Antibiotic stewardship program (ASP) in palliative care: antibiotics, to give or not to give.

Antimicrobial therapy in terminally ill patients remains controversial as goals of care tend to be focused on optimizing comfort. International guidelines recommend for antibiotic stewardship program (ASP) involvement in antibiotic decisions in palliative patients. The primary objective was to evaluate the clinical impact of ASP interventions made to stop broad-spectrum intravenous antibiotics in terminally ill patients. This was a retrospective chart review of 459 terminally ill patients in Singapore General Hospital audited by ASP between December 2010 and December 2018. Antibiotic duration, time-to-terminal discharge for end-of-life care, time-to-mortality, and mortality rates of patients with antibiotics ceased or continued upon ASP recommendations were compared. A total of 283 and 176 antibiotic courses were ceased and continued post-intervention, respectively. The intervention acceptance rate was 61.7%. The 7-day mortality rate (47.3% vs 61.9%, p = 0.003) was lower in the ceased group, while 30-day mortality rate (76.0% vs 81.2%, p = 0.203) and time-to-mortality post-intervention (3 [0-24] vs 2 [0-27] days, p = 0.066) did not differ between the ceased and continued groups. After excluding the 57 patients who had antibiotics continued until death within 48 h of intervention, only time-to-mortality post-intervention was statistically significantly shorter in the ceased group (3 [0-24] vs 4 [0-27], p < 0.001). Of the 131 terminally discharged patients, antibiotic duration (4 [0-17] vs 6.5 [1-14] days, p = 0.001) and time-to-terminal discharge post-intervention (6 [0-74] vs 10.5 [3-63] days, p = 0.001) were shorter in the ceased group. Antibiotic cessation in terminally ill patients was safe, and was associated with a significantly shorter time-to-terminal discharge.

Critical Appraisal of the Impact of the Systematic Adoption of Advanced Minimally Invasive Hepatobiliary and Pancreatic Surgery on the Surgical Management of Mirizzi Syndrome.

BACKGROUND: Minimally invasive surgery (MIS) for Mirizzi syndrome (MS) remains a technically challenging procedure with a high open conversion rate. We critically evaluated the impact of the systematic adoption of MI-HBP surgery on the surgical outcomes of MS. METHODS: Ninety-five patients who underwent surgery for MS were retrospectively reviewed. Systematic adoption of advanced MI-HBP surgery started in 2012. The cohort was classified into a preadoption (2002-2012) (Era 1, n = 58) and post-adoption (2013-2017) (Era 2, n = 37). Furthermore, Era 2 was divided into a cohort operated by advanced minimally invasive surgeons (AMIS) (Era 2 AMIS, n = 19) and those by other surgeons (Era 2 others, n = 19). RESULTS: Comparison between Era 2 and Era 1 demonstrated a significant increase in the frequency of MIS attempted (89% vs 33%, p < 0.01), increase in the use of choledochoplasty (24% vs 2%, p < 0.01), increase operation time (180 min vs 150 min, p = 0.03) and significantly lower open conversion rate (24% vs 58%, p < 0.01). Comparison between Era 2 AMIS and Era 2 others demonstrated a significantly greater adoption of MIS (100% vs 78%, p = 0.046) with lower open conversion rate (5% vs 50%, p = 0.005). Comparison between all attempted MIS cases with open procedures demonstrated a significantly higher proportion of subtotal cholecystectomies performed (40% vs 23%, p = 0.04), choledochoplasty (17% vs 2%, p = 0.04) and shorter hospital stay (4 days vs 9 days, p < 0.01). CONCLUSIONS: Systematic adoption of advanced MI-HBP surgery allowed surgeons to perform MIS for MS more frequently and with a significantly lower open conversion rate. Patients who underwent successful MIS had the shortest hospital stay compared to patients who underwent open surgery or required open conversion.

Pre-operative predictors of early recurrence/mortality including the role of inflammatory indices in patients undergoing partial hepatectomy for spontaneously ruptured hepatocellular carcinoma.

