Relationship between skin microbial counts and surgical site infection after neurosurgery

Efficiency of octenidine dihydrochloride alcohol combination compared to ethanol based skin antiseptics for preoperative skin preparation in dogs

OBJECTIVE

To quantify the bacterial burden after skin disinfection using an alcohol octenidine dihydrochloride combination (Octenisept®) compared to an 74.1% ethanol 10% 2-propanol combination (Softasept N®).

STUDY DESIGN

Prospective randomized clinical trial.

MATERIAL & METHODS

61 dogs undergoing clean or clean-contaminated surgeries (excluding surgeries on the gastrointestinal tract) were randomly assigned to group O (skin disinfection with alcohol and octenidine dihydrochloride after washing with octenidine containing soap) or to control group C (skin disinfection using the ethanol-2-propanol combination after washing with a neutral soap without antiseptic ingredients). Samples were then taken from 8 different locations within the surgical field at four different stages: after clipping, after washing, after disinfection and one hour later. At each stage, two different sampling techniques (wet-dry swab technique (WDS) and contact plates (CP)) were used for quantitative analysis of bacterial counts.

RESULTS

WDS detected about 100-fold more bacteria compared to CP sampling in cases with high bacterial burden, but was not accurate enough to detect small numbers. CP sampling was therefore used for comparison of treatment protocols. 30 dogs were assigned to group O and 31 to group C. A relative reduction of 69% in group O and 77 percent in group C was observed after the soap wash. No significant differences were detected between both groups. Washing and disinfection resulted in a reduction of bacterial counts of 99.99% in group O versus 99.7% in group C (p = 0.018). Bacterial reduction one hour after washing and disinfection was significantly higher in group O (99.9%) than in group C (98.5%, p = 0.001).

CONCLUSION

Additional octenidine dihydrochloride provided a slightly better decontamination effect after disinfection, particularly one hour after, which means it may only be indicated in longer surgeries. WDS is more sensitive but less specific to detect bacteria on the skin than the CP sampling.

Bacterial reservoir in deeper skin is a potential source for surgical site and biomaterial-associated infections

BACKGROUND

The origin of surgical site and biomaterial-associated infection is still elusive. Micro-organisms contaminating the wound may come from the air in the operating theatre, the surgical team or the skin of the patient. The skin of patients is disinfected prior to surgery, but bacteria deeper in the skin (e.g. in sweat glands or sebaceous glands) may not be reached.

METHODS

A preliminary cohort study was performed to study the origin of surgical site and biomaterial-associated infection between May 2020 and February 2021. In order to investigate whether cutaneous microbiota colonize the wound when released from the skin upon cutting, aerobic and anaerobic bacteria were isolated, quantified and identified from the skin of 99 patients undergoing trauma surgery, before and after skin disinfection, from knife blades and from the wound directly after the first cut.

RESULTS

Ninety-nine percent of the patients were culture-positive before disinfection with chlorhexidine. Of these, 40% were still culture-positive after disinfection. Of these, 54% had a positive culture of the wound after cutting the skin. Twenty percent of the patients with a negative culture after disinfection had a positive wound culture after cutting the skin. Staphylococcus epidermidis and Cutibacterium acnes were the most commonly cultured bacterial species. In 9% of cases, more than 100 bacterial colonies were cultured from the wound; this may cause biomaterial-associated infection.

CONCLUSION

Bacteria residing in the skin and not eradicated by disinfection may enter the surgical wound upon cutting, resulting in contamination which may cause biomaterial-associated infection.

Effectiveness of Gentamicin Wound Irrigation in Preventing Surgical Site Infection During Lumbar Spine Surgery: A Retrospective Study at a Rural Teaching Hospital in India

BACKGROUND

Surgical site infections (SSIs) are an opposing result of surgery and account for the majority of healthcare-related infections worldwide. It is one of the most common complications associated with open-spine surgery and is associated with high rates of mortality and high demand for healthcare resources. Surgical site infections are the result of a variety of reasons, which is why a range of prevention strategies have been proposed. Intraoperative wound irrigation (IOWI) is a simple procedure that involves moving a solution through an open wound to help hydrate the tissue. It is a type of prophylactic wound irrigation. It removes and dilutes bodily fluids, bacteria, and cellular debris. It may also act as a bactericidal agent when used with antibiotics and antiseptics.

AIMS AND OBJECTIVES

To evaluate the incidence of SSI in lumbar spine surgeries by comparing IOWI with normal saline containing gentamicin (NS-G) and normal saline (NS) alone.

MATERIALS AND METHOD

A hospital-based retrospective study was conducted among 40 patients who underwent elective lumbar spine surgery at the Department of Orthopaedics, RL Jalappa Hospital Centre, Kolar, Karnataka, India.

RESULT

Out of the total participants enrolled, 60% were males and 40% were females. There was no statistically significant difference found between mean age, mean BMI, mean hemoglobin level, mean WBC counts, and mean fasting blood sugar (FBS) levels among both groups. The overall prevalence of SSI among patients was 25%. In Group A (NS-G), the prevalence of SSI was 15%, and in Group B (NS), it was 35%. In total, 17.5% of study participants had superficial SSI, while 7.5% had deep SSI.

CONCLUSION

Gentamicin, an aminoglycoside antibiotic, is bactericidal and efficient against gram-positive organisms like Staphylococcus, the most frequent pathogen causing SSI in spine surgery. During lumbar spine surgery, IOWI with saline and gentamicin before closure is more effective in preventing SSI than simple saline irrigation.

Prevention of Surgical Site Infection Following Open Spine Surgery: The Efficacy of Intraoperative Wound Irrigation with Normal Saline Containing Gentamicin Versus Dilute Povidone-Iodine

BACKGROUND

Intraoperative wound irrigation (IOWI) is an important step in preventing surgical site infection (SSI). This study compared the effectiveness of saline with gentamicin versus povidine-iodine (PI) as IOWI solutions in preventing SSI in open spine surgery.

METHODS

It is a prospective comparative study. Patients who had noninstrumented open spine surgery were randomized into 2 groups. Group A and B patients had their surgical wounds irrigated with saline containing gentamicin solution and dilute PI solution, respectively. Both groups were assessed for the occurrence of SSI.

