Prevention of Surgical Site Infection

Volatiles extracted from Melaleuca Rugulosa (Link) Craven leaves: comparative profiling, bioactivity screening, and metabolomic analysis

BACKGROUND

Melaleuca species (family Myrtaceae) are characterized by their wide-ranging applications as antimicrobials and in skin-related conditions. Herein, we estimated the volatile profile and biological significance of M. rugulosa (Link) leaves for the first time supported by a dereplication protocol.

MATERIALS AND METHODS

Volatile components were extracted using hydrodistillation (HD), supercritical fluid (SF), and headspace (HS) techniques and identified using GC/MS. The variations among the three extracts were assessed using principal component analysis and orthogonal partial least square discriminant analysis (OPLS-DA). The extracted volatiles were tested for radical scavenging activity, anti-aging, and anti-hyperpigmentation potential. Finally, disc diffusion and broth microdilution assays were implemented to explore the antibacterial capacity against Streptococcus pyogenes, Staphylococcus aureus, Clostridium perfringens, and Pseudomonas aeruginosa.

RESULTS

The yield of the SF technique (0.8%) was three times higher than HD. GC/MS analysis revealed that the oxygenated compounds are the most proponents in the three extracts being 95.93% (HD), 80.94% (HS), and 48.4% (SF). Moreover, eucalyptol (1,8-cineol) represents the major component in the HD-EO (89.60%) and HS (73.13%) volatiles, while dl-α-tocopherol (16.27%) and α-terpineol (11.89%) represent the highest percentage in SF extract. Regarding the bioactivity profile, the HD-EO and SF-extract showed antioxidant potential in terms of oxygen radical absorbance capacity, and β- carotene assays, while exerting weak activity towards DPPH. In addition, they displayed potent anti-elastase and moderate anti-collagenase activities. The HD-EO exhibited potent anti-tyrosinase activity, while the SF extract showed a moderate level compared to tested controls. OPLS-DA and dereplication studies predicted that the selective antibacterial activity of HD-EO to S. aureus was related to eucalyptol, while SF extract to C. perfringens was related to α-tocopherol.

CONCLUSIONS

M. rugulosa leaves are considered a vital source of bioactive volatile components that are promoted for controlling skin aging and infection. However, further safety and clinical studies are recommended.

Chemical analysis, antibacterial and anti-inflammatory effect of Achillea fragrantissima essential oil growing wild in Egypt

BACKGROUND

Achillea fragrantissima (F. Asteraceae) is traditionally used to treat skin infections and inflammation. The present work intended to prepare essential oils (EOs) from A. fragrantissima aerial parts growing widely in Egypt and investigate its antibacterial activity against skin-related pathogens and in vitro cell-based anti-inflammatory activity.

METHODS

EOs of the fresh aerial parts were extracted by hydrodistillation (HD), microwave-assisted hydrodistillation (MAHD), and head-space (HS), while those of the dried ones were prepared by supercritical fluid (SF). The result EOs were analyzed using GC/MS. The antibacterial activity was evaluated alongside Pseudomonas aeruginosa ATCC 9027, Escherichia coli ATCC 8739, Staphylococcus aureus ATCC 25923, Streptococcus pyogenes ATCC 12344, Clostridium perfringens ATCC 13124 by agar diffusion, microwell dilution, and biofilm formation tests. The anti-inflammatory activity was evaluated by measuring tumor necrosis factor-alpha (TNF-α), interleukin 2 (IL-2), and 6 (IL-6) in lipopolysaccharides (LPS)- stimulated RAW 264.7 cells using ELISA assays in addition, expression of nitric oxide synthase (iNOS) was measured via western blot.

RESULTS

The SF method gave the highest EO yield (1.50 mL v/w). Oxygenated components constituted the highest percentage in the four methods, 84.14, 79.21, 73.29 and 33.57% in the HS, HD, MAHD, and SF, respectively. Moreover, variation in the amount of identified compounds was apparent; in HS EO α-thujone (29.37%), artemisia ketone (19.59%), and santolina alcohol (14.66%) are major components, while α-thujone (20.38%) and piperatone (12.09%) were significant in HD. Moreover, ( +)-spathulenol (12.22%) and piperatone (10.48%) were significant in MAHD, while piperatone (14.83%) and β-sitosterol (11.07%) were significant in SF EO. HD, MAHD, and SF EOs exhibited susceptibility against P. aeruginosa (IZ = 9-14 mm), E. coli (11-13 mm), and C. perfringens (IZ = 10-14 mm) in agar diffusion assay. MAHD EOs demonstrated potent growth inhibition (MICs = 0.25-2 mg/mL), followed by HD EOs (MICs = 13-52 mg/mL) to all tested microorganisms in well microdilution assay. Also, they exert MBC values equal to or higher than the MICs. Furthermore, SF EOs inhibited the biofilm formation of all tested microorganisms by 65.12-80.84%. Specifically, MAHD and HD EOs efficiently suppress the biofilm of S. pyogenes (77.87%) and P. aeruginosa (60. 29%), respectively. Ultimately, HD and SF EOs showed anti-inflammatory activity by suppressing the TNF-α, IL-2, and IL-6 release and iNOS expression in LPS-stimulated RAW 264.7 macrophages.

CONCLUSION

A. fragrantissima EO is rich in oxygenated volatile compounds with antibacterial and anti-inflammatory activities. It is encouraged as a bioactive agent for adjusting skin infections, though additional studies are essential for their safety in clinical settings.

Spatial Resolution for X-ray Excited Luminescence Chemical Imaging (XELCI)

Measuring chemical concentrations at the surface of implanted medical devices is important for elucidating the local biochemical environment, especially during implant infection. Although chemical indicator dyes enable chemical measurements in vitro, they are usually ineffective when measuring through tissue because the background obscures the dye signal and scattering dramatically reduces the spatial resolution. X-ray excited luminescent chemical imaging (XELCI) is a recent imaging modality which overcomes these limitations using a focused X-ray beam to excite a small spot of red light on scintillator-coated medical implants with well-defined location (because X-rays are minimally scattered) and low background. A spectrochemical indicator film placed over the scintillator layer, e.g., a polymer film containing pH-indicator dyes, absorbs some of the luminescence according to the local chemical environment, and this absorption is then detected by measuring the light intensity/spectrum passing through the tissue. A focused X-ray beam is used to scan point-by-point with a spatial resolution mainly limited by the X-ray beam width with minimum increase from X-ray absorption and scattering in the tissue. X-ray resolution, implant surface specificity, and chemical sensitivity are the three key features of XELCI. Here, we study spatial resolution using optically absorptive targets. For imaging a series of lines, the 20-80% knife-edge resolution was ∼285 (±15) μm with no tissue and 475 ± 18 and 520 ± 34 μm, respectively, through 5 and 10 mm thick tissue. Thus, doubling the tissue depth did not appreciably change the spatial resolution recorded through the tissue. This shows the promise of XELCI for submillimeter chemical imaging through tissue.

Preventing Staphylococci Surgical Site Infections with a Nitric Oxide-Releasing Poly(lactic acid-co-glycolic acid) Suture Material

Of the 27 million surgeries performed in the United States each year, a reported 2.6% result in a surgical site infection (SSI), and Staphylococci species are commonly the culprit. Alternative therapies, such as nitric oxide (NO)-releasing biomaterials, are being developed to address this issue. NO is a potent antimicrobial agent with several modes of action, including oxidative and nitrosative damage, disruption of bacterial membranes, and dispersion of biofilms. For targeted antibacterial effects, NO is delivered by exogenous donor molecules, like S-nitroso-N-acetylpenicillamine (SNAP). Herein, the impregnation of SNAP into poly(lactic-co-glycolic acid) (PLGA) for SSI prevention is reported for the first time. The NO-releasing PLGA copolymer is fabricated and characterized by donor molecule loading, leaching, and the amount remaining after ethylene oxide sterilization. The swelling ratio, water uptake, static water contact angle, and tensile strength are also investigated. Furthermore, its cytocompatibility is tested against 3T3 mouse fibroblast cells, and its antimicrobial efficacy is assessed against multiple Staphylococci strains. Overall, the NO-releasing PLGA copolymer holds promise as a suture material for eradicating surgical site infections caused by Staphylococci strains. SNAP impregnation affords robust antibacterial properties while maintaining the cytocompatibility and mechanical integrity.

