Is there a role of calprotectin testing in the diagnosis of surgical site infections after total hip and knee arthroplasty? A preliminary study.

BACKGROUND: Recent studies have revealed the usefulness of synovial calprotectin (CLP) in diagnosing chronic periprosthetic joint infections (PJIs). However, there is still a lack of evidence to support the use of serum CLP in the diagnosis of early PJIs and surgical site infections (SSIs) after total joint arthroplasties (TJAs). OBJECTIVES: The primary aim of this study is to investigate the standard kinetics of CLP concentrations in the blood during the very early postoperative period after non-complicated total hip arthroplasty (THA) and total knee arthroplasty (TKA). The secondary aim was to perform a preliminary comparison of CLP concentrations between non-infected patients and patients with recognized SSIs. MATERIAL AND METHODS: A total of 64 consecutive patients who underwent primary THA and TKA were included in this prospective research. Sixty patients (30 THA and 30 TKA) were scheduled to determine the standard shape of the blood CLP curve and the expected concentrations during the first 5 postoperative days after non-complicated TJAs. In 4 additonal patients, early SSI was confirmed, and they were included in a separate SSI subgroup. RESULTS: Calprotectin demonstrated a linear increase during the first 5 postoperative days. Statistically significant differences in CLP concentrations between non-infected cases and SSIs were not observed. The preoperative median results with interquartile range (Q1-Q3) were 0.52 (0.39-0.64) mg/dL and 0.5 (0.47-0.52) mg/dL (p = 0.77), while post operation they were as follows: on postoperative day 1: 0.88 (0.53-1.3) mg/dL and 0.86 (0.62-1.1) mg/dL (p = 0.84), on postoperative day 3: 1.77 (1.29-2.08) mg/dL and 1.85 (1.70-1.95) mg/dL (p = 0.72), and on postoperative day 5: 2.32 (1.79-2.67) mg/dL and 2.56 (2.25-2.83) mg/dL (p = 0.55), respectively. CONCLUSION: Serial CLP measurements during the early postoperative period revealed a linear (statistically significant) increase in concentration to postoperative day 5 without an evident point of decrease. A significant difference in median values and the course of curve patterns between the non-complicated and SSI groups was not observed.

Inflammatory biomarkers to predict postoperative infectious complications after cytoreductive surgery and HIPEC for peritoneal carcinomatosis.

BACKGROUND: Early detection of postoperative infectious complications (IC) is crucial after Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC). The aim of this study was to evaluate the predictive role of early postoperative inflammatory biomarkers level for the detection of postoperative IC. METHODS: a retrospective study was performed including 199 patients treated with complete CRS/HIPEC for PC from various primary origins from September 2012 to January 2021. Patients were monitored by a routine measurement of inflammatory biomarkers (CRP, leukocytes, neutrophils, lymphocytes, neutrophile-to-lymphocyte ratio and platelets-to-lymphocyte ratio). Inflammatory biomarkers were compared between patients with vs without IC. RESULTS: IC occurred for 68 patients (34.2%). CRP values were significantly higher in patients with IC on POD 3, 5 and 7 (CRP = 166 mg/L [128-244], 155 mg/L [102-222] and 207 mg/L [135-259], respectively). The CRP on POD7, with a cut-off value of 100 mg/L, was an excellent predictor of postoperative IC (AUC = 90.1%). The CRP on POD 5, with a cut-off value of 90 mg/L, was a good predictor of postoperative IC (AUC = 83.2%). NLR values were significantly higher in patients with IC on POD 3, 5 and 7. NLR on POD 5 and 7 higher than 9.7 and 6.3, respectively, were fair predictors (AUC = 70.8 and 79.6, respectively). CONCLUSION: CRP levels between POD3 and 7 are the best predictors of postoperative IC after CRS/HIPEC. The presence of postoperative IC should be suspected in patients with CRP higher than 140 mg/L, 90 mg/L or 100 mg/L on PODs 3, 5 or 7.

The incidence of incision infections after lumbar fusion and the significance of dynamically monitoring serum albumin and C-reactive protein levels.

