Subsequent Wound Infection Research Articles

Salvage of Failed Ankle Arthrodesis by Conversion to Total Ankle Arthroplasty: Intermediate Term Results

Category: Ankle; Hindfoot Introduction/Purpose: As ankle arthroplasty has become a reliable treatment for painful ankle arthritis, it has also been employed as a salvage procedure for failed ankle arthrodeses. Published studies of conversion have generally combined patients treated by several surgeons using a variety of different prostheses, with short-term follow-up. Early reports showed failure in patients with an absent distal fibula, and more recently that has been considered a contraindication. Some reports have expressed concerns about doing hindfoot arthrodeses at the same setting. This retrospective study examines the mid-term follow-up of 19 patients treated by a single surgeon using a standard technique with a single prosthesis, and includes patients with a deficient distal fibula and concomitant hindfoot fusions. Methods: Between May 2010 and August 2019, 28 patients underwent conversion of their failed ankle arthrodesis to a total ankle arthroplasty using a prosthesis with an intramedullary tibial component. Nineteen patients (10 males and 9 females) with an average age of 49.8 (45-81) years at the time of surgery were included in the study. Three modes of ankle arthrodesis failure were identified: 1) solid tibial-talar-calcaneal arthrodesis with a painful malposition (n=3); 2) painful pseudarthrosis of the ankle (n=4); and 3) solid ankle fusion with painful adjacent hindfoot arthritis (n=12). The patients in the first two groups were treated with arthroplasty alone, while those in the third group had an arthroplasty and hindfoot fusion. Four patients had a deficient distal fibula. Outcomes were evaluated post-operatively with a Visual Analog Scale, the AOFAS Ankle and Hindfoot Scale, a satisfaction survey, and radiographic assessment of the arthroplasty and any concomitant hindfoot fusions. Results: Mean follow-up was 7.6 (2.6-11.8) years. Complications included fracture with or without subsequent surgery (n=4), subsequent sub-talar fusion (n=1), varus deformity (n=1), and wound dehiscence or infection (n=2). Three patients had revision of their talar components. Postoperative dorsiflexion was 7.8 ± 12.6 degrees and plantarflexion 20.9±13.37 degrees. Two patients developed lucencies about the tibial stem, and two had mild subsidence of the talar components. There were no hindfoot pseudarthroses. Four patients with a deficient distal fibula were all able to be salvaged with an intact ankle arthroplasty. Mean (± SD) VAS Score was 4.6 ± 3.0 and AOFAS score was 71.2±21.7. Sixty-seven percent reported that they were satisfied or very satisfied. Forty-four percent had significant limitations in either activity or ADLs in their ankle function. Conclusion: Total ankle arthroplasty should be considered as a salvage procedure for patients with a failed ankle arthrodesis. With the described techniques it can be combined with concomitant hindfoot arthrodesis procedures and can be used successfully in patients who have a deficient distal fibula. While there can be a high prosthetic retention rate in the medium term, prospective patients must be counseled about potential limitations.

Utility of Routine Preoperative Urinalysis in the Prevention of Surgical Site Infections

Preoperative assessment is important for neurosurgical risk stratification, but the level of evidence for individual screening tests is low. In preoperative urinalysis (UA), testing may significantly increase costs and lead to inappropriate antibiotic treatment. We prospectively evaluated whether eliminating preoperative UA was noninferior to routine preoperative UA as measured by 30-day readmission for surgical site infection in adult elective neurosurgical procedures. A single-institution prospective, pragmatic study of patients receiving elective neurosurgical procedures from 2018 to 2020 was conducted. Patients were allocated based on same-day versus preoperative admission status. Rates of preoperative UA and subsequent wound infection were measured along with detailed demographic, surgical, and laboratory data. The study included 879 patients. The most common types of surgery were cranial (54.7%), spine (17.4%), and stereotactic/functional (19.5%). No preoperative UA was performed in 315 patients, while 564 underwent UA. Of tested patients, 103 (18.3%) met criteria for suspected urinary tract infection, and 69 (12.2%) received subsequent antibiotic treatment. There were 14 patients readmitted within 30 days (7 without UA [2.2%] vs. 7 with UA [1.2%]) for subsequent wound infection with a risk difference of 0.98% (95% confidence interval-0.89% to 2.85%). The upper limit of the confidence interval exceeded the preselected noninferiority margin of 1%. In this prospective study of preoperative UA for elective neurosurgical procedures using a pragmatic, real-world design, risk of readmission due to surgical site infection was very low across the study cohort, suggesting a limited role of preoperative UA for elective neurosurgical procedures.

