Technology and the prevention of surgical site infections

Intra-operative tissue oxygen tension is increased by local insufflation of humidified-warm CO2 during open abdominal surgery in a rat model

INTRODUCTION

Maintenance of high tissue oxygenation (PtO2) is recommended during surgery because PtO2 is highly predictive of surgical site infection and colonic anastomotic leakage. However, surgical site perfusion is often sub-optimal, creating an obstructive hurdle for traditional, systemically applied therapies to maintain or increase surgical site PtO2. This research tested the hypothesis that insufflation of humidified-warm CO2 into the abdominal cavity would increase sub-peritoneal PtO2 during open abdominal surgery.

MATERIALS AND METHODS

15 Wistar rats underwent laparotomy under general anesthesia. Three sets of randomized cross-over experiments were conducted in which the abdominal cavity was subjected to alternating exposure to 1) humidified-warm CO2 & ambient air; 2) humidified-warm CO2 & dry-cold CO2; and 3) dry-cold CO2 & ambient air. Sub-peritoneal PtO2 and tissue temperature were measured with a polarographic oxygen probe.

RESULTS

Upon insufflation of humidified-warm CO2, PtO2 increased by 29.8 mmHg (SD 13.3; p<0.001), or 96.6% (SD 51.9), and tissue temperature by 3.0°C (SD 1.7 p<0.001), in comparison with exposure to ambient air. Smaller, but significant, increases in PtO2 were seen in experiments 2 and 3. Tissue temperature decreased upon exposure to dry-cold CO2 compared with ambient air (-1.4°C, SD 0.5, p = 0.001).

CONCLUSIONS

In a rat model, insufflation of humidified-warm CO2 into the abdominal cavity during open abdominal surgery causes an immediate and potentially clinically significant increase in PtO2. The effect is an additive result of the delivery of CO2 and avoidance of evaporative cooling via the delivery of the CO2 gas humidified at body temperature.

Colorectal surgery surgical site infection reduction program: a national surgical quality improvement program--driven multidisciplinary single-institution experience

BACKGROUND

Surgical site infections (SSI) are a major cause of morbidity in surgical patients and they increase health care costs considerably. Colorectal surgery is consistently associated with high SSI rates. No single intervention has demonstrated efficacy in reducing colorectal SSIs. The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) is a nationally validated system that uses clinically abstracted data on surgical patients and their outcomes to assist participating institutions drive quality improvement.

STUDY DESIGN

A multidisciplinary team was assembled to develop a colorectal SSI-reduction bundle at an academic tertiary care medical center. The ACS NSQIP data were used to identify patterns of SSIs during a 2-year period. Multiple interventions across the entire surgical episode of care were developed and implemented in January 2011. Monthly ACS NSQIP data were used to track progress.

RESULTS

Our ACS NSQIP overall colorectal SSI rate for 2009 and 2010 was 9.8%. One year after implementation of the SSI reduction bundle, we demonstrated a significant decline (p < 0.05) in both overall and superficial SSIs, to 4.0% and 1.5%, respectively. Organ space infections declined to 2.6%, which was not a significant change (p = 0.10). During the entire analysis period (2009 to 2011), there was no change in our colorectal-specific Surgical Care Improvement Program performance.

CONCLUSIONS

Using our ACS NSQIP colorectal SSI outcomes, a multidisciplinary team designed a colorectal SSI reduction bundle that resulted in a substantial and sustained reduction in SSIs. Our study is not able to identify which specific elements contributed to the reduction.

Impact of a surgical site infection (SSI) surveillance program in orthopedics and traumatology

Surveillance of surgical site infections (SSI) is a priority. One of the fundamental principles for the surveillance of SSI is based on receiving effective field feedback (retro-information). The aim of this study was to report the results of a program of SSI surveillance and validate the hypothesis that there is a correlation between creating a SSI surveillance program and a reduction in SSI.

MATERIALS AND METHODS

The protocol was based on the weekly collection of surveillance data obtained directly from the different information systems in different departments. A delay of 3 months was established before extraction and analysis of data and information from the surgical teams. The NNIS index (National Nosocomial Infections Surveillance System) developed by the American surveillance system and the reduction of length of hospital stay index Journées d'hospitalisation évitées (JHE).

RESULTS

Since the end of 2009, 7156 surgical procedures were evaluated (rate of inclusion 97.3%), and 84 SSI were registered with a significant decrease over time from 1.86% to 0.66%. A total of 418 days of hospitalization have been saved since the beginning of the surveillance system.

DISCUSSION

Our surveillance system has three strong points: follow-up is continuous, specifically adapted to orthopedic traumatology and nearly exhaustive. The extraction of data directly from hospital information systems effectively improves the collection of data on surgical procedures. The implementation of a SSI surveillance protocol reduces SSI.

LEVEL OF EVIDENCE

Level III. Prospective study.

