Characteristics of Antibiotic Prophylaxis and Risk of Surgical Site Infections in Open Colectomies

Six Long-Standing Questions about Antibiotic Prophylaxis in Surgery

Surgical site infections (SSIs) are the most common adverse event occurring in surgical patients. Optimal prevention of SSIs requires the bundled integration of a variety of measures before, during, and after surgery. Surgical antibiotic prophylaxis (SAP) is an effective measure for preventing SSIs. It aims to counteract the inevitable introduction of bacteria that colonize skin or mucosa into the surgical site during the intervention. This document aims to guide surgeons in appropriate administration of SAP by addressing six key questions. The expert panel identifies a list of principles in response to these questions that every surgeon around the world should always respect in administering SAP.

Impact of Patient-Reported Penicillin Allergy on Antibiotic Prophylaxis and Surgical Site Infection Among Patients Undergoing Colorectal Surgery

BACKGROUND

Surgical site infections are a major preventable source of morbidity, mortality, and increased health care expenditures after colorectal surgery. Patients with penicillin allergy may not receive the recommended preoperative antibiotics, putting them at increased risk for surgical site infections.

OBJECTIVE

This study aimed to evaluate the impact of patient-reported penicillin allergy on preoperative antibiotic prophylaxis and surgical site infection rates among patients undergoing major colon and rectal procedures.

DESIGN

This is a retrospective observational study.

SETTING

This study was conducted at a tertiary teaching hospital in Dallas.

PATIENTS

Adults undergoing colectomy or proctectomy between July 2012 and July 2019 were included.

MAIN OUTCOME MEASURES

The primary outcomes measured were preoperative antibiotic choice and surgical site infection.

RESULTS

Among 2198 patients included in the study, 12.26% (n = 307) reported a penicillin allergy. Patients with penicillin allergy were more likely to be white (82%) and female (54%; p < 0.01). The most common type of allergic reaction reported was rash (36.5%), whereas 7.2% of patients reported anaphylaxis. Patients with self-reported penicillin allergy were less likely to receive beta-lactam antibiotics than patients who did not report a penicillin allergy (79.8% vs 96.7%, p < 0.001). Overall, 143 (6.5%) patients had surgical site infections. On multivariable logistic regression, there was no difference in rates of surgical site infection between patients with penicillin allergy vs those without penicillin allergy (adjusted OR 1.14; 95% CI, 0.71-1.82).

LIMITATIONS

A limitation of this study was its retrospective study design.

CONCLUSIONS

Self-reported penicillin allergy among patients undergoing colorectal surgery is common; however, only a small number of these patients report any serious adverse reactions. Patients with self-reported penicillin allergy are less likely to receive beta-lactam antibiotics and more likely to receive non-beta-lactam antibiotics. However, this does not affect the rate of surgical site infection among these patients, and these patients can be safely prescribed non-beta-lactam antibiotics without negatively impacting surgical site infection rates. See Video Abstract at http://links.lww.com/DCR/B838 .IMPACTO DE LA ALERGIA A LA PENICILINA INFORMADA POR EL PACIENTE EN LA PROFILAXIS ANTIBIÓTICA Y LA INFECCIÓN DEL SITIO OPERATORIO ENTRE PACIENTES DE CIRUGÍA COLORECTAL.

ANTECEDENTES

Las infecciones del sitio operatorio son una de las principales fuentes prevenibles de morbilidad, mortalidad y aumento del gasto sanitario después de cirugía colorrectal. Es posible que los pacientes con alergia a la penicilina no reciban los antibióticos preoperatorios recomendados, lo que los pone en mayor riesgo de infecciones en el sitio operatorio.

OBJETIVO

Este estudio tuvo como objetivo evaluar el impacto de la alergia a la penicilina informada por el paciente sobre la profilaxis antibiótica preoperatoria y las tasas de infección del sitio operatorio entre pacientes sometidos a procedimientos mayores de colon y recto.

DISEO

Estudio observacional retrospectivo.

AJUSTE

Hospital universitario terciario en Dallas.

PACIENTES

Adultos sometidos a colectomía o proctectomía entre julio de 2012 a julio de 2019.

PRINCIPALES MEDIDAS DE DESENLACE

Elección de antibióticos preoperatorios e infección del sitio operatorio.