RESULTS

A total of 80 patients, divided into 2 groups of 40 each completed the study. Overall, the SSI rate was 17.5% for patients in the normal saline containing gentamicin group (A) and 2.5% for those in the dilute PI group (B), this difference was statistically significant (P = 0.025). The cervical and thoracic spine regions have the same SSI rate (7.1% and 0%, respectively) in both groups. However, in the lumbosacral region, the SSI rate was 31.6% in A and 0% in B, this was statistically significant (P = 0.006). The isolated organisms in patients with SSI were staphylococcus species (42.86% of SSI in A and 0% in B) and pseudomonas species (42.86% of SSI in group A and 100% in group B), and this difference was profound in the lumbosacral spine region (P = 0.008).

CONCLUSIONS

IOWI with 3.5% dilute PI solution is more efficacious in preventing SSI and has wider microbial coverage compared to normal saline containing gentamicin solution as IOWI fluid in noninstrumented open spine surgery.

Impact of Plastic Surgery and an Enhanced Prophylaxis Protocol on Cervical Spine Surgery Infection

Background: Reduction of surgical site infections (SSIs) is important in improving cervical spine surgery outcomes. Plastic surgery involvement and an enhanced modified prophylaxis protocol may reduce infection rates. Methods: A total of 962 cervical spine operations were conducted by a single surgeon (TFC). An enhanced modified prophylaxis protocol and plastic surgery were used in some operations. Differences in infection rates, surgical approach, previous operations, prophylaxis use, and plastic surgery involvement were compared using Fisher’s exact tests and multivariate linear regression. Results: Four patients (0.42%) experienced SSIs. All 4 infections involved the standard protocol, posterior approach, and did not involve plastic surgery. The infection rate was lower in the enhanced protocol group when compared to the standard protocol (β −0.78, 95% CI −1.23 to −0.33, P = .0008). The enhanced protocol group had an increased percentage of operations with plastic surgery (β 0.19, 95% CI 0.10 to 0.28, P < .0001). The infection rate among the plastics group was 0.00% compared to 0.60% for the non-plastics group ( P = .32). The plastics group had a lower rate of anterior approach when compared to the non-plastics group (β −0.20, 95% CI −0.24 to −0.15, P = .049). Among the posterior approach group, procedures with plastic surgery had an infection rate of 0.00% compared to 2.53% without plastic surgery ( P = .13). Conclusion: The enhanced protocol was associated with a lower SSI rate and increased plastic surgery involvement. Posterior approaches were associated with increased infection rates and the likelihood of utilizing plastic surgery. Both the enhanced protocol and plastic surgery may decrease infection.

Association of Methicillin-Resistant Coagulase-Negative Staphylococci on Preoperative Skin and Surgical Site Infection in Patients Undergoing Spinal Surgery: A Retrospective Cohort Study

Introduction

The aim of this study was to investigate the association of methicillin-resistant coagulase-negative staphylococci (MRCNS) on preoperative skin and surgical site infections (SSIs) in patients undergoing spinal surgery.

Methods

A total of 507 cases (239 males and 268 females; mean age: 56.1 years) were included in this retrospective study, using prospectively collected data. All patients underwent skin culturing of the surgical site preoperatively. To identify independent risk factors for SSIs as the dependent variable, sequential multivariate logistic regression analyses were conducted. Age, sex, body mass index, presence of rheumatoid arthritis (RA), steroid uses, the American Society of Anesthesiologists Physical Status (ASA-PS) ≥3, MRCNS-positivity on skin bacterial culture, instrumentation, and Japanese Orthopedic Association (JOA) score were used as independent variables.

Results

Preoperatively, MRCNS was detected from skin culture in 50 (9.9%) cases. The frequency of RA, steroid uses, and ASA-PS ≥3 was significantly higher in MRCNS-positive cases than in MRCNS-negative cases. There were 21 (4.1%) post-spinal surgery SSI cases. Multivariate logistic regression analyses revealed that JOA scores (odds ratio (OR), 0.864; 95% confidence interval (CI), 0.764-0.977) and MRCNS-positivity (OR, 5.060; 95% CI, 1.787-14.323) were significantly associated with SSIs.

Conclusions

Preoperatively, the incidence of MRCNS was 9.9%; it was the most common cause of postoperative SSIs. MRCNS-positivity was the most associated factor for SSIs.

Randomized Trial of Dilute Povidone-Iodine Soak and Scrub for Orthopaedic Foot and Ankle Surgery

BACKGROUND

There is no consensus as to which skin antiseptic solution is most effective at reducing infection following orthopaedic foot and ankle surgery. The purpose of this study is to determine if the addition of a dilute povidone-iodine soak and scrub to a standard preparation with alcohol and chlorhexidine decreases positive bacterial culture rates from the hallux nailfold.

METHODS

In this prospective, randomized controlled trial, 242 subjects undergoing orthopaedic foot and ankle surgery were randomized to one of 2 groups. The control group received our standard 2-step skin antiseptic preparation of an alcohol scrub (step 1) followed by chlorhexidine/alcohol paint (step 2). The intervention group received a 3-minute dilute povidone-iodine soak and scrub followed by that same standard 2-step skin preparation. Immediately before skin incision, culture swabs were taken from the hallux nailfold of both groups.

RESULTS

Of the 257 subjects enrolled and randomized, 242 (94.2%) completed the study, satisfying the a priori sample size requirement of 242 subjects. There were no crossovers between groups. There were no differences in baseline characteristics between groups (P > .05 for each). There was no difference in bacterial growth rates between groups (26.8% growth in the intervention group vs 26.9% growth in the control group, P = .991).

CONCLUSION

The hallux nailfold is one of the most difficult to sterilize areas prior to orthopaedic foot and ankle surgery. This randomized controlled trail found no benefit to adding a 3-minute dilute povidone-iodine soak and scrub to a standard skin preparation with alcohol and chlorohexidine.

LEVEL OF EVIDENCE

Level I, randomized controlled trial.

Nuchal thickness and increased risk of surgical site infection in posterior cervical operations

OBJECTIVE

Surgical site infections (SSI) are a common post-operative complication, which increase cost, length of stay, and morbidity. Many risk factors have been, identified including body mass index (BMI). The purpose of this study was to evaluate, whether nuchal thickness rather than BMI increases risk for post-operative SSI in, posterior approach cervical spine operations.

METHODS

A retrospective review of 180 patients who underwent posterior cervical spine, surgery at the University of Florida was performed. Nuchal thickness was measured, from the ventral most point of the spinous process of C5 to the skin on mid-sagittal preoperative, imaging. Diabetes status, BMI, smoking status, duration of anesthesia, prior, operations, and subcutaneous layer thickness was also collected. Infections were, identified according to the Centers for Disease Control (CDC) definitions for SSI. Univariate and multivariate analyses were performed by a biostatistician.

