There is no significant benefit to the use of nanocrystalline-coated silver dressings over standard wound dressings, following coronary revascularisation, in patients with type 2 diabetes, according to the results of a study conducted with 194 patients. Results of the investigation—which took place at the Silesian Center for Heart Disease, Zabrze, Poland—showed that the frequency of sternotomy wound infection is comparable between groups who received either silver or traditional dressings.
Described as “one of the most serious and costly challenges of modern cardiac surgery”, the incidence of surgical site infection (SSI) during the postoperative course is as high as 20% in some institutions and has the potential for increasing medical costs significantly. Moreover, type 2 diabetes is listed as one of the most common comorbidities of patients undergoing cardiac surgery, increasing the risk of wound complications due to impaired collagen production.
Focusing on a newer option of self-adhesive wound dressings containing nanocrystalline silver—which have demonstrated a high level of efficacy in the treatment of diabetic foot ulcers and wounds infected with multidrug-resistant bacteria—the study published in Advances in Skin and Wound Care aimed to assess the suitability of nanocrystalline-coated silver dressings versus standard wound dressings in patients with type 2 diabetes after coronary revascularisation.
In order to conduct the pilot, single-centre clinical trial, lead author Monika Parys (Silesian Center for Heart Disease, Zabrze, Poland) and colleagues established inclusion criteria for the study, requiring patients to be older than 18 years, have multivessel coronary disease qualifying for surgical treatment, and be scheduled for cardiac surgery using full sternotomy as surgical access. Alternatively, patients with glucose intolerance, coexisting heart defects requiring surgery, or a life expectancy of less than one year following surgery, as well as those who had undergone cardiac surgery previously, were excluded.
Once enrolled, patients were randomised into one of two homogenous cohorts; those who entered the control group (97 patients) received a standard sterile dressing, while the study group (97 patients) received a 10cm x 10cm silver dressing. In addition, a 10cm x 25cm silver dressing was applied to study patients after three days. Blood draws were required from all patients enrolled in the trial to assess glycated haemoglobin, fructosamine, and creatinine levels, and dressings were administered in the operating room after surgery.
The primary endpoint of the trial was defined as the emergence of a superficial wound infection within 30 days of surgery, while deep wound infections were also listed as a secondary endpoint. It was found, after 30 days, that 26 patients (13.4%) had developed a superficial wound infection, including 11 patients (11.7%) from the study group and 15 (16.7%) in the control group (p=0.45). This difference was not statistically significant, and no deep wound infections were recorded in patients from either group. Although patients were divided by occurrence of infection in order to establish determinants, “none of the analysed parameters appeared to be a significant factor”.
Ultimately, it was determined that the incidence of sternotomy wound infection was comparable between patients who received standard dressings and those who were treated with silver dressings. As a result, it has been advised by the research authors that, in order to maximise cost savings, providers should consider using standard wound dressings in this patient population, despite the success of the silver dressings in other studies.
It was also emphasised by Parys et al that, despite the advantages of a prospective randomised study, this sample of patients was small and a further, larger-scale investigation is required to support these findings