Guideline for Prevention of Surgical Site Infection, 1999 ☆ ☆☆ ★ ★★

Inefficient vascular supply and the resultant reduction in tissue oxygen tension often lead to neovascularization in order to satisfy the needs of the tissue. Examples include the compensatory development of collateral blood vessels in ischaemic tissues that are otherwise quiescent for angiogenesis and angiogenesis associated with the healing of hypoxic wounds. But the presumptive hypoxia-induced angiogenic factors that mediate this feedback response have not been identified. Here we show that vascular endothelial growth factor (VEGF; also known as vascular permeability factor) probably functions as a hypoxia-inducible angiogenic factor. VEGF messenger RNA levels are dramatically increased within a few hours of exposing different cell cultures to hypoxia and return to background when normal oxygen supply is resumed. In situ analysis of tumour specimens undergoing neovascularization show that the production of VEGF is specifically induced in a subset of glioblastoma cells distinguished by their immediate proximity to necrotic foci (presumably hypoxic regions) and the clustering of capillaries alongside VEGF-producing cells.

Vascular endothelial growth factor induced by hypoxia may mediate hypoxia-initiated angiogenesis.

SOLID tumors are composed of two discrete but interdependent compartments: the malignant cells themselves and the stroma that they induce and in which they are dispersed.1 , 2 In tumors of epitheli...

Tumors: wounds that do not heal. Similarities between tumor stroma generation and wound healing.

The “Guideline for Prevention of Surgical Site Infection, 1999” presents the Centers for Disease Control and Prevention (CDC)'s recommendations for the prevention of surgical site infections (SSIs), formerly called surgical wound infections. This two-part guideline updates and replaces previous guidelines.Part I, “Surgical Site Infection: An Overview,” describes the epidemiology, definitions, microbiology, pathogenesis, and surveillance of SSIs. Included is a detailed discussion of the pre-, intra-, and postoperative issues relevant to SSI genesis.

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Guideline for Prevention of Surgical Site Infection, 1999

Representatives from many countries serve as a network for the dissemination and implementation of programs for diagnosis, management, and prevention of COPD. The GOLD Board of Directors is grateful to the many GOLD National Leaders who participated in discussions of concepts that appear in GOLD reports.

Global initiative for chronic obstructive lung disease.

When cultured in a hypoxic environment similar to that found in the center of a wound, macrophages secreted active angiogenesis factor into the medium. Under conditions similar to those of well-oxygenated tissue, macrophages did not secrete active angiogenesis factor. Macrophages that secreted the factor at hypoxic conditions stopped secreting it when returned to room air. Thus the control of angiogenesis in wound healing may be the result of macrophages responding to tissue oxygen tension without the necessity of interacting with other cell types or biochemical signals.

https://science.sciencemag.org/content/sci/221/4617/1283.full.pdf

Oxygen tension regulates the expression of angiogenesis factor by macrophages

Previous animal data showed that platelets contain growth factors that stimulate capillary endothelial migration (angiogenesis), fibroblast proliferation and migration, and collagen synthesis. This study utilized autologous platelet-derived wound healing factors (PDWHF) to treat 49 patients with chronic nonhealing cutaneous ulcers. Patients were classified on the basis of 20 clinical and wound status parameters to generate a wound severity index. Forty-nine patients--58% diabetic (20% with renal transplants); 16% with trauma, vasculitis, etc.; 14% with decubitus ulcers; and 6% each with venous stasis or arterial insufficiency--with a total of 95 wounds had received conventional wound care for an average of 198 weeks (range: 1-1820 weeks). After informed consent was obtained, patients received autologous PDWHF. Mean 100% healing time for all patients was 10.6 weeks. There was no abnormal tissue formation, keloid, or hypertrophic scarring. A multivariant analysis showed a direct correlation to 100% healing with initial wound size and the initiation of PDWHF therapy. This is the first clinical demonstration that locally acting growth factors promote healing of chronic cutaneous ulcers.

Classification and treatment of chronic nonhealing wounds. Successful treatment with autologous platelet-derived wound healing factors (PDWHF).

The hypothesis that optimizing hemodynamics using pulmonary artery (PA) catheter (preoperative 'tune-up') would improve outcome in patients undergoing limb-salvage arterial surgery was tested Eighty-nine patients were randomized to preoperative tune-up either in the surgical intensive care unit (SICU) (group 1) or the preinduction room (group 2) or to control (group 3) The tune-up consisted of fluid loading, afterload reduction, and/or inotropic support to achieve predetermined endpoints Patients with a PA catheter had significantly fewer adverse intraoperative events (p less than 005), less postoperative cardiac morbidity (p less than 005), and less early graft thrombosis (p less than 005) than the control group The overall study mortality rate was 34%, with a mortality rate of 95% in the control group and 15% in the PA catheter groups There were no differences in ICU length of stay (LOS), hospital LOS, or total hospital costs, although the percentage of cost from complications was higher in group 3 (p greater than 005) In this group of patients, preoperative cardiac assessment and optimization is associated with improved outcome

Preoperative optimization of cardiovascular hemodynamics improves outcome in peripheral vascular surgery. A prospective, randomized clinical trial.

• Granulocytes' in vitro bactericidal capacity for certain bacteria depends on an adequate environmental oxygen supply. Oxygen available to granulocytes in infected tissue is decreased by local conditions and can be altered significantly by small changes in its inspired concentration. We modified Burke's and Miles' bacteria-injection model in animals to test the effect of breathing 12%, 21%, and 45% oxygen on the size of lesions produced by intradermal injections of Escherichia coli . Moderately increased inspired oxygen concentrations (fraction of inspired oxygen [Fio 2 ]) significantly decreased the size and number of necrotic lesions, whereas hypoxia increased both. Increasing Fio 2 to 45% after three and 24 hours of hypoxia also significantly decreased lesion size. Suppression of infection by moderate hyperoxia is comparable with that reported by Burke after timely, adequate doses of type-specific antibiotics. ( Arch Surg 1984;119:199-204)

Oxygen as an antibiotic. The effect of inspired oxygen on infection.

The signals that initiate repair are poorly characterized. These studies investigate the capacity of platelets and fibrin to initiate angiogenesis, fibroplasia, collagen synthesis and monocyte migration in the rabbit cornea assay. Methods: Autologous platelets and platelet-free fibrin were isolated from rabbit blood. Released and control platelet preparations and autologous and commercial fibrin were implanted in rabbit corneas. Results: Thrombin-released platelets produced angiogenesis and opacification. Histology showed fibroplasia, corneal thickening, and neovascularization. Collagen synthesis was elevated to twice control levels in thrombin-activated platelet preparations. Various control platelet preparations produced no angiogenesis, no opacification, and no histologic change. All fibrin injections elicited a cellular exudate from the limbal vessels, followed by angiogenesis and corneal opacification. Histology showed a mononuclear infiltrate with neovascularization and fibroplasia. Control injections of rabbit skin collagen and fibroblasts produced no response.

David R. Knighton

Papers

Oxygen tension regulates the expression of angiogenesis factor by macrophages

Classification and treatment of chronic nonhealing wounds. Successful treatment with autologous platelet-derived wound healing factors (PDWHF).

Preoperative optimization of cardiovascular hemodynamics improves outcome in peripheral vascular surgery. A prospective, randomized clinical trial.

Oxygen as an antibiotic. The effect of inspired oxygen on infection.

Role of platelets and fibrin in the healing sequence: an in vivo study of angiogenesis and collagen synthesis.