Antioxidant and antibacterial hydrogel formed by protocatechualdehyde-ferric iron complex and aminopolysaccharide for infected wound healing

To better treat bacteria-infected wounds and promote healing, new wound dressings must be developed. In this study, we obtained PA@Fe by chelating iron trivalent ions (Fe3+) with protocatechualdehyde (PA), which has a catechol structure. Subsequently, we reacted it with ethylene glycol chitosan (GC) via a Schiff base reaction and loaded vancomycin to obtain an antibacterial Gel@Van hydrogel with a photothermal response. The as-prepared Gel@Van hydrogel exhibited good injectability, self-healing, hemostasis, photothermal stability, biocompatibility, and antioxidant and antibacterial properties. Moreover, Gel@Van hydrogel achieved highly synergistic antibacterial efficacy through photothermal and antibiotic sterilization. In a mouse skin-damaged infection model, Gel@Van hydrogel had a strong ability to promote the healing of methicillin-resistant Staphylococcus aureus (MRSA)-infected wounds, indicating the great potential application value of Gel@Van hydrogel in the field of treating and promoting the healing of infected wounds.

Surgical Site Infections in Elective and Emergency Abdominal Surgeries: A Prospective Observational Study About Incidence, Risk Factors, Pathogens, and Antibiotic Sensitivity at a Government Tertiary Care Teaching Hospital in India

Background Surgical site infections (SSIs), the third most common nosocomial infection, endanger hospitals and patients. SSIs must be monitored continuously. This present study examined SSI incidence, risk factors, pathogens, and antibiotic sensitivity in emergency and elective or planned abdominal surgeries. Methods The Dr. S.N. Medical College General Surgery Department in Jodhpur, India, operated on 100 patients. The sample was divided into two 50-person groups. Group A includes emergency surgery patients, while Group B includes elective surgery patients. The samples were aseptically collected and processed according to microbiological methods. Data were processed with IBM SPSS Statistics for Windows, version 20 (released 2011; IBM Corp., Armonk, New York, United States). Results Out of a sample size of 100 patients, 17 individuals experienced SSIs. SSI incidence was 16.66% in male patients and 18.18% in female patients. In addition, the rate of SSIs was 26% in the emergency group and 8% in the planned group. The association was stronger among elderly individuals, diabetics (33.33% in Group A and 12.5% in Group B), and anemics with a history of smoking. The association was higher in those who underwent surgery for more than 60 minutes (34.37% in Group A and 18.8% in Group B). The incidence of SSIs was higher in emergency cases compared to elective surgeries, with rates of 26% and 8%, respectively, but was statistically insignificant. The infection rate in clean cases during planned surgery was 3.70%, while clean contaminated cases during planned surgery had a wound infection rate of approximately 13.04%. In emergency surgery, no clean case was operated on, but the SSI rate in the emergency group was 9.09%, 22.22%, and 47.36% in the clean-contaminated, contaminated, and dirty cases, respectively. In Group A, Escherichia coli was the predominant organism found in SSI wounds, while in Group B, Staphylococcus aureus was the predominant organism, accounting for 46.15% and 50% of infections, respectively. Amikacin and metronidazole exhibited the highest efficacy against E. coli, with amikacin demonstrating the highest sensitivity. Conclusion SSIs are more common in emergencies than planned procedures. Age, gender, diabetes, hypertension, smoking, and prolonged surgery are risk factors for SSIs. Effective antibiotic policy and infection control can greatly prevent SSIs.

Assessment of risk factors associated with surgical site infection following abdominal surgery: a systematic review

Objective

Surgical site infections (SSIs) are among the most common healthcare-associated infections occurring following 1%-3% of all surgical procedures. Their rates are the highest following abdominal surgery. They are still associated with increased morbidity and healthcare costs despite the advancement in the medical field. Many risk factors for SSIs following abdominal surgery have been identified. The aim of this study is to comprehensively assess these risk factors as published in peer-reviewed journals.

Design

A systematic review was conducted with accordance to Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines.

Setting

The databases for search were PubMed and Cochrane Library, in addition to reference lists. Studies were retrieved and assessed for their quality. Data were extracted in a designed form, and a stratified synthesis of data was conducted to report the significant risk factors.

Participants

Patients undergoing general abdominal surgery.

Intervention

The intervention of general abdominal surgery.

Main outcome measures

To identify and assess the risk factors for SSI following abdominal surgery.

Results

Literature search yielded 813 articles, and the final screening process identified 11 eligible studies. The total number of patients is 11 996. The rates of SSI ranged from 4.09% to 26.7%. Nine studies were assessed to be of high quality, the remaining two studies have moderate quality. Stratified synthesis of data was performed for risk factors using summary measures (OR/risk ratio, 95% CI, and p value). Male sex and increased body mass index (BMI) were identified as significant demographic risk factors, and long operative time was among the major significant procedure-related risk factors.

Conclusions

Male sex, increased BMI, diabetes, smoking, American Society of Anesthesiologists classification of >2, low albumin level, low haemoglobin level, preoperative hospital stay, long operative time, emergency procedure, open surgical approach, increased wound class, intraoperative blood loss, perioperative infection, perioperative blood transfusion, and use of drains are potential independent risk factors for SSI following abdominal surgery.

Data-Driven Technologies as Enablers for Value Creation in the Prevention of Surgical Site Infections: a Systematic Review

Despite the advances in modern medicine, the use of data-driven technologies (DDTs) to prevent surgical site infections (SSIs) remains a major challenge. Scholars recognise that data management is the next frontier in infection prevention, but many aspects related to the benefits and advantages of using DDTs to mitigate SSI risk factors remain unclear and underexplored in the literature. This study explores how DDTs enable value creation in the prevention of SSIs. This study follows a systematic literature review approach and the PRISMA statement to analyse peer-reviewed articles from seven databases. Fifty-nine articles were included in the review and were analysed through a descriptive and a thematic analysis. The findings suggest a growing interest in DDTs in SSI prevention in the last 5 years, and that machine learning and smartphone applications are widely used in SSI prevention. DDTs are mainly applied to prevent SSIs in clean and clean-contaminated surgeries and often used to manage patient-related data in the postoperative stage. DDTs enable the creation of nine categories of value that are classified in four dimensions: cost/sacrifice, functional/instrumental, experiential/hedonic, and symbolic/expressive. This study offers a unique and systematic overview of the value creation aspects enabled by DDT applications in SSI prevention and suggests that additional research is needed in four areas: value co-creation and product-service systems, DDTs in contaminated and dirty surgeries, data legitimation and explainability, and data-driven interventions.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41666-023-00129-2.

Do postoperative complications correlate to chronic pain following inguinal hernia repair? A prospective cohort study from the Swedish Hernia Register

PURPOSE

To analyse if postoperative complications constitute a predictor for the risk of developing long-term groin pain.

METHODS

Population-based prospective cohort study of 30,659 patients operated for inguinal hernia 2015-2017 included in the Swedish Hernia Register. Registered post-operative complications were categorised into hematomas, surgical site infections, seromas, urinary tract complications, and acute post-operative pain. A questionnaire enquiring about groin pain was distributed to all patients 1 year after surgery. Multivariable logistic regression analysis was used to find any association between postoperative complications and reported level of pain 1 year after surgery.

RESULTS

The response rate was 64.5%. In total 19,773 eligible participants responded to the questionnaire, whereof 73.4% had undergone open anterior mesh repair and 26.6% had undergone endo-laparoscopic mesh repair. Registered postoperative complications were: 750 hematomas (2.3%), 516 surgical site infections (1.6%), 395 seromas (1.2%), 1216 urinary tract complications (3.7%), and 520 hernia repairs with acute post-operative pain (1.6%). Among patients who had undergone open anterior mesh repair, an association between persistent pain and hematomas (OR 2.03, CI 1.30-3.18), surgical site infections (OR 2.18, CI 1.27-3.73) and acute post-operative pain (OR 7.46, CI 4.02-13.87) was seen. Analysis of patients with endo-laparoscopic repair showed an association between persistent pain and acute post-operative pain (OR 9.35, CI 3.18-27.48).