RESULTS

Twenty patients (11%) had SSI. Smoking status, nuchal thickness of greater, than 55 mm or less than 29.8 mm, and subcutaneous fat thickness were all associated, with SSI. Age (OR 0.99, p = 0.45), diabetes (OR 0.50, p = 0.37), BMI (OR 1.03, p = 0.35), and use of intraoperative antibiotic powder (OR 0.62, p = 0.35) were not associated with, infection. On multivariate analysis (adjusted for smoking status), nuchal thickness, (p < 0.0001), subcutaneous fat thickness (p < 0.0001), and the ratio of subcutaneous fat to, nuchal thickness (p < 0.0001) all remained associated with SSI.

CONCLUSIONS

Nuchal thickness and subcutaneous fat thickness are associated with SSI, in patients undergoing posterior cervical spine surgery. Risk of infection increases with very thin and very thick nuchal measurements.

Prevalence and Predictors of Bacterial Contamination in Excisional Lymph Node Biopsies: Implications for Diagnosis and Management

Routine tissue handling exposes lymph node specimens to microbial contamination that can confound microbiological culture results and interfere with diagnosis. The scope and impact of this problem remain poorly understood. We combined over 13 years of lymph node pathology, culture data, and patient records to define the prevalence, predisposing factors, microbiology, and clinical management of false-positive lymph node cultures at a large academic medical center. Nearly one third (31.9%) of 216 cultured lymph nodes yielded bacterial growth. Approximately 90% of positive bacterial cultures grew 1 of 2 common skin-resident taxa-coagulase-negative Staphylococcus and Cutibacterium acnes-with well-documented predispositions for contamination in other clinical settings. Lymph nodes excised from axillary, cervical, and inguinal regions yielded higher positive culture rates than nodes excised from the mediastinum, suggesting proximity to the skin surface may increase contamination risk. Accordingly, cultures from thoracoscopic pulmonary resections displayed contamination rates over 5-fold lower than those from percutaneously accessed lymph nodes. Lymph nodal tissue allocated for culture in the operating room yielded unexpectedly high contamination rates, significantly higher than cultures sent from the frozen section processing area. A significant minority of contamination events were noted in the clinical record and prompted antibiotic therapy on multiple occasions. Collectively, our results illuminate the risk factors contributing to bacterial contamination and argue that routine lymph node bacterial cultures provide minimal clinical benefit for adult patients. This widespread bacterial contamination also warrants cautious implementation of increasingly sensitive molecular microbiology tools for excised tissues.

Intra-operative wound irrigation with ceftriaxone does not reduce surgical site infection in clean neurosurgical procedures

BACKGROUND

The spectrum of post-operative infections in neurosurgical practice includes scalp infection, bone flap osteomyelitis, meningitis and intracranial abscesses and is associated with significant morbidity and mortality. There is a wide variation across neurosurgical centres in the use of perioperative antibiotic prophylaxis. The aim of this study was to determine whether intraoperative wound irrigation with ceftriaxone provides additional prevention of surgical site infection (SSI) in patients already receiving the drug parenterally.

METHODS

This was a prospective randomized clinical study of patients 18 years and above scheduled for clean neurosurgical procedures and assigned to either study or control group using table of random numbers. Both groups had parenteral ceftriaxone at the induction of anaesthesia and for 24-h post-operation. In the study group, there was intra-operative wound irrigation with a ceftriaxone-in-normal saline solution while the wound in the control group was irrigated with only normal saline. Clinical and or laboratory evidence of SSI was used as the outcome measure.

RESULTS

One hundred and thirty-two patients aged 18 years and above were recruited for this study. There were 66 patients in each group. The overall frequency of SSI was 2.27% (3 out of 132). The frequency in the ceftriaxone group was 3% (2 out of 66) while that in the control group was 1.5% (1 out of 66). These values were not significantly different (p = 1.00). There were four cases of wound edge necrosis, three of which developed SSIs.

CONCLUSION

In this study, intraoperative antibiotic irrigation did not confer additional benefit in the prevention of SSI in clean neurosurgical procedures in which prophylactic intravenous antibiotics were administered to the patient. Wound edge necrosis was the most significant but preventable risk factor for the development of SSI in the setting of this work.

Prevalence of Bacterial Contamination of Casting Material in a Pediatric Population

Surgical site infection is a relatively common and devastating complication following pediatric orthopedic surgery. Many infections have been determined to be the result of settled airborne particles on surgical equipment and the sterile field. Fiberglass casts are commonly used orthopedic fixation devices before and after surgery; however, fiberglass casting material is expelled during the removal process and represents an uninvestigated area for the possibility of cast saw dust as a source of airborne bacterial contamination in an operating room setting. This study evaluates the prevalence and distribution of microbiota on 90 pediatric casts by collecting and culturing fiberglass cast material from 90 pediatric casts. Bacterial identification was performed using a Bruker Biotyper Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry device. 81 out of 90 casts (90%) showed evidence of microbial contamination. Isolated species were very diverse and ranged from normal skin flora to opportunistic pathogens. The 5 most commonly isolated organisms were Acinetobacter pittii, Enterobacter cloacae, Micrococcus luteus, Staphylococcus epidermidis, and Staphylococcus hominis. Further investigation is required to determine if casting material is truly a cause of surgical site infection.

Sequential use of povidone-iodine and chlorhexidine for cutaneous antisepsis: A systematic review

Cutaneous antisepsis with chlorhexidine or povidone-iodine, usually with alcohol, has been extensively studied. This review of published studies reveals that sequential use of povidone-iodine and chlorhexidine leads to a greater reduction in the bioburden of aerobic and anaerobic bacteria on the skin, lower risk of intravascular catheter colonization, and lower risk of surgical site infection compared to use of either agent alone. As such, sequential use of cutaneous antiseptic agents may further reduce risk of surgical site infections, as well as infections associated with insertion of transdermal devices such as nephrostomy tubes, left-ventricular assistance devices, and intravascular catheters.

Risk factors for surgical site infections in neurosurgery

INTRODUCTION

Surgical site infections (SSIs) are of profound significance in neurosurgical departments, resulting in high morbidity and mortality. There are limited public data regarding the incidence of SSIs in neurosurgery. The aim of this study was to determine the rate of SSIs (particularly those requiring reoperation) over a seven-year period and identify factors leading to an increased risk.

