Bacterial Epidemiology of Surgical Site Infections after Open Fractures of the Lower Limb: A Retrospective Cohort Study

A rare case of ankle peri-implant infection by multi drug resistant Chryseobacterium indologenes

Chryseobacterium indologenes is a rare human pathogen which is nowadays considered an emerging fearsome organism because of its upcoming antibiotic resistance. We present a quite unique case of a multi drug resistant C. indologenes surgical wound infection in a patient submitted to cannulated screw fixation of a displaced medial malleolus fracture. The microorganism was identified only after three months of attempts to treat pharmacologically the unhealed wound, by removing the ostheosynthesis device and sonicating it, and the surgical wound progressively restored by second intention.

A Health Economic Analysis Exploring the Cost Consequence of Using a Surgical Site Infection Prevention Bundle for Hip and Knee Arthroplasty in Germany

Background

According to the European Centre for Disease Prevention and Control, surgical site infections (SSIs) constitute over 50% of all hospital-acquired infections. Reducing SSIs can enhance healthcare efficiency.

Objective

This study explores the cost consequences of implementing an SSI prevention bundle (SPB) in total hip and knee arthroplasty (THKA).

Methods

A health-economic model followed a cohort of THKA patients from admission to 90 days postdischarge. The perioperative process was modeled using a decision tree, and postoperative recovery and potential SSI evaluated using a Markov model. The model reflects the hospital payers' perspective in Germany. The SPB includes antimicrobial incision drapes, patient warming, and negative pressure wound therapy in high-risk patients. SSI reduction associated with these interventions was sourced from published meta-analyses. An effectiveness factor of 70% was introduced to account for potential overlap of effectiveness when interventions are used in combination. Sensitivity analyses were performed to assess the robustness of model outcomes.

Results

The cost with the SPB was €4274.32 per patient, €98.27, or 2.25%, lower than that of the standard of care (€4372.59). Sensitivity analyses confirmed these findings, indicating a median saving of 2.22% (95% credible interval: 1.00%-3.79%]). The SPB also reduced inpatient SSI incidence from 2.96% to 0.91%. The break-even point for the SPB was found when the standard of care had an SSI incidence of 0.938%. Major cost drivers were the cost of inpatient SSI care, general ward, and operating room, and the increased risk of an SSI associated with unintended, intraoperative hypothermia. Varying the effectiveness factor from 10% to 130% did not substantially impact model outcomes.

Conclusions

Introducing the SPB is expected to reduce care costs if the inpatient SSI rate (superficial and deep combined) in THKA procedures exceeds 1%. Research into how bundles of measures perform together is required to further inform the results of this computational analysis.

Stress-Induced Hyperglycemia is a Risk Factor for Surgical-Site Infections in Nondiabetic Patients with Open Leg Fractures

BACKGROUND

Nondiabetic patients with open leg fractures who have elevated blood glucose levels on arrival in the emergency department have an increased risk of surgical-site infections (SSIs).

OBJECTIVE

This study evaluates the association between the incidence of SSIs in nondiabetic patients with an open leg fracture and blood glucose levels registered on arrival in the ER. We also analyzed the correlation between patients' days of hospital stay and the incidence of SSIs and the time elapsed between the damage control with external fixation and final fixation and the incidence of SSI.

METHODS

We retrospectively studied nondiabetic patients admitted to our emergency unit from 2017 to 2021 with a diagnosis of open leg fracture consecutively treated. Based on the diagnosis of SSIs, all enrolled patients were divided into two groups based on the developed (group A) or not developed (group B) SSIs within 1 year after surgery. All patients enrolled in the study underwent damage control within 24 hours after admission to the ER. At stabilization of general clinical and local wound conditions, all patients underwent definitive surgery.

RESULTS

We enrolled 80 patients. In group A, glycemia on arrival in the ER was on average 148.35 ± 19.59 mg/dl, and in group B, it was 122.61 ± 22.22 mg/dl (p value: 0.0001). In group A, glycemia in the first postoperative day was on average 113.81 ± 21.07 mg/dl, and in group B, it was 99.02 ± 17.60 mg/dl (p value: 0.001). In group A, the average hospitalization was 57.92 ± 42.43 days, and in group B, it was 18.41 ± 14.21 days (p value: 0.01). Through Youden's J, we therefore analyzed the value with the highest sensitivity and specificity which proved to be 132 mg/dl.

CONCLUSION

Our findings show that nondiabetic patients with SIH have a significantly increased risk of SSIs compared to patients without SIH within 1 year after surgery. Patients with open leg fractures with SIH have a significantly higher average hospital stay than patients without SIH. Further studies are needed to confirm 132 mg/dl of blood glucose levels as a value to stratify the risk of SSIs in these patients.

Enterobacter cloacae Infection After Surgical Treatment of Ankle Fractures, a Multicenter Observational Study

BACKGROUND

Infection is one of the challenging complications after open reduction and internal fixation for ankle fractures. Previously published case series conclude that Staphylococcus aureus is the most frequent causative microorganism. An unexpected increase in Enterobacter cloacae infections after this surgery was observed in a preliminary analysis of data at the promoting center of the study. In traumatology, its incidence has been reported in chronic osteomyelitis, prosthetic infections, septic osteoarthritis, open fractures in children and adults, and fractures other than the ankle. Because of this unexpected finding, we decided to perform this study to analyze the demographic and microbiological variables of acute osteosynthesis infection after ankle fracture and determine the distinctive features of the patients with E cloacae infection.

METHODS

We performed a retrospective multicenter study including 4 university hospitals. All patients diagnosed with acute osteosynthesis infection after ankle fracture fixation between January 2015 and December 2018 were included. We analyzed demographic data, type of fracture, surgical technique, and microorganisms responsible for the infection. We performed a descriptive statistical analysis of the variables. Univariate and multivariate regression analysis were performed to compare patients with E cloacae infection to patients with infection caused by other microorganisms.

RESULTS

A total of 65 patients were included. A predominance of polymicrobial infections (24.62%), followed by infections caused by S aureus (23.07%) and E cloacae (23.07%) was observed. When E cloacae isolated in polymicrobial infections were added, the incidence of E cloacae as a causative microorganism increased to 32.3%. Patients with E cloacae infection were older (64/53, P = .008) and had a higher requirement of negative-pressure therapy after surgical debridement (71%/40%, P = .017).

CONCLUSION

A high incidence of E cloacae infections was observed. Patients with E cloacae infection were generally older and required a higher use of negative-pressure therapy after debridement.

LEVEL OF EVIDENCE

Level V, mechanism-based reasoningr.