CONCLUSION

Acute postoperative pain was a strong predictor for persistent pain following both open anterior and endo-laparoscopic hernia repair. Surgical site infection and hematoma were predictors for persistent pain following open anterior hernia repair, although the rate of reported postoperative complications was low.

Population pharmacokinetic model of cefazolin in total hip arthroplasty

Cefazolin is an antibiotic recommended for infection prevention in total hip arthroplasty (THA). However, the dosing regimen necessary to achieve therapeutic concentrations in obese patients remains unclear. The aim of this study was to conduct a population analysis of cefazolin pharmacokinetics (PK) and assess whether cefazolin administration should be weight adapted in THA. Adult patients undergoing THA surgery received an injection of 2000 mg of cefazolin, doubled in the case of BMI > 35 kg/m² and total body weight > 100 kg. A population PK study was conducted to quantify cefazolin exposure over time compared to the therapeutic concentration threshold. A total of 484 cefazolin measurements were acquired in 100 patients, of whom 29% were obese. A 2-compartment model best fitted the data, and creatinine clearance determined interpatient variability in elimination clearance. Our PK simulations using a 2000 mg cefazolin bolus showed that cefazolin concentrations remained above the threshold throughout surgery, regardless of weight or renal function. A 2000 mg cefazolin single injection without adaptation to weight or renal function and without intraoperative reinjection was efficient in maintaining therapeutic concentrations throughout surgery. The optimal target concentration and necessary duration of its maintenance remain unclear.

Characterization and Antibacterial Properties of Autoclaved Carboxylated Wood Nanocellulose

Cellulose nanofibrils (CNFs) were obtained by applying a chemical pretreatment consisting of autoclaving the pulp fibers in sodium hydroxide, combined with 2,2,6,6-tetramethylpiperidinyl-1-oxyl-mediated oxidation. Three levels of sodium hypochlorite were applied (2.5, 3.8, and 6.0 mmol/g) to obtain CNF qualities (CNF_2.5, CNF_3.8, and CNF_6.0) with varying content of carboxyl groups, that is, 1036, 1285, and 1593 μmol/g cellulose. The cytotoxicity and skin irritation potential (indirect tests) of the CNFs were determined according to standardized in vitro testing for medical devices. We here demonstrate that autoclaving (121 °C, 20 min), which was used to sterilize the gels, caused a modification of the CNF characteristics. This was confirmed by a reduction in the viscosity of the gels, a morphological change of the nanofibrils, by an increase of the ultraviolet-visible absorbance maxima at 250 nm, reduction of the absolute zeta potential, and by an increase in aldehyde content and reducing sugars after autoclaving. Fourier-transform infrared spectroscopy and wide-angle X-ray scattering complemented an extensive characterization of the CNF gels, before and after autoclaving. The antibacterial properties of autoclaved carboxylated CNFs were demonstrated in vitro (bacterial survival and swimming assays) on Pseudomonas aeruginosa and Staphylococcus aureus. Importantly, a mouse in vivo surgical-site infection model on S. aureus revealed that CNF_3.8 showed pronounced antibacterial effect and performed as good as the antiseptic Prontosan wound gel.

Incidence, risk factors and outcomes of surgical site infections among patients admitted to Jimma Medical Center, South West Ethiopia: Prospective cohort study

Background

Surgical site infections are one of the leading health care–associated infections in developing countries. Despite improvements in surgical technique and the use of best infection prevention strategies, surgical site infections remained the major cause of hospital acquired infections. Therefore, this study aimed to determine incidence, risk factors, and outcomes of surgical site infections among patients admitted to Jimma Medical Center, South West Ethiopia.

Methods

A hospital based prospective cohort study design was employed to follow adult patients admitted to general surgery ward, orthopaedic ward and gynaecologic/obstetrics ward of Jimma Medical Centre, from April 20 to August 20, 2019. All patients were followed daily before, during and after operation for 30 days to determine the incidence of surgical site infection and other outcomes. Data was entered using EpiData version 4.2 and analyzed using statistical software package for social science version 20.0. To identify the independent predictors of outcome, multiple stepwise backward cox regression analysis was done. Statistical significance was considered at p-value <0.05.

Results

Of total of 251 participants included to the study, about 126 (50.2%) of them were females. The mean ± SD age of patients was 38 ± 16.30 years. Considerable number of patients 53(21.1%) developed surgical site infections. American Society of Anaesthesiologists score ≥3 [ Adjusted Hazard Ratio (AHR) = 2.26; 95%CI = (1.03–4.93)], postoperative antibiotic prescription [AHR = 3.2; 95%CI = (1.71–6.01)], contaminated-wound [AHR = 7.9; 95%CI = (4.3–14.60)], emergency surgery [AHR = 2.8; 95% CI = (1.16–6.80)], duration of operation ≥ 2 h [AHR = 4; 95% CI = (2.17–7.50)] and comorbidity [AHR = 2.52; 95%CI = (1.28–4.94)] were independent predictors for surgical site infections. Twenty nine (11.6%) patients returned to operation room. The result of the multivariate cox regression analysis showed that SSI [AHR (95% CI) = 7(3.16–15.72)], and incision site [AHR (95% CI) = 2.5(1.14–5.42)] had statistically significant association with re-operation

Conclusion

The incidence of surgical site infection was high in the study setting. There were significant numbers of contributing factors for the occurrence of surgical site infections. Although no mortality observed during the study period, significant number of patients re-operated. Large multicenter study is urgently needed to confirm the outcome of this study.

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Surgical site infections are one of the leading health care–associated infections in developing countries.

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Considerable number of risk factors are associated with the occurrence of surgical site infection.

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Surgical site infection is associated with increased length of hospital stay and number of patients re-operated.

Population Pharmacokinetic and Pharmacodynamic Target Attainment Analysis of Cefazolin in the Serum and Hip Joint Capsule of Patients Undergoing Total Hip Arthroplasty

The objectives of this study were to evaluate the population pharmacokinetics of prophylactic cefazolin (CFZ) from its serum and hip joint capsule concentrations in patients undergoing total hip arthroplasty and to establish the pharmacodynamic target concentration exceeding the MIC for designing an effective dosing regimen for serum and the hip joint capsule. We analyzed 249 serum samples and 125 hip joint capsule samples from 125 individuals using a nonlinear mixed-effects model. The pharmacodynamic index target value obtained from our results indicates the probability of maintaining CFZ trough and hip joint capsule concentrations exceeding the MIC of 1 mg/liter to account for methicillin-susceptible S. aureus (MSSA). We estimated the population pharmacokinetics using a two-compartment model. The estimated population pharmacokinetic parameters were as follows: clearance (CL) (liters/h) = 1.46 × (creatinine clearance [CL_cr] [ml/min]/77)^0.891, volume of distribution of the central compartment (V_c) (liters) = 7.5, central-hip joint capsule compartment clearance (Q) (liters/h) = 3.38, and volume of distribution in the hip joint capsule compartment (V_JC) (liters) = 36.1. The probability of achieving concentrations exceeding the MIC₉₀ for MSSA was approximately 100% for serum and 100% for the hip joint capsule at 3 h after the initial dose. Our findings suggest that population-based parameters are useful for evaluating CFZ pharmacokinetics and that individual dosages should be determined based on the dosage regimen that achieves and maintains adequate tissue CFZ concentration.

Study of incidence and risk factors of surgical site infections in lower segment caesarean section cases of tertiary care hospital of north India

OBJECTIVES

To determine the incidence density, risk factors and common pathogens associated with surgical site infections (SSI) following lower segment caesarean section (LSCS) surgeries.

METHODS

In this Non-interventional prospective observational study, a total of 611 post caesarean emergency and elective cases were enrolled among the 1018 LSCS cases conducted for the period of May-August 2016. The demographic, risk factors and clinical data for appearance of signs and symptoms of SSI were recorded in a preformatted proforma. SSI's were classified as superficial, deep and organ space as per Centre for Disease Control (CDC), USA definitions. Pus specimens were processed and antimicrobial susceptibility results of the organisms were determined as standard microbiological techniques.