RESULTADOS

Entre los 2198 pacientes incluidos en el estudio, el 12,26% (n = 307) informó alergia a la penicilina. Los pacientes con alergia a la penicilina tenían más probabilidades de ser blancos (82%) y mujeres (54%) ( p < 0,01). El tipo más común de reacción alérgica notificada fue erupción cutánea (36,5%), mientras que el 7,2% de los pacientes notificó anafilaxia. Los pacientes con alergia a la penicilina autoinformada tenían menos probabilidades de recibir antibióticos betalactámicos en comparación con los pacientes que no informaron alergia a la penicilina (79,8% frente a 96,7%, p < 0,001). En general, hubo 143 (6,5%) pacientes con infecciones del sitio operatorio. En la regresión logística multivariable no hubo diferencias en las tasas de infección del sitio operatorio entre los pacientes con alergia a la penicilina frente a los que no tenían alergia a la penicilina (razón de probabilidades ajustada 1,14; intervalo de confianza del 95%, 0,71-1,82).

LIMITACIONES

Diseño de estudio retrospectivo.

CONCLUSIONES

La alergia a la penicilina autoinformada entre los pacientes de cirugía colorrectal es común, sin embargo, solo un pequeño número de estos pacientes informan reacciones adversas graves. Los pacientes con alergia a la penicilina autoinformada tienen menos probabilidades de recibir antibióticos betalactámicos y más probabilidades de recibir antibióticos no betalactámicos. Sin embargo, esto no afecta la tasa de infección del sitio quirúrgico entre estos pacientes y se les puede recetar de forma segura con antibióticos no betalactámicos sin afectar negativamente las tasas de infección del sitio quirúrgico. Consulte Video Resumen en http://links.lww.com/DCR/B838 . (Traducción-Dr. Juan Carlos Reyes ).

Double blind randomized controlled trial for subjects undergoing surgery receiving surgical antimicrobial prophylaxis at tertiary hospital: the clinical pharmacist's interventions

Background

A surgical site infection (SSI) has significant clinical, humanistic and economic consequences. Surgical antimicrobials prophylaxis (SAP) is a reliable standard to prevent SSIs.

Objective

The objective was to test that the clinical pharmacist's interventions may facilitate the implementation of SAP protocol and subsequent reduction of SSIs.

Methods

This was double blinded randomized controlled interventional hospital-based-study at Khartoum State-Sudan. A total of 226 subjects underwent general surgeries at four surgical units. Subjects were randomized to interventions and controls in a (1:1) ratio where patient, assessors and physician were blinded. The surgical team has received structured educational and behavioral SAP protocol mini courses by way of directed lecturers, workshops, seminars and awareness campaigns delivered by the clinical pharmacist. The clinical pharmacist provided SAP protocol to the interventions group. The outcome measure was the primary reduction in SSIs.

Results

There were (51.8%, 117/226) females, (61/113 interventions versus 56/113 controls), and (48.2%, 109/226) males (52 interventions and 57 controls). The overall rate of SSIs was assessed during 14 days post-operatively and was documented in (35.4%, 80/226). The difference in adherence to locally developed SAP protocol regarding the recommended antimicrobial was significant (P <0.001) between the interventions group (78, 69%) and the controls group (59, 52.2%). The clinical pharmacist's implementation of the SAP protocol revealed significant differences in SSIs with reduction in SSIs from 42.5% to 25.7% versus the controls group from 57.5% to 44.2% respectively, P = 0.001 between the interventions group and the controls group respectively.

Conclusion

The clinical pharmacist's interventions were very effective in sustainable adherence to SAP protocol and subsequent reduction in SSIs within the interventions group.

Predictive performance of pharmacokinetic models for target concentration-controlled infusion of cefoxitin as a prophylactic antibiotic in patients with colorectal surgery

We aimed to evaluate the predictive performance of previously constructed free (C_free) and total (C_total) cefoxitin pharmacokinetic models and the possibility of administering cefoxitin via the target‐controlled infusion (TCI) method in clinical practice. Two external validation studies (N = 31 for C_free model, N = 30 for C_total model) were conducted sequentially. Cefoxitin (2 g) was dissolved in 50 mL of normal saline to give a concentration of 40 mg mL⁻¹. Before skin incision, cefoxitin was infused with a TCI syringe pump. Target concentrations of free concentration and total concentration were set to 25 and 80 μg mL⁻¹, respectively, which were administered throughout the surgery. Three arterial blood samples were collected to measure the total and free plasma concentrations of cefoxitin at 30, 60 and 120 min, after the start of cefoxitin administration. The predictive performance was evaluated using four parameters: inaccuracy, divergence, bias and wobble. The pooled median (95% confidence interval) biases and inaccuracies were − 45.9 (−47.3 to −44.5) and 45.9 (44.5 to 47.3) for C_free model (Choi_F model), and − 16.6 (−18.4 to −14.8) and 18.5 (16.7 to 20.2) for C_total model (Choi_T_old model), respectively. The predictive performance of the newly constructed model (Choi_T_new model), developed by adding the total concentration data measured in the external validation, was better than that of the Choi_T_old model. Models constructed with total concentration data were suitable for clinical use. Administering cefoxitin using the TCI method in patients maintained the free concentration above the minimal inhibitory concentration (MIC) breakpoints of the major pathogens causing surgical site infection throughout the operation period.