METHODS

An age matched retrospective analysis was undertaken of a series of 16,513 patients at a single centre. All patients who required reoperation for suspected SSIs within a 7-year period were identified. Exclusion criteria comprised absence of infective material intraoperatively and patients presenting with primary infections. Clinical notes were reviewed to confirm presence or absence of suspected risk factors.

RESULTS

Of the 16,513 patients in the study, 1.20% required at least one further operation to treat a SSI. Wound leak (odds ratio [OR]: 27.41), dexamethasone use (OR: 3.55), instrumentation (OR: 2.74) and operative duration >180 minutes (OR: 1.85) were statistically significant risk factors for reoperation.

CONCLUSIONS

This is the first UK study of such a duration that has documented a SSI reoperation rate in a cohort of this size. Various risk factors are associated with the development of SSIs, making it essential to have robust auditing and monitoring of high risk patients to ensure excellent standards of healthcare. Departmental and public registers to record all SSIs may be beneficial, particularly for those treated solely by general practitioners, allowing units to address potential risk factors prior to surgical intervention.

Cranioplasty Using Autologous Bone versus Porous Polyethylene versus Custom-Made Titanium Mesh : A Retrospective Review of 108 Patients

Objective

The purpose of this study was to compare the cosmetic outcome and complications after cranioplasty (CP) due to three different implant materials, and analyze the mean implant survival and cumulative survival rate based on these results.

Methods

We reviewed 108 patients retrospectively who underwent CP between January 2014 and November 2016. Autologous bone (AB; 45 patients) and synthetic materials with porous polyethylene (PP; 32 patients) and custom-made 3-dimensional printed titanium mesh (CT; 31 patients) were used as implants.

Results

Regardless of implanted materials, more than 89.8% of the CP patients were satisfied with the cosmetic outcome. No statistically significant difference was observed among the three groups. The overall postoperative complication rates of each group were 31.1% in the AB group, 15.6% in the PP group and 3.2% in the CT group. The CT group showed lower complication rates compared with AB and PP groups (χ²-test : AB vs. PP, p=0.34; AB vs. CT, p=0.00; PP vs. CT, p=0.03). The AB and PP groups demonstrated a higher post-CP infection rate (11.1% and 6.3%) than the CT group (3.2%). However, no significant difference in the incidence of post-CP infection was observed among the three groups. The PP and CT groups demonstrated a higher mean implant survival time and cumulative survival rate than the AB group at the last follow-up (p<0.05).

Conclusion

In comparison with AB and PP, cranioplasty with CT shows benefits in terms of lower post-CP complication, less intraoperative bleeding loss, shorter operation time and in-hospital stay. The PP and CT groups showed higher implant survival time and cumulative survival rate compared with the AB group.

Skin Microbiota in Obese Women at Risk for Surgical Site Infection After Cesarean Delivery

The obesity pandemic in the obstetrical population plus increased frequency of Cesarean delivery (CD) has increased vulnerability to surgical site infection (SSI). Here we characterized the microbiome at the site of skin incision before and after CD. Skin and relevant surgical sites were sampled before and after surgical antisepsis from obese (n = 31) and non-obese (n = 27) pregnant women. We quantified bacterial biomass by qPCR, microbial community composition by 16sRNA sequencing, assigned operational taxonomic units, and stained skin biopsies from incision for bacteria and biofilms. In obese women, incision site harbors significantly higher bacterial biomass of lower diversity. Phylum Firmicutes predominated over Actinobacteria, with phylotypes Clostridales and Bacteroidales over commensal Staphylococcus and Propionbacterium spp. Skin dysbiosis increased post-surgical prep and at end of surgery. Biofilms were identified post-prep in the majority (73%) of skin biopsies. At end of surgery, incision had significant gains in bacterial DNA and diversity, and obese women shared more genera with vagina and surgeon's glove in CD. Our findings suggest microbiota at incision differs between obese and non-obese pregnant women, and changes throughout CD. An interaction between vaginal and cutaneous dysbiosis at the incision site may explain the a priori increased risk for SSI among obese pregnant women.

Skin asepsis protocols as a preventive measure of surgical site infections in dogs: chlorhexidine-alcohol versus povidone-iodine

Background

Most of surgical site infections (SSI) are caused by commensal and pathogenic agents from the patient’s microbiota, which may include antibiotic resistant strains. Pre-surgical asepsis of the skin is one of the preventive measures performed to reduce SSI incidence and also antibiotic resistance dissemination. However, in veterinary medicine there is no agreement on which biocide is the most effective.

The aim of this study was to evaluate the effectiveness of two pre-surgical skin asepsis protocols in dogs. A total of 46 animals were randomly assigned for an asepsis protocol with an aqueous solution of 7.5% povidone-iodine or with an alcoholic solution of 2% chlorhexidine. For each dog, two skin swab samples were collected at pre-asepsis and post-asepsis, for bacterial quantification by conventional techniques and isolation of methicillin-resistant species.

Results

Most samples collected at the post-asepsis did not present bacterial growth, both for the animals subjected to the povidone-iodine (74%) or to the chlorhexidine (70%) protocols. In only 9% of the cases a significant bacterial logarithmic reduction was not observed, indicating possible resistance to these agents. Also, the logarithmic reduction of the bacterial quantification from pre- and post-asepsis time, was not statistically different for povidone-iodine (6.51 ± 1.94 log10) and chlorhexidine (6.46 ± 2.62 log10) protocol.

From the 39% pre-asepsis swabs which showed bacterial growth in MRSA modified chromogenic agar medium, only one isolate was identified as Staphylococcus aureus and one as S. epidermidis. False positives were mainly other staphylococci species, as well as Enterobacteriaceae.

Conclusions

Pre-surgical skin asepsis protocols with povidone-iodine or chlorhexidine showed similar efficacy in the elimination of methicillin resistant bacteria and preventing surgical site infections in dogs undergoing surgery.

Culture characterization of the skin microbiome in Type 2 diabetes mellitus: A focus on the role of innate immunity

AIMS

The current study aimed at determining the differences between the cutaneous microbial flora of patients with Type 2 diabetes mellitus (T2DM) and those without, and thus evaluate for cutaneous microbiome dysbiosis in diabetes.

METHODS

We employed a case-control study design with 41 participants in each group. The skin over the toe-web space was swabbed and cultured aerobically. Data was analyzed for differences in microbial prevalences and growths between the two groups. Predictors for heavy colonization by microbes were analysed using logistic regression.