Wool keratin/zeolitic imidazolate framework-8 composite shape memory sponge with synergistic hemostatic performance for rapid hemorrhage control.

Uncontrollable hemorrhage and subsequent wound infection pose severe threats to life, especially in the case of deep, non-compressible, massive bleeding. Here, a wool keratin/zeolitic imidazolate framework-8 (WK/ZIF-8) composite shape memory sponge is prepared by incorporating ZIF-8 nanoparticles into wool keratin. The combination of keratin and ZIF-8 particles not only reduces the effect of ZIF-8 particles on cell viability but also bolsters the mechanical properties of the keratin sponge and endows it with antibacterial efficacy. Due to the synergistic effect of the excellent hemostatic performance of keratin and Zn2+ release from ZIF-8 nanoparticles, the porous structure suitable for blood cell adhesion and the shape recovery ability of sponges, the WK/ZIF-8 composite sponge exhibits superior hemostatic performance to commercial medical sponges in SD rat and rabbit hemorrhage models. In addition, in vitro and in vivo antibacterial experiments demonstrate the anti-infection activity of the composite sponge. Overall, the WK/ZIF-8 composite sponge provides a promising approach to rapidly control bleeding and promote wound healing.

Incidence, Risk Factors, and Subsequent Complications of Postoperative Hematomas Requiring Reoperation After Primary Total Hip Arthroplasty

BackgroundStudies analyzing the incidence and clinical implications of postoperative hematomas after total hip arthroplasty (THA) remain limited. The purpose of the present study was to use the National Surgical Quality Improvement Program (NSQIP) dataset to determine rates, risk factors, and subsequent complications of postoperative hematomas requiring reoperation after primary THA. MethodsStudy population included patients who underwent primary THA (CPT code: 27130) from 2012-2016 recorded in NSQIP. Patients who developed a hematoma requiring reoperation in the 30-day postoperative period were identified. Multivariate regressions were created to identify patient characteristics, operative variables, and subsequent complications that were associated with a postoperative hematoma requiring reoperation. ResultsAmong the 149,026 patients who underwent primary THA, 180 (0.12%) developed a postoperative hematoma requiring reoperation. Risk factors included body mass index (BMI) ≥ 35 (relative risk [RR]: 1.83, P = .011), American Society of Anesthesiologists (ASA) class ≥3 (RR: 2.11, P < .001), and history of bleeding disorder (RR: 2.71, P < .001). Associated intraoperative characteristics were an operative time ≥100 minutes (RR: 2.03, P < .001) and use of general anesthesia (RR: 1.41, P = .028). Patients developing a hematoma requiring reoperation were at higher risk of subsequent deep wound infection (RR: 21.57, P < .001), sepsis (RR: 4.3, P = .012), and pneumonia (RR: 3.69, P = .023). ConclusionsSurgical evacuation for a postoperative hematoma was performed in about 1 in 833 cases of primary THA. Several nonmodifiable and modifiable risk factors were identified. Given the 21.6 times increased risk of subsequent deep wound infection, select, at-risk patients may benefit from closer monitoring for signs of infection.

Recrudescent infection after deep brain stimulator reimplantation.