BACKGROUND AND OBJECTIVES: Spontaneous rupture of Hepatocellular Carcinoma (srHCC) is a life-threatening emergency. We sought to identify the pre-operative predictors of early tumor recurrence/mortality including the role of inflammatory indices after partial hepatectomy for srHCC. METHODS: Between 2000-2015, 79 patients with srHCC were identified to have undergone upfront partial hepatectomy following srHCC. Clinicopathologic data were retrospectively analyzed to identify pre-operative predictors of early (<1 year) recurrence and mortality. RESULTS: Seventy-nine patients were identified to have undergone partial hepatectomy for srHCC. The 1-year mortality and 1-year recurrence rate in our series was 30.3% and 41.8% respectively. On multivariate analyses, free tumor rupture and a tumor size > 10 cm were identified to be independent predictors of early recurrence while an alpha fetoprotein (AFP) > 200 ng/mL was an independent predictor of early mortality. Neutrophil-to-lymphocyte ratio > 3 and prognostic nutritional index < 40 were predictors of early recurrence while PLR > 180 was a predictor of early mortality on univariate analyses but not multivariate analyses. CONCLUSIONS: Tumor size > 10 cm, free tumor rupture, and an AFP > 200 ng/mL were useful predictors in avoiding "futile surgery" in patients with srHCC undergoing a partial hepatectomy. Preoperative inflammatory markers appear to be less useful as predictors of early recurrence/mortality in this cohort of patients.

Prevalence of Healthcare-Associated Infections and Antimicrobial Use Among Adult Inpatients in Singapore Acute-Care Hospitals: Results From the First National Point Prevalence Survey.

BACKGROUND: We conducted a national point prevalence survey (PPS) to determine the prevalence of healthcare-associated infections (HAIs) and antimicrobial use (AMU) in Singapore acute-care hospitals. METHODS: Trained personnel collected HAI, AMU, and baseline hospital- and patient-level data of adult inpatients from 13 private and public acute-care hospitals between July 2015 and February 2016, using the PPS methodology developed by the European Centre for Disease Prevention and Control. Factors independently associated with HAIs were determined using multivariable regression. RESULTS: Of the 5415 patients surveyed, there were 646 patients (11.9%; 95% confidence interval [CI], 11.1%-12.8%) with 727 distinct HAIs, of which 331 (45.5%) were culture positive. The most common HAIs were unspecified clinical sepsis (25.5%) and pneumonia (24.8%). Staphylococcus aureus (12.9%) and Pseudomonas aeruginosa (11.5%) were the most common pathogens implicated in HAIs. Carbapenem nonsusceptibility rates were highest in Acinetobacter species (71.9%) and P. aeruginosa (23.6%). Male sex, increasing age, surgery during current hospitalization, and presence of central venous or urinary catheters were independently associated with HAIs. A total of 2762 (51.0%; 95% CI, 49.7%-52.3%) patients were on 3611 systemic antimicrobial agents; 462 (12.8%) were prescribed for surgical prophylaxis and 2997 (83.0%) were prescribed for treatment. Amoxicillin/clavulanate was the most frequently prescribed (24.6%) antimicrobial agent. CONCLUSIONS: This survey suggested a high prevalence of HAIs and AMU in Singapore's acute-care hospitals. While further research is necessary to understand the causes and costs of HAIs and AMU in Singapore, repeated PPSs over the next decade will be useful to gauge progress at controlling HAIs and AMU.

Clinical Efficacy of Polymyxin Monotherapy versus Nonvalidated Polymyxin Combination Therapy versus Validated Polymyxin Combination Therapy in Extensively Drug-Resistant Gram-Negative Bacillus Infections.