RESULTS

The SSI rate was found to be 10.3 per 100 surgeries in our study with superficial SSI (66.7%) being most common. Inappropriate pre-surgical antibiotic prophylaxis, anaemia, previous LSCS as indication of LSCS, intra-operative blood transfusion and comorbid illness like heart disease, hypothyroidism, chronic liver and kidney disease were found to be significantly associated with SSI. Predominance of gram negative isolates (55.3%) was seen in comparison to gram positive isolates (44.7%) as cause of surgical site infections.

CONCLUSIONS

SSIs rates observed are much higher than those observed in NHSN participating hospitals. Many of the risk factors identified are low hanging fruits and can be targeted to effectively reduce SSI rates.

Perioperative body temperature maintenance and occurrence of surgical site infection: A systematic review with meta-analysis

BACKGROUND

Current guidelines recommend perioperative warming as one of the strategies to prevent surgical site infection, although there are gaps in the knowledge produced on this issue.

AIM

Assess the efficacy of active warming methods to maintain perioperative patients' body temperature and its effect on the occurrence of surgical site infection.

METHODS

A systematic review with meta-analysis was carried out. PubMed, CINAHL, LiLACS, CENTRAL, and EMBASE databases were searched.

FINDINGS

Of the 956 publications identified, 9 studies were selected for quantitative synthesis and 6 for the meta-analysis. The forced-air warming system was investigated in 8 studies. The generated evidence indicated that the use of an active warming method could maintain higher average body temperature as well as could decrease the surgical site infection incidence. Exposure of the patient to temperatures below 36°C in the perioperative period increased the chances of developing this type of infection. The meta-analysis indicated that the association between perioperative active warming methods compared with others to reduce the chances of developing surgical site infection remains unclear (odds ratio = e^-3.59 = 2.718^-0.59 = 0.552, 95% confidence interval (odds ratio) = (0.269-1.135), P = 0.106 I² = 54.34%).

CONCLUSIONS

The employment of an active warming method is effective to maintain higher averages of body temperature. However, more randomized clinical trials are needed to assess the efficacy of that intervention to prevent surgical site infection.

The Effect of Ten Essential Oils on Several Cutaneous Drug-Resistant Microorganisms and Their Cyto/Genotoxic and Antioxidant Properties

In this study, we determined the antimicrobial activity of ten essential oils (EOs)—oregano, thyme, clove, arborvitae, cassia, lemongrass, melaleuca, eucalyptus, lavender, and clary sage—against drug-resistant microorganisms previously isolated from patients with skin infections. The essential oil compositions were determined using gas chromatography coupled to mass spectrometry (GC/MS). The assayed bacteria included Pseudomonas aeruginosa, Proteus vulgaris, Citrobacter koseri, and Klebsiella pneumoniae. Two drug-resistant yeasts (Candidaalbicans and Candida parapsilosis) were also involved in our survey. Oregano, thyme, cassia, lemongrass and arborvitae showed very strong antibacterial and antifungal activity against all tested strains. These results show that these essential oils may be effective in preventing the growth of the drug-resistant microorganisms responsible for wound infections. In this study, the genotoxic effects of tested essential oils on healthy human keratinocytes HaCaT were evaluated using the comet assay for the first time. These results revealed that none of the essential oils induced significant DNA damage in vitro after 24 h. Moreover, the treatment of HaCaT cells with essential oils increased the total antioxidant status (TAS) level. The obtained results indicate that EOs could be used as a potential source of safe and potent natural antimicrobial and antioxidant agents in the pharmaceutical and food industries.

Effects of Operating Room Size on Surgical Site Infection Following Lumbar Fusion Surgery

Background

Surgical site infections (SSIs) represent a devastating complication after spine surgery. Many factors have been identified, but the influence of operating room (OR) size on infection rate has not been assessed.

Methods

Two thousand five hundred and twenty-three patients who underwent open lumbar spine fusion at a single institution between 2010 and 2016 were included. Patients were dichotomized into large versus small groups based on OR volume. Bivariate logistic regression and a final multivariate model following a multicollinearity check were used to calculate odds of infection for all variables.

Results

A total of 63 patients (2.5%) developed SSIs with 46 (73%) in the larger OR group and 17 (27%) in the smaller OR group. The rate of SSIs in larger ORs was 3.02% compared with 1.81% in smaller ORs. Significant parameters impacting SSI in bivariate analysis included an earlier year of surgery, BMI > 30, more comorbidities, more levels decompressed and fused, smoking, and larger OR volumes. Multivariate analysis identified BMI > 30, Elixhauser scores, smoking, and increasing levels decompressed as significant predictors. Topical vancomycin was found to significantly decrease rate of infection in both analyses.

Conclusions

OR size (large versus small) was ultimately not a significant predictor of infection related to rates of SSIs, although it did show a clinical trend toward significance, suggesting association. Future prospective analysis is warranted.

Level of Evidence

3.

Are Perioperative Antibiotics Necessary During Direct Microlaryngoscopy?

OBJECTIVES/HYPOTHESIS

There are currently no established recommendations for the use of perioperative antibiotics (PAs) to prevent surgical site infections (SSIs) for direct microlaryngoscopy (DML). This study examined the incidence of SSI in patients undergoing DML with and without PAs.

STUDY DESIGN

Retrospective, multi-institutional chart review.

METHODS

A retrospective, multi-institutional chart review was performed at four tertiary referral academic medical centers. Patients undergoing DML from 2010 to 2017 were identified using Current Procedural Terminology codes. Medical records of patients undergoing DML with biopsy, microsurgery, laser ablation, or vocal fold injection who had adequate follow-up were reviewed. Procedures with significant cartilage destruction, concurrent open surgery, or esophageal surgery were excluded. Data recorded included age, gender, pacemaker history, American Society of Anesthesiologists class, wound class, indication for surgery, use of laser, complications, emergency room visits, hospitalizations, pain, fever, and postoperative steroid and antibiotic prescriptions. Presence or absence of SSIs was evaluated by a fellowship-trained laryngologist.

RESULTS

There were 834 patients who met inclusion criteria. Of those, 698 did not receive PAs and 136 received PAs. The median age of patients was 54 years of age in the PA group and 57.5 years of age in the non-PA group, and all cases were recorded as wound class II. Overall, 58% of surgeries involved use of carbon dioxide or potassium-titanyl-phosphate laser. Only one SSI was reported on follow-up in a patient who did receive PAs.

CONCLUSIONS

SSIs are exceedingly rare following DML. PA use is not indicated for routine DML.

LEVEL OF EVIDENCE

4 Laryngoscope, 128:2838-2843, 2018.

Skeletal muscle and plasma concentrations of cefazolin during complex paediatric spinal surgery

BACKGROUND

Surgical site infections (SSIs) can have devastating consequences for children who undergo spinal instrumentation. Prospective evaluations of prophylactic cefazolin in this population are limited. The purpose of this study was to describe the pharmacokinetics and skeletal muscle disposition of prophylactic cefazolin in a paediatric population undergoing complex spinal surgery.

METHODS

This prospective pharmacokinetic study included 17 children with adolescent idiopathic scoliosis undergoing posterior spinal fusion, with a median age of 13.8 [interquartile range (IQR) 13.4-15.4] yr and a median weight of 60.6 (IQR 50.8-66.0) kg. A dosing strategy consistent with published guidelines was used. Serial plasma and skeletal muscle microdialysis samples were obtained during the operative procedure and unbound cefazolin concentrations measured. Non-compartmental pharmacokinetic analyses were performed. The amount of time that the concentration of unbound cefazolin exceeded the minimal inhibitory concentration for bacterial growth for selected SSI pathogens was calculated.

RESULTS

Skeletal muscle concentrations peaked at a median of 37.6 (IQR 26.8-40.0) µg ml(-1) within 30-60 min after the first cefazolin 30 mg kg(-1) dose. For patients who received a second 30 mg kg(-1) dose, the peak concentrations reached a median of 40.5 (IQR 30.8-45.7) µg ml(-1) within 30-60 min. The target cefazolin concentrations for SSI prophylaxis for meticillin-sensitive Staphylococcus aureus (MSSA) and Gram-negative pathogens were exceeded in skeletal muscle 98.9 and 58.3% of the intraoperative time, respectively.

CONCLUSIONS

For children with adolescent idiopathic scoliosis undergoing posterior spinal fusion, the cefazolin dosing strategy used in this study resulted in skeletal muscle concentrations that were likely not to be effective for intraoperative SSI prophylaxis against Gram-negative pathogens.

