28 The effect of the number of operating room door openings on surgical site infection risk: an individual patient data meta-analysis

Preliminary studies that analyzed surrogate markers have suggested that operating room (OR) door openings may be a risk factor for surgical site infection (SSI). We therefore aimed to estimate the effect of OR door openings on SSI risk in patients undergoing cardiac surgery. This prospective, observational study involved consecutive patients undergoing cardiac surgery in 2 prespecified ORs equipped with automatic door-counting devices from June 2016 to October 2017. Occurrence of an SSI within 30 days after cardiac surgery was our primary outcome measure. Respective outcome data were obtained from a national SSI surveillance cohort. We analyzed the relationship between mean OR door opening frequencies and SSI risk by use of uni- and multivariable Cox regression models. A total of 301 594 OR door openings were recorded during the study period, with 87 676 eligible door openings being logged between incision and skin closure. There were 688 patients included in the study, of whom 24 (3.5%) developed an SSI within 30 days after surgery. In uni- and multivariable analysis, an increased mean door opening frequency during cardiac surgery was associated with higher risk for consecutive SSI (adjusted hazard ratio per 5-unit increment, 1.49; 95% confidence interval, 1.11-2.00; P = .008). The observed effect was driven by internal OR door openings toward the clean instrument preparation room. Frequent door openings during cardiac surgery were independently associated with an increased risk for SSI. This finding warrants further study to establish a potentially causal relationship between OR door openings and the occurrence of SSI.

The effect of door openings in the operating room on surgical site infections remains a controversial topic and has led to strict door-opening policies. The aim of this individual-patient data meta-analysis was to evaluate the effect of the number of door openings in the operating room on surgical site infection. MEDLINE (PubMed) and Embase (Ovid) were searched up to 2 December 2024. Authors with individual-patient data on surgical site infections and door openings were invited to collaborate. A one-stage individual-patient data meta-analysis accounting for heterogeneity was performed to examine effects overall and in subgroup analyses (wound class, implant surgery, and income level). The primary outcome was surgical site infection. The risk of bias and Grading of Recommendations, Assessment, Development, and Evaluation framework were used to determine the certainty of evidence. Individual-patient data from 8 observational studies, encompassing 4412 patients, revealed a 6.0% incidence of surgical site infection. Each extra door opening per hour was associated with increased risk of surgical site infection (odds ratio 1.012, 95% c.i. 1.005 to 1.019; τ2 = 0.095; very low certainty of evidence). This means that, for example, at a baseline infection risk of 2%, approximately 35 additional door openings per hour per surgery would be needed to cause one additional surgical site infection per 100 patients. In subgroup analyses, no differences in effect were found. The cumulative effect was more pronounced in patients with a high baseline risk of surgical site infection. Very low certainty of evidence suggests a marginal increase in the risk of surgical site infection for each additional door opening per hour. Although the relative effect is minimal, the cumulative effect has an impact on patients with a higher baseline surgical site infection risk more than others. However, the certainty of the available evidence is too low and the relative effect on clinical outcomes too small to support a rigorous zero door-openings policy to reduce rates of surgical site infections.

