Long-term Health Outcomes and Health System Costs Associated With Surgical Site Infections: A Retrospective Cohort Study

Associations of preoperative anaemia with healthcare resource use and outcomes after colorectal surgery: a population-based cohort study

BACKGROUND

Preoperative anaemia is common in patient undergoing colorectal surgery. Understanding the population-level costs of preoperative anaemia will inform development and evaluation of anaemia management at health system levels.

METHODS

This was a population-based cohort study using linked, routinely collected data, including residents from Ontario, Canada, aged ≥18 yr who underwent an elective colorectal resection between 2012 and 2022. Primary exposure was preoperative anaemia (haemoglobin <130 g L-1 in males; <120 g L-1 in females). Primary outcome was 30-day costs in 2022 Canadian dollars (CAD), from the perspective of a publicly funded healthcare system. Secondary outcomes included red blood cell transfusion, major adverse events (MAEs), length of stay (LOS), days alive at home (DAH), and readmissions.

RESULTS

We included 54,286 patients, with mean 65.3 (range 18-102) years of age and 49.0% females, among which 21 264 (39.2%) had preoperative anaemia. There was an absolute adjusted cost increase of $2671 per person at 30 days after surgery attributable to preoperative anaemia (ratio of means [RoM] 1.05, 95% confidence interval [CI] 1.04-1.06). Compared with the control group, 30-day risks of transfusion (odds ratio [OR] 4.34, 95% CI 4.04-4.66), MAEs (OR 1.14, 95% CI 1.03-1.27), LOS (RoM 1.08, 95% CI 1.07-1.10), and readmissions (OR 1.16, 95% CI 1.08-1.24) were higher in the anaemia group, with reduced DAH (RoM 0.95, 95% CI 0.95-0.96).

CONCLUSIONS

Approximately $2671 CAD per person in 30-day health system costs are attributable to preoperative anaemia after colorectal surgery in Ontario, Canada.

Usability and outcomes of self-monitored surgical wound healing using a smartphone-based application by patients following neurosurgery

BACKGROUND

The Radboudumc developed a smartphone application (WondGezond) to collect surgical wound-healing information provided by the patient.

AIM

To evaluate usability and outcomes to assess its potential for early surgical site infection (SSI) detection.

METHODS

Patients surgically treated for degenerative spinal disorders or carpal tunnel syndrome between August 2020 and February 2023 were enrolled one day post surgery and asked to download the app via a quick-response (QR) code. Participants uploaded a photo and answered four questions about their wound daily, for 14 days. Afterwards, participants indicated whether they received treatment for a suspected SSI (participant-reported outcome). Two neurosurgeons independently assessed photos and questionnaire answers for suspected SSIs (physician-assessed outcome). The association between both outcomes was determined by calculating sensitivity, specificity, and positive and negative predictive value (PPV/NPV).

FINDINGS

After 2009 surgeries, 1695 QR-codes were distributed and 412 (21%) were activated. In all, 232 (56%) participants completed the 14-day period of whom 22 (10%) reported SSI treatment. Physician assessment identified 15 (7%) SSIs. Concordance was reached in 88% of cases. Among 27 discordant cases were 17 false-positives and 10 false-negatives, resulting in low sensitivity (33%) and PPV (23%), but high NPV (95%).

CONCLUSION

WondGezond provides clinicians with information regarding wound healing and SSIs to follow-up on patients at risk, while possibly also reducing antibiotic (over)treatment and unnecessary visits for patients without issues in wound healing. However, the low participation and false-positive results render the app in its current form unsuitable for surveillance purposes. Further validation of WondGezond is required.

Estimation of the contribution to intraoperative pathogen transmission from bacterial contamination of patient nose, patient groin and axilla, anesthesia practitioners' hands, anesthesia machine, and intravenous lumen

BACKGROUND

Earlier studies showed net cost saving from anesthesia practitioners' use of a bundle of infection prevention products, with feedback on monitored Staphylococcus aureus intraoperative transmission. ESKAPE pathogens also include Enterococcus and gram-negative pathogens: Klebsiella, Acinetobacter, Pseudomonas, and Enterobacter. We evaluated whether bacterial contamination of patient nose, patient groin and axilla, anesthesia practitioners' hands, anesthesia machine, and intravenous lumen all contribute meaningfully to ESKAPE pathogen transmission within anesthesia work areas.