Compliance with perioperative prophylaxis guidelines and the use of novel outcome measures

Postoperative wound infections represent an important source of morbidity and mortality in children. Perioperative antibiotic prophylaxis has been shown to decrease the risk of developing infections and hospital guidelines surrounding antibiotic use exist to standardize patient care. Despite supporting evidence, rates of compliance with guidelines vary. Quality improvement initiatives have been introduced to improve compliance with intraoperative antibiotic guidelines. Thorough infection surveillance, including antibiotic provision in presurgical checklists, computerized voice antibiotic administration prompts, and national feedback systems are now increasingly common. Few studies have been conducted investigating the effectiveness of prophylactic antibiotics in children. Outcome measures such as morbidity and mortality and return to the operating room can be used to examine the relationship between antibiotic use and patient outcome but these measures are limited in that they occur infrequently or are subjective and difficult to measure. Metrics such as days alive out of hospital and length of hospital stay may be useful alternatives for ongoing monitoring of infections and identifying improvements in patient outcomes. Guidelines on antibiotic prophylaxis have facilitated an increase in the correct provision of perioperative antibiotics and a reduction in the incidence of postoperative infection. Measures of patient outcome such as days alive out of hospital and length of hospital stay are easy to collect and calculate but further work is needed to confirm the utility of these measures for monitoring infection rates.

Comparative efficacy of three antiseptics as surgical skin preparations in dogs

OBJECTIVE

To compare the antimicrobial efficacy of a 2% chlorhexidine gluconate and 70% ethanol solution (CG+A) with that of F10 Skin Prep Solution (F10) and electrochemically activated water (EAW) when used as a surgical preparation in canine patients.

STUDY DESIGN

Prospective randomized clinical study.

SAMPLE POPULATION

One hundred sixteen dogs presented for ovariohysterectomy.

METHODS

Dogs were randomly divided into 1 of the 3 antiseptic groups (CG+A, F10, EAW). Skin samples with replicating organism detection and counting plates were taken at 4 different perioperative sites and time intervals (postskin preparation, postskin antisepsis, 2 hours after the second sample, and at the end of surgery) during ovariohysterectomies performed by students. The colony forming unit (CFU) counts from each sample were quantified according to the level of bacterial contamination. Zero CFU was defined as no contamination, 1-12 CFU was defined as low contamination, and greater than 12 CFU was defined as high contamination. The 3 antiseptics were compared with respect to the level of contamination.

RESULTS

There was no difference in the level of colonization between the antiseptics at the first sampling time (P = .454). However, the level of contamination for CG+A was lower compared with F10 and EAW at the second, third, and fourth sampling times (P =  .001, P =  .01, P =  .02, respectively).

CONCLUSION

CG+A was more effective at achieving a zero CFU count and low levels of contamination compared with F10 and EAW for surgical preparation in dogs undergoing ovariohysterectomy.

CLINICAL SIGNIFICANCE

This study does not provide evidence to support the use of F10 and EAW instead of CG+A for the surgical skin preparation of dogs undergoing ovariohysterectomy.

Efficacy of vaporized hydrogen peroxide for repeated sterilization of a single-use single-incision laparoscopic surgery port

OBJECTIVE

To determine the ability of vaporized hydrogen peroxide (VHP) to sterilize a single-use single-incision laparoscopic surgery port and its associated components after repeated simulated uses.

STUDY DESIGN

Prospective in vitro experimental study.

SAMPLE POPULATION

Six single-use single-incision laparoscopic surgery ports with associated cannulas and insufflation tubing.

METHODS

Ports, cannulas, and tubing were subjected to 10 cycles of simulated use, bacterial inoculation with Staphylococcus pseudintermedius and Escherichia coli, decontamination and sterilization, and testing via culture based on their treatment group designation. Bacteriological scores were compared among the negative control, positive control, and 4 treated ports and components.

RESULTS

There was no difference in bacteriological scores between treated ports, cannulas, and insufflation tubing and the negative control port and components. Bacteriological scores of ports and components undergoing 6-10 cycles were not significantly different from scores of ports and components undergoing 5 or fewer sterilization cycles. No difference was found in detection of bacteria from treated ports by biopsy of the foam versus sampling via wash.

CONCLUSION

This study suggests that a single-use single-incision laparoscopic port and its associated components can be effectively sterilized after multiple simulated uses by using VHP.

CLINICAL SIGNIFICANCE

Reuse of a single-use single-incision laparoscopic port is a safe and effective method of cost reduction in veterinary patients.

Surgical site infection in overweight and obese Total Knee Arthroplasty patients

Purpose

This aim of this study was to evaluate the rate of surgical site infection (SSI) in patients undergoing Total Knee Arthroplasty (TKA), to improve our understanding of the associations between infection rate and obesity.

Methods

Data was reviewed for 839 primary TKA procedures performed at a National Arthroplasty Centre over one year (April 2007-March 2008). SSI data was collected at 30 days and one year post-operatively. Patients were grouped guided by the WHO classifications of obesity; normal (BMI < 25.0), overweight (BMI 25.00-29.99), obese class I (BMI 30.00-34.99), obese class II (BMI 35.00-39.99), obese class III (BMI ≥ 40.00). Statistical significance was assessed by Fisher's Exact Test.

Results

When grouped by BMI, 30.9% of patients were obese class I, 19.0% obese class II and 8.7% obese class III. Of the total cohort, 22 patients (2.6%) had superficial SSI and 13 (1.5%) had deep SSI. When comparing the obese class III cohort to all other cohorts (non-obese class III), the odds ratios for superficial SSI was 4.20 (95% CI [1.59, 11.09]; p = 0.009) and deep SSI was 6.97 (95% CI [2.22, 21.89]; p = 0.003). In the obese class III cohort, superficial SSI rate was higher in females (8.9%) than males (5.9%), yet deep SSI demonstrated the opposite, with a higher occurrence in males (11.8%) compared to females (5.4%).

Conclusion

This study suggests that obese class III TKA patients are at increased odds of superficial and deep SSI compared to other BMI cohorts. Interestingly, male obese class III patients demonstrated a higher rate of deep infection compared to their female counterparts. However, it must be noted that study findings are limited as confounders were unable to be accounted for in this retrospective study design.

Novel approaches to surgical site infections: what recommendations can be made?

INTRODUCTION

Surgical site infections (SSI) are one of the most frequent healthcare-associated infections worldwide, representing a substantial burden on the healthcare system and the individual patient. Various risk factors for SSI have been identified, which can be separated into patient-related, procedure-related and other risk factors. Areas covered: Other risk factors relevant for SSI are the season in which surgery is performed, the volume of surgeries in a department, the working atmosphere in the operating room and the indications for surgery. Overall, the risk of SSI is higher during summertime. Higher-volume departments appear to be protective against SSI as does a calm working atmosphere. The frequency of certain types of surgery differs greatly among European countries. The decision to perform surgery appears to be dependent on the patient's condition as well as the healthcare system and financial incentives. Expert commentary: When possible, elective surgery should not be executed during summertime but during cooler times of year. Departments with a high volume of surgical procedures should be given preference. The establishment of a calm working atmosphere is beneficial to a surgeon's performance and can reduce SSI rates. The indications for performing surgery should be carefully reevaluated whenever possible.

Extracorporeal magnetic approach to reduce the unwanted side-effects and improve antibacterial activity of Ag/Fe3 O4 nanocomposites in rat

While Ag nanoparticles hold great promise for broad spectrum antibacterial activity, the potential risks of Ag nanoparticles (NPs) on human health remain a challenge. In this study, Ag/Fe₃ O₄ composites have been successfully prepared and characterized by transmission electron microscopy, X-ray powder diffraction, and Fourier-transform infrared spectroscopy, and their magnetic and antibacterial properties have been assessed. In vivo results show that the antibacterial effect of 500 μg/mL Ag/Fe₃ O₄ nanocomposites was significantly higher than that of 1000 μg/mL AgNPs after 72 h of treatment (p < 0.01). Hematoxylin and eosin (HE) staining showed that squamous epithelium and dermis collagen fibers formed in the Ag/Fe₃ O₄ group after 8 days treatment. Wound closure was significantly better for the Ag/Fe₃ O₄ group than for the AgNPs group. On the other hand, there was less Ag in blood, liver, and kidney in the Ag/Fe₃ O₄ group, as more Ag was retained in the wound. According to lactate dehydrogenase, γ-glutamyl transpeptidase, and reactive oxygen species results, Ag/Fe₃ O₄ nanocomposites caused less unwanted side-effects. This work presents a new paradigm to reduce the unwanted side-effects of AgNPs and improve their antibacterial activity, providing a new avenue for wound healing. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2029-2036, 2018.

