Cath Lab Digest

Porcine model studies have suggested that nanocrystalline silver dressings modulate the activity of matrix metalloproteinases in vivo. A pilot prospective clinical study was conducted to evaluate the impact of these dressings on individuals with chronic ulcers of various etiologies. The study evaluated the level of matrix metalloproteinases activity of wound fluids recovered from patient dressings before and after dressing with nanocrystalline silver. The recovered wound fluid was examined by enzyme zymography in combination with fluorogenic matrix metalloproteinases activity assays. The results indicated that within 2 days following the switch to the test dressings, the activity level of matrix metalloproteinases dropped substantially, although not uniformly, in all patients. The decrease in matrix metalloproteinases activity in wound fluid was associated with an improvement in the appearance of the ulcers. The authors concluded that nanocrystalline silver is able to modulate matrix metalloproteinases activity rapidly in wounds without eliminating the matrix metalloproteinases activity required for wound healing.

  Product notation: Acticoat(TM) Antimicrobial Barrier Dressing, Westaim Biomedical Corporation, Fort Saskatchewan, Alberta, Canada.

A Wound Model Utilizing Artificial Wound Fluid to Compare Wear Time of Hydrocolloid Dressings
L.K. Sproule, 3M Canada Company Inc. London, Ontario, Canada; N.P. Atwood, 3M Health Care, St. Paul, Minn.; C.T. Lyle, 3M Health Care, St. Paul, Minn.; S.E. Solfest, 3M Health Care, St. Paul, Minn.; and J.B. Lutz, 3M Health Care, St. Paul, Minn.
  Applying hydrocolloid dressings to moist skin is a challenge for healthcare professionals. Moisture can be endogenous (eg, exudate) or exogenous in nature (eg, sweat, incontinence). A model using healthy volunteers for comparing wear time of hydrocolloid dressings under moist skin conditions has been developed that simulates common environments seen in everyday clinical practice. The objective of this study was to use this procedure to compare wear times of two commercially available hydrocolloid dressings. The two dressings were randomly applied over wound models on both volar forearms of 18 subjects. The simulated wound consisted of a nonstick absorbent pad cut to approximate a 2.5-cm x 2.5-cm wound with a 0.7-mm microcannula inserted into the pad. The absorbent pad served as a fluid reservoir into which artificial wound fluid was infused. Saline is often used to compare absorptive capacities of dressings; however, saline is chemically very different from wound fluid and various absorptive wound care products react differently to saline. This model uses a formulation of artificial wound fluid based on reported components of human extracellular fluid and of chronic wound fluid. In this study, artificial wound fluid was infused at a rate of 7.2 mL/day for a maximum of 5 days in order to mimic a moderately exudating chronic wound. Additionally, subjects entered an environmental chamber for 30 minutes/day maintained at 98 degrees F and 94% relative humidity to induce sweating. To simulate incontinence in the chamber, subjects soaked the dressings with wet paper towels. Dressings were checked daily for lift and leakage. Results indicate significant differences (P < 0.05) in time to failure between the two dressings.

Implementation of a Comprehensive Wound Care Program in a Tertiary Care Hospital
L.M. Teague, J. Li, and J.L. Mahoney, St. Michael's Hospital, Toronto, Ontario, Canada
  Reducing hospital-acquired (incidence) pressure ulcers requires vigilant risk assessment. The application of evidence-based interventions can prevent these devastating wounds.