Polymyxins have emerged as a last-resort treatment of extensively drug-resistant (XDR) Gram-negative Bacillus (GNB) infections, which present a growing threat. Individualized polymyxin-based antibiotic combinations selected on the basis of the results of in vitro combination testing may be required to optimize therapy. A retrospective cohort study of hospitalized patients receiving polymyxins for XDR GNB infections from 2009 to 2014 was conducted to compare the treatment outcomes between patients receiving polymyxin monotherapy (MT), nonvalidated polymyxin combination therapy (NVCT), and in vitro combination testing-validated polymyxin combination therapy (VCT). The primary and secondary outcomes were infection-related mortality and microbiological eradication, respectively. Adverse drug reactions (ADRs) between treatment groups were assessed. A total of 291 patients (patients receiving MT, n = 58; patients receiving NVCT, n = 203; patients receiving VCT, n = 30) were included. The overall infection-related mortality rate was 23.0% (67 patients). In the multivariable analysis, treatment of XDR GNB infections with MT (adjusted odds ratio [aOR], 8.49; 95% confidence interval [CI], 1.56 to 46.05) and NVCT (aOR, 5.75; 95% CI, 1.25 to 25.73) was associated with an increased risk of infection-related mortality compared to that with treatment with VCT. A higher Acute Physiological and Chronic Health Evaluation II (APACHE II) score (aOR, 1.14; 95% CI 1.07 to 1.21) and a higher Charlson comorbidity index (aOR, 1.28; 95% CI, 1.11 to 1.47) were also independently associated with an increased risk of infection-related mortality. No increase in the incidence of ADRs was observed in the VCT group. The use of an individualized antibiotic combination which was selected on the basis of the results of in vitro combination testing was associated with significantly lower rates of infection-related mortality in patients with XDR GNB infections. Future prospective randomized studies will be required to validate these findings.

Candida Surveillance in Surgical Intensive Care Unit (SICU) in a Tertiary Institution.

BACKGROUND: Colonization of patients occurs before development into invasive candidiasis. There is a need to determine the incidences of Candida colonization and infection in SICU patients, and evaluate the usefulness of beta-D-glucan (BDG) assay in diagnosing invasive candidiasis when patients are colonized. METHODS: Clinical data and fungal surveillance cultures in 28 patients were recorded from November 2010, and January to February 2011. Susceptibilities of Candida isolates to fluconazole, voriconazole, amphotericin B, micafungin, caspofungin and anidulafungin were tested via Etest. The utilities of BDG, Candida score and colonization index for candidiasis diagnosis were compared via ROC. RESULTS: 30 BDG assays were performed in 28 patients. Four assay cases had concurrent colonization and infection; 23 had concurrent colonization and no infection; three had no concurrent colonization and infection. Of 136 surveillance swabs, 52 (38.24 %) were positive for Candida spp, with C. albicans being the commonest. Azole resistance was detected in C. albicans (7 %). C. glabrata and C. tropicalis were, respectively, 100 and 7 % SDD to fluconazole. All 3 tests showed high sensitivity of 75-100 % but poor specificity ranging 15.38-38.46 %. BDG performed the best (AUC of 0.89). CONCLUSIONS: Despite that positive BDG is common in surgical patients with Candida spp colonization, BDG performed the best when compared to CI and CS.

A retrospective study of intravenous pentamidine for Pneumocystis jirovecii pneumonia prophylaxis in adult patients with hematologic malignancies-its utility during respiratory virus pandemics.

OBJECTIVES: In hematology, prophylaxis for Pneumocystis jirovecii pneumonia (PCP) is recommended for patients undergoing hematopoietic stem cell transplantation and in selected categories of intensive chemotherapy for hematologic malignancies. Trimethoprim-sulfamethoxazole (TMP-SMX) is the recommended first-line agent; however, its use is not straightforward. Inhaled pentamidine is the recommended second-line agent; however, aerosolized medications were discouraged during respiratory virus outbreaks, especially during the COVID-19 pandemic, in view of potential contamination risks. Intravenous (IV) pentamidine is a potential alternative agent. We evaluated the effectiveness and tolerability of IV pentamidine use for PCP prophylaxis in adult allogeneic hematopoietic stem cell transplantation recipients and patients with hematologic malignancies during COVID-19. RESULTS: A total of 202 unique patients who received 239 courses of IV pentamidine, with a median of three doses received (1-29). The largest group of the patients (49.5%) who received IV pentamidine were undergoing or had received a hematopoietic stem cell transplant. The most common reason for not using TMP-SMX prophylaxis was cytopenia (34.7%). We have no patients who had breakthrough PCP infection while on IV pentamidine. None of the patients developed an infusion reaction or experienced adverse effects from IV pentamidine. CONCLUSIONS: Pentamidine administered IV monthly is safe and effective.

Outcomes of appropriate empiric combination versus monotherapy for Pseudomonas aeruginosa bacteremia.