BACKGROUND: To explore the incidence of incision infections and dynamically monitor albumin (ALB) and C-reactive protein (CRP) levels after lumbar fusion. METHODS: A total of 1,773 patients undergoing lumbar fusion in our hospital from March 2011 to March 2021 were selected and divided into the infection group and the non-infection group according to whether incision infections occurred postoperatively. The incidence of postoperative incision infections, the pathogenic characteristics and drug resistance of the pathogenic bacteria in patients in the infection group were analyzed. The general clinical data, serum ALB and CRP levels at different time points were compared between the two groups of patients, and the correlation between ALB and CRP levels was analyzed. ROC curve was used to evaluate the predictive value of serum ALB and CRP levels on the incidence of postoperative incision infections. RESULTS: Of the 1,773 patients, 41 (2.31%) experienced postoperative incision infections. A total of 57 pathogens were detected, including 36 gram-negative bacteria (63.16%), 18 gram-positive bacteria (31.58%), and 3 fungi (5.26%). Among gram-negative bacteria, Pseudomonas aeruginosa had the highest resistance to ampicillin. Among gram-positive bacteria, Staphylococcus aureus had the highest resistance to penicillin and erythromycin. The age, BMI, the number of diabetes patients, levels of serum tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and procalcitonin (PCT) IL-8 at 1 d after operation in the infection group were significantly higher than those in the non-infection group (P<0.05). The serum ALB and CRP levels of the two groups differed over time, and the differences were statistically significant in terms of time, inter-group, time and inter-group interaction factors (P<0.05). Correlation analysis showed that ALB was significantly negatively correlated with CRP expression. Receiver operating characteristic (ROC) curve analysis showed that the area under the curve (AUC) value of combined ALB and CRP detection was 0.856, which was significantly higher than that of single detection with ALB or CRP (P<0.05). CONCLUSIONS: Gram-negative bacterial infection was the main type of incision infection in patients after lumbar fusion. The changes in ALB and CRP levels were related to the incidence of postoperative incision infections.

Interleukin-6 versus Common Inflammatory Biomarkers for Diagnosing Fracture-Related Infection: Utility and Potential Influencing Factors.

Currently, the utility of white blood cell count (WBC), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP), for diagnosis of fracture-related infection (FRI), is still controversial, and potential efficiency of interleukin-6 (IL-6) as a novel cytokine in assisted diagnosis of FRI remains unclear. This study is aimed at investigating the utility and potential influencing factors of IL-6 and the common biomarkers for diagnosing FRI. Preoperative serological levels of IL-6 and the three biomarkers were compared between 407 FRI patients and 195 fracture-healed (FH) patients. Diagnostic efficiency of the indicators was evaluated using the areas under the receiver operating characteristic (ROC) curves, and their potential influencing factors were also analyzed. Outcomes showed that the median levels of all of the four biomarkers were significantly higher among the FRI patients than those among the FH patients (P < 0.01). The areas below the ROC curves of ESR, CRP, and IL-6 were 76.5%, 76.4%, and 71.8%, respectively, with WBC of only 56.9%. Compared with ESR and CRP, IL-6 displayed a lower sensitivity (ESR vs. CRP vs. IL - 6 = 72.7% vs. 65.6% vs. 57.5%) but a higher specificity (ESR vs. CRP vs. IL - 6 = 70.3% vs. 75.4% vs. 83.6%). Serological IL-6 level was influenced by pathogen culture result and pathogen number; nonetheless, bacteria type appeared to have no influence on the levels of the four biomarkers. In short, this study displayed similar value of IL-6 with that of ESR and CRP in assisted diagnosis of FRI. Whether IL-6 can be regarded as a promising diagnostic indicator requires more studies.

C-reactive protein after major abdominal surgery in daily practice.