RESULTS

We found significantly higher prevalences of Staphylococcus epidermidis among patients with T2DM (77.5% vs. 53.7%, p=0.02). Further, when prevalent, these bacteria showed a significantly greater degree of skin colonization i.e. CFUs/cm² among these patients, p=0.03. Highly pathogenic bacteria such as S. aureus were more prevalent among patients with T2DM. The regression model determined a significant association between T2DM status and heavy colonization by S. epidermidis (OR - 5.40, p=0.02). Also, agricultural workers were significantly more likely to have heavy colonization by S. epidermidis (OR - 3.75, p=0.02). Other predictor variables did not show significant association with heavy colonization by any of the isolated microbes.

CONCLUSIONS

Our findings support the existence of cutaneous microbiome dysbiosis among patients with T2DM. Literature suggests that microbiome dybiosis in T2DM could stem from the same activated innate immune response that is thought to be central to the development of T2DM. This dysbiosis could increase the risk of developing skin infections.

Reduced Surgical Site Infection Rates Following Spine Surgery Using an Enhanced Prophylaxis Protocol

BACKGROUND

Postoperative surgical site infection (SSI) is a common complication after spine surgery. Reduction of SSI has many benefits including, but not limited to, the reduced length of stay, readmission rates, and morbidity and mortality.

OBJECTIVE

To determine whether an enhanced antibiotic prophylaxis reduced the rate of surgical site infections in spine surgery.

METHODS

This is a retrospective observation study which analyzed the incidence of postoperative SSI following a consecutive series of 1,486 cervical, thoracic and lumbar spine operations performed at a single institution by the senior author between the dates of October 2001 to March 2014. Patients with surgeries between October 2001 and November 2005 received a standard institutional antibiotic prophylaxis. Patients between December 2005 and March 2014 underwent an enhanced antibiotic protocol.

RESULTS

A total of nine cases met the criteria for SSI. All nine cases were recorded during the initial time period when the standard institutional prophylaxis was used. Further, these cases were only observed under posterior operative approaches. No further cases of SSI were observed after the institution of the enhanced antibiotic prophylaxis (p < 0.0001). This was statistically significant in the cervical and lumbar regions (p < 0.0042 and p < 0.0119, respectively).

CONCLUSIONS

Although difficult to predict the incidence of SSI, this study found that the use of an enhanced antibiotic prophylaxis protocol significantly reduced one surgeon's overall rates of surgical site infections after spine surgery.

Systematic Review and Meta-Analysis of Preoperative Antisepsis with Combination Chlorhexidine and Povidone-Iodine

Importance  Effective preoperative antisepsis is recognized to prevent surgical site infection (SSI), although the definitive method is unclear. Many have compared chlorhexidine (CHG) with povidone-iodine (PVI), but there is emerging evidence for combination usage.

Objective  To conduct a systematic review and meta-analysis to evaluate if combination skin preparation (1) reduces colonization at the operative site and (2) prevents SSI compared with single-agent use.

Data Sources  A literature search of MEDLINE, Embase, and Cochrane Database of Clinical Trials was performed.

Study Selection  Comparative, human trials considering the combination use of CHG and PVI, as preoperative antisepsis, to single-agent CHG or PVI use were included. Studies were excluded from meta-analysis if the use or absence of alcohol was inconsistent between study arms.

Data Extraction and Synthesis  The study was performed using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines.

Main Outcomes and Measures  The primary outcome for meta-analysis was surgical site infection. The secondary outcome was colonization at the operative site.

Results  Eighteen publications with a combination of CHG and PVI use were identified. Of these, 12/14 inferred promise for combination usage, including four trials eligible for meta-analysis. Only one trial reported SSI as its outcome. The remaining three considered bacterial colonization. Combination preparation had a pooled odds ratio for complete decolonization of 5.62 (95% confidence interval 3.2 to 9.7, p  < 0.00001). There was no evidence of heterogeneity (Cochran's Q 2.1, 2 df , p  = 0.35).

Conclusions and Relevance  There is emerging, albeit low-quality, evidence in favor of combination CHG and PVI preoperative antisepsis. Further rigorous investigation is indicated.

Analysis of Factors Contributing to Infections After Cranioplasty: A Single-Institution Retrospective Chart Review

OBJECTIVE

Cranioplasty is one of the most common neurosurgical procedures, yet has one of the greatest rates of infection among cranial operations. Although studies have reported on cranioplasty complications, it is unclear what factors contribute to the high rate of infection. This study aims to determine which patient characteristics and operative factors lead to postcranioplasty infections.

METHODS

This was a retrospective chart review of 186 patients. Factors analyzed included sex, reason for cranioplasty, type of infection, medical comorbidities, and surgical factors.

RESULTS

The overall infection rate was 24%. Skin flora was the most common pathogen. Wound dehiscence and presence of a postoperative fluid collection were associated significantly with a greater rate of infection (P < 0.001), whereas the use of autologous bone flap and a state of immunosuppression trended toward statistical significance (P = 0.075 and P = 0.089, respectively). Male sex, history of previous infection, history of craniectomy for trauma, cranioplasty size, and time to cranioplasty were not found to be significant factors related to cranioplasty infection.

CONCLUSIONS

Although wound dehiscence and postoperative fluid collections were associated significantly with infection in this study, the number in each sample size was small, and further studies with a larger number of patients in each subgroup is necessary to validate our findings.

Risk factors for surgical site infections after neurosurgery: A focus on the postoperative period

BACKGROUND

Surgical site infection (SSI) after neurosurgery has potentially devastating consequences.

METHODS

A prospective cohort study was conducted over a period of 24 months in a university center. All adult patients undergoing neurosurgical procedures, with exception of open skull fractures, were included. Multivariate logistic regression analysis was used to identify independent risk factors.

RESULTS

We included 949 patients. Among them, 43 were diagnosed with SSI (4.5%). A significant reduction in postneurosurgical SSI from 5.8% in 2009 to 3.0% in 2010 (P = .04) was observed. During that period, an active surveillance with regular feedback was established. The most common microorganisms isolated from SSI were Staphylococcus aureus (23%), Enterobacteriaceae (21%), and Propionibacterium acnes (12%). We identified the following independent risk factors for SSI postcranial surgery: intensive care unit (ICU) length of stay ≥7 days (odds ratio [OR] = 6.1; 95% confidence interval [CI], 1.7-21.7), duration of drainage ≥3 days (OR = 3.3; 95% CI, 1.1-11), and cerebrospinal fluid leakage (OR = 5.6; 95% CI, 1.1-30). For SSIs postspinal surgery, we identified the following: ICU length of stay ≥7 days (OR = 7.2; 95% CI, 1.6-32.1), coinfection (OR = 9.9; 95% CI, 2.2-43.4), and duration of drainage ≥3 days (OR = 5.7; 95% CI, 1.5-22).