The efficacy of deep brain stimulation (DBS) in treating the symptoms of movement disorders can be life changing for patients. Thus, the 5%-15% incidence of stimulator-related infection requiring removal of the device can be particularly disheartening. Although DBS system reimplantation is generally successful, this is not always the case. The literature is replete with publications describing the incidence of infection and the associated features. However, the literature is sparse in terms of information on the incidence of recurrent or recrudescent infection after system reimplantation. The goal of this paper was to evaluate factors leading to unsuccessful reimplantation of a DBS system following initial infection. Data were reviewed for all DBS procedures performed by one surgeon (K.L.H.) over 19 years including the infectious agent, location of infection, treatment regimen, and subsequent reimplantation of a DBS system and long-term outcome. In this series of 558 patients who had undergone DBS surgery, 37 (6.6%) subsequently developed an infection. Infections with methicillin-sensitive Staphylococcus aureus, Enterobacter species, or coagulase-negative staphylococci were predominant. Four patients had cerebritis, one had meningitis, and the rest had soft tissue infections of the pocket or scalp. All had their entire DBS system explanted, followed by 4-6 weeks of intravenous antibiotics and surveillance for recrudescence for an additional period of at least 30 days. Twenty-five patients subsequently underwent DBS system reimplantation, and the procedure was successful in 22. Three of the 4 patients with cerebritis developed a subsequent wound infection after system reimplantation. None of the other 22 patients developed a recurrence. The odds ratio for developing a recurrent infection after cerebritis was 28.5 (95% CI 1.931-420.5, p = 0.007). This study, the largest series of DBS system reimplantations following infection, demonstrated that most patients can have successful reimplantations without recurrent infection. However, patients who have had DBS-related cerebritis have a nearly 30-fold increased risk of developing reinfection after reimplantation. Alternative strategies for these patients are discussed.

822 The Use of Prophylactic Antibiotics Pre-Orchidectomy – a Retrospective Cohort Study

Abstract Aim NICE guidance recommends the use of antibiotic prophylaxis in clean-contaminated procedures and when a prosthetic is placed. However, the use in orchidectomies is not specified under the treatment summary heading of ‘Urological Procedures, Antibacterial Prophylaxis’. The use of prophylactic antibiotics pre-orchidectomy varied amongst senior urologists within a District General Hospital, where no specific protocol was in use. This retrospective cohort study aimed to decipher if the use of prophylactic antibiotics reduced post-operative infection incidence following radical orchidectomies. Method 50 consecutive orchidectomies, performed between February 2019 and July 2021, were analysed. It was identified whether the patient had antibiotics administered pre-operatively and if they developed a subsequent wound infection through post-operative ward rounds, clinic letters and presentations to the Emergency Department. Orchidectomies performed by general surgeons were excluded from analysis. Results Of the 50 orchidectomies analysed, 30 patients received pre-operative antibiotics, four of whom subsequently developed a post-operative infection. Of the 20 patients that did not receive prophylactic antibiotics, nine developed a post-operative infection. The relative risk was calculated at 0.2963 with a 70.4% relative risk reduction if prophylactic antibiotics were administered. Chi squared tests calculated a p-value of 0.012 highlighting statistical significance. Eight patients had primary prosthesis placed at the time of orchidectomy, all of whom received prophylactic antibiotics. Conclusion Prophylactic antibiotics were effective in preventing post-orchiectomy wound infections and routine local protocols should advise the use in orchidectomies, which classify as clean-contaminated procedures as per NICE guidance.

Injectable shape memory hydroxyethyl cellulose/soy protein isolate based composite sponge with antibacterial property for rapid noncompressible hemorrhage and prevention of wound infection

Uncontrollable hemorrhage and subsequent wound infection are severe threats to life, especially for the deep noncompressible massive bleeding. However, traditional hemostatic materials are ineffective for extreme bleeding and subsequent wound infection. Here, we prepared an injectable shape memory hydroxyethyl cellulose/soy protein isolate based composite sponge (EHSS) for rapid noncompressible hemorrhage and prevention of wound infection. The nano silver (AgNPs)-loaded shape memory sponge (EHP@Ag) was fabricated by mussel-inspired polydopamine coating EHSS sponge, then reducing and immobilizing AgNPs in situ. The EHP@Ag sponges showed rapid blood-triggered shape recovery speed, which is beneficial for administering noncompressible hemorrhage. The results of the hemostatic experiment in vivo demonstrated that EHP@Ag sponge exhibited a desirable hemostasis effect (hemostasis time: 22.75 ± 3.86 s, blood loss: 285.25 ± 24.93 mg) compared to the commercial gelatin sponge (hemostasis time: 49.25 ± 3.30 s, blood loss: 755.50 ± 24.45 mg). Meanwhile, the EHP@Ag sponge has an efficient antibacterial property. Furthermore, the antibacterial experiment in vivo showed that the EHP@Ag sponges could kill bacteria effectively and reduce the bacteria-induced inflammatory response. In summary, the shape memory sponges can quickly control bleeding and avoid bacterial infection, which shows great potential for clinical application as a multifunctional hemostatic agent.