Clinical experiences in the use of a gentamicin-coated titanium nail in tibia fractures

Despite the improvement of surgical techniques surgical site infections (SSIs) still remain clinically challenging in high risk patients undergoing osteosynthesis for tibia fractures. The use of an antibiotic coated implant might reduce the adhesion of bacteria on the implant surface and could therefore reduce the rate of implant-related infection or osteomyelitis. A gentamicin-coated tibia nail was evaluated in a prospective study. Four centers enrolled 100 patients (99 treated) with fresh open or closed tibia fractures, or for non-union revision surgery and followed them for 18 months. Data collected included infection events, radiographs, SF-12, EQ-5D, Iowa Ankle score, and the WOMAC questionnaire. Sixty-eight of the 99 treated patients suffered from a fresh fracture, while in 31 patients, the intramedullary nail was implanted for revision purposes, including non-unions due to infection. Fifteen (22%) of the fresh fractures were GA Type III. The follow-up rate was 87% and 82% at 12 months and 18 months, respectively. Deep surgical site infections occurred in 3 fresh fractures and two in revision surgeries. We did not observe any local or systemic toxic effects related to gentamicin during this study. The use of the antibiotic coated nail is an option in patients with a high infection risk, like open factures or infected non unions, in the prevention of the onset of an implant-related infection or osteomyelitis.

Hospital-wide comparison of health care-associated infection among 8 intensive care units: A retrospective analysis for 2010-2015

BACKGROUND

Exploring the distribution of nosocomial pathogens among different categories of intensive care units (ICUs) is critical to improving the management of health care-associated infection (HAI). Despite both single- and multicenter studies, the nature of the variations of HAIs within various ICUs remains inadequately evaluated.

METHODS

Data on HAIs at our hospital during the period January 2010-December 2015 were collected from 8 ICUs, namely, respiratory, cardiovascular, neurology, neonatal, hematology, emergency, cardiothoracic surgery, and neurosurgery ICUs, at a tertiary hospital.

RESULTS

We observed a cumulative HAI incidence of 15.6/1,000 patient-days among 6,254 cases of infection at the hospital, as well as obvious interunit variations in HAI distribution. Acinetobacter baumannii was the leading organism of infection in almost every ICU, especially in emergency, neurosurgery, and neonatal ICUs. The most common pathogens were Pseudomonas aeruginosa in the cardiothoracic surgery, emergency, and neonatal ICUs; Klebsiella pneumoniae and Escherichia coli in the neurosurgery, emergency, neonatal, and neurology ICUs; and Candida albicans in both neurology and emergency ICUs.

CONCLUSIONS

Our findings revealed that A baumannii and P aeruginosa were the most common pathogens associated with invasive operations, whereas K pneumoniae and E coli were the most common pathogens in the medical ICUs.

Sepsis, parenteral vaccination and skin disinfection

ASBSTRACT Disinfection should be required for all skin penetrative procedures including parenteral administration of vaccines. This review analyses medically attended infectious events following parenteral vaccination in terms of their microbiological aetiology and pathogenesis. Like 'clean' surgical site infections, the major pathogens responsible for these events were Staphylococcal species, implicating endogenous con-tamination as a significant source of infection. As 70% isopropyl alcohol swabbing has been shown to effectively disinfect the skin, it would be medico-legally difficult to defend a case of sepsis with the omission of skin disinfection unless the very low risk of this event was adequately explained to the patient and documented prior to vaccination. There was a significant cost-benefit for skin disinfection and cellulitis. Skin disinfection in the context of parenteral vaccination represents a new paradigm of medical practice; the use of a low cost intervention to prevent an event of very low prevalence but of significant cost.

Intrawound Vancomycin Powder Decreases Staphylococcal Surgical Site Infections After Posterior Instrumented Spinal Arthrodesis

STUDY DESIGN

A retrospective historical cohort design.

OBJECTIVE

To determine what effect the addition of intrawound vancomycin powder to the prophylactic regimen of posterior instrumented spinal arthrodesis procedures has had on acute surgical site infections (SSIs).

SUMMARY OF BACKGROUND DATA

SSIs are known complications in instrumented spinal arthrodesis procedures, and are predominately caused by Staphylococcus aureus. Recent reports have suggested that placing vancomycin powder into the surgical wound before closure prevents SSIs in spinal surgery. Risk factors for SSIs in the setting of intrawound vancomycin powder use have not been previously reported on.

MATERIALS AND METHODS

SSI rates after 342 posterior instrumented spinal arthrodeses (October 2008-September 2011) in which intrawound vancomycin powder was used in addition to the standard antimicrobial prophylaxis (Vanco cohort) were compared with 341 posterior instrumented spinal arthrodeses (April 2005-October 2008) in which no vancomycin powder was added (non-Vanco cohort). Both 2 sample t test and χ test (Fisher where appropriate) were used for group comparisons. A subanalysis of the Vanco cohort was undertaken to identify risk factors for SSIs despite intrawound vancomycin use.

RESULTS

There was a significant reduction in the number of acute staphylococcal SSIs in the Vanco cohort (1.1%) compared with the non-Vanco cohort (3.8%; P=0.029). Deep staphylococcal infections decreased to 0 compared with 7 in the non-Vanco cohort (2.1%; P=0.008). Deep methicillin-resistant S. aureus infections decreased to 0 compared with 5 in the non-Vanco cohort (1.5%; P=0.031). A subanalysis of the Vanco cohort identified that being discharged to an inpatient rehabilitation or skilled nursing facility was associated with developing a SSI.

CONCLUSIONS

Intrawound vancomycin powder use has decreased the rate of acute staphylococcal SSIs in our posterior instrumented spine arthrodesis surgeries. Patients who are discharged to skilled nursing or rehabilitation facilities are at an increased risk for developing SSIs despite intrawound vancomycin use.

A pilot and feasibility study of the plasma and tissue pharmacokinetics of cefazolin in an immature porcine model of pediatric cardiac surgery

BACKGROUND

Surgical site infection (SSI) prevention for children with congenital heart disease is imperative and methods to assess and evaluate the tissue concentrations of prophylactic antibiotics are important to help maximize these efforts.

AIM

The purposes of this study were to determine the plasma and tissue concentrations with standard of care, perioperative cefazolin dosing in an immature porcine model of pediatric cardiac surgery, and to determine the feasibility of this model.

METHODS

Piglets (3-5 days old) underwent either median sternotomy (MS) or cardiopulmonary bypass with deep hypothermic circulatory arrest (CPB + DHCA) and received standard of care prophylactic cefazolin for the procedures. Serial plasma and microdialysis sampling of the skeletal muscle and subcutaneous tissue adjacent to the surgical site was performed. Cefazolin concentrations were measured, noncompartmental pharmacokinetic analyses were performed, and tissue penetration of cefazolin was assessed.

RESULTS

Following the first intravenous dose, maximal cefazolin concentrations in the subcutaneous tissue and skeletal muscle were similar between groups with peak tissue concentrations 15-30 min after administration. After the second cefazolin dose given with the initiation of CPB, total plasma cefazolin concentrations remained relatively constant until the end of DHCA and then decreased while muscle- and subcutaneous-unbound cefazolin concentrations showed a second peak during or after rewarming. For the MS group, 60-67% of the intraoperative time showed subcutaneous and skeletal muscle concentrations of cefazolin >16 μg·ml(-1) while this percentage was 78-79% for the CPB + DHCA group. There was less tissue penetration of cefazolin in the group that underwent CBP + DHCA (P = 0.03).

CONCLUSIONS

The cefazolin dosing used in this study achieves plasma and tissue concentrations that should be effective against methicillin-sensitive Staphylococcus aureus but may not be effective against some gram-negative pathogens. The timing of the cefazolin administration prior to incision and a second dose given during cardiopulmonary bypass may be important factors for achieving goal tissue concentrations.