METHODS

The retrospective cohort study used bacterial count data from nine hospitals, 43 months, and 448 ESKAPE pathogen transmission events within anesthesia areas of 86 operating rooms. Transmission was measured within and between pairs of successive surgical cases performed in the same operating room on the same day.

RESULTS

There were 203 transmission events with S. aureus, 72 with Enterococcus, and 173 with gram negatives. ESKAPE pathogens in the nose contributed to transmission for 50% (99% confidence limit ≥45%) of case pairs, on the groin or axilla for 54% (≥49%), on the hands for 53% (≥47%), on the anesthesia machine for 21% (≥17%), and in the intravenous lumen for 24% (≥20%). ESKAPE pathogens in the nose started a transmission pathway for 27% (≥22%) of case pairs, on the groin or axilla for 24% (≥19%), on the hands for 38% (≥33%), on the anesthesia machine for 11% (≥7.6%), and in the intravenous lumen for 8.0% (≥5.3%). All P ≤ 0.0022 compared with 5%.

CONCLUSIONS

To prevent intraoperative ESKAPE pathogen transmission, anesthesia practitioners would need to address all five categories of infection control approaches: nasal antisepsis (e.g., povidone-iodine applied the morning of surgery), skin antisepsis (e.g., chlorhexidine wipes), hand antisepsis with dispensers next to the patient, decontamination of the anesthesia machine before and during anesthetics, and disinfecting caps for needleless connectors, disinfecting port protectors, and disinfecting caps for open female Luer type connectors.

Using multiple indicators to predict the risk of surgical site infection after ORIF of tibia fractures: a machine learning based study

Objective

Surgical site infection (SSI) are a serious complication that can occur after open reduction and internal fixation (ORIF) of tibial fractures, leading to severe consequences. This study aimed to develop a machine learning (ML)-based predictive model to screen high-risk patients of SSI following ORIF of tibial fractures, thereby aiding in personalized prevention and treatment.

Methods

Patients who underwent ORIF of tibial fractures between January 2018 and October 2022 at the Department of Emergency Trauma Surgery at Ganzhou People's Hospital were retrospectively included. The demographic characteristics, surgery-related variables and laboratory indicators of patients were collected in the inpatient electronic medical records. Ten different machine learning algorithms were employed to develop the prediction model, and the performance of the models was evaluated to select the best predictive model. Ten-fold cross validation for the training set and ROC curves for the test set were used to evaluate model performance. The decision curve and calibration curve analysis were used to verify the clinical value of the model, and the relative importance of features in the model was analyzed.

Results

A total of 351 patients who underwent ORIF of tibia fractures were included in this study, among whom 51 (14.53%) had SSI and 300 (85.47%) did not. Of the patients with SSI, 15 cases were of deep infection, and 36 cases were of superficial infection. Given the initial parameters, the ET, LR and RF are the top three algorithms with excellent performance. Ten-fold cross-validation on the training set and ROC curves on the test set revealed that the ET model had the best performance, with AUC values of 0.853 and 0.866, respectively. The decision curve analysis and calibration curves also showed that the ET model had the best clinical utility. Finally, the performance of the ET model was further tested, and the relative importance of features in the model was analyzed.

Conclusion

In this study, we constructed a multivariate prediction model for SSI after ORIF of tibial fracture through ML, and the strength of this study was the use of multiple indicators to establish an infection prediction model, which can better reflect the real situation of patients, and the model show great clinical prediction performance.

The costs of surgical site infection after abdominal surgery in middle income countries: Key resource use In Wound Infection (KIWI) study

BACKGROUND

Surgical site infection (SSI) is the most common complication of abdominal surgery, with substantial costs to patients and health systems. Heterogeneity in costing methods in existing SSI studies makes multi-country comparison challenging. The objective of the study was to assess the costs of SSI across middle-income countries.

METHODS

Centres from a randomised controlled trial assessing interventions to reduce SSI (FALCON, ClinicalTrials.gov, NCT03700749NCT) were sampled from two upper-middle (India, Mexico) and two lower-middle (Ghana, Nigeria) income countries. The Key resource use In Wound Infection (KIWI) study collected data on postoperative resource use and costs from consecutive patients undergoing abdominal surgery with an incision >5cm (including caesarean section) that were recruited to FALCON between April and October 2020. The overall costs faced by patients with and without SSI were compared by operative field contamination (clean-contaminated versus contaminated-dirty), country and timing (inpatient versus outpatient).