Total laparoscopic management of uterocutaneous fistulas

Uterocutaneous fistulae are rare fistulas of the female genitourinary tract. It mostly follows caesarean section and subsequent post-operative wound infection. Only a handful of cases have been published in the literature. Surgical excision is the definitive management in most cases. Laparoscopic management has been used by many authors and gives good results. A 30-year-old multigravida presented with symptoms typical of uterocutaneous fistula and confirmed by magnetic resonance imaging of the pelvis. On diagnostic laparoscopy, the tract was delineated by methylene blue dye both through the opening in the skin as well as through the cervix. The complete excision of fistulous tract was done laparoscopically along with omental interposition between the uterus and the abdominal wall at the site of the fistula. Histopathologic examination of the tract confirmed endometriotic tissues without any chronic inflammation, typical of uterocutaneous fistula. The patient had an uneventful recovery, was started on diet the following day and discharged the next day. There was minimal post-operative pain and helped in early ambulation. On follow-up at 12 months, the tract had completely healed and the patient was completely asymptomatic. Uterocutaneous fistula is a rare complication that follows wound infection or suboptimal wound closure following caesarean section. As compared to the traditional excision by laparotomy, laparoscopy not only aids in confirmation of the diagnosis but also helps in complete excision of the tract with good results.

Antibacterial, antioxidant and anti-inflammatory PLCL/gelatin nanofiber membranes to promote wound healing

Epigallocatechin-3-O-gallate (EGCG) is a green biomedical agent for promoting wound healing, which possess excellent antibacterial, antioxidant and anti-inflammatory activities. For improving the low bioavailability challenges of EGCG in vivo, we had successful created a low-cost and simple wound dressing Poly (L-Lactic-co-caprolactone) (PLCL)/Gelatin/EGCG/Core-shell nanofiber membrane (PGEC) with drug sustained release capacity through coaxial electrospinning technology. In vitro experimental indicated that the core-shell structure wound dressing had excellent biocompatibility, antibacterial and antioxidant ability, which could support cell viability and proliferation, encourage re-epithelialization during the healing process, inhibit subsequent wound infection and thus promote wound regeneration. In vivo experimental demonstrated that PGEC wound dressing could promote wound healing, the histological results further demonstrated that PGEC not only facilitated early wound closure but also influenced cellular differentiation and tissue organization. Meanwhile, PGEC had excellent hemostatic ability. Taken all together, we believed that the PGEC wound dressing, which could localize delivery of EGCG, had high potential clinical application for promoting wound healing, hemostasis or other related clinical applications in the future.

Comparison of the wound-healing efficacy of gelatin sponge dressings and that of artificial dermis using atelocollagen in a rat cranial periosteal defect model.

In oral surgery, tissue loss may occur in some cases, resulting in bone exposure and subsequent wound infection and possible scar formation during secondary healing. In this study, Terudermis® Artificial Dermis (AD-T), a dermal defect graft made from processed bovine dermis collagen and gelatin sponge (GS) were used as dressings on 100-mm2 wounds with exposed bone on the heads of rats. For the control group, the wound was left exposed. The wound-healing efficacy of the treatment was compared macroscopically and histologically among the three groups at 1, 2, and 4 weeks after surgery. Complete wound healing was achieved faster in the AD-T group than in the GS group, and osteoblasts appeared on the bone surface, indicating accelerated bone remodeling. Furthermore, in the AD-T group, there was an increased production of newly formed blood vessels, fibroblasts and osteoblasts positive for anti-cortactin antibodies, which are believed to contribute to wound healing. Our findings suggest that AD-T is better than GS as a wound dressing material.

Timing of Flap Coverage With Respect to Definitive Fixation in Open Tibia Fractures.