CONCLUSION

Active surveillance with regular feedback proved effective in reducing SSI rates. The postoperative period is associated with overlooked risk factors for neurosurgical SSI. Infection control measures targeting this period are therefore promising.

Post-operative shampoo effects in neurosurgical patients: a pilot experimental study

BACKGROUND

Neurosurgical site infections are an important issue. Among the acknowledged preventive tactics, the non-shaving technique is well established in the neurosurgical setting. However, given that patient's hair around the surgical site may retain biologic material that emerges during the surgical procedure or that may simply become dirty, which may increase the risk of surgical site infections, if and when shampooing should be offered remains under debate.

METHODS

A pilot experimental study was undertaken from 2011 to 2012. A series of neurosurgical patients not affected by conditions that would increase the risk of post-operative infection were assigned randomly to the exposed group (receiving shampoo 72 h after surgical procedure) or control group (receiving standard dressing surveillance without shampooing). Comfort, surgical site contamination (measured as the number of colony-forming units [CFU]), and SSIs at 30 d after surgery were the main study outcomes.

RESULTS

A total of 53 patients were included: 25 (47.2%) received a shampoo after 72 h whereas 28 (52.8%) received standard care. Patients who received a shampoo reported a similar level of comfort (average=8.04; standard deviation [SD] 1.05) compared with those receiving standard care (average 7.3; SD 3.2) although this was not statistically significant (p=0.345). No statistically significant difference emerged in the occurrence of surgical site contamination between the groups, and no SSIs were detected within 30 d.

CONCLUSIONS

In our pilot study, the results of which are not generalizable because of the limited sample of patients involved, a gentle shampoo offered 72 h after the surgical procedure did not increase the SSIs occurrence or the contamination of the surgical site, although it may increase the perception of comfort by patients. Further studies are strongly recommended involving a larger sample size and designed to include more diversified neurosurgical patients undergoing surgical procedures in different centers.

Postoperative wound dealing and superficial surgical site infection in open radical prostatectomy

The number of open radical prostatectomy (RP) surgeries has been decreasing owing to the spread of laparoscopic and robotic surgery, which has implications for postoperative wound healing. The purpose of this study was to investigate and document the current status of postoperative wound healing and superficial surgical site infection (SSI) in open RPs. One hundred and seventy-five antegrade RPs with the same or similar kinds of prophylactic antibiotic administration were divided into two groups: (i) 'no intervention' (wound covering group) and (ii) 'washing', using a washing solution from the second postoperative day to the day of skin staple removal (wound washing group). We compared these groups for the occurrence of superficial SSI. The wound covering group had three (3·03%) cases of superficial SSI, with one case caused by methicillin sensitive Staphylococcus aureus (MSSA). The wound washing group had nine (11·8%) cases of superficial SSI, with three cases caused by MSSA, two cases caused by methicillin resistant Staphylococcus aureus (MRSA) and one by Pseudomonas aeruginosa. The wound covering group showed a significantly lower ratio of superficial SSI (P = 0·0472). In conclusion, the postoperative wound status data in this study suggests that no wound intervention after RP resulted in a comparatively lower ratio of superficial SSI than in the wound washing group.

The impact of surgical wound bacterial colonization on the incidence of surgical site infection after lower limb vascular surgery: a prospective observational study

OBJECTIVE

To study the relationship between surgical wound bacterial colonization and the development of surgical site infection (SSI) after lower limb vascular surgery. SSI is a major problem after lower limb vascular surgery. Most SSIs in vascular surgery are caused by Staphylococcal species that are part of normal skin flora. A prospective observational investigator blind study to examine quantitative and qualitative analysis of surgical wound bacterial colonization and the correlation with the development of SSI has been conducted.

METHODS

The study cohort comprised 94 consecutive patients with 100 surgical procedures. Swabs for microbiological analyses were taken from surgical wounds at four different time intervals: before surgery, just before the surgical area had been scrubbed, at the end of surgery, and on the first and second postoperative days. Postoperative complications were recorded.

RESULTS

Three hundred and eighty-seven skin bacterial samples from 100 surgical wounds were analyzed. The most common bacteria isolated were coagulase-negative staphylococci (80%), Corynebacterium species (25%), and Propionibacterium species (15%). In 13 (62%) cases, the same bacterial isolates were found in the perioperative study samples as in the infected wounds. The incidence of SSI was 21%. Multivariate analysis revealed that high bacterial load on the second postoperative day and diabetes independently increased the risk of SSI. Elective redo surgery was protective against the development of SSI.

CONCLUSIONS

A high bacterial load in the postoperative surgical wound independently increases the risk of the development of SSI after lower limb vascular surgery.

Thickness of subcutaneous fat as a risk factor for infection in cervical spine fusion surgery

BACKGROUND

Surgical site infections increase the incidence of morbidity and mortality as well as health-care expenses. The cost of care increases threefold to fourfold as a consequence of surgical site infection after spinal surgery. The aim of the present study was to determine the role of subcutaneous fat thickness in the development of surgical site infection following cervical spine fusion surgery.

METHODS

We performed a retrospective review of a consecutive cohort of 213 adult patients who underwent posterior cervical spine fusion between 2006 and 2008 at Duke University Medical Center. The horizontal distance from the lamina to the skin surface at the C5 level and the thickness of subcutaneous fat were measured, and the ratio of the fat thickness to the total distance at the surgical site was determined. Previously identified risk factors for the development of surgical site infection were also recorded.

RESULTS

Twenty-two of the 213 patients developed a postoperative infection. Obesity (body mass index ≥ 30 kg/m2) was not a significant risk factor for surgical site infection; the body mass index (and 95% confidence interval) was 29.4 ± 1.2 kg/m2 in the patients who developed a surgical site infection compared with 28.9 ± 0.94 kg/m2 in the patients without an infection. However, the thickness of subcutaneous fat and the ratio of the fat thickness to the lamina-to-skin distance were both significant risk factors for infection. The thickness of subcutaneous fat was 27.0 ± 2.5 mm in the patients who developed a surgical site infection group compared with 21.4 ± 0.88 mm in the patients without an infection (p = 0.042). The ratio of fat thickness to total thickness was 0.42 ± 0.019 in the patients who developed a surgical site infection compared with 0.35 ± 0.01 in the patients without an infection (p = 0.020). Multivariate analysis revealed this ratio to be an independent risk factor for developing a postoperative infection (odds ratio, 3.18; 95% confidence interval, 1.02 to 9.97).