FINDINGS

335 patients were included in KIWI; SSI occurred in 7% of clean-contaminated cases and 27% of contaminated-dirty cases. Overall, SSI was associated with an increase in postoperative healthcare costs by 75.3% (€412 international euros) after clean-contaminated surgery and 66.6% (€331) after contaminated-dirty surgery. The highest and lowest cost increases was in India for clean-contaminated cases (€517) and contaminated-dirty cases (€223), respectively. Overall, inpatient costs accounted for 96.4% of the total healthcare costs after clean-contaminated surgery and 92.5% after contaminated-dirty surgery.

CONCLUSION

SSI was associated with substantial additional postoperative costs across a range of settings. Investment in health technologies to reduce SSI may mitigate the financial burden to patients and low-resource health systems.

The modified 5-item frailty index determines the length of hospital stay and accompanies with mortality rate in patients with bone and implant-associated infections after trauma and orthopedic surgery

BACKGROUND

Bone and implant-associated infections are severe complications after trauma and orthopedic surgery. The modified 5-item frailty index (mFI-5) is an easily applicable score to predict adverse outcome after surgery. The current literature regarding mFI-5 is focused on a period of 30-days postoperative.

PURPOSE

This study aims to assess the impact of frailty in orthopedic trauma patients with bone and implant-associated infections. mFI-5 was calculated from a database, which prospectively collects data about factors potentially correlated with peri- and postoperative complications since 2014.

METHODS

In a level I trauma center a total of 345 patients with surgical site infections were enrolled in this study. Hereof, patients with fracture-related infections after osteosynthesis, periprosthetic joint infections of the hip and knee and post-operative osteomyelitis were included. Extensive medical baseline examination was performed in 2013/14, a three-year follow-up was organized as a telephone interview. The mFI-5 score was calculated based on the 5 factor-principle as established by Subramaniam. The nutritional status was assessed using the Nutritional Risk Screening (NRS-2002).

RESULTS

130 patients were included, whereof seven had died, resulting in 123 patients. A grouping of our patients was performed in mFI-5 = 0 (n = 46; 36,4%), mFI-5 = 1 (n = 41; 33,3%) or mFI-5 ≥ 2 (n = 36; 29,3%). Sex distribution showed 69,1% male and 30,9% female patients. Frailty did neither impact on the re-admission (p = 0,433) nor the reoperation (p = 0,327) rate in our cohort. The mortality risk nearly doubled (1,7 times) in frail patients, but did not reach significance. In hospital stay was prolonged due to frailty (12,1 ± 11,8; p = 0,004) compared to those with a mFI-5 = 0 (5,9 ± 5,1) or mFI-5 = 1 (6,9 ± 5,9). Frailty goes along with a risk of malnutrition and increases with age.

CONCLUSION

The modified 5-item frailty index is not a suitable screening tool for predicting revision rate, re-admission rate, and mortality in our orthopedic trauma patient population with bone and implant-associated infections. Nevertheless, frailty is associated with an increased risk of malnutrition and increases with age.

Postoperative Supplemental Oxygen in Liver Transplantation (PSOLT) does not reduce the rate of infections: results of a randomized controlled trial

BACKGROUND

Despite inconsistent evidence, international guidelines underline the importance of perioperative hyperoxygenation in prevention of postoperative infections. Further, data on safety and efficacy of this method in liver transplant setting are lacking. The aim was to evaluate efficacy and safety of postoperative hyperoxygenation in prophylaxis of infections after liver transplantation.

METHODS

In this randomized controlled trial, patients undergoing liver transplantation were randomly assigned to either 28% or 80% fraction of inspired oxygen (FiO₂) for 6 postoperative hours. Infections occurring during 30-day post-transplant period were the primary outcome measure. Secondary outcome measures included 90-day mortality, 90-day severe morbidity, 30-day pulmonary complications, durations of hospital and intensive care unit stay, and 5-day postoperative bilirubin concentration, alanine and aspartate transaminase activity, and international normalized ratio (INR) (clinicatrials.gov NCT02857855).