We conducted a large, U.S wide, observational study of type III tibial fractures, with the hypothesis that delays between definitive fixation and flap coverage might be a substantial modifiable risk factor associated with nosocomial wound infection. A retrospective analysis of a multicenter database of open tibial fractures requiring flap coverage. Fourteen level-1 trauma centers across the United States. Two hundred ninety-six (n = 296) consecutive patients with Gustilo III open tibial fractures requiring flap coverage at 14 trauma centers were retrospectively analyzed from a large orthopaedic trauma registry. We collected demographics and the details of surgical care. We investigated the patient, and treatment factors leading to infection, including the time from various points in care to the time of soft-tissue coverage. Delay definitive fixation and flap coverage in tibial type III fractures. (1) Results of multivariate regression with time from injury to coverage, debridement to coverage, and definitive fixation to coverage in the model, to determine which delay measurement was most associated with infection. (2) A second multivariate model, including other factors in addition to measures of flap delay, to provide the estimate between delay and infection after adjustment for confounding. Of 296 adults (227 M: 69 F) with open Gustilo type III tibial fractures requiring flap coverage, 96 (32.4%) became infected. In the multivariate regression, the time from definitive fixation to flap coverage was most predictive of subsequent wound infection (odds ratio 1.04, 95% confidence interval 1.01 to 1.08, n = 260, P = 0.02) among the time measurements. Temporary internal fixation was not associated with an increased risk of infection in both univariate (P = 0.59) or multivariate analyses (P = 0.60). Flap failure was associated with the highest odds of infection (odds ratio 6.83, 95% confidence interval 3.26 to 14.27, P < 0.001). Orthoplastic teams that are dedicated to severe musculoskeletal trauma, that facilitate coordination of definitive fixation and flap coverage, will reduce the infection rates in Gustilo type III tibial fractures. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

A Murine Model of Full-Thickness Scald Burn Injury with Subsequent Wound and Systemic Bacterial Infection.

Infection is the leading cause of death and prolonged hospitalization in severely burned patients that survive the acute phase of injury. Here we describe a murine model of severe burn injury followed by subsequent postburn infection, both local and systemic, that leads to sepsis. A detailed description of the full-thickness scald burn procedure is provided, followed by description of infection with two common burn-associated nosocomial pathogens, Pseudomonas aeruginosa and Staphylococcus aureus.

Bilateral Gastrocnemius Flap For Harlequin Defects Around The Knee

&#x0D; &#x0D; &#x0D; &#x0D; Background : Tibial plateau fractures (especially bicondylar Schatzker type 5 and type 6) are a result of high energy trauma. Along with bony component, soft tissue injury is a major determinant in the treatment and final outcome. Bicondylar fractures needs bicolumnar fixation and as such require separate approaches: postero-medial and lateral incisions. The soft tissue of the proximal tibia swells significantly after the injury, coupled with extensive soft tissue dissection during fixation this can lead to subsequent wound breakdown and infection along either side of the proximal tibia which resembles “harlequin eyes”. This study describes outcome of management of post operative soft tissue complications following bicolumnar fixation of proximal tibia with medial and lateral gastrocnemius flap.&#x0D; Method : Three patients who had bilateral soft tissue necrosis at surgical incision sites treated with debridement and bilateral gastrocnemius flaps between January 2016 and December 2017 were included in this study. The mean age was 38 years (range 18–50 years) and the mean duration of follow-up was 10 months. Outcome assessments included the condition of the flap and fracture healing time.&#x0D; Result : All fractures united after surgery. There were no soft tissue complications and all flaps healed well. The mean bony union time was 6 months.&#x0D; Conclusion: Our technique of covering soft tissue loss at surgical site on medial and lateral side of proximal tibia with bilateral gastrocnemius flap in the same setting is a reliable and safe surgical method for these conditions.&#x0D; &#x0D; &#x0D; &#x0D;

Study of microbilogical flora and role of primary bacterial cultures in management of open fractures of long bones

Background: Microbiology of open fracture wounds is constantly changing. A clear understanding of the bacterial flora that could be expected is needed in order to administer a rational and effective antibiotic treatment for open fractures. The role and efficacy of primary bacterial cultures in management of open fractures is also debatable and needs further evaluation. Methods: One hundred patients with one hundred and seven open fractures of long bones were studied prospectively, from March 1st 2001 till February 28th 2002. Wound swabs were obtained at pre-debridement, intra-operative, post debridement, 1st dressing/after 24hrs intervals, subsequently every week and sent for cultures. The infecting organism, its antibiotic susceptibility and its correlation between cultures at different stages was noted. Results: An infection rate of 43.9% was noted. Most of the initial wound cultures, showed growth of Gram-negative organisms (76%), commonest being Pseudomonas (36%) and Acinitobacter(20.7%). However, majority of infections after 2nd week were caused by Gram-positive organisms. Staphylococcus aureus (93.5%) was the predominant Gram-positive organism. None of the organisms grown on admission and pre-debridemet cultures eventually caused infection; however, 28% of cases with negative cultures eventually got infected. Post debridement cultures were positive in none. Among the cultures obtained at 1st dressing 40% of organisms grown eventually caused infection whereas 60% showed growth with different organism. Conclusions: A shift in the bacterial flora occurs in compound fracture wounds from Gram-negative to Gram-positive organisms after the 2nd week. Cultures obtained at admission, predebridment, posted brid ment and at 1st dressing or after 24hrs are not reliable indicators of subsequent wound infection.