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Background: Various studies have linked periods of warmer temperatures to an increased occurrence of surgical site infections (SSIs) and healthcare-associated infections in general. In an observational study, we sought to determine the pathogens for which this association was especially strong. Method: Patient- and procedure-related data of the SSI-module of the German nosocomial infection surveillance system were linked with monthly aggregated meteorological data from the German Meteorological Service for a period from 2000 to 2016. Due to high correlation with other meteorological parameters, analyses were executed focusing on the outside ambient temperature. Temperature was regarded as both a continuous variable and a categorical variable with different temperature intervals (5°C steps ranging from <5°C to ≥20°C). Through multivariable logistic regression analysis, adjusted odds ratios (OR) with 95% confidence intervals were calculated for SSI rates relating to temperature. SSIs were stratified by pathogen and depth of infiltration. Result: Altogether, 2,004,793 procedures, conducted in 1,455 German surgical departments and resulting in 32,118 SSIs, were included. A general association of warmer mean temperatures in the month of surgery with an increased SSI-risk was observed, particularly for SSIs caused by gram-negative pathogens. Stratification by pathogen revealed that the association was especially prominent for Acinetobacter spp, Pseudomonas aeruginosa, and certain Enterobacteriaceae. Per additional 1°C, we observed a 6% increase in the risk for SSIs caused by Acinetobacter spp (OR, 1.06; 95% CI, 1.04–1.09), and a 4% increase in the risk for SSIs caused by Enterobacter spp (OR, 1.04; 95% CI, 1.03–1.05). Among gram-positive pathogens, temperature-association was strongest for Staphylococcus aureus. Superficial SSIs showed a higher temperature-association than deeper SSIs. The risk for superficial SSIs with Acinetobacter spp significantly increased >10-fold after surgeries conducted in months with a mean temperature of ≥20°C in reference to <5°C. For Pseudomonas aeruginosa, we observed a >2-fold statistically significant increase in the risk for superficial SSIs, when comparing the same temperature categories (≥20°C vs <5°C). Conclusions: Our study demonstrated that higher temperatures were associated with increased SSI-rates caused by gram-negative bacteria. As a consequence, future SSI-prevention measures should place a higher emphasis on the parameter season as part of a more tailormade, personalized approach at infection prevention. For instance, it may be conceivable to seasonally adjust decolonizing regimes and certain prophylaxes. Underlying shifts in microbiome composition due to meteorological factors should be considered in further analyses. Given the expected rise of global temperatures until the end of the century, the topic gains relevance from multiple perspectives.Funding: NoneDisclosures: None

Background: Surgical site infections (SSIs) are among the most common postoperative complications. Environmental factors, including intraoperative traffic and door openings in the operating room (OR), have been identified as critical contributors to microbial air contamination. Nurses play a pivotal role in managing these factors, directly influencing infection control practices. Methods: An integrative review was conducted to synthesize current evidence on the association between intraoperative traffic, door openings, and SSIs. A structured methodology was employed to identify, assess, and analyze the existing literature, with a specific focus on the nursing role in infection prevention. Results: Findings from a single-center prospective cohort study indicate that ORs with more than 10 personnel present exhibit a threefold increase in SSI risk [Relative Risk (RR) = 3.12; 95% Confidence Interval (CI): 0.71–13.66] compared to ORs with fewer personnel. Additionally, every five door openings per procedure were associated with a significant increase in SSI incidence [Hazard Ratio (HR) = 2.00; 95% CI: 1.24–3.20, p = 0.005]. Conclusions: These findings underscore the importance of strict protocols to limit intraoperative traffic and unnecessary OR access. A multidisciplinary approach plays a crucial role in ensuring surgical safety and preventing SSIs by regulating OR access and adhering to infection control best practices.

Surgical site infections are common postoperative complications. Some operating rooms have open-floor drainage systems for fluid disposal during endourologic cases, although nonendoscopy cases are not always allowed in these rooms. We hypothesized that operating rooms with open-floor drainage systems would not materially affect risk of surgical site infections for patients undergoing open and laparoscopic procedures. Patients who had surgical site infections from 2016 through 2020 were identified from data of the National Surgical Quality Improvement Program. Patients without surgical incisions, with open wounds, and with surgical site infections at surgery were excluded. The primary outcome was surgical site infection occurrence within 30 days of surgery. Multilevel multivariable logistic regression was used to estimate the observed-to-expected surgical site infection ratio for each operating room (2 with and 23 without open-floor drainage systems). We identified 8,419 surgical cases, of which 802 (9.5%) were performed in operating rooms with open-floor drainage systems; 166 patients (2.0%) had surgical site infections. Of the surgical site infections, 7 (4.2%) occurred in operating rooms with open-floor drainage systems. Surgical specialty, American Society of Anesthesiologists physical status, higher case acuity, dyspnea, immunosuppression, longer surgical duration, and wound classification were associated with surgical site infections (P < .05 for all). The observed-to-expected ratios of surgical site infections occurring in the 2 operating rooms with open-floor drainage systems were 0.85 and 1.15. The odds ratio of surgical site infections for urologic cases performed in room with vs without open-floor drainage systems was 1.30 (P = .65). Urology operating room designs often include open-floor drainage systems for water-based cases. These drainage systems were not associated with an increased risk of surgical site infections.