Rational Hyperoxia in the Perioperative Period: a Safe and Effective Tool in the Reduction of SSI

Oxygen supplemented at a concentration higher than 40-50 % for at least 2 h perioperatively is expected to reduce surgical site infections (SSI). Although supplementation of 80 % of oxygen perioperatively has shown to reduce SSI in various studies, this concentration is known to be associated with airway complications. This study was taken up to assess the efficacy of 60 %, i.e. <80 and >50 %, inspired oxygen supplemented perioperatively in reducing SSI. One hundred and eighty-eight patients who underwent elective class I and II surgeries were studied. Patients were divided equally into two groups and subgroups and matched for age, sex, type of surgeries, etc. The control group received 30 % and the study group received 60 % oxygen supplementation perioperatively for 2 h. Wounds were observed for the development of SSI. 8/94 patients in the study group and 13/94 patients in the control group developed SSI (p < 0.01). The results indicate a relative risk of 1.62, risk difference of 0.0531 and attributable risk of 38.42 %. Hence, it may be concluded that perioperative oxygen supplementation at 60 % concentration reduces SSI.

Antibiotic Susceptibility Pattern of Aerobic and Anaerobic Bacteria Isolated From Surgical Site Infection of Hospitalized Patients

BACKGROUND

Surgical Site Infections (SSIs) are infections of incision or deep tissue at operation sites. These infections prolong hospitalization, delay wound healing, and increase the overall cost and morbidity.

OBJECTIVES

This study aimed to investigate anaerobic and aerobic bacteria prevalence in surgical site infections and determinate antibiotic susceptibility pattern in these isolates.

MATERIALS AND METHODS

One hundred SSIs specimens were obtained by needle aspiration from purulent material in depth of infected site. These specimens were cultured and incubated in both aerobic and anaerobic condition. For detection of antibiotic susceptibility pattern in aerobic and anaerobic bacteria, we used disk diffusion, agar dilution, and E-test methods.

RESULTS

A total of 194 bacterial strains were isolated from 100 samples of surgical sites. Predominant aerobic and facultative anaerobic bacteria isolated from these specimens were the members of Enterobacteriaceae family (66, 34.03%) followed by Pseudomonas aeruginosa (26, 13.4%), Staphylococcus aureus (24, 12.37%), Acinetobacter spp. (18, 9.28%), Enterococcus spp. (16, 8.24%), coagulase negative Staphylococcus spp. (14, 7.22%) and nonhemolytic streptococci (2, 1.03%). Bacteroides fragilis (26, 13.4%), and Clostridium perfringens (2, 1.03%) were isolated as anaerobic bacteria. The most resistant bacteria among anaerobic isolates were B. fragilis. All Gram-positive isolates were susceptible to vancomycin and linezolid while most of Enterobacteriaceae showed sensitivity to imipenem.

CONCLUSIONS

Most SSIs specimens were polymicrobial and predominant anaerobic isolate was B. fragilis. Isolated aerobic and anaerobic strains showed high level of resistance to antibiotics.

Antimicrobial Analysis of an Antiseptic Made from Ethanol Crude Extracts of P. granatum and E. uniflora in Wistar Rats against Staphylococcus aureus and Staphylococcus epidermidis

INTRODUCTION

Surgical site infection remains a challenge for hospital infection control, especially when it relates to skin antisepsis in the surgical site.

OBJECTIVE

To analyze the antimicrobial activity in vivo of an antiseptic from ethanol crude extracts of P. granatum and E. uniflora against Gram-positive and Gram-negative bacteria.

METHODS

Agar drilling and minimal inhibitory tests were conducted for in vitro evaluation. In the in vivo bioassay were used Wistar rats and Staphylococcus aureus (ATCC 25923) and Staphylococcus epidermidis (ATCC 14990). Statistical analysis was performed through variance analysis and Scott-Knott cluster test at 5% probability and significance level.

RESULTS

In the in vitro, ethanolic extracts of Punica granatum and Eugenia uniflora and their combination showed the best antimicrobial potential against S. epidermidis and S. aureus. In the in vivo bioassay against S. epidermidis, there was no statistically significant difference between the tested product and the patterns used after five minutes of applying the product.

CONCLUSION

The results indicate that the originated product is an antiseptic alternative source against S. epidermidis compared to chlorhexidine gluconate. It is suggested that further researches are to be conducted in different concentrations of the test product, evaluating its effectiveness and operational costs.

Wound Care

Wound care requires an understanding of normal wound healing, causes of delays of wound healing, and the management of wounds. Every wound must be treated as an individual with regard to cause, chronicity, location, and level of microbial contamination, as well as patient factors that affect wound healing. Knowledge of wound care products available and when negative pressure wound therapy and drain placement is appropriate can improve outcomes with wound healing. Inappropriate product use can cause delays in healing. As a wound healing progresses, management of a wound and the bandage material used must evolve.

Killing bacteria within biofilms by sustained release of tetracycline from triple-layered electrospun micro/nanofibre matrices of polycaprolactone and poly(ethylene-co-vinyl acetate)

We report the controlled release of the antibiotic tetracycline (tet) HCl from a triple-layered electrospun matrix consisting of a central layer of poly(ethylene-co-vinyl acetate (PEVA) sandwiched between outer layers of poly-ε-caprolactone (PCL). These micro/nanofibre layers with tet successfully encapsulated (essentially quantitatively at 3 and 5 % w/w) in each layer, efficiently inhibited the growth of a panel of bacteria, including clinical isolates, as shown by a modified Kirby-Bauer disc assay. Furthermore, they demonstrated high biological activity in increasingly complex models of biofilm formation (models that are moving closer to the situation in a wound) by stopping biofilm formation, by killing preformed biofilms and killing mature, dense biofilm colonies of Staphylococcus aureus MRSA252. Tet is clinically useful with potential applications in wound healing and especially in complicated skin and skin-structure infections; electrospinning provides good encapsulation efficiency of tet within PCL/PEVA/PCL polymers in micro/nanofibre layers which display sustained antibiotic release in formulations that are anti-biofilm.

Surgical site infections in patients who undergo radical cystectomy: Excess mortality, stay prolongation and hospital cost overruns

BACKGROUND

The aim of this study was to analyze the impact of surgical site infections (SSI) in patients who underwent radical cystectomy, in terms of excess hospital mortality, stay prolongation and cost overruns.

MATERIAL AND METHODS

A retrospective observational study was conducted on a sample of patients who underwent radical cystectomy as recorded in the basic minimum data sets of 87 Spanish hospitals from 2008-2010.

RESULTS

We studied 4377 patients who underwent radical cystectomy (3904 men and 473 women) of whom 849 (19.4%) experienced an SSI. The patients with SSI were predominantly men, elderly and had a higher prevalence of alcohol-related disorders and more comorbidities. The patients with SSI had significant excess mortality (125.6%), undue stay prolongation (17.8 days) and cost overruns (14,875.70 euros).

CONCLUSIONS

After controlling for demographic variables, hospital type, addiction disorders and comorbidities using multivariate pairing, the onset of SSI in patients who underwent radical cystectomy significantly increased the mortality, stay and cost. Certain preventive measures already established in previous studies could reduce the incidence of SSI and its healthcare and financial impact.

A meta-analysis of spinal surgical site infection and vancomycin powder

Object

Surgical site infection (SSI) is a serious and costly complication of spinal surgery. There have been several conflicting reports on the use of intrawound vancomycin powder in decreasing SSI in spine surgery. The purpose of this study is to answer the question: “Does intrawound vancomycin powder reduce the rate of SSIs in spine surgery?”

Methods

A comprehensive search of multiple electronic databases and bibliographies was conducted to identify clinical studies that evaluated the rates of SSI with and without the use of intrawound vancomycin powder in spine surgery. Independent reviewers extracted data and graded the quality of each paper that met inclusion criteria. A random effects meta-analysis was then performed.