BACKGROUND: Infectious complications are frequently encountered after abdominal surgery. Early recognition, diagnosis, and subsequent timely treatment is the single most important denominator of postoperative outcome. This study prospectively addressed the predictive value of routine assessment of C-reactive protein levels as an early marker for infectious complications after major abdominal surgery. METHODS: Consecutive patients undergoing major abdominal surgery between November 2015 and November 2019 were prospectively enrolled. Routine C-reactive protein measurements were implemented on postoperative days 3, 4, and 5, and additional computed tomography examinations were performed on demand. The primary endpoint was the occurrence of Clavien-Dindo grade III or higher infectious complications. RESULTS: Of 350 patients, 71 (20.3%) experienced a major infectious complication, and median time to diagnosis was 7 days. C-reactive protein levels were significantly higher in patients with major infectious complications compared to minor or no infectious complications. The optimal cut-off was calculated for each postoperative day, being 175 mg/L on day 3, 130 mg/L on day 4, and 144 mg/L on day 5, and corresponding sensitivities, specificities, and positive and negative predictive values were over 80%, 65%, 40%, and 92% respectively. Alternative safe discharge cut-offs were calculated at 105 mg/L, 71 mg/L and 63 mg/L on days 3, 4, and 5, respectively, each having a negative predictive value of over 97%. CONCLUSION: The C-reactive protein cut-offs provided in this study can be used as a discharge criterion or to select patients that might require an invasive intervention due to infectious complications. These diagnostic criteria can easily be implemented in daily surgical practice.

Pre-surgical peripheral blood inflammation markers predict surgical site infection following mesh repair of groin hernia.

ABSTRACT: Surgical site infection (SSI) is a costly postoperative complication with a decrease in the quality of life. We aimed to probe the predictive role of peripheral blood inflammation markers for SSI following mesh repair of groin hernia (GH).This retrospective study assessed the data of 1177 patients undergoing elective mesh repair of GH (open/laparoscopy) in the absence of antibiotic prophylaxis. The relation between demographics, surgical factors, pre-surgical laboratory results and the occurrence of SSI were investigated by univariate and multivariate analyses. Receiver operating characteristic analysis was performed to determine the optimal threshold of parameters and compare their veracity.The overall SSI rate was 3.2% with 1-year follow-up (38 superficial and 1 deep SSI). Patients with SSI had significant higher pre-surgical neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) than those without (P = .029 and P = .045, respectively); their NLR and PLR correlated positively with postoperative total days of antibiotic treatment for SSI (r = .689, P = .000; r = .493, P = .001; respectively). NLR and PLR had larger areas under the receiver operating characteristics curves than neutrophil (.875 vs. .601; P = .000; .726 vs. .601; P = .017). The combination of PLR and neutrophil/NLR raised the predictive sensitivity of PLR for SSI (sensitivity: PLR: 74.36%; PLR + neutrophil: 82.05%; PLR + NLR: 83.57%). On multivariate analyses, higher preoperative NLR (cut-off 2.44) and PLR (cut-off 125.42) were independent predictors for SSI.Higher pre-surgical NLR and PLR may be valuable predictors for SSI following elective mesh repair of GH.

Early Predictive Value of Procalcitonin for the Diagnosis of Pulmonary Infections after Off-pump Coronary Artery Bypass Grafting.