IntroductionIncisional surgical site infection is an important cause of postoperative morbidity which results in extended hospital stay and may result in future incisional hernia. We intended to evaluate the thickness of subcutaneous fat with a cut-off value of 2.5cm as a risk factor in causing surgical site infection using a simple, cost-effective, and direct intraoperative method for measuring subcutaneous fat thickness.MethodsA total of 147 patients who underwent abdominal surgeries from September 2017 to April 2019 were included in this prospective study. A proforma was used to collect information of all patients regarding various variables. Abdominal subcutaneous fat thickness was measured in the supine position intraoperatively with a measuring scale from below dermis to rectus sheath at 1cm caudal to umbilicus level.ResultsThe study's overall incidence of incisional surgical site infection (SSI) in laparotomy surgeries was 10.8%. Subcutaneous fat thickness was independently associated with incisional SSI. Subcutaneous fat thickness association with SSI was more statistically significant than that of BMI. The other associated risk factors were found to be obesity, diabetes, and emergency surgery.ConclusionOur results suggest that the risk of incisional SSI increases with the increased subcutaneous fat thickness of more than 2.5cm. Placement of subcutaneous drain in patients undergoing laparotomy with increased subcutaneous fat thickness plays a significant role in reducing the incidence of surgical site infection. Risk of SSI increases in obesity, diabetes, increased age group, dirty surgery, and emergency surgeries. Subcutaneous fat thickness is an independent risk factor for surgical site infection and subcutaneous drain decreases the risk of SSI in thick subcutaneous fat.

To evaluate the effect of intraoperative wound protectors on the risk of surgical site infection (SSI) in patients undergoing pancreatoduodenectomy. In compliance with PRISMA statement standards, electronic databases were searched to identify all studies comparing wound protector use with no wound protector use in patients undergoing pancreatoduodenectomy. SSI (superficial or deep) was considered primary outcome measure. The secondary outcome measures included superficial SSI, deep SSI, and organ-space SSI. Random effects modelling was applied to calculate pooled outcome data. The certainty of evidence was assessed using GRADE system. A total of 12159 patients from four studies were included. The included populations in both groups were comparable in terms of baseline characteristics. The use of wound protector was associated with lower risk of superficial or deep SSI (OR: 0.55, 95% CI 0.43-0.70, P<0.00001), superficial SSI (OR: 0.59, 95% CI 0.46-0.76, P<0.0001), and organ-space SSI (OR: 0.80, 95% CI 0.72-0.90, P=0.0002). There was no difference between the two groups in terms of the risk of deep SSI (OR: 0.68, 95% CI 0.43-1.06, P=0.09) although this may be subject to type 2 error. The results of current study suggests that the use of intraoperative wound protector during pancreatoduodenectomy may reduce the risk of postoperative SSI. The quality of the available evidence is moderate with high certainty. While evidence from future randomised controlled trials could increase the robustness of our conclusions, we do not hesitate to recommend the use of wound protectors during pancreatoduodenectomy based on the current evidence.