Risk factors for surgical site infection in patients undergoing colorectal surgery: A meta-analysis of observational studies

OBJECTIVE

Surgical site infection (SSI) is the second most prevalent hospital-based infection and affects the surgical therapeutic outcomes. However, the factors of SSI are not uniform. The main purpose of this study was to understand the risk factors for the different types of SSI in patients undergoing colorectal surgery (CRS).

METHODS

PubMed, EMBASE, and Cochrane Library databases were searched using the relevant search terms. The data extraction was independently performed by two investigators using a standardized format, following the pre-agreed criteria. Meta-analysis for the risk factors of SSI in CRS patients was carried out using Review Manager 5.3 (RevMan 5.3) and Stata 15.1 software. The quality of evidence was evaluated using total sample size, Egger's P-value, and intergroup heterogeneity, which contained three levels: high-quality (Class I), moderate-quality (Class II/III), and low-quality (Class IV). The publication bias of the included studies was assessed using funnel plots, Begg's test, and Egger's test.

RESULTS

Of the 2660 potentially eligible studies, a total of 31 studies (22 retrospective and 9 prospective cohort studies) were included in the final analysis. Eventually, the high-quality evidence confirmed that SSI was correlated with obesity (RR = 1.60, 95% confidence interval (CI): 1.47-1.74), ASA score ≥3 (RR = 1.34, 95% CI: 1.19-1.51), and emergent surgery (RR = 1.36, 95% CI: 1.19-1.55). The moderate-quality evidence showed the correlation of SSI with male sex (RR = 1.30, 95% CI: 1.14-1.49), diabetes mellitus (RR = 1.65, 95% CI: 1.24-2.20), inflammatory bowel disease (RR = 2.12, 95% CI: 1.24-3.61), wound classification >2 (RR = 2.65, 95% CI: 1.52-4.61), surgery duration ≥180 min (RR = 1.88, 95% CI: 1.49-2.36), cigarette smoking (RR = 1.38, 95% CI: 1.14-1.67), open surgery (RR = 1.81, 95% CI: 1.57-2.10), stoma formation (RR = 1.89, 95% CI: 1.28-2.78), and blood transfusion (RR = 2.03, 95% CI:1.34-3.06). Moderate-quality evidence suggested no association with respiratory comorbidity (RR = 2.62, 95% CI:0.84-8.13) and neoplasm (RR = 1.24, 95% CI:0.58-2.26). Meanwhile, the moderate-quality evidence showed that the obesity (RR = 1.28, 95% CI: 1.24-1.32) and blood transfusion (RR = 2.32, 95% CI: 1.26-4.29) were independent risk factors for organ/space SSI (OS-SSI). The high-quality evidence showed that no correlation of OS-SSI with ASA score ≥3 and stoma formation. Furthermore, the moderate-quality evidence showed that no association of OS-SSI with open surgery (RR = 1.37, 95% CI: 0.62-3.04). The high-quality evidence demonstrated that I-SSI was correlated with stoma formation (RR = 2.55, 95% CI: 1.87-3.47). There were some certain publication bias in 2 parameters based on asymmetric graphs, including diabetes mellitus and wound classification >2. The situation was corrected using the trim and fill method.

CONCLUSIONS

The understanding of these factors might make it possible to detect and treat the different types of SSI more effectively in the earlier phase and might even improve the patient's clinical prognosis. Evidence should be continuously followed up and updated, eliminating the potential publication bias. In the future, additional high-level evidence is required to verify these findings.

Examining the role of healthcare access in racial/ethnic disparities in receipt of provider-patient discussions about smoking: A latent class analysis

Using insurance as a single indicator of healthcare access in examining the association between race/ethnicity and healthcare encounter-based interventions for smoking may not be adequate. In this study, we assessed the role of healthcare access using multifactorial measures in accounting for racial/ethnic disparities in the receipt of provider-patient discussions, defined as either being asked about smoking or advised to quit smoking by providers. We identified adult current smokers from the 2015 National Health Interview Survey. We first conducted a latent class analysis (LCA) to identify the underlying patterns of healthcare access measured by 13 indicators of healthcare access and utilization. We then used a propensity score - based weighting approach to examine racial/ethnic disparities in receiving provider-patient discussions about smoking or quitting in stratified groups by the distinct healthcare access clusters. Out of the 4134 adult current smokers who visited a doctor or a healthcare provider during the past 12 months, 3265 (79.90%) participants were classified as having high healthcare access and 869 (20.10%) participants as having low healthcare access. Compared to non-Hispanic whites, Hispanics had significantly lower odds of being asked about smoking (OR 0.46, 95% CI (0.27-0.77)) and being advised to quit (OR 0.57, 95% CI (0.34-0.97)) in the low access group, but neither association was significant in the high access group. In addition to increasing health insurance coverage, reducing other healthcare access barriers for Hispanics will likely facilitate provider-patient discussion and promote tobacco cessation among Hispanic smokers.