BACKGROUND: Cardiac surgery can cause similar inflammatory reactions with infection; antibacterial treatment may be inappropriately used. Early and accurate diagnosis of infection still is a difficult problem worldwide. Procalcitonin (PCT) helps to identify sepsis caused by bacterial infections. However, its application in the diagnosis of pulmonary infections after off-pump coronary artery bypass grafting (OPCABG) has not been well studied. We investigated the early predictive value of PCT for the diagnosis of pulmonary infections after OPCABG. METHODS: We retrospectively analyzed the clinical data, including conditions in the intensive care unit, postoperative complications, mortality rate, plasma PCT in the morning on the first postoperative day, routine white blood cell (WBC) count, and high-sensitivity C-reactive protein (hs-CRP) levels of patients who underwent elective OPCABG. Patients were divided into an infection group and a noninfection group, according to the occurrence of pulmonary infections. A receiver operating characteristic (ROC) curve was used to analyze the predictive value of PCT for the diagnosis of postsurgical infections. RESULTS: In total, 131 patients who underwent OPCABG were included, of whom 23 (17.6%) developed pulmonary infections. The plasma PCT level significantly was higher in the infection group than in the noninfection group (6.0 ± 6.3 ng/ml vs. 2.0 ± 2.2 ng/ml, P = 0.007). WBC and hs-CRP values were not significantly different between the infection group and the noninfection group (12.3 ± 3.9×109/L vs. 11.1 ± 2.8×109/L, P = 0.171 and 12.4 ± 0.7 mg/L vs. 12.4 ± 0.8 mg/L, P = 0.903, respectively). The area under the ROC for predicting pulmonary infections after OPCABG by plasma PCT was 0.783 (P < 0.001, with a 95% confidence interval of 0.674-0.893), with a cut-off value of 3.55 ng/ml, a sensitivity of 0.609, and a specificity of 0.861. CONCLUSION: From our study results, we postulate that PCT has a high early predictive value for the diagnosis of pulmonary infections after OPCABG.

Interleukin-6 as inflammatory marker of surgical site infection following spinal surgery.

BACKGROUND: In order to elucidate whether serum inflammatory markers identify patients with local surgical site infection(SSI) as underlying disease for recurrent or new symptomatology following spine surgery, we evaluated the diagnostic potential of interleukin-6(IL-6) as a marker of SSI. The diagnostic significance of IL-6 was compared to the standard serum inflammatory markers C-reactive protein(CRP) and white blood cell count (WBCC). METHOD: Ninety-eight consecutive patients with readmission due to recurrent or new symptomology after spinal surgery of degenerative spine disorders entered the study. Baseline patients' characteristics and the abovementioned inflammatory markers were collected, and arithmetical means with standard deviation, area under the curve (AUC), thresholds, sensitivity, specificity, positive(+)likelihood ratio (LR), and negative(-)LR with corresponding 95% confidence interval(95%CI) were calculated and correlated with presence or absence of SSI. RESULTS: Nine patients suffered from a SSI, whereas the remaining 89 patients had a recurrent/adjacent-segment degenerative disorder without evidence of infection. The most significant parameter for diagnosing a SSI was serum IL-6 (cut-off value > 15.3 pg/ml, AUC = 0.954, SE = 85.7%, SP = 97.3%), followed by CRP (cut-off value = 0.8 mg/dl, AUC = 0.916, SE = 88.9%, SP = 84.5%) CONCLUSIONS: In the case of recurrent or new symptomatology following spinal surgery, serum IL-6 has the highest diagnostic potential for diagnosing spinal SSI.

Diagnostic performance of suction drainage fluid culture for acute surgical site infection after aseptic instrumented spine surgery: a retrospective analysis of 363 cases.

PURPOSE: Analyze the diagnostic performance of suction drainage fluid culture for acute surgical site infection, which has not been specifically reported in spine surgery patients. METHOD: This was a retrospective single-center observational study including data from 363 patients who underwent aseptic instrumented spine surgery between 2015 and 2017. A suction drain was inserted in all cases. Data analyzed were patient age, gender, ASA score, indication for surgery (degenerative disease, tumor, trauma), spine level (cervical, thoracic, lumbar), procedure performed and spine level, operative time, body temperature, postoperative C-reactive protein time-curve, clinical aspect of surgical scar, bacteriology results of suction drainage fluid, and in case of revision surgery, lavage fluid. Major criteria for periprosthetic infection proposed by the Musculoskeletal Infection Society (MSIS) were accepted as the gold standard for the diagnosis of acute surgical site infection. RESULTS: The overall rate of surgical site infection was 6.9% (5.76% for 1- or 2-level fusion, 5.81% for 3- or 4-level fusion, and 15.6% for 5-level fusion and above). The suction drain was withdrawn on the second postoperative day in 44.1% of cases and the third day in 39.1%. The sensitivity of suction drainage fluid culture for the diagnosis of surgical site infection was 20% [95%CI 6.8-40.7%] with a 96.2% [95%CI 93.2-97.9] specificity. CONCLUSION: The diagnostic performance of suction drainage fluid culture after aseptic instrumented spine surgery for acute surgical site infection is insufficient to warrant its use in routine practice.