Nasal colonization of Staphylococcus aureus and the risk of surgical site infection after spine surgery: a meta-analysis

This study aimed to evaluate whether the implementation of extra perioperative safety measures and precautions through adopted standard operating procedures (SOPs) to ensure optimal anti-microbial conditions has led to less surgical site infections (SSI) after alloplastic breast reconstruction (BR). This retrospective study compared two Cohorts of patients treated before and after the implementation of new SOPs (2009-2014: Cohort 1 versus 2014-2019: Cohort 2). Multivariate logistic regression analyses, adjusting for patient confounders, were implemented to compare SSI incidence between both Cohorts. Overall, SSI incidence was equal in both groups (10%, p=0.545). The incidence of deep SSI was 9% for Cohort 1 and 5% for Cohort 2 (p=0.074). Incidence of SSI-related explantation was 8% and 5%, respectively (p=0.136). After adjusting for patient confounders, no statistically significant difference was seen between both Cohorts in overall SSI, deep SSI incidence, and explantation due to SSI (ORadjusted: -0.31, p=0.452, ORadjusted: 0.16, p=0.747 and ORadjusted: 0.18, p=0.712). Higher BMI, smoking, one-stage BR, and immediate BR were associated with the risk for SSI (p<0.001, p=0.036, p<0.001, and p=0.022, respectively). Extra safety measures to assure optimal anti-microbial conditions did not contribute to lower SSI incidence or SSI-related explantation after alloplastic BR. Confounders such as BMI, smoking, immediate BR, and one-stage BR were correlated to an increased risk for overall SSI, deep SSI, and SSI-related explantation of TE/implants.