RESULTS

A total of 193 patients were included and randomized to 28% (n = 99) and 80% (n = 94) FiO₂. With similar patient, operative, and donor characteristics in both groups, infections occurred in 34.0% (32/94) of patients assigned to 80% FiO₂ as compared to 23.2% (23/99) of patients assigned to 28% FiO₂ (p = 0.112). Patients randomized to 80% FiO₂ more frequently developed severe complications (p = 0.035), stayed longer in the intensive care unit (p = 0.033), and had higher bilirubin concentration over first 5 post-transplant days (p = 0.043). No significant differences were found regarding mortality, duration of hospital stay, pulmonary complications, and 5-day aspartate and alanine transaminase activity and INR.

CONCLUSIONS

Postoperative hyperoxygenation should not be used for prophylaxis of infections after liver transplantation due to the lack of efficacy.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02857855. Registered 7 July 2016.

Landscape of esophageal submucosal tunneling endoscopic resection-related adverse events in a standardized lexicon: a large volume of 1701 cases

BACKGROUND

Submucosal tunneling endoscopic resection (STER) has been widely applied for esophageal submucosal tumors. This large volume study aims to provide a standard landscape of STER-related AEs for reference.

METHODS

1701 patients with esophageal SMTs undergoing STER were included at Zhongshan Hospital, Fudan University. Data of clinical characteristics and adverse events were collected and analyzed in depth. Adverse events were recorded by ASGE lexicon and graded by ASGE grading/Clavien-Dindo system. Risk factors for major AEs were analyzed by univariate and multivariate logistic regression.

RESULTS

Three hundred and twenty (18.8%) patients with 962 cases of adverse events were observed. Accordingly, 84 (5.0%) were classified as major AEs (moderate and severe) by ASGE grading and 37 (2.2%) were classified as major AEs (grades III-V) by Clavien-Dindo grading. First 1 year operation, distance > 6 cm from incision to tumor, piecemeal resection, partially extraluminal location, mucosal injury, and operation time > 60 min were included in the risk score model for major AEs of STER, with 57.1% sensitivity and 87.5% specificity.

CONCLUSIONS

STER was a safe procedure for diagnosis and treatment of esophageal SMTs with a total 18.8% incidence of AEs, among which only 5.0% were major AEs requiring therapeutic measurements.

Construct and Validate a Predictive Model for Surgical Site Infection after Posterior Lumbar Interbody Fusion Based on Machine Learning Algorithm

Purpose. Surgical site infection is one of the serious complications after lumbar fusion. Early prediction and timely intervention can reduce the harm to patients. The aims of this study were to construct and validate a machine learning model for predicting surgical site infection after posterior lumbar interbody fusion, to screen out the most important risk factors for surgical site infection, and to explore whether synthetic minority oversampling technique could improve the model performance. Method. This study reviewed 584 patients who underwent posterior lumbar interbody fusion for degenerative lumbar disease at our center from January 2019 to August 2021. Clinical information and laboratory test data were collected from the electronic medical records. The original dataset was divided into training set and validation set in a 1 : 1 ratio. Seven machine learning algorithms were used to develop predictive models; the training set of each model was resampled using synthetic minority oversampling technique. Finally, the model performance was assessed in the validation set. Results. Of the 584 patients, 33 (5.65%) occurred surgical site infection. Stepwise logistic regression showed that preoperative albumin level (OR 0.659, 95% CI 0.563-0.756), diabetes (OR 9.129, 95% CI 3.816-23.126), intraoperative dural tear (OR 8.436, 95% CI 2.729-25.334), and rheumatic disease (OR 8.471, 95% CI 1.743-39.567) were significant predictors associated with surgical site infection. The performance of the AdaBoost Classification Trees model was the best among the seven machine learning models, and synthetic minority oversampling technique improved the performance of all models. Conclusion. The prediction model we constructed based on machine learning and synthetic minority oversampling technique can accurately predict surgical site infection, which is conducive to clinical decision-making and optimization of perioperative management.

A mobile application for wound and symptom surveillance after colorectal surgery: a feasibility randomized controlled trial protocol

Background

Surgical site infections (SSIs) are the most common nosocomial infection and occur in 16.3% of patients undergoing colorectal surgery at our institution (The Ottawa Hospital), the majority of which are identified after discharge from hospital. Patients who suspect having an SSI generally present to the emergency department or surgery clinic. Both options for in-person interaction are costly to the health care system and patients. A mobile app, how2trak, has proven to be beneficial for patients with complex wounds at our institution by facilitating at-home monitoring and virtual consultations.