Simultaneous LC-MS/MS-Based Quantification of Free 3-Nitro-l-tyrosine, 3-Chloro-l-tyrosine, and 3-Bromo-l-tyrosine in Plasma of Colorectal Cancer Patients during Early Postoperative Period.

Quantification with satisfactory specificity and sensitivity of free 3-Nitro-l-tyrosine (3-NT), 3-Chloro-l-tyrosine (3-CT), and 3-Bromo-l-tyrosine (3-BT) in biological samples as potential inflammation, oxidative stress, and cancer biomarkers is analytically challenging. We aimed at developing a liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based method for their simultaneous analysis without an extract purification step by solid-phase extraction. Validation of the developed method yielded the following limits of detection (LOD) and quantification (LOQ) for 3-NT, 3-BT, and 3-CT: 0.030, 0.026, 0.030 ng/mL (LODs) and 0.100, 0.096, 0.098 ng/mL (LOQs). Coefficients of variation for all metabolites and tested concentrations were <10% and accuracy was within 95-105%. Method applicability was tested on colorectal cancer patients during the perioperative period. All metabolites were significantly higher in cancer patients than healthy controls. The 3-NT was significantly lower in advanced cancer and 3-BT showed a similar tendency. Dynamics of 3-BT in the early postoperative period were affected by type of surgery and presence of surgical site infections. In conclusion, a sensitive and specific LC-MS/MS method for simultaneous quantification of free 3-NT, 3-BT, and 3-CT in human plasma has been developed.

Nomogram prediction of surgical site infection of HIV-infected patients following orthopedic surgery: a retrospective study.

BACKGROUND: Surgical site infection (SSI) is a devastating complication of orthopedic surgery, related with increased morbidity and mortality. This study was performed with the aim to compare the SSI rate in human immunodeficiency virus HIV-positive patients, to identify other risk factors for SSI and to establish a nomogram model to predict the risk of SSI. METHODS: A total of 101 HIV-positive individuals following orthopedic surgery patients admitted to Beijing Ditan Hospital. Their characteristics were gathered. The univariate and multiple logistic regression analysis were performed to explore the risk factors of SSI. And the Nomogram prediction model was constructed and verified. RESULTS: The independent predictive factors of SSI included CD4 (Odds ratio [OR], 0.041; P = 0.040), erythrocyte sedimentation rate (ESR) (OR, 89.773; P = 0.030), and procalcitonin (PCT) (OR, 220.746; P = 0.006). The scoring nomogram model was as follows: Logit (SSI) = - 2.63589-0.00314*CD4 < 430.75 = 1) + 0.04695*(ESR < 17.46 = 1) + 2.93694*(PCT < 0.22 = 1). The area under the Receiver Operating Characteristic (ROC) curve was 0.946. The cutoff score was - 2.1026 with a sensitivity of 93.33% and a specificity of 84.88%. CONCLUSIONS: CD4, ESR, PCT might affect the occurrence of SSI after orthopedic surgery. The nomogram model constructed in this study is helpful for predicting the probability of SSI.

Assessment of Silver Levels in a Closed-Incision Negative Pressure Therapy Dressing: In Vitro and In Vivo Study.