Intravenous cephalosporin versus non-cephalosporin-based prophylaxis to prevent surgical site infections in colorectal surgery patients: A systematic review and meta-analysis

Background

Surgical site infection (SSI) is common in colorectal surgery patients and associated with morbidity and mortality. Guidelines recommend preoperative intravenous antimicrobial prophylaxis with aerobic and anaerobic coverage to reduce SSI risk. Cephalosporin based prophylaxis (CBP) regimens are recommended as first-line prophylaxis, and non-cephalosporin based are recommended as alternative prophylaxis (AP). We evaluate the efficacy of CBP versus AP in preventing surgical site infections in colorectal surgery patients.

Methods

A systematic review and meta-analysis was conducted of studies published between 2005 and 2020 in MEDLINE and Web of Science. Studies were excluded if intravenous antimicrobial prophylaxis was not administered, or if oral and intravenous prophylaxis were routinely co-administered. Heterogeneity was reported using the Q-statistic and I²-statistic. Publication bias was evaluated using a funnel plot and Egger test for small study effects. Statistical significance was defined as a two-sided p < 0.05.

Results

11 studies met inclusion criteria. AP was not associated with increased SSI risk at 30 days compared to CBP (OR 1.01, 95% CI 0.91, 1.13; OR < 1 favors AP). There was no effect size variability in subgroup analysis comparing higher-to lower-quality studies (I² = 99%, P = 0.17). Subgroup analysis by publication year approached a significant difference in effect size between studies published prior to 2014 and later than 2014 (I² = 99%, P = 0.06).

Conclusions

Meta-analysis of 11 studies of SSI risk in adult colorectal surgery patients suggest that SSI risk is similar for patients receiving CBP or AP, subgroup analysis of studies published since 2014 suggest increased SSI risk with AP compared to CBP.

•

Meta-Analysis found that surgical site infection risk is similar for patients receiving intravenous cephalosporin based or alternative prophylaxis.

•

Subgroup analysis of studies published since 2014 suggest increased surgical site infection risk with alternative prophylaxis compared to cephalosporin based prophylaxis.

•

RCT’s are needed to evaluate trends in SSI risk in cephalosporin-based prophylaxis compared to alternative prophylaxis.

Development of a new pharmacokinetic model for target-concentration controlled infusion of cefoxitin as a prophylactic antibiotic in colorectal surgical patients

AIMS

There are several limitations to the existing method of administering cefoxitin as a prophylactic antibiotic, and the limitations may be overcome by applying the target-concentration controlled infusion (TCI) method. Population pharmacokinetic parameters are required to administer cefoxitin by the TCI method. The aim of this study was to construct a new pharmacokinetic model of cefoxitin for the TCI method in colorectal surgical patients.

METHODS

In patients undergoing colorectal surgery, 2 g of cefoxitin was dissolved in 50 mL of saline and administered for 10 minutes prior to skin incision. Arterial blood samples were obtained at preset intervals to measure the total and free plasma concentrations of cefoxitin. Population pharmacokinetic analysis was performed using NONMEM software (ICON Development Solutions, Dublin, Ireland). Additionally, stochastic simulation was used to indirectly evaluate the effectiveness of the two administration methods (standard method vs TCI).

RESULTS

In total, 297 plasma concentration measurements from 31 patients were used to characterize the pharmacokinetics of cefoxitin. A three-compartment mammillary model described the pharmacokinetics of cefoxitin. Body weight and creatinine clearance were significant covariates for clearance. The stochastic simulation showed that when compared with the standard method, the TCI method has a significantly higher fraction of time that the free concentration of cefoxitin is maintained above the minimum inhibitory concentration (P < .001).

CONCLUSIONS

TCI has the potential to become a new infusion method for patient-tailored dosing in surgical patients. To administer cefoxitin via TCI in clinical practice, the newly constructed pharmacokinetic model should undergo proper external validation.