IN this issue of Anesthesiology, Stæhr et al. 1report the lack of effect of perioperative hyperoxia on preventing surgical site infection (SSI) in obese patients undergoing laparotomy. The study was a secondary analysis of data from the PROXI Trial, a Danish multicenter study of 1,400 patients undergoing elective or emergency laparotomy who were randomized to receive a 30% or 80% oxygen concentration intraoperatively and for the first 2 h after surgery.2Although no significant reduction in the frequency of SSI was observed in the high-concentration group in that trial, it was hypothesized that the results for the subpopulation of 213 obese patients (body mass index ≥30 kg/m2, 15% of the sample) might be different. However, on reanalysis the researchers again found no significant differences in the rates of SSI or pulmonary complications.Surgical site infection, which accounts for 15–20% of all healthcare-associated infections, is the second most common preventable adverse outcome of major surgery.3The incidence of SSI, which differs according to surgical procedure, is highest for gastrointestinal interventions.4If we are to decrease the SSI rates in the various surgical settings and attenuate the consequences, it will be necessary to identify risk factors as a first step. Age, duration of surgery, hypoalbuminemia, obesity, diabetes mellitus, and a history of chronic obstructive pulmonary disease are some of the predictors that have been linked with SSI.4,5Obesity is associated with a higher incidence of SSI.6Glance et al. 7recently studied a population of 310,208 patients in the American College of Surgeons National Surgical Quality Improvement Program database, more than 95,000 of whom were overweight. Obese and morbidly obese patients with metabolic syndrome (obesity, hypertension, and diabetes), who accounted for 19% of all the obese patients in the study, had higher risk of postoperative complications, including death and SSI, in comparison with normal-weight and obese patients without metabolic syndrome. In addition, percentage of body fat8and thickness of subcutaneous fat9have been shown to be better predictors of SSI than body mass index, suggesting that obesity is not a homogeneous clinical state and body mass index may be too simplistic a measure for this complex illness. In other words, individuals classified as obese may be more or less healthy and have different levels of risk.In recent years, interest has grown in identifying factors amenable to management to reduce the risk of SSI, and anesthesiologists may have partial control over some of them.3Measures such as the avoidance of hypothermia10and the careful timing and selection of antibiotics11seem to be effective in preventing SSI.The rationale for proposing hyperoxia as another manageable factor for preventing SSI is well established.3Neutrophils safeguard against infection through nonspecific phagocytosis and elimination of bacteria from wounds; the oxygen tension in subcutaneous tissue is critical for these functions. Tissue oxygen tension12and concentration13have been shown to predict SSI after colorectal surgery, and supplemental oxygen (e.g. , 80%) can double oxygen partial pressure in tissue.14In vitro studies have shown that hyperoxia exerts significant influence on multiple cellular and immune system parameters, improving the functional capacity of the innate immune response as reflected by increasing concentrations of reactive oxygen species, a major component of the bactericidal defense.15Adequate wound oxygen tension is also important in the development of collagen and epithelium required for healing.3Hyperoxia increases the availability of molecular oxygen to tissues by increasing oxygen dissolved in plasma and enhancing the driving force between capillary blood and cells.16Achieving a subcutaneous oxygen tension greater than 90 mmHg seems to protect against infection,12and at least 40 mmHg would be needed to support the leukocyte-mediated oxidative burst and collagen formation. Good capillary perfusion of tissue also determines cell oxygenation, and helpful actions that can be managed by anesthesiologists are fluid replacement and the avoidance of vasoconstriction triggered by activation of the sympathetic nervous system by hypothermia and pain.3However, all actions intended to increase cell oxygen tension can be offset if tissue perfusion is compromised (e.g. , in diabetes or peripheral vascular disease) or when the oxygen pressure gradient along the axial capillary drops rapidly.16The results of the clinical translation of this rationale, in controlled trials testing perioperative hyperoxia, have been mixed. Two randomized trials comparing 30% and 80% oxygen in a total of almost 800 patients undergoing colorectal surgery reported significant reductions in the rate of SSI.14,17A large trial to test the effect of nitrous oxide on events after major surgery indirectly compared high (80%) and low (30%) oxygen concentrations and found significantly fewer cases of SSI in patients breathing the high concentration.18In contrast, 165 patients undergoing major abdominal surgery, including laparoscopically assisted procedures, were randomized to breathe 35% or 80% oxygen, and no improvement in SSI outcome was observed.19Finally, the multicenter PROXI Trial likewise found no significant reduction in risk of SSI with hyperoxia; however, the study included many different elective and emergency surgical procedures, ranging from high-risk colorectal interventions (fewer than 50% of all patients) to cholecystectomies, appendectomies, and hernia repair.2This heterogeneity could partly explain the negative findings.The secondary analysis of data for the PROXI Trial's high-risk subgroup of obese patients in this issue1is therefore welcome. It was hypothesized that the subcutaneous oxygen tension might be reduced in this subpopulation because of their anatomic, histologic, functional, and immune status. We know that in obese patients tissue oxygen tension is significantly increased when 80% oxygen is given,20favoring the defense mechanisms against an SSI. However, the authors observed no reduction in the incidence of SSI. Two sampling characteristics could have created bias leading to this negative result. First, the mean body mass index of the obese patients in this trial was relatively low (33.5 kg/m2), and hypertension was present in fewer than half the patients, suggesting that a large proportion did not have metabolic syndrome and probably had less risk. Second, the patients had undergone a large variety of procedures, and only 45% were operations such as colorectal surgery, which is associated with high risk for SSI.Thus, the issue of a clinical role for hyperoxia remains unsettled. Should we routinely administer high oxygen concentration perioperatively in the hope of reducing the risk of SSI? This intervention is attractive because oxygen therapy does not significantly increase costs, and the potential benefits might be great. But SSIs develop as the result of very complex circumstances, and prevention does not appear to be possible by taking a single step because a variety of other surgical, anesthetic, functional, and immune factors also play important roles. Even genetic factors seem to increase risk for severe infections.21Our poor understanding of those factors probably explains the conflicting results of trials to date. The answer to the question posed above seems to be that hyperoxia should not be provided routinely and individualized clinical vigilance is essential. Probably in some patients who are theoretically at high risk of infection (e.g. , in colorectal surgery) but whose tissue perfusion is well preserved, hyperoxia with 80% oxygen concentration may be beneficial. Additional research with high-risk patients undergoing high-risk procedures is needed. New studies on general populations probably will yield negative results because the beneficial effect of hyperoxia by itself can be marginal, or at least not comparable to antibiotic prophylaxis.11Thus, to reduce risk of SSI, we would argue in favor of a multimodal approach, including several surgical and anesthetic factors amenable to management. In such an approach, hyperoxia might well be one of the tools to select.*Department of Anesthesiology and Postoperative Care, Hospital Universitari Germans Trias i Pujol, Barcelona, Spain. jcanet.germanstrias@gencat.cat. †Department of Anesthesia and Critical Care, Hospital Clínico Universitario, Valencia, Spain.