Objective: In recent years, reticulated open-cell foam-based closed-incision negative pressure therapy (ROCF-ciNPT) has shown effectiveness in management of various postoperative incisions. These dressings consist of a skin interface layer that absorbs fluid from the skin surface and reduces the potential for microbial colonization within the dressing by means of ionic silver. This study examines the ability of silver to reduce the bioburden within the dressing as well as the localized effect due to potential silver mobility. Approach: Ability of silver to reduce bioburden within the ROCF-ciNPT dressing was assessed using Staphylococcus aureus, Pseudomonas aeruginosa, and Candida spp. Furthermore, silver mobility was assessed using an in vitro skin model to study the zone of inhibition along with released silver quantification. Using a porcine model, diffusion of silver into blood and tissue was studied using emission spectrometry and histology. Results: Microbial growth in the ROCF-ciNPT dressing was significantly reduced (∼2.7-4.9 log reduction) compared to a silver-free negative control. No zone of inhibition was observed for microbial colonies for up to 7 days with minimal localized silver release (<5.5 ppm release). In vivo studies demonstrated no measurable concentration (<0.2 µg/g) of silver in the blood, urine, feces, kidney, and liver tissue biopsy. Innovation: This study provides an important insight into silver concentration and mobility within the ROCF-ciNPT dressing, given emerging concerns associated with potential silver cytotoxicity. Conclusion: These results indicate the concentration of silver (0.019% silver by weight) in the ROCF-ciNPT dressings has been adequate to reduce bioburden within the skin interface layer, while severely limiting the amount of silver leaching out.

Surgical site infection in hepatobiliary surgery patients and its relationship with serum vitamin D concentration. / Infección del sitio quirúrgico en cirugía hepatobiliopancreática y su relación con la concentración sérica de vitamina D.

INTRODUCTION: While several studies have examined the correlation between vitamin D concentrations and post-surgical nosocomial infections, this relationship has yet to be characterized in hepatobiliary surgery patients. We investigated the relationship between serum vitamin D concentration and the incidence of surgical site infection (SSI) in patients in our hepatobiliary surgery unit. METHODS: Participants in this observational study were 321 successive patients who underwent the following types of interventions in the hepatobiliary surgery unit of our center over a 1-year period: cholecystectomy, pancreaticoduodenectomy, total pancreatectomy, segmentectomy, hepatectomy, hepaticojejunostomy and exploratory laparotomy. Serum vitamin D levels were measured upon admission and patients were followed up for 1 month. Mean group values were compared using a Student's T-test or Chi-squared test. Statistical analyses were performed using the Student's T-test, the Chi-squared test, or logistic regression models. RESULTS: Serum concentrations >33.5 nmol/l reduced the risk of SSI by 50%. Out of the 321 patients analyzed, 25.8% developed SSI, mainly due to organ-cavity infections (incidence, 24.3%). Serum concentrations of over 33.5 nmol/l reduced the risk of SSI by 50%. CONCLUSIONS: High serum levels of vitamin D are a protective factor against SSI (OR, 0.99). Our results suggest a direct relationship between serum vitamin D concentrations and SSI, underscoring the need for prospective studies to assess the potential benefits of vitamin D in SSI prevention.

Post-operative hyperglycemia and its association with surgical site infection after instrumented spinal fusion.

OBJECTIVE: To evaluate the correlation between postoperative hyperglycemia and surgical site infection among patients who underwent primary instrumented spinal fusion surgery. PATIENTS AND METHODS: We collected data on all eligible patients treated at our institution over the course of 2005-2017. We defined serum hyperglycemia using a primary threshold of serum glucose ≥140 mg/dL and used ≥115 mg/dL as a secondary test. We used logistic regression techniques to evaluate unadjusted results for serum hyperglycemia on revision surgeries for infection, followed by sequential adjustment for sociodemographic and procedural characteristics. RESULTS: We included 3664 patients. Surgical site infections occurred in 4%. Post-operative hyperglycemia was significantly associated with a higher rate of revision surgery for infection (p = 0.02). Following adjusted analysis, hyperglycemia remained a statistically significant predictor for revision surgery due to infection (OR 2.19; 95 % CI 1.13, 4.25). Similar results were evident when using the lower threshold of ≥115 mg/dL (OR 2.36; 95 % CI 1.06, 5.23). CONCLUSIONS: This study highlights the importance of measuring serum glucose after spinal fusion and the need for heightened surveillance and/or treatment in those who exhibit postoperative hyperglycemia. In this context, it could be advantageous to use a lower threshold for hyperglycemia (115 mg/dL) in order to trigger interventions for glycemic control.

Limited diagnostic value of serum inflammatory biomarkers in the diagnosis of fracture-related infections.