Cost-Effectiveness Analysis of the Prophylactic Use of Ertapenem for the Prevention of Surgical Site Infections after Elective Colorectal Surgery

Standard surgical antimicrobial prophylaxis (SAP) regimens are less effective in preventing surgical site infections (SSIs) due to rising antimicrobial resistance (AMR) rates, particularly for patients undergoing colorectal surgery. This study aimed to evaluate whether ertapenem should be a preferred strategy for the prevention of SSIs following elective colorectal surgery compared to three standard SAP regimens: amoxicillin-clavulanate, cefoxitin, and cefazolin plus metronidazole. A cost-effectiveness analysis was conducted using decision tree models. Probabilities of SSIs and AMR-SSIs, costs, and effects (in terms of quality-adjusted life-years) were considered in the assessment of the alternative strategies. Input parameters integrated real data from the Italian surveillance system for SSIs with data from the published literature. A sensitivity analysis was conducted to assess the potential impact of the decreasing efficacy of standard SAP regimens in preventing SSIs. According to our models, ertapenem was the most cost-effective strategy only when compared to amoxicillin-clavulanate, but it did not prove to be superior to cefoxitin and cefazolin plus metronidazole. The sensitivity analysis found ertapenem would be the most cost-effective strategy compared to these agents if their failure rate was more than doubled. The findings of this study suggest ertapenem should not be a preferred strategy for SAP in elective colorectal surgery.

Determinants of surgeons' adherence to preventive intraoperative measures of surgical site infection in Gaza Strip hospitals: a multi-centre cross-sectional study

Background

Surgical site infection (SSI) is one of the most common hospital-acquired infections and is associated with serious impact on the rates of morbidity, mortality as well as healthcare costs. This study examined factors influencing the application of several intraoperative preventive measures of SSI by surgeons and surgical residents in the Gaza Strip.

Methods

A cross-sectional study was conducted from December 2016 to February 2017 at the operation rooms of the three major hospitals located in the Gaza-Strip, Palestine. Inclusion criteria for patients were being adult (aged ≥18 years), no history of wound infection at time of operation and surgical procedure under general anaesthesia with endotracheal intubation. The association between different patient- and procedure-related SSI risk factors and adherence to several intraoperative SSI preventive measures was tested.

Results

In total, 281 operations were observed. The mean patient age ± standard deviation (SD) was 38.4 ± 14.6 years and the mean duration of surgery ± SD was 58.2 ± 32.1 minutes. A hundred-thirty-two patients (47.0%) were male. Location and time of the operation were found to have significant associations with adherence to all SSI preventive measures except for antibiotic prophylaxis. Type of operation had a significant association with performing all measures except changing surgical instruments. Patient age did not have a statistically significant association with adherence to any measure.

Conclusion

The results suggest that the surgeon could be a major factor that can lead to a better outcome of surgical procedures by reducing postoperative complications of SSI. Operating department professionals would benefit from clinical guidance and continuous training, highlighting the importance of persistent implementation of SSI preventive measures in everyday practice to improve the quality of care provided to surgical patients.

A Protocol-Driven Reduction in Surgical Site Infections After Colon Surgery

BACKGROUND

Surgical site infection (SSI) is an established quality indicator and predictor for adverse patient outcomes. Multiple strategies have been established to reduce SSI; however, optimum protocol remains unclear. The aim of the study was to assess the impact of established protocol on SSI after colon surgery.

METHODS

We established a colon SSI bundle in 2017, which includes a chlorhexidine prescrub followed by chloraPrep, betadine wound wash, antibiotic infused irrigation, use of closure tray, and incision coverage with silver impregnated dressing. Retrospective analysis of a 2-y (2016-2017) prospectively collected before and after analysis of all patients undergoing elective colon surgery was performed. Patients were divided into two groups: preprotocol (PP: year 2016) and postprotocol (PoP: year 2017). Patients in the two groups were matched using propensity score matching for age, gender, comorbidities, Anesthesiology Severity Score, indication of procedure, and procedure type. Outcome measures were SSI, hospital length of stay, and readmission rate.

RESULTS

A total of 328 patients were analyzed, and after propensity matching, 94 patients (PP:47 and PoP:47) were included. The mean age was 63.7 ± 16.4 y, 43.6% male, and 44.6% of procedures were performed laparoscopically. There was no difference in demographics, comorbidities, and procedure details between two groups. PoP patients had significantly lower superficial (odds ratio: 0.91 [0.74-0.98]; P = 0.045) and deep SSI (odds ratio:0.97 [0.65-0.99]; P = 0.048) than PP patients. PoP patient had shorter length of stay (P = 0.049) and trend toward lower readmission rate (P = 0.098) compared with PP patients and an 85% reduction in the Centers for Medicare and Medicaid Services standardized infection rate.