Pseudomonas aeruginosa bacteremia is associated with high hospital mortality. Empirical combination therapy is commonly used to increase the likelihood of appropriate therapy, but the benefits of employing >1 active agent have yet to be established. The purpose of this study was to compare outcomes of patients receiving appropriate empirical combination versus monotherapy for P. aeruginosa bacteremia. This was a retrospective, multicenter, cohort study of hospitalized adult patients with P. aeruginosa bacteremia from 2002 to 2011. The primary endpoint (30-day mortality) was assessed using multivariate logistic regression, adjusting for underlying confounding variables. Secondary endpoints of hospital mortality and time to mortality were assessed by Fisher's exact test and the Cox proportional hazards model, respectively. A total of 384 patients were analyzed. Thirty-day mortality was higher for patients receiving inappropriate therapy than for those receiving appropriate empirical therapy (43.8% versus 21.5%; P = 0.03). However, there were no statistical differences in 30-day mortality following appropriate empirical combination versus monotherapy after adjusting for baseline APACHE II scores and lengths of hospital stay prior to the onset of bacteremia (P = 0.55). Observed hospital mortality was 36.6% for patients administered combination therapy, compared with 28.7% for monotherapy patients (P = 0.17). After adjusting for baseline APACHE II scores, the relationship between time to mortality and combination therapy was not statistically significant (P = 0.59). Overall, no significant differences were observed for 30-day mortality, hospital mortality, and time to mortality between combination and monotherapy for P. aeruginosa bacteremia. Empirical combination therapy did not appear to offer an additional benefit, as long as the isolate was susceptible to at least one antimicrobial agent.

Reducing prophylactic antibiotics use in laparoscopic cholecystectomy and liver resections.

Laparoscopic cholecystectomy and liver resections are commonly performed surgical procedures which require no or less (cefazolin only) antimicrobial prophylaxis respectively in light of recent evidence. To assess the validity of this data in the local context and increase compliance to such regimens, a multi-modal intervention including, changes to hospital antibiotic prophylaxis guidelines, departmental emphasis, information technology aids (involving the creation of order templates within our electronic medical system) and physical aids (in the form of cards given to junior staff) was implemented. Results comparing a 6-month preintervention period (January 2018 to June 2018) showed no significant increase in 30-day hospital readmission rates (P = 0.8, 0.7) despite a significant rise in compliance (P = 0.04, 0.03) in laparoscopic cholecystectomy (n = 371) and liver resections respectively (n = 193) compared to the 6-month intervention period (July 2018 to December 2018). Additionally, prescription behavior for liver resections was more varied than that of laparoscopic cholecystectomy likely due to the different anatomical considerations in the prior. In conclusion, removal of antibiotic prophylaxis in laparoscopic cholecystectomy and use of cefazolin only in liver resection is not associated with any significant increase in 30-day hospital readmission rates.

Discontinuation of Antibiotics in Patients with Neurological Conditions - A Study on the Impact of an Antimicrobial Stewardship Program (ASP) in a Tertiary Institution.

BACKGROUND: Up to 50% of antibiotics are prescribed either unnecessarily or inappropriately in most hospitals worldwide. In the largest tertiary hospital in Singapore, patients with neurological conditions were often initiated on antibiotics for change in mental state or isolated fevers. We hypothesize that Antimicrobial Stewardship Program (ASP) interventions to discontinue empirical antibiotics in neurological patients with no clinical evidence of bacterial infection are safe. The aim of this study was to compare clinical impact and safety outcomes of ASP interventions between accepted and rejected groups. METHODS: A retrospective review of the ASP database was conducted for all patients admitted to the neurology department in Singapore General Hospital between January 2014 and December 2017. Interventions were followed up and patients were classified into two intervention groups, the accepted and rejected groups. Demographic data, age-adjusted Charlson co-morbidity index, duration of antibiotic therapy, length of hospital stay post-ASP intervention (PLOS), infection-related readmissions and mortality were compared between the two groups. Data were expressed as mean ± standard deviation for continuous variables, and unpaired Student's t-test was performed to determine intergroup differences between mean values. RESULTS: The ASP team recommended 184 interventions, with an overall acceptance rate of 82.6% (152/184). There was no significant difference in demographics and age-adjusted Charlson co-morbidity index between the two groups. The accepted group had a shorter duration of therapy by 1.67 days (4.99±2.50 days vs. 6.66±2.34 days; P<0.01) and a shorter PLOS by 2 days, although this was not statistically significant (22.5±22.2 days vs. 24.5±51.4 days; P=0.83). There were no significant differences between the two groups in 14-day mortality and readmission rates. CONCLUSION: In neurological patients with no clinical evidence of bacterial infections, ASP interventions to discontinue empirical antibiotics were not associated with increased mortality and readmissions but were associated with significant reduction in duration of therapy.

