Operating room staff and surgeon documentation curriculum improves wound classification accuracy

Preoperative Prediction of Postoperative Infections Using Machine Learning and Electronic Health Record Data

OBJECTIVE

To estimate preoperative risk of postoperative infections using structured electronic health record (EHR) data.

BACKGROUND

Surveillance and reporting of postoperative infections is primarily done through costly, labor-intensive manual chart reviews on a small sample of patients. Automated methods using statistical models applied to postoperative EHR data have shown promise to augment manual review as they can cover all operations in a timely manner. However, there are no specific models for risk-adjusting infectious complication rates using EHR data.

METHODS

Preoperative EHR data from 30,639 patients (2013-2019) were linked to the American College of Surgeons National Surgical Quality Improvement Program preoperative data and postoperative infection outcomes data from 5 hospitals in the University of Colorado Health System. EHR data included diagnoses, procedures, operative variables, patient characteristics, and medications. Lasso and the knockoff filter were used to perform controlled variable selection. Outcomes included surgical site infection, urinary tract infection, sepsis/septic shock, and pneumonia up to 30 days postoperatively.

RESULTS

Among >15,000 candidate predictors, 7 were chosen for the surgical site infection model and 6 for each of the urinary tract infection, sepsis, and pneumonia models. Important variables included preoperative presence of the specific outcome, wound classification, comorbidities, and American Society of Anesthesiologists physical status classification. The area under the receiver operating characteristic curve for each model ranged from 0.73 to 0.89.

CONCLUSIONS

Parsimonious preoperative models for predicting postoperative infection risk using EHR data were developed and showed comparable performance to existing American College of Surgeons National Surgical Quality Improvement Program risk models that use manual chart review. These models can be used to estimate risk-adjusted postoperative infection rates applied to large volumes of EHR data in a timely manner.

The Concept of Treatment for Surgical Infection in the Hindfoot

Background

Chronic osteomyelitis of the calcaneus (OC) and open infected calcaneal fractures, especially when complicated by infected soft tissue defects, present significant surgical challenges. Accepted recommendations for the surgical treatment of this pathology are yet to be established.

Methods

Drawing from our experience and the consensus among experts, we have developed a concept for selecting optimal, well-known surgical approaches based on the specific pathologic presentation. This concept distinguishes 4 main forms of hindfoot infection: infected wounds, open infected fractures, OC, and their mixed forms. Patients with conditions that could confound the treatment outcomes, such as diabetes mellitus and neurotrophic diseases, were excluded from this analysis. We present a retrospective analysis of the treatment outcomes for 44 patients (4 women and 40 men) treated between 2009 and 2022 using some refined surgical techniques. Treatment success was evaluated based on the absence of disease recurrence within a 2-year follow-up, the avoidance of below-knee amputations, and the restoration of weightbearing function.

Results

The treatment results were considered through the prism of our proposed concept and according to the Cierny-Mader classification. There were 4 instances of disease recurrence, necessitating 6 additional surgeries, 2 of which (4.5% of the patient cohort) resulted in amputations. In the remaining cases, we were able to restore weightbearing function and eliminate the infection through reconstructive surgeries, employing skin grafts when necessary.

Conclusion

Surgical infections of the hindfoot area remain a significant challenge. The strategic concept we propose for surgical decision making, tailored to the specific pathology, represents a potential advancement in addressing this challenge. This framework could provide valuable guidance for orthopaedic surgeons in their clinical decision-making process.

Level of Evidence

Level IV, case series.

A Comparison of Interobserver Reliability Between Orthopedic Surgeons Using the Centers for Disease Control Surgical Wound Class Definitions

BACKGROUND

The Centers for Disease Control (CDC) created a classification to help stratify surgical wounds based on contamination and risk of developing a surgical site infection. The classification includes four options (I to IV) depending on the level of contamination present. Although universally applied to a variety of surgical specialties, it is unknown whether the current system is reliable when considering orthopaedic surgeries. The purpose of this study was to compare the degree of interobserver reliability between orthopaedic surgeons using the current CDC wound class definitions.