CONCLUSIONS

Protocol-driven patient care improves patient outcomes. SSI bundle reduced SSI in patient undergoing colon surgery. Establishing national SSI bundles will help standardize care and help optimize patient outcomes.

β-Lactam vs Non-β-Lactam Antibiotics and Surgical Site Infection in Colectomy Patients

BACKGROUND

Surgical site infections (SSIs) represent a significant preventable source of morbidity, mortality, and cost. Prophylactic antibiotics have been shown to decrease SSI rates, and β-lactam antibiotics are recommended by national guidelines. It is currently unclear whether recommended β-lactam and recommended non-β-lactam antibiotic regimens are equivalent with respect to SSI risk reduction in colectomy patients.

STUDY DESIGN

We conducted a retrospective cohort study of SSI rates between prophylactic intravenously administered recommended β-lactam and non-β-lactam in colectomy patients (25 CPT codes) collected by the Michigan Surgical Quality Collaborative from January 2013 to February 2018. Surgical site infection rates were compared as a dichotomous variable (no SSI vs SSI). Mixed-effects regression was used to compare the association between receiving a β-lactam or non-β-lactam antibiotic and likelihood of having an SSI.

RESULTS

Of 9,949 patients, 9,411 (94.6%) received β-lactam antibiotics and 538 (5.4%) received non-β-lactam antibiotics. Overall, there were 622 (6.3%) patients with SSIs. Of the patients receiving β-lactam antibiotics, SSIs developed in 571 (6.1%) compared with 51 (9.5%) patients in the non-β-lactam group. After applying mixed-effects logistic regression, prophylactic treatment with a non-β-lactam regimen was associated with significantly higher odds of surgical site infection (odds ratio 1.65; 95% CI 1.20 to 2.26; p < 0.01).

CONCLUSIONS

Colectomy patients receiving β-lactam antibiotics had a lower likelihood of SSI compared with those receiving non-β-lactam antibiotics, even when antibiotics were compliant with national recommendations. Our findings suggest that surgeons should prescribe β-lactam antibiotics for prophylaxis whenever possible, reserving alternatives for those rare patients with true allergies or clinical indications for non-β-lactam antibiotic prophylaxis.

Reassessing the dosing of cefoxitin prophylaxis during major abdominal surgery: insights from microdialysis and population pharmacokinetic modelling

Objectives

Cefoxitin is frequently used for surgical antibiotic prophylaxis (SAP). Using microdialysis, we evaluated whether the currently recommended dosing regimen is appropriate to maintain cefoxitin subcutaneous tissue concentrations above the MIC for pathogens involved in abdominal surgical site infection.

Methods

Data from eight patients undergoing major abdominal surgery were analysed using population pharmacokinetic modelling, and Monte Carlo simulations were conducted to determine the PTA for aerobic and anaerobic pathogens. ClinicalTrials.gov: NCT02703857.

Results

Only 2.3% and 47.4% of the simulated patients maintained cefoxitin subcutaneous concentrations above the MIC breakpoint for anaerobic (MIC = 16 mg/L) and aerobic (MIC = 8 mg/L) pathogens, respectively. New simulations with administration of a loading dose followed by a constant infusion of cefoxitin were conducted and demonstrate that, notwithstanding using the same total dose per unit of time, continuous infusion of cefoxitin can cover aerobes in 96.6% of the simulated patients, but remains insufficient for anaerobic bacteria.

Conclusions

The recommended dosing regimen of cefoxitin is insufficient for covering the usual bacteria during abdominal surgery. Administration of a loading dose followed by a constant infusion should be considered for aerobic bacteria and cefoxitin should be avoided as SAP for anaerobic bacteria.

Effects of a multifaceted individualized pneumoperitoneum strategy in elderly patients undergoing laparoscopic colorectal surgery: A retrospective study

BACKGROUND

Laparoscopic colorectal surgery may adversely affect respiration, circulation, and acid-base balance in elderly patients, owing to the relatively long duration of CO2 absorption. We conducted this retrospective study to determine the safety and efficacy of warmed, humidified CO2 pneumoperitoneum in elderly patients undergoing laparoscopic colorectal surgery.

METHODS

We enrolled 245 patients between January 2016 and August 2018.The experimental group (warming and humidification group [WH]) received warmed (37°C), humidified (98%) insufflation of CO2, and the control group (cold, dry CO2/control group [CD]) received standard CO2 (19°C, 0%). All other aspects of patient care were standardized. Intraoperative hemodynamic data, arterial blood pH, and lactic acid levels were recorded. We also recorded intra-abdominal pressure, incidence of shivering 1 hour after surgery, satisfaction scores of patients and surgeons 24 hours after surgery, times to first flatus/defecation, first bowel movement, and tolerance of semiliquid food, discharge time, and incidence of vomiting, diarrhea, and surgical site infections.

