What is the evidence for tissue regeneration impairment when using a formulation of PVP-I antiseptic on open wounds?

Bioactivity and antibacterial activity of iodine-containing calcium titanate against implant-associated infection

Developing antimicrobial biomaterials is a major challenge in the fields of orthopaedic and dental implants. In this study, we evaluated the bone-bonding ability and antibacterial activity of a novel biomaterial for preventing implant-associated infections. We have previously reported that NaOH heat treatment improved the bone-bonding ability of titanium, which was later modified to release target ions from the calcium titanate surface. Iodine, an essential nutrient, exhibits broad-spectrum antimicrobial activity; hence, we designed a calcium titanate that releases iodine ions (Ca-I-Ti). The material was prepared from a simple solution using heat treatments as well as inexpensive devices and chemical agents. MC3T3-E1 cells seeded on Ca-I-Ti displayed high degrees of bioactivity and viability, and Ca-I-Ti exhibited antibacterial activity against methicillin-susceptible Staphylococcus aureus. In vivo biomechanical and histological experiments showed that Ca-I-Ti had excellent bone-bonding ability at 8 weeks after implantation. In a subcutaneous infection model in rats, methicillin-susceptible Staphylococcus aureus on the implant was reduced by approximately 95% compared to that on commercially pure titanium, indicating that Ca-I-Ti has antibacterial effects in vivo. In addition, no local or systemic complications were observed, and active infection in the surrounding tissues was histologically inhibited. Thus, iodine-containing calcium titanate is a safe biomaterial with excellent bioactivity and antibacterial properties, indicating its potential in preventing implant-associated infections.

Randomized clinical trial evaluating the effect of bandaging on the healing of sole ulcers in dairy cattle

This randomized clinical trial investigated the effect of bandaging on 56 uncomplicated sole ulcers (SU) among a sample of 52 dairy cows. Following therapeutic hoof trimming and povidone-iodine treatment, all cows received a wooden block on the unaffected claw and were randomly assigned into either a bandaged or non-bandaged group. The bandaging process was standardized and applied by the same veterinarian. Wound size and locomotion were measured weekly. Overall, 19 of 32 SU (59.4%) in the non-bandaged group were healed at week 4 compared to 7 of 24 ulcers (29.2%) in the bandaged group. Healing was significantly higher for non-bandaged than bandaged SU (P = 0.024). Bandaging had no effect on locomotion (P = 0.9). Cows with a lower locomotion (Sprecher 1 + 2) had significantly smaller lesion sizes (median lesion size, 0.5 cm², IQR = 0.21 to 0.92 cm²) than animals with locomotion score 3-5 (median lesion size, 0.9 cm², IQR = 0.42 to 1.81 cm²; P < 0.001). A multivariate cox proportional hazard regression indicated that bandaging and parity had a significant effect on healing. Specifically, bandaged SU had a significantly lower hazard ratio (HR) to cure compared to non-bandaged SU (HR = 0.32; P = 0.01; 95% CI = 0.13 to 0.78). Furthermore, cows with parity ≥3 had a significantly higher HR to cure compared to cows in their first lactation (HR = 2.73; P = 0.025; 95% CI = 1.14 to 6.56).

Impact of Chlorhexidine Gluconate Intolerance on Driveline Infection during Chronic Heartmate II Left Ventricular Assist Device Support

Purpose

Driveline exit site (DLES) management following left ventricular assist device implantation is important for preventing driveline infection (DLI). While chlorhexidine gluconate (CHG) is generally recommended for DLES antisepsis, CHG intolerance can develop, resulting in a need for alternative antiseptics. We reviewed our institutional experience with DLES antisepsis methods in HeartMate II patients, comparing outcomes of patients with and without CHG intolerance.

Methods

Between October 2011 and March 2016, 44 patients underwent primary HeartMate II implantation. CHG was used for DLES antisepsis and povidone-iodine (PVP-I) was used in patients with CHG intolerance. DLI was defined by Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) criteria.

Results

Of 44 patients, 37 (84%) received CHG and 7 (16%) received PVP-I antisepsis due to CHG intolerance. Five patients (11.4%) developed a DLI, with an event per patient-year rate of 0.07. Median length of support was 521 days (interquartile range 202–881 days). Characteristics were similar between patients with and without DLI. However, a larger proportion of patients with DLI had CHG intolerance compared to patients without DLI (60.0% vs. 10.3%, p<0.05). Causative organisms were Staphylococcus aureus in CHG-intolerant patients and Stenotrophomonas and Acinetobacter in CHG-tolerant patients. Kaplan-Meier method and log-rank test demonstrated decreased infection-free days in patients using PVP-I rather than CHG (p<0.01).