Microbiome Medicine: This Changes Everything

Microbiome Medicine: This Changes Everything

Effects of Prehospital Wound Prophylaxis in Iraq and Afghanistan on Mortality

Introduction: A significant proportion of traumatic injuries sustained during the recent conflicts in Afghanistan and Iraq developed subsequent wound infections. Previous studies demonstrate lower infectious rates with timely administration of antibiotics, but do not evaluate impact on mortality. We compare demographics, injury characteristics, and survival rates among adult combat casualties receiving prehospital wound prophylaxis versus casualties not receiving antibiotic prophylaxis.Methods: We used a series of emergency department (ED) procedure codes to identify subjects within the Department of Defense Trauma Registry (DODTR) from January 2007 to August 2016. We included subjects that sustained a gunshot wound (GSW), traumatic amputation, or open-fracture proximal to the digits. We stratified our comparisons of characteristics between casualties receiving antibiotic prophylaxis to those not receiving antibiotic prophylaxis by specific injury pattern.Results: During the study period, our predefined ED search codes captured 28222 of the total 38769 subjects encountered in the DODTR. We identified 6662 subjects with a GSW, 1899 subjects with an amputation, and 6553 subjects with an open fracture. Among subjects with these injuries, 9.8% (1483 of 15114) received prehospital wound prophylaxis. There was no difference in survival to discharge rates between casualties that received prehospital wound prophylaxis and those that did not among subjects who sustained amputations (93.9% vs. 90.7%, p=0.271) or open fractures (96.8% versus 95.9%, p=0.368). In the GSW group, subjects that received antibiotics had a significantly higher survival rate compared to subjects that did not receive prehospital wound prophylaxis (96.2% versus 92.8%, p<0.001). This association persisted on multivariable regression analysis (OR 1.61, 95% CI 1.09-2.38).Conclusion: Military prehospital providers infrequently administered wound prophylaxis during the recent conflicts in Afghanistan and Iraq. There is an association between prehospital administration of antibiotics and increased survival among casualties suffering gunshot wounds.

Bacterial colonisation of suture material after routine neurosurgical procedures: relevance for wound infection.

Wound healing impairment is a serious problem in surgical disciplines which may be associated with chronic morbidity, increased cost and patient discomfort. Here we aimed to investigate the relevance of bacterial colonisation on suture material using polymerase chain reaction (PCR) to detect and taxonomically classify bacterial DNA in patients with and without wound healing problems after routine neurosurgical procedures. Repeat surgery was performed in 25 patients with wound healing impairment and in 38 patients with well-healed wounds. To determine the presence of bacteria, a 16S rDNA-based PCR detection method was applied. Fragments of 500bp were amplified using universal primers which target hypervariable regions within the bacterial 16S rRNA gene. Amplicons were separated from each other by single-strand conformation polymorphism (SSCP) analysis, and finally classified using Sanger sequencing. PCR/SSCP detected DNA of various bacteria species on suture material in 10/38 patients with well-healed wounds and in 12/25 patients with wound healing impairment including Staphylococcus aureus, Staphylococcus epidermidis, Propionibacterium acnes and Escherichia coli. Microbiological cultures showed bacterial growth in almost all patients with wound healing impairment and positive results in PCR/SSCP (10/12), while this was the case in only one patient with a well-healed wound (1/10). Colonisation of suture material with bacteria occurs in a relevant portion of patients with and without wound healing impairment after routine neurosurgical procedures. Suture material may provide a nidus for bacteria and subsequent biofilm formation. Most likely, however, such colonisation of sutures is not a general primer for subsequent wound infection.

Synthesis and characterization of arginine-NIPAAm hybrid hydrogel as wound dressing: In vitro and in vivo study.