RESULTS

Compared with the WH group, heart rate and mean arterial pressure were significantly higher from T3 to T8 (P < .05), lactic acid levels were significantly higher from T4 to T9 (P < .05), and recovery time in the post-anesthesia care unit (PACU) was significantly longer in the CD group (P < .05). Patient and surgeon satisfaction scores were significantly higher in the WH group than the CD group (P < .05). In addition, the times to first flatus/defecation and bowel movement were significantly longer in the CD group (P < .05). No significant differences were noted between the groups in the time to tolerance of semiliquid food and time of discharge (P > .05). The incidence of vomiting, diarrhea, and shivering was significantly lower in the WH group (P < .05). The number of patients with a shivering grade of 0 was significantly higher in the WH group, whereas the number with a shivering grade of 3 was significantly higher in the CD group (P < .05).

CONCLUSION

Warmed, humidified insufflation of CO2 in elderly patients undergoing laparoscopic colorectal surgery could stabilize hemodynamics, and reduce lactic acid levels, recovery time in the PACU, and the incidence of acute gastrointestinal injury-related symptoms.

Prevention of Infections in Cardiac Surgery study (PICS): study protocol for a pragmatic cluster-randomized factorial crossover pilot trial

Background

A wide range of prophylactic antibiotic regimens are used for patients undergoing open-heart cardiac surgery. This reflects clinical equipoise in choice and duration of antibiotic agents. Although individual-level randomized control trials (RCT) are considered the gold standard when evaluating the efficacy of an intervention, this approach is highly resource intensive and a cluster RCT can be more appropriate for testing clinical effectiveness in a real-world setting.

Methods/design

We are conducting a factorial cluster-randomized crossover pilot trial in cardiac surgery patients to evaluate the feasibility of this design for a definite trial to evaluate the optimal duration and choice of perioperative antibiotic prophylaxis. Specifically, we will evaluate: (a) the non-inferiority of a single preoperative dose compared to prolonged prophylaxis and (b) the potential superiority of adding vancomycin to routine cefazolin in terms of preventing deep and organ/space sternal surgical site infections (s-SSIs). There are four strategies: (i) short-term cefazolin, (ii) long-term cefazolin, (iii) short-term cefazolin + vancomycin, and (iv) long-term cefazolin + vancomycin. These strategies are delivered in a different order in each health-care center participating in the trial. The centers are randomized to an order, and the current strategy becomes the standard operating procedure in that center during the study.

The three feasibility outcomes include: (1) the proportion of patients receiving preoperative, intra-operative, and postoperative antibiotics according to the study protocol, (2) the proportion of completed follow-up assessments, and (3) a full and final assessment of the incidence of s-SSIs by the outcome adjudication committee.

Discussion

We believe that a cluster-randomized factorial crossover trial is an effective and feasible design for these research questions, allowing an evaluation of the clinical effectiveness in a real-world setting. A waiver of individual informed consent was considered appropriate by the research ethics boards in each participating site in Canada as long as an information letter with an opt-out option was provided. However, a waiver of consent was not approved at two sites in Germany and Switzerland, respectively.

Trial registration

Clinicaltrials.gov, NCT02285140. Registered on 15 October 2015.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-3080-y) contains supplementary material, which is available to authorized users.

Higher versus Lower Dose of Cefotetan or Cefoxitin for Surgical Prophylaxis in Patients Weighing One Hundred Twenty Kilograms or More

BACKGROUND

Clinical practice guidelines recommend a 2-g dose of cefotetan and cefoxitin for surgical prophylaxis. Pharmacokinetic data suggest benefit from higher cefotetan and cefoxitin dosing in obese patients. However, clinical studies examining higher dosing strategies in this at-risk population are lacking. The purpose of this study was to determine whether 3 g of cefotetan or cefoxitin administered pre-operatively for patients who weigh 120 kg or more is associated with a lower proportion of surgical site infection (SSI) compared with 2 g.

PATIENTS AND METHODS

Medical records of patients weighing 120 kg or more who had received cefotetan or cefoxitin (2 or 3 g) as surgical prophylaxis for intra-abdominal procedures between July 2012 and August 2015 were reviewed for the development of an SSI (primary outcome), study drug-related adverse events, and re-admissions attributed to SSIs (secondary outcomes). Relative risk calculations were performed for analysis of the primary and secondary outcomes.