Results

The search identified 9 retrospective cohort studies (Level III evidence) and 1 randomized controlled trial (Level II evidence). There were 2574 cases and 106 infections in the control group (4.1%) and 2518 cases and 33 infections (1.3%) in the treatment group, yielding a pooled absolute risk reduction and relative risk reduction of 2.8% and 68%, respectively. The meta-analysis revealed the use of vancomycin powder to be protective in preventing SSI (relative risk = 0.34, 95% confidence interval 0.17–0.66, p = 0.021). The number needed to treat to prevent 1 SSI was 36. A subgroup analysis found that patients who had implants had a reduced risk of SSI with vancomycin powder (p = 0.023), compared with those who had noninstrumented spinal operations (p = 0.226).

Conclusions

This meta-analysis suggests that the use of vancomycin powder may be protective against SSI in open spinal surgery; however, the exact population in which it should be used is not clear. This benefit may be most appreciated in higher-risk populations or in facilities with a high baseline rate of infection.

Surgical site infections

Surgical site infections are a major contributor to morbidity and mortality in postsurgical care. Risk for surgical site infection is multifactorial and includes a host of microbial, patient-related, and procedure-related factors. Prevention of surgical infection relies on optimization of patient factors and use of a variety of evidence-based pharmacologic and nonpharmacologic measures. At the forefront of these measures is antimicrobial prophylaxis, which has been shown to be effective at reducing risk of surgical site infection. As guidelines for prevention of surgical site infection become increasingly complex and nuanced, surgical infection outcomes are increasing tied to quality outcome and performances measures.

Adherence to guidelines of antibiotic prophylactic use in surgery: a prospective cohort study in North West Bank, Palestine

Background

Surgical site infection is a major contributor to increased mortality and health care costs globally which can be reduced by appropriate antibiotic prophylactic use. In Palestine, there is no published data about preoperative antibiotic use. This study aims to find the pattern of antimicrobial prophylaxis use by evaluating time of the first dose, antibiotic selection and duration after surgery in three governmental hospitals in North West Bank/ Palestine during 2011.

Methods

After approval of Institutional Review Board, a prospective cohort study included a total of 400 abdominal, orthopedic, and gynecological operations which were performed during study period. Trained clinical pharmacists observed selected 301 operations and followed the patient’s files for the three intended study parameters. Compliance of prophylactic antibiotic administration was evaluated according to published guidelines of the American Society for Hospital Pharmacist. Data were analyzed using SPSS version 16 applying descriptive methods. Relationship between guideline compliance and selected operation factors such as type of surgery, patient care unit, and hospital shift, in addition to provider’s age, gender, experience, and specialization were examined applying chi square test. The statistically significant factors with p < 0.01 were further analyzed using logistic regression model.

Results

Overall compliance for the studied parameters was very low (2%); only 59.8% received their first dose in appropriate time, 18.5% had appropriate antibiotic selection, and 31.8% of patients received antibiotic in appropriate duration. The OBGYN department had much better compliance regarding timing and duration of antibiotic use (P < 0.001), however the proper antibiotic selection was best adhered to for the abdominal surgeries (OR = 3.64, P = 0.002). Male providers were statistically significantly much less adherent to the timing of antibiotic dose (OR = 0.28, p < 0.001), but better adherent in antibiotic selection (OR = 0.191, p = 0.028). Anesthetic technicians showed higher compliance than nurses in timing and duration of antibiotic use.

Conclusions

Lack of guidelines explains the low adherence to appropriate surgical antibiotic prophylaxis in Palestine, with high rate of broad spectrum antibiotic use, long duration and inappropriate time of first dose .We recommend adopting guidelines for prophylaxis and training all health care providers accordingly.

Intraoperative angiography does not lead to increased rates of surgical site infections

BACKGROUND

Intraoperative angiography (IOA) is essential in evaluating residual aneurysm following clip ligation, but it does lead to an additional procedure which increases the duration of the procedure as well as increasing room traffic. We examined whether IOA during microsurgery is a risk factor for developing cranial surgical site infection.

MATERIALS AND METHODS

A retrospective cohort study was performed of all patients undergoing craniotomy for aneurysm treatment between 2005 and 2012 at the University of Michigan. IOA was used at the surgeons' discretion. The primary outcome of interest was occurrence of a surgical site infection and the secondary outcome of interest was clip repositioning following IOA. Variables including IOA were tested for their independent association with the occurrence of a surgical site infection.

RESULTS

During the study period 676 intracranial aneurysms were treated by craniotomy; IOA was used in 104 of these cases. There were a total of 20 surgical site infections, 2 in the IOA group (1.9%) and 18 in the non-IOA group (3.1%), indicating that IOA was not a statistically significant variable for infection (p=0.50). No additional single variable measured could be shown to have a statistically significant increase in infection, and there were no direct complications related to the use of IOA (stroke, dissection, perforation).

CONCLUSIONS

IOA does not increase the risk of developing a surgical site infection. It can be conducted without exposing patients to an undue risk of infection.

Skeletal muscle and plasma concentrations of cefazolin during cardiac surgery in infants

OBJECTIVE

To describe the pharmacokinetics and tissue disposition of prophylactic cefazolin into skeletal muscle in a pediatric population undergoing cardiac surgery.

METHODS

The subjects included 12 children, with a median age of 146 days (interquartile range, 136-174) and median weight of 5.5 kg (interquartile range, 5.2-7.3) undergoing cardiac surgery and requiring cardiopulmonary bypass with or without deep hypothermic circulatory arrest. Institutional cefazolin at standard doses of 25 mg/kg before incision and 25 mg/kg in the bypass prime solution were administered. Serial plasma and skeletal muscle microdialysis samples were obtained intraoperatively and the unbound cefazolin concentrations measured. Noncompartmental pharmacokinetic analyses were performed and the tissue disposition evaluated.

RESULTS

After the first dose of cefazolin, the skeletal muscle concentrations peaked at a median microdialysis collection interval of 30 to 38.5 minutes. After the second dose, the peak concentrations were delayed a median of 94 minutes in subjects undergoing deep hypothermic circulatory arrest. Skeletal muscle exposure to cefazolin measured by the area under concentration time curve 0-last measurement was less in the subjects who underwent deep hypothermic circulatory arrest than in those who received cardiopulmonary bypass alone (P = .04). The skeletal muscle concentrations of cefazolin exceeded the goal concentrations for methicillin-sensitive Staphylococcus aureus prophylaxis; however, the goal concentrations for gram-negative pathogens associated with surgical site infections were achieved only 42.1% to 84.2% and 0% to 11.2% of the intraoperative time in subjects undergoing cardiopulmonary bypass alone or deep hypothermic circulatory arrest, respectively.

CONCLUSIONS

This cefazolin dosing strategy resulted in skeletal muscle concentrations that are likely not effective for surgical prophylaxis against gram-negative pathogens but are effective against methicillin-sensitive S aureus in infants undergoing cardiac surgery.

Effect of low-concentration povidone iodine on postoperative complications after third molar surgery: a pilot split-mouth study

PURPOSE

Povidone iodine is used primarily as an antiseptic to decrease surgical site infection. Its hemostatic and antiedematous properties in oral surgery also have been investigated recently.

PATIENTS AND METHODS

A randomized controlled clinical trial was performed in 30 patients undergoing mandibular third molar removal in a split-mouth design. In the study group, a povidone iodine solution with a concentration of 0.5 mg/mL was used as the coolant and irrigant solution, whereas normal saline was used in the control group. Swelling (orotragus and mentotragus distances), trismus (maximum interincisal opening), and pain (visual analog scale score) were evaluated on postoperative days 2 and 7.

RESULTS

In the study group, a significant decrease in swelling and trismus was observed at the 2 postoperative visits (P = .00) compared with the control group. The decrease of pain in the study group was not statistically significant at either postoperative visit (P > .05). More patients (63%) were subjectively satisfied with the side treated with povidone iodine.

CONCLUSION

Povidone iodine irrigation is an inexpensive and safe method to lessen the postoperative sequelae of third molar surgery.

Perioperative strategies to prevent surgical-site infection

Colon and rectal resections are among the most common surgical procedures performed in the United States. Complication rates of up to 25% have been reported and result in a substantial impact on quality of life and cost of care. Recently, the Surgical Care Improvement Program (SCIP) has promoted guidelines to prevent postoperative and potentially preventable complications. A comprehensive evidenced-based review of these guidelines and other perioperative strategies for practicing colorectal surgeons is the basis of this review.