Operating Room Traffic as a Modifiable Risk Factor for Surgical Site Infection

Simulating the effects of operating room staff movement and door opening policies on microbial load

OBJECTIVE

To identify factors that increase the microbial load in the operating room (OR) and recommend solutions to minimize the effect of these factors.

DESIGN

Observation and sampling study.

SETTING

Academic health center, public hospitals.

METHODS

We analyzed 4 videotaped orthopedic surgeries (15 hours in total) for door openings and staff movement. The data were translated into a script denoting a representative frequency and location of movements for each OR team member. These activities were then simulated for 30 minutes per trial in a functional operating room by the researchers re-enacting OR staff-member roles, while collecting bacteria and fungi using settle plates. To test the hypotheses on the influence of activity on microbial load, an experimental design was created in which each factor was tested at higher (and lower) than normal activity settings for a 30-minute period. These trials were conducted in 2 phases.

RESULTS

The frequency of door opening did not independently affect the microbial load in the OR. However, a longer duration and greater width of door opening led to increased microbial load in the OR. Increased staff movement also increased the microbial load. There was a significantly higher microbial load on the floor than at waist level.

CONCLUSIONS

Movement of staff and the duration and width of door opening definitely affects the OR microbial load. However, further investigation is needed to determine how the number of staff affects the microbial load and how to reduce the microbial load at the surgical table.

Surgical site infection prevention protocol for pediatric spinal deformity surgery: does it make a difference?

STUDY DESIGN

Retrospective.

OBJECTIVE

Can a standardized, hospital-wide care bundle decrease surgical site infection (SSI) rate in pediatric spinal deformity surgery? SSI is a major concern in pediatric spinal deformity surgery.

METHODS

We performed a retrospective review of our primary scoliosis surgeries between 1999 and 2017. In 2008, we implemented a standardized infection reduction bundle. Interventions included preoperative nares screening for methicillin-resistant staphylococcus aureus or methicillin-sensitive Staphylococcus aureus 2 weeks preoperatively, and treatment with intranasal mupirocin when positive, a bath or shower the night before surgery, a preoperative chlorohexidine scrub, timing of standardized antibiotic administration, standardized intraoperative re-dosing of antibiotics, limiting operating room traffic, and standardized postoperative wound care. In 2011, we added intrawound vancomycin powder at wound closure. Our inclusion criteria were patients 21 years of age or less with idiopathic, neuromuscular, syndromic, or congenital scoliosis who had a primary spinal fusion or a same day anterior and posterior spine fusion with segmental spinal instrumentation of six levels or more. We compared the incidence of early (within 90 days of surgery) and late (> 91 days) SSI during the first postoperative year.

RESULTS

There were 804 patients who met inclusion criteria: 404 in the non-bundle group (NBG) for cases prior to protocol change and 400 in the bundle group (BG) for cases after the protocol change. Postoperatively, there were 29 infections (7.2% of total cases) in the NBG: 9 early (2.2%) and 20 late (5.0%) while in the BG there were only 10 infection (2.5%): 6 early (1.5%) and 4 late (1.0%). The reduction in overall SSIs was statistically significant (p = 0.01). There was a trend toward decreased early infections in the BG, without reaching statistical significance (p = 0.14).

CONCLUSION

Standardized care bundles appear effective in reducing the incidence of postoperative pediatric spine SSIs.

LEVEL OF EVIDENCE

Level III.

Effects of Operating Room Size on Surgical Site Infection Following Lumbar Fusion Surgery

Background

Surgical site infections (SSIs) represent a devastating complication after spine surgery. Many factors have been identified, but the influence of operating room (OR) size on infection rate has not been assessed.

Methods

Two thousand five hundred and twenty-three patients who underwent open lumbar spine fusion at a single institution between 2010 and 2016 were included. Patients were dichotomized into large versus small groups based on OR volume. Bivariate logistic regression and a final multivariate model following a multicollinearity check were used to calculate odds of infection for all variables.

Results

A total of 63 patients (2.5%) developed SSIs with 46 (73%) in the larger OR group and 17 (27%) in the smaller OR group. The rate of SSIs in larger ORs was 3.02% compared with 1.81% in smaller ORs. Significant parameters impacting SSI in bivariate analysis included an earlier year of surgery, BMI > 30, more comorbidities, more levels decompressed and fused, smoking, and larger OR volumes. Multivariate analysis identified BMI > 30, Elixhauser scores, smoking, and increasing levels decompressed as significant predictors. Topical vancomycin was found to significantly decrease rate of infection in both analyses.

Conclusions

OR size (large versus small) was ultimately not a significant predictor of infection related to rates of SSIs, although it did show a clinical trend toward significance, suggesting association. Future prospective analysis is warranted.

Level of Evidence

3.

