dressings (HMRD). Twelve PTW measuring 22 x 22 x 0.5 mm were made on the dorsum of six swine with a Castroviejo dermatome. Return of the epithelial barrier function was measured with an EP1 ServoMed evaporimeter. On postoperative day 4, the first alginate product under the NMRD and under the FMRD had a significantly slower healing rate than the HMRDs. By postoperative day 7, the second alginate product under the NMRD had a poorer rate of epidermal wound healing than the HMRD. Our results indicate that these alginate products have a satisfactory partial-thickness wound healing capability when used under MRDs. When used under MRDs, the return of the epithelial barrier function is delayed, indicating that these dressings should not be used on dry wounds or under gauze dressings.
Subject(s)
Alginates , Bandages , Wound Healing , Animals , Colloids , Evaluation Studies as Topic , Glucuronic Acid , Hexuronic Acids , Skin/injuries , SwineABSTRACT
To avoid the compensatory hemodynamic responses, which have limited interpretation of hemoglobin-oxygen affinity modifications in animal experimentation, an isolated blood-perfused rabbit heart model providing metabolic, functional, and vectorcardiographic measurements has been developed. Fixed-flow perfusions of unchanged or affinity-modified red blood cell suspensions were carried out to assess the benefits of high affinity during hypoxic hypoxia and of low affinity during posthypoxic recovery. Using fully saturated suspensions, the influence of affinity level during restricted flow and reperfusion was also studied. Higher myocardial oxygen consumption (MVO2) was associated with high-affinity blood during mild hypoxia and low-affinity blood during posthypoxic recovery. At low flows, heart rate and MVO2 tended to be lower in high-affinity perfusions, and to recover more completely during low-affinity reperfusions. Ventricular function, vectorcardiographic patterns, and lactate levels were affected by hypoxia and ischemia, but not by level of affinity. The relevance of these observations to the therapeutic potential of hemoglobin-oxygen affinity modification is discussed.