METHODS

A questionnaire containing 30 clinical vignettes was completed by 39 orthopaedic surgeons at our institution. After each vignette, respondents were asked to determine the appropriate wound class based on information provided in the vignette. The overall interobserver agreement among all participants was analyzed. In addition, respondents were queried about the adequacy of the current classification system in describing orthopaedic surgical wound class.

RESULTS

Interobserver agreement was poor at 66%, with a coefficient of concordance of 0.48. Only six physicians (15.4%) thought that the current wound classification system adequately covered orthopaedic surgery.

CONCLUSIONS

There is poor interobserver reliability using the CDC surgical wound class definitions for orthopaedic surgeries. Alternate definitions are needed to improve the validity of the system for subspecialty procedures.

Efficacy of Topical Epinephrine in Tympanoplasty

OBJECTIVES/HYPOTHESIS

To compare the hemostatic effects of commonly used concentrations of topical epinephrine in tympanoplasty.

STUDY DESIGN

Prospective, randomized, controlled clinical trial.

METHODS

Patients undergoing tympanoplasty were randomized to receive topical epinephrine at 1:1,000 or 1:10,000. With the investigators blinded, hemostasis was assessed with a modified Boezaart scale. Vasoconstriction was measured by laser Doppler. Blood pressure and pulse were tracked.

RESULTS

Thirty patients, 4 to 84 years old, were studied, with 15 patients per group. Boezaart scores dropped a mean of 67% and 62% with 1:1,000 and 1:10,000, respectively (P = .44). Capillary blood flow decreased a mean of 50.4% and 50.9% with 1:1,000 and 1:10,000, respectively (P = .95). The mean change in heart rate and mean arterial pressure after topical epinephrine exposure were -4.9 and -0.73 beats per minute (P = .15), and -0.60 and -0.73 mmHg (P = .96) for 1:1,000 and 1:10,000 respectively. No adverse events occurred in either group.

CONCLUSIONS

Topical epinephrine at 1:10,000 has hemostatic efficacy comparable to 1:1,000 in tympanoplasty. Although both concentrations appear safe, use of topical epinephrine 1:10,000 should be considered over 1:1,000 to minimize the potential for adverse events.

LEVEL OF EVIDENCE

2 Laryngoscope, 2021.

Surgical Wound Misclassification to Clean From Clean-Contaminated in Common Abdominal Operations

BACKGROUND

Wound classification helps predict wound-related complications and is useful in stratifying surgical site infection reporting. We sought to evaluate misclassification among commonly performed surgeries that are at least clean-contaminated.

MATERIALS AND METHODS

The National Surgical Quality Improvement Program database was queried from 2005 to 2016 by Current Procedural Terminology codes identifying common surgeries that are, by definition, not clean: colectomy, cholecystectomy, hysterectomy, and appendectomy. Univariate analysis and multivariate logistic regression were performed.

RESULTS

Of the 1,208,544 operative cases reviewed, 22,925 (1.90%) were misclassified as clean. Hysterectomy was the most commonly misclassified operation (3.11%), and colectomy the least (0.82%). Misclassification was higher in laparoscopic cases (1.92% versus 1.82%; P < 0.01). Misclassification increased from 2005 to 2016 (0.22% versus 3.11%; P < 0.01). Misclassified patients were younger (46.7 versus 47.7 y; P < 0.01); had lower rates of hypertension, chronic obstructive pulmonary disease, smoking history, and steroid use (P < 0.01); and had shorter length of stay (2.2 versus 3.2 d; P < 0.01), lower 30-d readmission rates (3.7% versus 5.0%; P < 0.01), and less surgical site infections (1.7% versus 3.4%; P < 0.01). Open hysterectomy was the most significant positive predictor for misclassification (odds ratio 3.34; P < 0.01). Open appendectomy was the most significant negative predictor (odds ratio 0.20; P < 0.01).

CONCLUSIONS

There is an increasing trend of misclassifying wounds as clean. Misclassified patients have better outcomes, and misclassification may be affected by patient characteristics, operative approach, and type of procedure rather than reflecting the true infectious burden. Further research is warranted.