Despite the zwitterionic characteristic and biocompatible property of arginine based hydrogels, the brittle behavior and non-transparency still remain as a significant problem for wound dressing. Furthermore promoting the antibacterial property of the zwitterionic hydrogel is also necessary to prevent the bacterial colonization and subsequent wound infection. Therefore, we created a hybrid hydrogel combined methacrylate arginine (M-Arg) and N-isopropyl acrylamide (NIPAAm). NIPAAm improves transparency and mechanical property as well as acts as a temperature-response drug release system. Additionally, chlorhexidine (CHX) was preloaded into the hydrogels and polyhexamethylene guanidine phosphate (PHMG) was grafted on the hydrogel surface, respectively, which make the hydrogel useful as a favorable antibacterial dressing. The hybrid hydrogel has a combination effect of biocompatibility, environmentally responsive transformation behavior, biodegradability, anti-protein adsorption and antimicrobial properties. This report proposes the preparation of P(M-Arg/NIPAAm) hydrogel that has a great potential for wound healing.

Bacteroides spp. isolation from pus or peritoneal fluid in patients with perforated peptic ulcer

From October 2001 till November 2007,two hundred eighty eight patients with perforated peptic ulcer including duodenal and gastric ulcer attending Baghdad teaching hospital and Al- Diwanyia teaching hospital were subjected for surgery and samples from free peritoneal fluid to obtain specimens for determining the rate of peritoneal colonization by bacteroides spp.and the risk factors which may increase this rate by direct questionnaire to obtain preliminary guides for methods of prophylaxis against subsequent possible wound infection and systemic sepsis .Specimens was obtained using sterile syringe aspirating about 2-5 ml of pus or fluid which is air free Diagnostic confirmatory tests for Bacteroides spp. identification has been made by anaerobic culture utilizing selective complex medium like brain heart agar containing amikacin which inhibit growth of facultative anaerobes. Culture were incubated at 35- 37c in an anaerobic atmosphere containing CO2. Results showed that 48.6% of the studied patients were found to be Bacteroides culture positive . Some risk factors have been evaluated which may or not contribute to increasing the rate of Bacteroides spp. Colonization, among these ,time from onset of perforation till the time of surgery or sampling which was found to be a significant risk factor if the patient underwent surgery after 12hr from onset of perforation 72.5% . Age was individually evaluated , it has appeared that increasing age is a risk factor and become significant after 50 years of age with 83.7% of patients in this age group was colonized with Bacteroides spp. The associated other medical illness , steroids consumption and immune suppression were also evaluated in which only steroids found to be a significant risk factor with a rate approaching 80.4%. Other risk factors which has been evaluated is the preoperative use of H2 blockers or proton pump inhibitors , which found to significantly increase the rate of bacteroides isolation( 80%.).

Timing of Antibiotic Prophylaxis for Preventing Surgical Site Infections in Foot and Ankle Surgery.

Surgical site infections (SSIs) are one of the most troublesome complications after foot and ankle surgery. Previous literature has emphasized the significance of appropriate timing of antibiotic prophylaxis. However, the optimal timing of antibiotic prophylaxis for SSI prevention is still inconclusive. Our study aimed to investigate the optimal timing of antibiotic administration and to elucidate the risk factors for SSIs in foot and ankle surgery. A retrospective review of 1933 foot and ankle procedures in 1632 patients from January 1, 2011, through August 31, 2015, was performed. Demographic data; type, amount, and timing of antibiotic administration; incision; and closure time were recorded. Subsequent wound infection and incision and drainage procedure (I&D) within 30 days and 90 days were documented. Outcomes and demographic variables were compared between procedures in which antibiotics were administered less than 15 minutes and between 15 to 60 minutes prior to incision. A total of 1569 procedures met inclusion criteria. There were 17 cases (1.1%) of subsequent wound infection, of which 6 required a subsequent I&D within 30 days. There were 63 additional cases (4%) of wound complications, which did not meet SSI criteria. When comparing SSI and non-SSI groups, the only significant independent predictors were longer surgeries and nonambulatory surgeries (both P < .05). Stepwise multivariate logistic regression analysis demonstrated that 91.8% of the risk of an SSI could be predicted by ASA score and length of surgery alone. In foot and ankle surgeries, the timing of intravenous antibiotic prophylaxis did not appear to play a significant role in the risk of SSI. Host factors and duration of surgery appear to have played a much larger role in SSI than the timing of antibiotic prophylaxis. Level III, retrospective comparative study.