AIMS: The aim of this study was to evaluate the diagnostic value of preoperative serum CRP, white blood cell count (WBC), percentage of neutrophils (%N), and neutrophil to lymphocyte ratio (NLR) when using the fracture-related infection (FRI) consensus definition. METHODS: A cohort of 106 patients having surgery for suspected septic nonunion after failed fracture fixation were studied. Blood samples were collected preoperatively, and the concentration of serum CRP, WBC, and differential cell count were analyzed. The areas under the curve (AUCs) of diagnostic tests were compared using the z-test. Regression trees were constructed and internally cross-validated to derive a simple diagnostic decision tree. RESULTS: Using the FRI consensus definition, 46 patients (43%) were identified as infected. Sensitivity, specificity, and AUC of CRP were 67% (95% confidence interval (CI) 52% to 80%), 61% (95% CI 47% to 74%), and 0.64 (95% CI 0.54 to 0.74); of WBC count were 17% (95% CI 9% to 31%), 95% (95% CI 86% to 99%), and 0.57 (95% CI 0.50 to 0.62); of %N 13% (95% CI 6% to 26%), 87% (95% CI 76% to 93%), and 0.50 (95% CI 0.43 to 0.56); and of NLR 28% (95% CI 17% to 43%), 80% (95% CI 68% to 88%), and 0.54 (95% CI 0.46 to 0.63), respectively. A better performance of serum CRP was shown in comparison to the leucocyte count (p = 0.006), %N (p < 0.001), and NLR (p = 0.001). A statistically lower serum CRP level was shown in patients with an infection caused by a low virulence microorganism in comparison to high virulence bacteria (p = 0.008). We found that a simple decision tree approach using only low serum neutrophils (< 3.615 × 109/l) and low CRP (< 2.45 mg/l) may allow better identification of aseptic cases. CONCLUSION: The evaluated serum inflammatory markers showed limited diagnostic value in the preoperative diagnosis of FRI when using the uniform FRI Consensus Definition. Therefore, they should remain as suggestive criteria in diagnosing FRI. Although CRP showed a higher performance in comparison to the other serum markers, it is insufficiently accurate to diagnose a septic nonunion, especially when caused by low virulence microorganisms. Cite this article: Bone Joint J 2020;102-B(7):904-911.

Glycosylated hemoglobin level in patients with and without surgical site infection after hysterectomy.

BACKGROUND: Surgical site infection (SSI) occurs in 11-12% of surgeries. The glycosylated hemoglobin (HbA1c) has been found to be significantly elevated in those who presented infection. OBJECTIVE: To compare the concentration of HbA1c between patients with and without SSI after hysterectomy. METHOD: In healthy, postoperative women with total abdominal (open) hysterectomy, the HbA1c serum concentration was measured (normal <5.7%) and the difference between those who presented SSI and other risk factors for SSI were compared with Mann Whitney U test was used. The HbA1c values were stratified as normal or abnormal and were contrasted with the presence or absence of SSI by means of X2. RESULTS: 27 women without SSI and 20 with SSI were studied. The preoperative glucose was and 88 (70-99) mg/dl and 86 (70-99) mg/dl for the groups with and without SSI respectively. The HbA1c was significantly higher in the group with ISQ 5.6% (5-8) vs. 6.5% (5.2-8.2). The sensitivity of HbA1c with cut point <5.7 was 80% and the specificity was 51.9%. CONCLUSION: HbA1c can serve as a prognostic criterion of ISQ.