Objective

This study aims to assess the feasibility of a randomized controlled trial to assess if how2trak can improve patients’ experience and increase detection of SSIs after colorectal surgery while reducing patients’ risk of COVID-19 exposure.

Methods

In this single-center prospective feasibility trial, eligible patients undergoing colorectal surgery will be randomized to either standard care or how2trak postoperative monitoring of their incision, symptoms, and ostomy function. Patient self-assessments will be monitored by a nurse specialized in wound and ostomy care who will follow-up with patients with a suspected SSI. The primary outcome is feasibility as measured by enrollment, randomization, app usability, data extraction, and resource capacity.

Results

This study was approved by our institution’s ethics board on February 26, 2021, and received support from The Ottawa Hospital Innovation and Care Funding on November 12, 2021. Recruitment started June 3, 2021, and 29 were patients enrolled as of September 2021. We expect to publish results in spring 2022.

Conclusions

This study will determine the feasibility of using a mobile app to monitor patients’ wounds and detect SSIs after colorectal surgery. If feasible, we plan to assess if this mobile app facilitates SSI detection, enhances patient experience, and optimizes their care.

Trial Registration

ClinicalTrials.gov NCT04869774; https://clinicaltrials.gov/ct2/show/NCT04869774

International Registered Report Identifier (IRRID)

DERR1-10.2196/26717

Predicting postoperative surgical site infection with administrative data: a random forests algorithm

Background

Since primary data collection can be time-consuming and expensive, surgical site infections (SSIs) could ideally be monitored using routinely collected administrative data. We derived and internally validated efficient algorithms to identify SSIs within 30 days after surgery with health administrative data, using Machine Learning algorithms.

Methods

All patients enrolled in the National Surgical Quality Improvement Program from the Ottawa Hospital were linked to administrative datasets in Ontario, Canada. Machine Learning approaches, including a Random Forests algorithm and the high-performance logistic regression, were used to derive parsimonious models to predict SSI status. Finally, a risk score methodology was used to transform the final models into the risk score system. The SSI risk models were validated in the validation datasets.

Results

Of 14,351 patients, 795 (5.5%) had an SSI. First, separate predictive models were built for three distinct administrative datasets. The final model, including hospitalization diagnostic, physician diagnostic and procedure codes, demonstrated excellent discrimination (C statistics, 0.91, 95% CI, 0.90–0.92) and calibration (Hosmer-Lemeshow χ² statistics, 4.531, p = 0.402).

Conclusion

We demonstrated that health administrative data can be effectively used to identify SSIs. Machine learning algorithms have shown a high degree of accuracy in predicting postoperative SSIs and can integrate and utilize a large amount of administrative data. External validation of this model is required before it can be routinely used to identify SSIs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-021-01369-9.

Standardized aseptic dressing change procedure: Optimizations and adherence in a prospective pre- and postintervention cohort study

BACKGROUND

The "HygArzt" project investigated the effectiveness of hygiene measures introduced by an infection prevention link physician (PLP).

OBJECTIVE

To investigate whether the introduction of a standardized aseptic dressing change concept (ADCC) by a PLP can increase hand hygiene adherence and adherence to specific process steps during an aseptic dressing change (ADC) in a trauma surgery and orthopedic department.

METHODS

We defined 4 required hand disinfection indications: (1) before the preparation of ADC equipment, (2) immediately before the ADC, (3) before the clean phase, and (4) after the ADC. A process analysis of the preintervention phase (331 ADCs) was used to develop a standardized ADCC. The ADCC was introduced and iteratively adopted during the intervention phase. The effect was evaluated during the postintervention phase (374 ADCs).

RESULTS

Hand hygiene adherence was significantly increased by the introduction of the ADCC for all indications: (1) before the preparation of the ADC equipment (from 34% before to 85% after, P <.001), (2) immediately before an ADC (from 32% before to 85% after; P < .001), (3) before the clean phase (from 42% before to 96% after; P < .001), and (4) after an ADC (from 74% before to 99% after; P < .001). Overall hand hygiene adherence was analyzed before the indications for an ADC (from 9.6% before to 74% after; P < .001). The same strategy was applied to the following process parameters: use of a clean work surface, clean withdrawal of equipment from the dressing trolley, and appropriate waste disposal.

CONCLUSIONS

A PLP sufficiently implemented a standardized concept for aseptic dressing change during an iterative improvement process, which resulted in a significant improvement in hand hygiene and adherence to other specific ADCC process steps.