Treatment and Outcomes of Infections Caused by Diverse Carbapenemase-Producing Carbapenem-Resistant Enterobacterales.

Background: Diverse sequence types (ST) and various carbapenemase-producing carbapenem-resistant Enterobacterales (CP-CRE) infections, which complicate treatment strategies, have emerged in Singapore. We aim to describe these CP-CRE infections and clinical outcomes according to their carbapenemase types and determine the hierarchy of predictors for mortality that are translatable to clinical practice. Methods: Clinically significant CP-CRE infections were identified in Singapore General Hospital between 2013 and 2016. Retrospectively, all clinically relevant data were retrieved from electronic medical records from the hospital. Univariate analysis was performed. To further explore the relationship between the variables and mortality in different subsets of patients with CP-CRE, we conducted recursive partitioning analysis on all study variables using the "rpart" package in R. Results: One hundred and fifty five patients were included in the study. Among them, 169 unique CP-CRE were isolated. Thirty-day all-cause in-hospital mortality was 35.5% (n = 55). There was no difference in the severity of illness, or any clinical outcomes exhibited by patients between the various carbapenemases. Root node began with patients with Acute Physical and Chronic Health Evaluation (APACHEII) score ≥ 15 (n = 98; mortality risk = 52.0%) and <15 (n = 57; mortality risk = 9.0%). Patients with APACHEII score ≥ 15 are further classified based on presence (n = 27; mortality risk = 23.0%) and absence (n = 71, mortality risk = 62.0%) of bacterial eradication. Without bacterial eradication, absence (n = 54) and presence (n = 17) of active source control yielded 70.0 and 35.0% mortality risk, respectively. Without active source control, the mortality risk was higher for the patients with non-receipt of definite combination therapy (n = 36, mortality risk = 83.0%) when compared to those who received (n = 18, mortality risk = 47.0%). Overall, the classification tree has an area under receiver operating characteristic curve of 0.92, with a sensitivity of 0.87 and specificity of 0.91. Conclusion: Different mortality risks were observed with different treatment strategies. Effective source control and microbial eradication were associated with a lower mortality rate but not active empiric therapy for CP-CRE infection. When source control was impossible, definitive antibiotic combination appeared to be associated with a reduction in mortality.

Who listens and who doesn't? Factors associated with adherence to antibiotic stewardship intervention in a Singaporean tertiary hospital.

INTRODUCTION: Antibiotic stewardship programmes (ASPs) can improve patient outcomes by prospective audit and feedback with interventions. However, adherence to ASP interventions is not mandatory. Identifying factors associated with improved adherence may help to enhance ASP recommendations and activities. METHODS: A retrospective cohort study was conducted, comprising all ASP interventions performed as part of the prospective audit and feedback strategy in our institution (an acute tertiary-care hospital in Singapore) from January 2016 to July 2018. Adherence to ASP intervention was ascertained based on documented compliance with the recommended interventions within 48h. Factors associated with adherence to ASP interventions, such as patient demographics, clinical condition, type of infection, and characteristics of ASP interventions were identified using the χ2 test for categorical variables. On multivariate analysis, factors independently associated with adherence to ASP intervention were identified using logistic regression. RESULTS: Adherence to ASP intervention was 81.9% (5758/7028). On univariate and multivariate analysis, interventions coupled with direct communication via phone call (adjusted odds ratio [aOR] 1.61, 95% CI 1.23-2.08) were associated with higher odds of adherence, whereas admission to a surgical unit, intervention involving carbapenem use, and recommendation to de-escalate or discontinue antibiotics were associated with lower odds of adherence to ASP interventions. CONCLUSION: Although adherence rates to ASP interventions were relatively high, interventions made to the surgical unit and recommendations related to carbapenem use were not so well received. Interventions communicated verbally via phone call were well received, highlighting the need for a close working relationship between ASP teams and hospital physicians.