RESULTS

One-hundred seventy-five procedures in 169 patients were included in the study. Cefotetan was used in 81% (141/175) of procedures. Three grams of cefotetan or cefoxitin was used in 20% (35/175) of procedures. The median body mass index (BMI) in both dosing groups was 42 kg/m² and patients who received 3 g more often weighed more than 130 kg (relative risk [RR] 1.36, 1.01-1.76; p = 0.04). Surgical site infections occurred in 20.7% within the 2-g group and 22.9% in the 3-g group (RR 1.10, 0.55-2.20; p = 0.78). There was no difference in the number of study drug-related adverse effects in the 3-g compared with the 2-g group. Thirty-day re-admissions because of SSI also did not differ between the 2-g and 3-g groups (7.9% vs. 17.1%, respectively; p = 0.11).

CONCLUSION

This small retrospective study did not find a difference in SSI rates between 3-g and 2-g surgical prophylaxis dosing for patients 120 kg or more with a median BMI >40 kg/m².

Use and Effectiveness of Peri-Operative Cefotetan versus Cefazolin Plus Metronidazole for Prevention of Surgical Site Infection in Abdominal Surgery Patients

BACKGROUND

Current practice guidelines for antimicrobial prophylaxis in surgery recommend a cephamycin or cefazolin plus metronidazole for various abdominal surgeries. In February 2016, cephamycin drug shortages resulted in a change in The Johns Hopkins Hospital's (JHH) recommendation for peri-operative antibiotic prophylaxis in abdominal surgeries from cefotetan to cefazolin plus metronidazole. The primary objective of this study was to quantify the percentage of abdominal surgeries adherent to JHH peri-operative antibiotic prophylaxis guidelines. A sub-group analysis investigated whether prophylaxis with cefazolin plus metronidazole was associated with a lower rate of surgical site infections (SSIs) versus cefotetan.

PATIENTS AND METHODS

This retrospective cohort study included adult inpatients who underwent an abdominal surgery at JHH in September 2015 (Study Period I: cefotetan) or February to March 2016 (Study Period II: cefazolin plus metronidazole).

RESULTS

Two hundred abdominal surgery cases were included in the primary analysis. A subset of 156 surgical cases were included in the sub-group analysis. The overall adherence rate to JHH guidelines was 75% in Study Period I versus 17% in Study Period II (p < 0.001). The largest difference in adherence was attributed to pre-operative administration time (87% vs. 23%, p < 0.001), primarily because of the longer infusion time required for metronidazole. Surgical site infections occurred in 14% (12/83) of surgeries with cefotetan versus 8.2% (6/73) with cefazolin plus metronidazole for prophylaxis (p = 0.19).

CONCLUSIONS

Adherence to an institution-specific peri-operative antibiotic prophylaxis guideline for abdominal surgeries was limited primarily by the longer infusion time required for pre-operative metronidazole. A higher percentage of SSIs occurred among abdominal surgeries with cefotetan versus cefazolin plus metronidazole for prophylaxis.

Surgical Site Infection in Colorectal Surgery: A Study in Antibiotic Duration

BACKGROUND

Despite distant historical studies that demonstrated the adequacy of preoperative antibiotic prophylaxis, current surgical practice continues to use antibiotics for postoperative coverage up to 24 hours.

OBJECTIVE

The aim of this study was to evaluate a change in antibiotic prophylaxis duration and its effect on surgical site infection in a high-volume modern colorectal practice.

DESIGN

A case-controlled series retrospectively reviewed outcomes through a prospective validated data base.

SETTING

The study was conducted at Mayo Clinic, Rochester, Minnesota.

PATIENTS

A total of 965 patients were evaluated. Our study analyzed patient outcomes related to surgical site infection comparing cohort 1 (2012-2013), which had the same antibiotic coverage preoperatively up to 24 hours postoperatively, and cohort 2 (2014-2015), which eliminated postoperative doses and relied solely on pre- and intraoperative dosing duration.

MAIN OUTCOME MEASURES

The primary outcomes of this study are superficial and deep surgical site infection.

RESULTS

There were no differences identified for superficial or deep surgical site infection rates between cohorts. Before the change in antibiotic dosing duration (2012-2013), 28 of 493 patients (5.7%) vs after the practice change (2014-2015), 25 of 472 patients (5.3%) were reported to have superficial or deep surgical site infection (p = 0.794).

LIMITATIONS

This study is limited by its retrospective design within a single institution.

CONCLUSION

These equivalent results present an opportunity for surgeons to reconsider optimal antibiotic duration and minimize unnecessary antibiotic dosing. See Video Abstract at http://links.lww.com/DCR/A322.