Conclusions

While the etiology of DLI is multifactorial, CHG intolerance appears to be a risk factor. Our findings highlight the need for larger studies comparing the efficacy of antiseptics for DLES care, particularly for patients with CHG contraindications.

Management of severe head injury with brain exposure in three loggerhead sea turtles Caretta caretta

The loggerhead Caretta caretta is the most common sea turtle in the Mediterranean. Currently, sea turtles are considered endangered, mainly due to the impact of human activities. Among traumatic lesions, those involving the skull, if complicated by brain exposure, are often life-threatening. In these cases, death could be the outcome of direct trauma of the cerebral tissue or of secondary meningoencephalitis. This uncontrolled study aims to evaluate the use of a plant-derived dressing (1 Primary Wound Dressing®) in 3 sea turtles with severe lesions of the skull exposing the brain. Following surgical curettage, the treatment protocol involved exclusive use of the plant-derived dressing applied on the wound surface as the primary dressing, daily for the first month and then every other day until the end of treatment. The wound and peri-wound skin were covered with a simple secondary dressing without any active compound (non-woven gauze with petroleum jelly). Data presented herein show an excellent healing process in all 3 cases and no side effects due to contact of the medication with the cerebral tissue.

The Betadine trial - antiseptic wound irrigation prior to skin closure at caesarean section to prevent surgical site infection: A randomised controlled trial

BACKGROUND

Surgical site infections (SSIs) occur in around 10% of women following a caesarean section. Efforts to reduce SSI include wound irrigation with povidone-iodine (PVI), but studies are nonconclusive, mostly old and few on women having caesarean section (CS).

AIMS

To assess povidone-iodine (PVI) (Betadine) irrigation of wound prior to skin closure in reducing incidence of SSI after CS. Our hypothesis was that there would be no benefit with its use in reducing SSIs.

MATERIALS AND METHODS

A randomised controlled trial with 3027 women. Women having CS were allocated to receive PVI irrigation or no irrigation after closure of fascia and before skin closure. Women were followed up to four weeks to assess for SSI. Main outcome measure was surgical site infection.

RESULTS

The two groups (1520 in Betadine and 1507 on no Betadine group) were well balanced. The incidence of SSI was similar in the two groups (9.5% vs 9.8%, RR 0.97; 95% CI 0.78-1.21). There was no difference between groups (2.6% vs 2.0%, RR 1.29, 95% CI 0.81-2.06 Betadine vs no Betadine, respectively) in readmission for wound infection requiring intravenous antibiotics; this was so in both the elective CS group as well as CS in labour group.

CONCLUSION

PVI irrigation after the closure of fascia and before closure of skin is of no benefit in the prevention of SSI in women undergoing CS.

Intra-operative wound irrigation to reduce surgical site infections after abdominal surgery: a systematic review and meta-analysis

PURPOSE

Surgical site infection (SSI) remains to be one of the most frequent infectious complications following abdominal surgery. Prophylactic intra-operative wound irrigation (IOWI) before skin closure has been proposed to reduce bacterial wound contamination and the risk of SSI. However, current recommendations on its use are conflicting especially concerning antibiotic and antiseptic solutions because of their potential tissue toxicity and enhancement of bacterial drug resistances.

METHODS

To analyze the existing evidence for the effect of IOWI with topical antibiotics, povidone-iodine (PVP-I) solutions or saline on the incidence of SSI following open abdominal surgery, a systematic review and meta-analysis of randomized controlled trials (RCTs) was carried out according to the recommendations of the Cochrane Collaboration.

RESULTS

Forty-one RCTs reporting primary data of over 9000 patients were analyzed. Meta-analysis on the effect of IOWI with any solution compared to no irrigation revealed a significant benefit in the reduction of SSI rates (OR = 0.54, 95 % confidence Interval (CI) [0.42; 0.69], p < 0.0001). Subgroup analyses showed that this effect was strongest in colorectal surgery and that IOWI with antibiotic solutions had a stronger effect than irrigation with PVP-I or saline. However, all of the included trials were at considerable risk of bias according to the quality assessment.

