Search PubMed⌕ Search

Biomedical subjects

R F Edlich

Publications and source records attributed to R F Edlich.

At least 289 records · Page 16Linked to original sources

Mechanical cleansing of contaminated wounds with a surfactant.

Mechanical cleansing of a wound with a sponge soaked in a surfactant has prevented the development of experimental wound infection. The surfactant utilized for wound cleansing is Pluronic F-68, a member of a family of block copolymers called Pluronic polyols. Long-term toxicity studies and clinical trials suggest that this surfactant is safe for human use. Pluronic F-68 is a nonionic detergent that does not have any intrinsic antibacterial activity. Although mechanical cleansing with saline-soaked sponges effectively removes bacteria, it damages the wound and impairs its resistance to infection. The severity of the damage to the skin exerted by the sponge can be correlated with its porosity. Sponges with a low porosity are abrasive and exert more damage to skin than do sponges with a higher porosity. The addition of Pluronic F-68 to even the most abrasive sponges ensures that the bacterial removal efficiency of the sponge scrub is maintained, while tissue trauma is minimized. This dual effect of the surfactant results in a dramatic reduction in the infection rate of contaminated wounds. On the basis of these results, a clinical trial with surfactant-soaked sponges would appear to be indicated.

Animals↗

Proteolytic enzymes as adjuncts to antimicrobial prophylaxis of contaminated wounds.

When a tissue is injured, its vessels exhibit a marked increase in vascular permeability. Blood proteins, including fibrinogen, traverse the vessel walls and lead to the development of a surface coagulum. This inflammatory response continues until primary closure of the wound edges is accomplished. The thickness of the surface coagulum is roughly proportional to the time interval between wounding and closure. This coagulum encompasses the surface contaminants, preventing contact with either topical or systemic antibiotics. The presence of this surface coagulum limits the time in which antibiotic prophylaxis is effective. At three hours after injury, antimicrobial prophylaxis of contaminated wounds has no therapeutic value. Hydrolysis of the protein coagulum by proteolytic enzymes enhances the activity of the antibiotic in experimental wounds. The success of proteolytic enzymes as adjuncts to delayed antibiotic treatment can be correlated with the clot lysis activity of the enzymes in vitro. Travase, the most potent fibrinolytic enzyme, is the most effective adjunct to delayed antibiotic therapy of contaminated wounds. In contrast, the active enzymes found in Elase, which exhibit no significant clot lysis activity in vitro, do not potentiate the activity of antibiotics in wounds subjected to a delay in treatment. Travase prolongs the period of effective topical antibiotic action for at least eight hours in experimental contaminated wounds. The therapeutic merit of Travase is also apparent when the antibiotic is administered systemically. Travase shows promise as an adjunct to a variety of antibiotics that are effective against both gram-positive and gram-negative organisms. The results of these experimental studies support our belief that clinical studies support our belief that clinical studies should now be initiated to test the therapeutic value of Travase as an adjunct to antibiotics in heavily contaminated wounds subjected to an unavoidable delay in treatment.

Animals↗

A new filtered sump tube for wound drainage.

A new filtered sump tube has been designed for drainage of collections of fluids from wounds without the danger of infection by airborne contaminants. A two-staged filter has been attached to the vent lumen that removes particulate matter and bacteria from the air that passes through the filter. A clinical evaluation of this tube confirms the superiority of sump drainage as compared with closed suction drainage in the removal of fluids from wounds or cavities.

Abdominal Injuries↗

A more reliable gram staining technic for diagnosis of surgical infections.

The purpose of this study was to identify pitfalls in the Gram staining technic that limit its diagnostic value. In our clinical experience, gram-positive organisms were often decolorized too easily. Factors have been identified that alter the susceptibility of gram-positive organisms to decolorization in the Gram staining technic. The age of the bacterial culture, the preparation of the smear, the fixation technic, and the mordant have an important influence on the ease with which gram-positive organisms are decolorized. On the basis of these studies, a more reliable and reproducible Gram staining technic has been developed for the diagnosis of surgical infections.

Bacteria↗

Mechanical performance of surgical sutures.

A comprehensive analysis of the mechanical performance of sutures has been made to provide information concerning the reliability and security of knotted sutures. The tests utilized in this analysis were designed to be easily reproduced by other investigators. The construction of the knot and the knot performance analysis were undertaken utilizing an Instron Tensile Tester. The mechanical reliability of each knotted suture was determined by measuring the number of throws to reach knot break, the expected slippage of the knot when it reaches knot break, and the maximal holding force at knot break. On the basis of these measurements, recommendations are made for the use of a suture at operation.

Biomechanical Phenomena↗

Biology of infections of split thickness skin grafts.

The purpose of this study was to identify determinants of split thickness skin graft infection. The bacterial count of the experimental wounds was proportional to the incidence of infection in split thickness skin grafts. When the wound was heavily contaminated with 107 organisms, infection developed under most grafts. Graft take frequently occurred in wounds subjected to a lower level of inoculum. The importance of bacterial counts as a determinant of potential skin graft infection was also suggested by a clinical study. We now routinely use quantitative bacterial counts to identify the granulating wounds that are ready for grafting. The type of organism played no significant role in the development of infection.

Animals↗

Streptococcal cellulitis of the scrotum and penis with secondary skin gangrene.

Cellulitis of the scrotum and penis is caused, in the majority of instances, by a beta hemolytic streptococci without a discernible portal of entry. Clostridium, occasionally, will result in this disease as a manifestation of a perirectal abscess. In either instance, fluid accumulates rapidly in the closed space between Colles' and Buck's fascia, producing intense swelling of the scrotum. If this compartment is not immediately decompressed by linear incisions, devascularization of the scrotal and penile skin will often occur, resulting in gangrene. Immediate treatment of the bacterial infection with penicillin also is essential. If gangrene does develop, radical debridement of the necrotic tissue as well as a wide margin of adjacent inflamed skin must be undertaken. Continual monitoring of the microflora of the debrided would is essential for the selection of the appropriate antibiotic against any secondary intruders. Coverage of the granulating would is accomplished when the would bacterial count is below 10-5 per gram of tissue.

Amphotericin B↗

Wound cleansing by high pressure irrigation.

All traumatic wounds are contaminated to some degree by both soil and bacteria. Specific infection potentiating factors in soil impair the defenses of the tissue and invite infection. These factors are small in size and resist removal by low pressure irrigation. The efficiency of wound irrigation is markedly improved by delivering the irrigant to the wound under continuous high pressure. Irrigation of the wound with saline solution delivered at 15 pounds per square inch removed 84.8 per cent of the soil infection potentiating factors from the wound. The residual infection potentiating factors remaining in the wound did not significantly impair tissue defenses. On the basis of these experimental studies, clinical studies are now being initiated to test the therapeutic value of high pressure irrigation in traumatic wounds in humans.

Animals↗