CONCLUSIONS

The study demonstrated that the thickness of subcutaneous fat at the surgical site is a factor in the development of surgical site infection following cervical spine fusion and deserves assessment in the preoperative evaluation.

Infection following operations on the central nervous system: deconstructing the myth of the sterile field

Neurosurgical patients are at a high risk for infectious sequelae following operations. For neurosurgery in particular, the risk of surgical site infection has a unique implication given the proximity of the CSF and the CNS. Patient factors contribute to some degree; for example, cancer and trauma are often associated with impaired nutritional status, known risk factors for infection. Additionally, care-based factors for infection must also be considered, such as the length of surgery, the administration of steroids, and tissue devascularization (such as a craniotomy bone flap). When postoperative infection does occur, attention is commonly focused on potential lapses in surgical “sterility.” Evidence suggests that the surgical field is not free of microorganisms. The authors propose a paradigm shift in the nomenclature of the surgical field from “sterile” to “clean.” Continued efforts aimed at optimizing immune capacity and host defenses to combat potential infection are warranted.

2012 Young Investigator Award winner: The distribution of body mass as a significant risk factor for lumbar spinal fusion postoperative infections

STUDY DESIGN

A retrospective review.

OBJECTIVE

The purpose of this study was to determine the role in body habitus and weight distribution on developing a surgical site infection (SSI).

SUMMARY OF BACKGROUND DATA

SSI after lumbar spine surgery remains a significant cause of morbidity. The literature demonstrates an increased risk of postoperative infections associated with obesity, diabetes, and multilevel surgeries.

METHODS

A retrospective review was performed on a consecutive cohort of 298 adult patients who underwent lumbar spine fusion surgeries between 2006 and 2008 at the Duke University Medical Center. Previously identified risk factors (i.e., number of levels, diabetes, body mass index [BMI]) were collected, as well as the horizontal distance from the lamina to the skin surface (measured at L4) and thickness of subcutaneous fat at the surgical site.

RESULTS

Among the 298 patients, 24 (8%) had postoperative infections. Of the previously identified risk factors, number of levels (P = 0.0078) was found to be significantly associated with infections, whereas BMI (P = 0.16) and diabetes (P = 0.13) were found not to be statistically significant. Obesity (BMI ≥30) (P = 0.025), skin to lamina distance (P = 0.046), and thickness of the subcutaneous fat (P = 0.035) were found to be significant risk factors for SSI.

CONCLUSION

Our findings suggest that in obese patients, the distribution of body mass is more predictive of SSI than the absolute BMI and deserves attention in preoperative evaluation.

Clinical significance of positive cranial bone flap cultures and associated risk of surgical site infection after craniotomies or craniectomies

OBJECT

The risk of surgical site infection (SSI) after craniotomies or craniectomies in patients in whom contaminated bone flaps have been reimplanted has not been determined. The objectives of this study were to identify the prevalence of bone flaps with positive cultures--especially those contaminated with Propionibacterium acnes--to assess the risk of SSI after reimplanting (either during the initial operation or subsequently) bone flaps with positive cultures, and to identify risk factors for SSI following the initial craniotomies or craniectomies.

METHODS

The authors conducted a retrospective review of cases in which patients underwent craniotomy/craniectomy procedures between January and October 2007 in the neurosurgery department at the University of Iowa Hospitals and Clinics. They also reviewed processes and procedures and did pulsed field gel electrophoresis of P. acnes isolates to look for a common source of contamination. They then conducted a prospective cohort study that included all patients who underwent craniotomy/craniectomy procedures between November 2007 and November 2008 and met the study criteria. For the cohort study, the authors obtained cultures from each patient's bone flap during the craniotomy/craniectomy procedures. Data about potential risk factors were collected by circulating nurses during the procedures or by a research assistant who reviewed medical records after the procedures. An infection preventionist independently identified SSIs through routine surveillance using the Centers for Disease Control and Prevention's definitions. Univariate and bivariate analyses were performed to determine the association between SSI and potential risk factors.

RESULTS

The retrospective review did not identify specific breaks in aseptic technique or a common source of P. acnes. Three hundred seventy-three patients underwent 393 craniotomy/craniectomy procedures during the cohort study period, of which 377 procedures met the study criteria. Fifty percent of the bone flaps were contaminated by microorganisms, primarily skin flora such as P. acnes, coagulase-negative staphylococci, and Staphylococcus aureus. Reimplanting bone flaps that had positive culture results did not increase the risk of infection after the initial craniotomy/craniectomy procedures and the subsequent cranioplasty procedures (p = 0.80). Allowing the skin antiseptic to dry before the procedures (p = 0.04, OR 0.26) was associated with lower risk of SSIs. Female sex (p = 0.02, OR = 3.49) was associated with an increased risk of SSIs; Gliadel wafer implants (p = 0.001, OR = 8.38) were associated with an increased risk of SSIs after procedures to treat tumors.

CONCLUSIONS

Operative factors such as the way the skin is prepared before the incision rather than the skin flora contaminants on the bone flaps may play an important role in the pathogenesis of SSIs after craniotomy/craniectomy. Gliadel wafers significantly increased the risk of SSI after procedures to treat tumors.

Surgical site infection associated with the use of bovine serum albumine-glutaraldehyde surgical adhesive (BioGlue) in cranial surgery: a case-control study

PURPOSE

To enhance the water tightness of dura mater closure in cranial surgery, an organic glue called BioGlue was used in our neurosurgical department between January 2006 and June 2007. During this period of time, we noticed an important increase in the surgical site infection (SSI) incidence. We conducted a case-control study to identify risk factors for these infections. Our objective was to test the hypothesis that BioGlue was one of the risk factors.

METHODS

Cases with infection were defined retrospectively. We included two controls per case. Study data were age, sex, time of year, in stay hospital preoperative time, length of surgery, type of surgery, surgeon, use of BioGlue, and use of duraplasty. We first performed a univariate analysis and then the significant variables were introduced in a logistic regression model.

RESULTS

Thirty patients were defined as cases (60 controls). In multivariate analysis, risk factors were young age (p = 0.04), extended operative length (p = 0.02) and the use of BioGlue (p = 0.007). The combined use of BioGlue and Neuropatch appeared to be a significant risk factor for SSI (p = 0.002).