CONCLUSION

These results suggest that IOWI before skin closure represents a pragmatic and economical approach to reduce postoperative SSI after abdominal surgery and that antibiotic solutions seem to be more effective than PVP-I solutions or simple saline, and it might be worth to re-evaluate their use for specific indications.

Sildenafil in the treatment of pressure ulcer: a randomised clinical trial

Pressure ulcer (PrU)-related hospitalisation and mortality are critical issues in medical and surgical patients. Although animal studies have suggested the beneficial effects of sildenafil on wound healing, related clinical data are lacking. This is the first clinical study that has evaluated the effects of topical sildenafil on PrU healing in human subjects. Enrolled patients were randomly allocated to receive topical sildenafil (10%) ointment or placebo daily. Wound healing was assessed visually and photographically by the change in wound score according to two-digit Stirling scale. Decreases in grades of the PrUs were significantly higher in sildenafil group compared with placebo group (P < 0·001). In addition, surface areas of ulcers in sildenafil group were significantly reduced compared to the control group at day 14 of intervention (P = 0·007). It appears that these effects may be mediated by improvement of microvascular reperfusion in the skin and soft tissue. Further study to emphasise the role of topical sildenafil in the prevention or treatment of PrUs in hospitalised patients is required.

Management of non-healable or maintenance wounds with topical povidone iodine

Although complete healing may appear to be the logical goal for most patients and clinicians, some wounds do not have the potential to heal due to a number of factors such as inadequate vasculature, coexisting medical conditions and medications that prohibit the healing process. Local management of wounds that are considered to have poor potential for healing remains elusive. The purpose of this article is to review the evidence that supports the use of topical antiseptic agents in non-healable wounds. Retrospective chart audit was conducted to evaluate the use of povidone iodine in the management of wounds that were deemed to have poor healing potential.

Limb wounding and antisepsis: iodine and chlorhexidine in the early management of extremity injury

Extremity injury and contamination as consequence are features of high-energy wounding. A leading cause of disability and the commonest cause of late complications, prevention of wound infection determines the ultimate outcome in these populations. Multiple variables influence the development of infection, one of which is the dressing used on the wound. Antiseptic-soaked gauze dressings feature in the early management of limb trauma despite a lack of evidence to support this. Iodine and chlorhexidine are ubiquitous in other aspects of health care however, and a plethora of studies detail their role in skin antisepsis, the recommendations from which are often anecdotally applied to acute wounding. To contextualize the role for antiseptic dressing use in acute, significant limb injury this review explores the evidence for the use of chlorhexidine and iodine in skin antisepsis. The paucity of experimental data available for antiseptic use in early wound management and the need for further research to address this evidence void is highlighted.

Measures to prevent surgical site infections: what surgeons (should) do

BACKGROUND

The present study was designed to evaluate surgeons' strategies and adherence to preventive measures against surgical site infections (SSIs).

MATERIALS AND METHODS

All surgeons participating in a prospective Swiss multicentric surveillance program for SSIs received a questionnaire developed from the 2008 National (United Kingdom) Institute for Health and Clinical Excellence (NICE) clinical guidelines on prevention and treatment of SSIs. We focused on perioperative management and surgical technique in hernia surgery, cholecystectomy, appendectomy, and colon surgery (COL).

RESULTS

Forty-five of 50 surgeons contacted (90%) responded. Smoking cessation and nutritional screening are regularly propagated by 1/3 and 1/2 of surgeons, respectively. Thirty-eight percent practice bowel preparation before COL. Preoperative hair removal is routinely (90%) performed in the operating room with electric clippers. About 50% administer antibiotic prophylaxis within 30 min before incision. Intra-abdominal drains are common after COL (43%). Two thirds of respondents apply nonocclusive wound dressings that are manipulated after hand disinfection (87%). Dressings are usually changed on postoperative day (POD) 2 (75%), and wounds remain undressed on POD 2-3 or 4-5 (36% each).

CONCLUSIONS

Surgeons' strategies to prevent SSIs still differ widely. The adherence to the current NICE guidelines is low for many procedures regardless of the available level of evidence. Further research should provide convincing data in order to justify standardization of perioperative management.