Staple versus suture closure for ankle fracture fixation: Retrospective chart review for safety and outcomes

INTRODUCTION/AIM

Recent comparisons of suture versus metal staple skin closure on the rates of wound complications in orthopaedic surgeries have yielded conflicting results. Several studies have since started to approach this question based on anatomic location, comparing suture versus staple closure in total hip and knee arthroplasty and acetabulum fracture surgery. Ankle fractures are one of the most commonly treated fractures by orthopaedic surgeons with unique challenges to skin closure due to the lack of subcutaneous support. However, to date there are no studies comparing superficial skin closure methods specifically in ankle surgery. The objective of this study was to evaluate the safety of staple versus suture closure for open fixation of acute traumatic ankle fractures.

METHODS

The medical records of patients treated at one institution by a single surgeon with open surgical fixation of an acute traumatic ankle fracture between 2011 and 2017 were retrospectively reviewed. Patients with less than 6 months of follow-up, polytrauma patients, diabetic patients, and patients with more than 3 medical comorbidities were excluded. Skin closure technique was determined by the presence or absence of metallic staples on postoperative imaging. Demographic variables, surgical characteristics, and postoperative outcomes up to one year were compared between patients who received superficial skin closure using staple versus suture techniques. Statistical analysis was performed using chi-squared tests and Fisher's exact tests, with p=0.05 used to denote statistical significance.

RESULTS

This study included 94 patients aged 18 to 75: two groups of 47 patients (Staple group and Suture group) that were demographically similar at baseline. Overweight and obese patients constituted the majority of the sample, 34% and 46% of patients, respectively. Current tobacco use was reported by 45% of patients. Fractures tended to be right-sided (63%), low energy (64%), and closed (98%), and the most common fracture types were bimalleolar (30%), lateral malleolar (24%), and pilon (19%) fractures. Ten patients (10.6%) developed local wound related complications within 4 months postoperatively, including five incidences of wound dehiscence, four superficial wound infections, and one deep infection. Eight patients (8.5%) required revision surgery due to wound related complications. There was no difference in the incidence of surgical site infections (p=0.361), local wound related complications (p=0.316), or revision surgeries (p=0.267) between wound closure techniques. Suture group patients required more staff in the operating room compared with staple group patients (p=0.001).

CONCLUSION

These results suggest that staples are a safe alternative to sutures for superficial skin closure in healthy, non-diabetic patients following open surgical fixation of acute traumatic ankle fractures. However, this retrospective, single-institution study was limited by the low number of available patients relative to the rare outcomes of interest. Larger, prospective studies are needed to validate the accuracy and generalizability of these results.

Intra-Operative Inspired Fraction of Oxygen and the Risk of Surgical Site Infections in Patients with Type 1 Surgical Incisions

BACKGROUND

Whether the fraction of inspired oxygen (F_IO₂) influences the risk of surgical site infection (SSI) is controversial. The World Health Organization and the World Federation of Societies of Anesthesiologists offer conflicting recommendations. In this study, we evaluate simultaneously three different definitions of F_IO₂ exposure and the risk of SSI in a large surgical population.

PATIENTS AND METHODS

Patients with clean (type 1) surgical incisions who developed superficial and deep organ/space SSI within 30 days after surgery from January 2003 through December 2012 in five surgical specialties were matched to specialty-specific controls. Fraction of inspired oxygen exposure was defined as (1) nadir F_IO₂, (2) percentage of operative time with F_IO₂ greater than 50%, and (3) cumulative hyperoxia exposure, calculated as the area under the curve (AUC) of F_IO₂ by time for the duration in which F_IO₂ greater than 50%. Stratified univariable and multivariable logistic regression models tested associations between F_IO₂ and SSI.

RESULTS

One thousand two hundred fifty cases of SSI were matched to 3,248 controls. Increased oxygen exposure, by any of the three measures, was not associated with the outcome of any SSI in a multivariable logistic regression model. Elevated body mass index (BMI; 35+ vs. <25, odds ratio [OR] 1.78, 95% confidence interval [CI] 1.43-2.24), surgical duration (250+ min vs. <100 min, OR 1.93, 95% CI 1.48-2.52), diabetes mellitus (OR 1.37, 95% CI 1.13-1.65), peripheral vascular disease (OR 1.52, 95% CI 1.10-2.10), and liver cirrhosis (OR 2.48, 95% CI 1.53-4.02) were statistically significantly associated with greater odds of any SSI. Surgical sub-group analyses found higher intra-operative oxygen exposure was associated with higher odds of SSI in the neurosurgical and spine populations.

CONCLUSION

Increased intra-operative inspired fraction of oxygen was not associated with a reduction in SSI. These findings do not support the practice of increasing F_IO₂ for the purpose of SSI reduction in patients with clean surgical incisions.