CONCLUSIONS

BioGlue seems to increase the risk of SSI for patients who underwent craniotomy, especially when associated with synthetic dural graft. BioGlue triggers an intense inflammatory response, which causes wound breaches allowing bacteria to spread down in the wound, and then creates an ideal environment for bacterial growth.

SURGICAL SITE INFECTIONS AFTER ELECTIVE NEUROSURGERY

OBJECTIVE

To evaluate the incidence and risk factors of postsurgical site infections (SSIs) in elective neurosurgical procedures in patients treated with an ultrashort antibiotic protocol.

METHODS

In this consecutive series of 1747 patients treated with elective neurosurgery and ultrashort prophylactic antibiotic therapy at the Fondazione Istituto Nazionale Neurologico “Carlo Besta” in Milan, the rate of SSIs was 0.7% (13 patients). When only clean neurosurgery was considered, there were 11 such SSIs (1.52%) in 726 craniotomies and one SSI (0.15) in 663 spinal operations. The antibiotic protocol was prolonged in every case of external communication as cerebrospinal fluid leaks or external drainages.

RESULTS

The infection rate of the whole series was low (0.72%), and a risk factor identified for SSIs in clean neurosurgery was longer surgery duration. The relative risk estimate was 12.6 for surgeries lasting 2 hours and 24.3 for surgeries lasting 3 or more hours. Patients aged older than 50 years had a lower risk of developing SSI with a relative risk of 0.23 when compared with patients aged younger than 50 years.

CONCLUSION

The present series reports a low incidence of SSIs for elective neurosurgery, even for high-risk complex craniotomies performed for tumor removal. Given that an antibiotic protocol prolongation was used to pretreat any early signs of infection and external communication, the protocol was appropriate for the case mix. The two identified risk factors (surgical duration &gt; 2 hours and middle-aged patients [16–50 yr]) may be indicators of other factors, such as the level of surgical complexity and poor neurological outcome.

Risk factors for surgical site infections in neurosurgery patients with antibiotic prophylaxis

BACKGROUND

This prospective study aimed to determine the spectrum and the main risk factors of surgical site infection (SSI) after neurosurgical procedures in our clinic.

METHODS

Consecutive patients undergoing neurosurgery between November 1, 2001, and November 1, 2002, were recruited for the study. All patients were followed for a minimum of 2 weeks postoperatively and all SSIs were recorded. The complete medical records of each case were reviewed, and data on 14 possible risk factors were extracted. Statistical analyses were performed to identify the risk factors for SSIs.

RESULTS

A total of 31 postoperative SSIs were identified among 503 cases included in the study, with a resulting overall infection rate of 6.2%. The risk of SSI was increased by age (odds ratio [OR], 1.1; 95% confidence interval [CI], 1.0-1.1; P = .039), operation type such as "shunt operations" (OR, 670.4; 95% CI, 2.6-171123.1; P = .021), presence of foreign body (OR, 141.0; 95% CI, 2.5-7925.9; P = .016), presence of diabetes mellitus (OR, 24.3; 95% CI, 2.1-284.9; P = .011), and intracranial pressure monitoring (OR, 4878.9; 95% CI, 23.8-1001229; P = .002). The predominantly isolated microorganisms in patients with SSIs were Staphylococcus aureus (22 [71.0%]), Acinetobacter baumanii (5 [16.1%]), and Staphylococcus epidermidis (4 [12.9%]).

CONCLUSIONS

SSIs remain an important problem in neurosurgery. Identification of the risk factors for SSI will help physicians to improve patient care and may decrease mortality, morbidity, and health care costs of neurosurgery patients.

Comparison of Traditional and Disposable Bed Baths in Critically Ill Patients

• Background For bedridden patients unable to perform personal hygiene measures because of acute illness or chronic debilitation, the bed bath, with either the traditional basin or, more recently, disposable baths, has long been a measure for improving hygiene and comfort.

• Objective To compare the traditional basin bed bath with a prepackaged disposable bed bath in terms of 4 outcomes: time and quality of bath, microbial counts on the skin, nurses’ satisfaction, and costs.

• Methods Forty patients in surgical, medical, or cardiothoracic intensive care units received both types of bath on different days. Baths were observed, timed, and scored for quality. Cultures of the periumbilicus and groin were obtained before and after each bath. At the end of the study, nurses were interviewed about their preferences.

• Results Neither total quality scores nor microbial counts differed significantly between the 2 bath types. Significantly fewer products (P &lt; .001) and less time were used, cost was lower, and nurses’ ratings were significantly better with the disposable bath.

• Conclusion The disposable bath is a desirable form of bathing for patients who are unable to bathe themselves in critical care and long-term care settings, and it may even be preferable to the traditional basin bath.

Risk factors for spinal surgical-site infections in a community hospital: a case-control study

OBJECTIVE

To characterize risk factors for surgical-site infection after spinal surgery.

DESIGN

A case-control study.

SETTING

A 113-bed community hospital.

METHOD

From January 1998 through June 2000, the incidence of surgical-site infection in patients undergoing laminectomy, spinal fusion surgery, or both increased at community hospital A. We compared 13 patients who acquired surgical-site infections after laminectomy, spinal fusion surgery, or both with 47 patients who were operated on during the same time period but did not acquire a surgical-site infection. Information collected included demographics, risk factors, personnel involved in the operations, length of hospital stay, and hospital costs.

RESULTS

Of 13 case-patients, 9 (69%) were obese, 9 (69%) had spinal compression, 5 (38.5%) had a history of tobacco use, and 4 (31%) had diabetes. Oxacillin-sensitive Staphylococcus aureus (6 of 13; 46%) was the most common organism isolated. Significant risk factors for postoperative spinal surgical-site infection were dural tear during the surgical procedure and the use of glue to cement the dural patch (3 of 13 [23%] vs 1 of 47 [2.1%]; P = .02) and American Society of Anesthesiologists risk class of 3 or more (6 of 13 [46.2%] vs 7 of 47 [15%]; P = .02). Case-patients were more likely to have prolonged length of stay (median, 16 vs 4 days; P< .001). The average excess length of stay was 11 days and the excess cost per case was $12,477.

CONCLUSION

Dural tear and the use of glue should be evaluated as potential risk factors for spinal surgical-site infection. Systematic observation for potential lapses in sterile technique and surgical processes that may increase the risk of infection may help prevent spinal surgical-site infection.