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Infections are a common complication of any surgery, often requiring a recovery period in hospital. Supplemental oxygen therapy administered during and immediately after surgery is thought to enhance the immune response to bacterial contamination. However, aerobic bacteria thrive in oxygen-rich environments, and so it is unclear whether oxygen has a net positive effect on recovery. Here, we develop a mathematical model of post-surgery infection to investigate the efficacy of supplemental oxygen therapy on surgical-site infections. A 4-species, coupled, set of non-linear partial differential equations that describes the space-time dependence of neutrophils, bacteria, chemoattractant and oxygen is developed and analysed to determine its underlying properties. Through numerical solutions, we quantify the efficacy of different supplemental oxygen regimes on the treatment of surgical site infections in wounds of different initial bacterial load. A sensitivity analysis is performed to investigate the robustness of the predictions to changes in the model parameters. The numerical results are in good agreement with analyses of the associated well-mixed model. Our model findings provide insight into how the nature of the contaminant and its initial density influence bacterial infection dynamics in the surgical wound., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The genetics of microbial pathogens have been extensively studied, but there has been little work on human genetic susceptibility to surgical site infection (SSI). We analyzed a large genealogical population database to study the familial contribution to SSI. We analyzed 651 individuals with International Classification of Disease, Ninth Revision codes indicating the presence of SSI. Matched hospital controls were randomly selected from the database based on birth year, sex, and birthplace. The average relatedness of all possible pairs of cases and separately of controls (×1000 sets) was compared empirically. The relative risk (RR) for SSI was estimated by comparing the number of observed affected individuals among the relatives of cases to the number of affected individuals observed among relatives of matched hospital controls. The genealogical index of familiality test for patients with SSI showed significant excess relatedness (p < 0.010); this excess was still observed when close relationships were ignored (p =  0.019). The RR for third-degree relatives of cases was significantly elevated (1.62, p = 0.029). The significant excess relatedness and the significantly elevated RR to distant relatives support a genetic predisposition to acquiring SSI., (© 2013 by the Wound Healing Society.)

Surgical wound infection remains a common and serious complication of surgery. Patient factors are a major determinant of wound outcome following surgery. Co-morbidities clearly contribute, but environmental stressors as well the individual response to stress may be equally important. In particular, wounds are exquisitely sensitive to hypoxia, which is both common and preventable. Perioperative management can promote postoperative wound healing and resistance to infection. Maintaining perfusion and oxygenation of the wound is paramount. Once perfusion is assured, addition of increased inspired oxygen substantially reduces surgical site infection in at risk patients. A greater degree of hyperoxemia, achievable with administration of hyperbaric oxygen, is useful as an adjunct to the treatment of serious soft tissue and bone infections in selected patients. This article will review the basic science underlying these observations, along with the clinical data that support the use of hyperoxia in preventing and treating infections.

Despite major advances in surgical management and approaches, including aseptic techniques, prophylactic antibiotics, and laparoscopic surgery, surgical wound infection and wound failure remain common complications of surgery. In a review of the literature, the authors found that a growing body of literature supports the concept that patient factors are a major determinant of wound outcome after surgery. In particular, wounds are exquisitely sensitive to hypoxia, which is both common and preventable. Perioperative management can be adapted to promote postoperative wound healing and resistance to infection. The most important factors are fluid management, temperature management, pain control, increased arterial oxygen tension, and, as has been long recognized, appropriate sterile techniques and administration of prophylactic antibiotics. This article reviews how knowledge of and attention to physiology can improve quality of care in both acute and chronic wounds.

Objective: To test the hypothesis that subcutaneous wound oxygen tension (PsqO2) has a predictive relation to the development of wound infection in surgical patients., Design: A noninterventional, prospective study., Setting: A university department of surgery., Patients: One hundred thirty operative general surgical patients at notable risk of infection as predicted by an anticipated Study on the Effect of Nosocomial Infection Control (SENIC) score of 1 or greater., Outcome Measures: PsqO2 was measured perioperatively. Its relation to the subsequent incidence of surgical wound infection was then determined and compared with the SENIC score as a criterion standard., Results: Although the SENIC score and PsqO2 are inversely correlated, PsqO2 is the stronger predictor of infection. Low PsqO2 identified patients at risk and concentrated them in a cohort that was about half the size of that identified by the SENIC score., Conclusions: Subcutaneous perfusion and oxygenation are important components of immunity to wound infections. The SENIC score identifies systemic physiological variables that are important to the development of wound infection. Nevertheless, PsqO2 is the more powerful predictor of wound infection. Moreover, PsqO2 can be manipulated by available clinical means, and thus may direct interventions to prevent infection.

Wound healing can be enhanced and wound infections prevented, often by simple, inexpensive, readily available means. Preoperative evaluation for impediments to healing, such as malnutrition, vasoconstriction, hyperglycemia, and steroid use, allows correction prior to operation. Intraoperatively, the surgeon should concentrate on surgical technique, appropriate antibiotic use, and prevention of vasoconstriction (volume, warming). Postoperatively, the focus should be on prevention of vasoconstriction through pain relief, warming, and adequate volume resuscitation and on maintaining nutrition and normoglycemia. These approaches apply as well to chronic wounds. Additionally, maintenance of a moist environment, correction of local vasospasm with sympathetic blockade or warming, and stimulation of angiogenesis through aggressive debridement or hyperbaric oxygen therapy enhance healing of chronic wounds.