Surgical site infections (SSIs) following cesarean sections (CS) are significant contributors to maternal morbidity and healthcare burdens worldwide. Despite adherence to preoperative guidelines, certain risk factors remain associated with increased SSI rates. Identifying and addressing these factors is essential for improving patient outcomes. Objective: To identify and evaluate the risk factors associated with surgical site infection (SSI) following cesarean section (CS) based on the World Health Organization’s recommended preoperative measures in a tertiary care hospital in Mirpur, AJ &amp; K. Methods: A prospective cohort study was conducted from January 2022 to December 2023 at a tertiary care hospital in Mirpur, AJ&amp;K. A total of 1,500 patients undergoing cesarean sections were enrolled and followed for 30 days post-surgery to monitor for the occurrence of SSI. Data on potential risk factors, such as body mass index (BMI), diabetes, hypertension, preoperative antibiotic use, duration of surgery, type of cesarean section (elective vs. emergency), anemia, and personal hygiene practices, were collected at baseline. The primary outcome was the incidence of SSI, diagnosed according to the Centers for Disease Control and Prevention (CDC) criteria. Risk factors were compared between patients who developed SSI (cases) and those who did not (controls). Statistical analyses, including Chi-squared and Fisher’s Exact tests, were performed to identify significant risk factors. Multivariate logistic regression was used to control for confounding factors. Results: Out of the 1,500 patients, 18% (n=270) developed SSI within 30 days of surgery. Significant risk factors for SSI included obesity (BMI &gt;30), which increased the odds of SSI by 2.5 times (p=0.001); prolonged hospital stay of more than 5 days, associated with a 1.8-fold increase in SSI risk (p=0.004); emergency cesarean sections, which raised the risk by 2.1 times compared to elective procedures (p=0.002); and anemia (hemoglobin &lt;10 g/dL), which increased SSI risk by 1.9 times (p=0.005). Poor personal hygiene practices were also significantly associated with a higher incidence of SSI (p=0.003). On the other hand, the use of preoperative prophylactic antibiotics was protective, reducing the incidence of SSI by 3.2-fold (p=0.0001). No significant associations were observed between the duration of surgery (p=0.21) or patient age (p=0.15) and the occurrence of SSI. Conclusions: This prospective cohort study identified obesity, prolonged hospital stay, emergency cesarean section, anemia, and personal hygiene practices as significant risk factors for the development of SSI following cesarean section, consistent with the World Health Organization’s preoperative guidelines. The use of preoperative prophylactic antibiotics was shown to be an effective intervention in reducing SSI risk. These findings underscore the importance of targeted preventive measures, including weight management, prompt hospital discharge, enhanced personal hygiene education, and the routine use of prophylactic antibiotics, in reducing the burden of SSIs in cesarean sections.