Feasibility and clinical applicability of polihexanide for treatment of second-degree burn wounds

OBJECTIVES

Due to a partial rejection of mesh split-thickness skin grafts (mesh grafts) after application of povidone-iodine and silver nitrate and due to its better in vitro tolerance, polihexanide was investigated as an alternative and its applicability in the treatment of second-degree burn wounds.

METHODS

In 4 patients with poorly healing decubitus ulcers the mesh grafts were each divided into three areas which were pre-treated with either undiluted povidone-iodine solution, 1% silver nitrate solution or 0.04% polihexanide solution. After 7 days of application the wound areas were compared clinically and histologically. Thereafter 14 patients (average extent of burns 28% TBSA) were treated in the same way.

RESULTS

Clinically and histologically the mesh grafts treated with polihexanide showed by far the best re-epithelialization compared with the deep tissue necrosis and marked fibrin discharge observed for application of povidone-iodine and silver nitrate. The second-degree burn wounds treated with polihexanide epithelialized without any further débridement after an average of 10 days with remarkable freedom from pain. Compared with silver nitrate treatment, no fibrin film was observed on the wound.

CONCLUSION

Polihexanide proved clinically and histologically superior to povidone-iodine and silver nitrate. For the treatment of second-degree burns, which cannot primarily be covered by plastic surgery, polihexanide is suitable because in addition to its antiseptic efficacy it does not inhibit the re-epithelialization process.

Iodine revisited

Iodine is an antiseptic that has been used in wound care for more than 150 years. Traditional formulations of iodine had serious limitations that were reduced in later products. Much has been written about iodine and opinions on its clinical efficacy are divided. There have been reviews of the chemical properties of iodine, its antimicrobial activity, human physiology, cytotoxicity and its clinical effectiveness, but few have addressed all these aspects. With the recent development of iodine-containing wound care products and the continued publication of laboratory and clinical studies, it seems timely to reassess the evidence relating to the effectiveness of iodine for treating wounds. This literature review attempts to provide an appropriate chemical and physiological background of the characteristics of iodine in order to provide a sound basis for understanding the available microbiological and clinical data. It will show that understanding the factors that contribute to the activity and potential cytotoxicity of iodine are important in evaluating the clinical evidence. Although definitive studies are needed, the sustained delivery of low doses of free iodine offers the potential to inhibit a broad range of microbial species without selecting for resistant strains or inducing cytotoxic effects.

Microengineered surface topography facilitates cell grafting from a prototype hydrogel wound dressing with antibacterial capability

Skin wounds derive therapeutic benefit from redeployment of dermal tissues, whether as split-thickness allo- and autografts or as biological dressings comprising cultured cells. However, the clinical outcome is strongly influenced by the techniques used for cell/tissue grafting and also the microbiological status of the wound. Here we report that microtopography incorporated into the surface of a novel polymeric material, derivatized with fibronectin to promote attachment and encourage motility, improved the efficiency of cell transfer onto de-epithelialized human skin ex vivo. The microtopography had two functions, first as a conduit for migrating cells to cross between the vehicle and recipient surface and second to shield adherent cells from destruction by mechanical shearing during handling and application. Quantitative analysis showed that topographic projections (columns) rather than recesses (pits) in the hydrogel surface achieved the highest efficiency of cell transfer. In order to address the crucial relevance of microbiological contamination to the success of wound grafting, the effect of iodine on several common bacterial pathogens was examined using an XTT+C(Q10) kinetic cell viability assay. Increasing concentrations of iodine initially stressed and after 0.5% v/v were subsequently bacteriocidal for Gram-negative Pseudomonas aeruginosa and Escherichia coli and Gram-positive Bacillus subtillis and Staphylococcus aureus. Slightly higher doses of iodine (approx 1-1.5% v/v) were required to kill HaCaT cells outright, but for both pro- and eukaryotes the major determinant of cytotoxicity was absolute dose rather than duration of exposure. Iodine delivered by the hydrogel at low concentration was bacteriostatic but not apparently cytotoxic to epithelial cells as measured by MTT end-point cell viability assay. Zone of inhibition studies confirmed that bacteriocidal quantities of neomycin, phenol red, and silver could also be delivered using the same hydrogel. This research suggests that grafting cell-based biological dressings to wounds using a topographically modified hydrogel dressing capable of simultaneous reducing the microbiological threat to a successful outcome may be a realistic clinical proposition.