ANTECEDENTES: La infección del sitio quirúrgico (ISQ) se presenta en el 11-12% de las cirugías. La hemoglobina glucosilada (HbA1c) se ha encontrado significativamente elevada en los pacientes que presentan infección. OBJETIVO: Comparar la concentración de HbA1c entre pacientes con y sin ISQ posterior a una histerectomía. MÉTODO: En mujeres sanas posoperadas de histerectomía total abdominal (abierta) se midió la concentración sérica de HbA1c (normal < 5.7%) y se comparó la diferencia entre las que presentaron ISQ y las que no. Se investigaron también otros factores de riesgo para ISQ. Se utilizó la prueba U de Mann Whitney. Los valores de HbA1c se estratificaron como normales o anormales, y se contrastaron con la presencia o no de ISQ por medio de la prueba ji al cuadrado. RESULTADOS: Se estudiaron 27 mujeres sin ISQ y 20 con ISQ. La glucosa preoperatoria fue de 88 (70-99) y 86 (70-99) mg/dl para los grupos con y sin ISQ, respectivamente. La HbA1c fue significativamente mayor en el grupo con ISQ (5.6%; 5-8) que en el grupo sin ISQ (6.5%; 5.2-8.2). La sensibilidad de la HbA1c con un punto de corte < 5.7 fue del 80% y la especificidad fue del 51.9%. CONCLUSIÓN: La HbA1c puede servir como criterio pronóstico de ISQ.

Predictive value of CRP/albumin ratio in major abdominal surgery.

INTRODUCTION: Surgical site infection (SSI) is a major cause of morbidity, resulting in significant healthcare and economic implications. The ability to predict patients at high risk of SSI may enable targeted follow-up and management. This study sought to examine the relationship between the CRP/albumin ratio in the prediction of SSI in patients undergoing emergency major abdominal surgery. METHODS: A retrospective study of all patients who underwent emergency major abdominal surgery in our institution over 2 years was performed. Patients were identified from a prospectively maintained database of SSI's and cross-referenced with hospital records. Patient demographics including age, gender, ASA grade, and wound classification (clean, clean/contaminated, contaminated, and dirty) were collated. RESULTS: CRP preoperatively of greater than 5 was statistically significant in predicting an SSI (P < 0.05). In addition, preoperative serum albumin of < 32 was also significant in predicting a superficial site infection. Interestingly, preoperative CRP/albumin ratio did not predict SSI, but postoperative CRP/albumin ratio was predictive at both 24 and 48 hour time points (P < 0.05). Median length of stay in the SSI group was statistically significantly longer at 27.88 days (range 7-76) versus 18.32 days (1-56) (P < 0.01). CONCLUSIONS: Though CRP and albumin have merit in isolation in preoperative identification of patients at risk of SSI, CRP/albumin ratio is a useful postoperatively adjunct in predicting SSI postoperatively at 24 and 48hrs postoperatively.

Multiple preoperative biomarkers are associated with incidence of surgical site infection following surgeries of ankle fractures.

The aim of the study was to investigate the epidemiologic characteristics of surgical site infection (SSI) following surgeries of ankle fractures. This was a retrospective study. Patients who underwent surgeries for ankle fractures in our hospital between January 2016 and June 2019 were included. Inpatient medical records were inquired for data collection, including demographics, comorbidities, injury-related data, laboratory biomarkers, and confirmation of the SSI cases. Univariate analyses and multivariate logistic regression analyses were used to identify the independent risk factors. Among the 1532 patients, 45 had a postoperative SSI, indicating the incidence rate of 2.9%. About 18% of SSIs were identified after discharge. Twenty percent of SSIs were caused by mixed bacteria, and 39% were caused by drug-resistant bacteria. In the final multivariate model, 7 factors including 5 biomarkers were identified to be independently associated with SSI: gender (male vs female, OR, 2.69; 95% CI, 1.33-4.76), perioperative blood transfusion (OR. 3.02; 95% CI, 1.30-7.04), albumin <35 g/L (OR, 2.87; 95% CI, 1.31-6.31), lower high-density lipoprotein cholesterol (HDL-C) (OR, 2.34; 95% CI, 1.19-4.60), haemoglobin (OR, 2.16; 95% CI, 1.03-4.67), elevated alanine aminotransferase (OR, 2.09; 95% CI, 1.10-3.95) and neutrophile/lymphocyte rate (NLR, OR, 3.45; 95% CI, 1.33-6.74). These epidemiologic data on SSI may help counsel patients about the risk of SSI, individualised assessment of the risk factors, and accordingly the risk stratification.