Wound complications are known to occur after nipple-sparing mastectomy (NSM), especially in procedures involving a periareolar incision. We sought to determine the independent risk of infection and overall wound complications associated with NSM vs skin-sparing mastectomy (SSM) in a contemporary cohort of women undergoing immediate implant reconstruction. We identified 352 women 21 years of age or older undergoing mastectomy and immediate implant reconstruction from September 2021 to December 2022 using electronic health records from 2 hospitals. The relative risk (RR) of surgical site infection (SSI) and of serious wound complication (infection or noninfectious wound complication [NIWC; dehiscence or tissue necrosis] requiring surgical treatment in the operating room) within 180 days after surgery associated with NSM vs SSM was determined using a modified Poisson regression model, controlling for established risk factors for SSI. NSM was performed in 128 women (36.4%), most commonly via an inframammary fold incision (73.4%). SSI occurred in 49 (13.9%) women within 180 days after surgery, whereas 70 (19.9%) women developed an SSI or NIWC. Although the incidence of SSI and the composite SSI/NIWC outcomes was similar after NSM vs SSM (14.8% vs 13.4% and 21.1% vs 19.2%, respectively); in multivariable analysis, NSM was associated with increased risk of both SSI (RR 2.13, 95% CI 1.26 to 3.59) and SSI/NIWC (RR 2.19, 95% CI 1.40 to 3.43). NSM was associated with increased risk of both SSI and NIWCs requiring surgical treatment after controlling for other established risk factors, despite uncommon use in this cohort of a periaerolar incision. This information should be communicated to women at the time of presurgical counseling to facilitate shared decision-making.

Category: Midfoot/Forefoot Introduction/Purpose: Diabetes mellitus has been associated with an increased risk for postoperative surgical site infection (SSI) following foot and ankle surgery; however, among patients with diabetes, the level of perioperative glycemic control may affect the risk of postoperative SSI. There remains little evidence to support a perioperative hemoglobin A1c (HbA1c) level that could serve as a threshold for a significantly increased risk of postoperative SSI following foot surgery. The primary goal of the present study was to evaluate the association of perioperative glycemic control as demonstrated by hemoglobin a1c (HbA1c) in patients with diabetes with the incidence of postoperative SSI following elective foot surgery. Our secondary objective was to calculate a threshold level of HbA1c above which the risk of postoperative SSI after foot surgery increases significantly in patients with diabetes. Methods: A national administrative database was queried for patients who underwent common elective foot surgeries, including hallux valgus corrections, hallux rigidus correction and hammertoe corrections among others. Patients who underwent more complex procedures and patients with concomitant hindfoot procedures were excluded. Patients with diabetes mellitus who had a perioperative HbA1c level recorded within 3 months of surgery were identified; and were then stratified into thirteen mutually exclusive groups based on their hemoglobin a1c in 0.5 mg/dl increments from &lt; 5.49 mg/dl to &gt; 11.5 mg/dl. The incidence of SSI was determined by either a diagnosis or procedure for SSI within 1 year postoperatively using CPT and ICD-9 codes, and was calculated for each HbA1c patient group. A receiver operating characteristic (ROC) analysis was performed to determine an optimal threshold value of the HbA1c above which the risk of postoperative SSI was significantly increased. Results: 4,744 patients who underwent forefoot surgery with diabetes and a perioperative HbA1c recorded within 3 months of surgery in the database were included in the study. The rate of deep SSI requiring irrigation and debridement within one year postoperatively stratified by HbA1c is pictured in Figure 1, which ranged from a low of 2.5% to a high of 11.8% and was significantly correlated with increasing HbA1c levels (P &lt; 0.0001). The results of ROC analysis determined that the inflection point of the ROC curve corresponded to an HbA1c level above 7.5 mg/dL (P &lt; 0.0001, AUC = 0.622, spec. = 75%, sens. = 44%). Conclusion: The risk of postoperative SSI following elective foot surgery in patients with diabetes mellitus increases significantly as the perioperative HbA1c increases. ROC analysis determined that a perioperative HbA1c above 7.5 mg/dL could serve as a threshold for a significantly increased risk of postoperative SSI following elective foot surgery.

Incisional surgical site infection following cesarean section: A national retrospective cohort study