Perioperative antibiotic prophylaxis: improved compliance and impact on infection rates

The aims of this study were to determine adherence to the perioperative antibiotic prophylaxis (PAP) protocol used at a large Italian teaching hospital during a 6-year period, to assess the variables associated with inappropriate administration, and to measure the impact on surgical site infection (SSI) rates. There were 28 621 patients surveyed of which 74·6% received PAP. An improvement in adherence to the PAP protocol was registered for 58·8% of patients. Significant risk factors were an American Society of Anesthesiologists (ASA) score ⩾2 [odds ratios (OR) from 1·28 (95% confidence interval (CI) 1·19–1·37) to 1·87 (95% CI 1·43–2·44)], prolonged duration of surgery (OR 1·68, 95% CI 1·56–1·82) and urgent surgery (OR 2·16, 95% CI 1·96–2·37). During the study period, a significant reduction in SSIs rates was detected. We concluded that the global reduction of inadequate PAP administration signifies the efficacy of a multidisciplinary quality improvement initiative on antimicrobial utilization, and this is supported by the observed reduction of the SSI rate.

Effect of anaesthesia maintained with sevoflurane and propofol on surgical site infection after elective open gastrointestinal surgery

Perioperative increase in oxidative activity in surgical patients reportedly prevents postoperative surgical site infection (SSI). Several clinical studies have shown that oxidative activity under sevoflurane anaesthesia was higher than that under propofol anaesthesia. Therefore, we hypothesised that sevoflurane anaesthesia would discourage SSI compared with propofol anaesthesia. To examine the effect of anaesthesia maintained with sevoflurane and propofol on SSI, a total of 265 consecutive adult patients, with American Society of Anesthesiologists physical status 1-3, who underwent elective open gastrointestinal surgery under general anaesthesia, were surveyed for SSI between January 2007 and December 2008. Sevoflurane or propofol was selected to maintain anaesthesia in 95 and 170 patients, respectively. A propensity score was used for pairwise matching of these patients to avoid selection biases between the two methods of anaesthesia. Propensity matching yielded 84 pairs of patients. We compared standardised infection ratios (SIRs), i.e. the quotient of the number of SSI cases observed and the number of SSI cases expected, calculated using data from the National Nosocomial Infection Surveillance, between sevoflurane and propofol anaesthesia. After propensity matching, SIR after sevoflurane anaesthesia was 1.89 [95% confidence interval (CI): 1.46-2.32], which was significantly lower than after propofol anaesthesia (4.78; 95% CI: 4.30-5.27) (P=0.02). This study suggests that sevoflurane tends to suppress SSI after elective open gastrointestinal surgery compared with propofol.

[Association between the pattern of prophylactic antibiotic use and surgical site infection rate for major surgeries in Korea]

OBJECTIVES

The purpose of this study was to analyze the association between the pattern of prophylactic antibiotic use (PAU) and the surgical site infection (SSI) rate for major surgeries in Korea.

METHODS

We retrospectively reviewed the medical records of patients who underwent cardiac, colon and gastric surgery, hysterectomies and hip/knee replacements at 20 hospitals, and inclusive of over 500 beds. We randomly sampled 60 cases per surgery type for patients discharged between September and November, 2006. A total fo 2,924 cases were included in our analysis. Cox's proportional hazard analysis was conducted to evaluate the association between the pattern of PAU and SSI rate.

RESULTS

The proportion of patients who received their first prophylactic antibiotics (PA) 1 hour before incision was 65.5%, who received inappropriate PAs was 80.8%, and the proportion of patients whose PA was discontinued within 24 hours of surgery was 0.5%. The average duration of PAU after surgery was 9 days. The relative risk (RR) of SSI in patients who received their first PA more than 1 hour before incision was significantly higher than for those who received it within 1 hour prior to incision (RR=8.20, 95% CI=4.81-13.99). Inappropriate PA selection increased SSI rate, albeit with marginal significance (RR=1.97, 95% CI=0.96-4.03). Also, prolonged PAU following surgery had no effect on SSI rate.

CONCLUSIONS

These results suggest that the pattern of PAU in the surgeries examined was not appropriate. Errors in the timing of PAU and of PA selection increase SSI rate. SSI rate remained unaltered following prolonged PAU after surgery.

The "six sigma approach" to the operating room environment and infection

The patient's external environment plays a significant, and in some cases dominant, role in his or her infection risk. The use of ultraclean air for certain procedures, as well as avoidance of hypothermia have been proven to reduce the risk of infection. There is no data to support the routine use of surgical masks (by surgeons or staff), ventilating helmets, or routine cleaning of all environmental surfaces in between cases. More research needs to be done in order to determine whether OR design changes, in addition to increasing OR efficiency and thus reducing case times, can also reduce infection rates. Further research is also needed to determine whether or not double gloves and/or the use of antiseptic scrubbing in addition to painting are efficacious.