Discontinuation of antibiotic therapy within 24 hours of treatment initiation for patients with no clinical evidence of bacterial infection: a 5-year safety and outcome study from Singapore General Hospital Antimicrobial Stewardship Program.

BACKGROUND: Overprescribing antibiotics for patients with no bacterial infection is of growing global concern. It is important for timely Antimicrobial Stewardship Program (ASP) intervention to discontinue antibiotics for patients whose symptoms can be explained by non-infective causes, and without availability of bacterial cultures and susceptibilities reports. This study aimed to evaluate clinical outcomes and safety of early ASP review in these patients. METHODS: A retrospective review of the ASP database (January 2010 to December 2014) was conducted to identify patients for whom ASP recommended discontinuation of empiric antibiotics within 24 hours of prescribing. Demographics were collected. Clinical outcomes - duration of therapy, length of hospital stay (LOS), infection-related readmissions, and all-cause mortality - were compared between interventions accepted and rejected groups. Continuous data were analysed via unpaired Student's t-test. Categorical data were analysed using χ2 test or Fisher's exact test, as appropriate. RESULTS: The ASP team recommended 794 interventions (overall acceptance rate of 72.9%, 579 of 794). There were no significant between-group differences in underlying demographics, and Charlson comorbidity index score. However, the interventions acceptance group had significantly shorter duration of therapy by 2.61 days (2.72 ± 3.04 vs. 5.33 ± 2.54 days; P < 0.01) and LOS by 7.41 days (7.98 ± 13.14 vs. 15.39 ± 22.62 days; P < 0.01), with estimated cost savings of SGD10 817 per patient. There were no significant between-group differences in 14-day mortality and readmission rates. CONCLUSION: Prompt ASP interventions at Singapore General Hospital were associated with significant reductions in duration of therapy and LOS, with cost savings. It was demonstrated that it is safe to discontinue antibiotics within 24 hours of prescribing for patients with no evidence of bacterial infections.

Liver Resection for Nonalcoholic Fatty Liver Disease-Associated Hepatocellular Carcinoma.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD)-related hepatocellular carcinoma (HCC) is on the rise worldwide, but data on long-term outcomes after curative operations are limited. The primary aim of this study was to characterize the perioperative and long-term outcomes after liver resection. The secondary aim was to investigate the influence of the histologic severity of nonalcoholic steatohepatitis and its impact on perioperative outcomes and long-term survival. METHODS: A total of 996 patients who underwent liver resection for HCC in our institution were analyzed. Patients were categorized into subgroups of NAFLD vs non-NAFLD HCC based on histologic evidence of hepatic steatosis. Comparisons of patients' demographic, clinical, and surgical characteristics; postoperative complications; and survival outcomes were performed. RESULTS: Eight hundred and forty-four patients had non-NAFLD HCC and 152 patients had NAFLD HCC. Comorbidities were significantly more common in the NAFLD group (p < 0.0001). In the non-NAFLD group, larger median tumor size, higher liver cirrhosis, and lower median neutrophil to lymphocyte ratio were observed (p < 0.0001). The NAFLD group had a greater amount of intraoperative blood loss, more postoperative complications, and longer length of stay. Five-year overall survival was significantly better in the NAFLD group (p = 0.0355). Significant factors that contribute to poorer survival outcomes include age, congestive cardiac failure, Child-Pugh's class B, cirrhosis, tumor size, multinodularity, and R1 resection. For NAFLD group, patients with abnormal parenchyma showed poorer survival and 5-year overall survival rates (64.8% vs 75.6%; p = 0.2291). CONCLUSIONS: Nonalcoholic fatty liver disease-related HCC is associated with greater surgical morbidity and post-hepatectomy liver failure. Despite this, long-term survival outcomes are favorable compared with non-NAFLD etiologies.

Do antimicrobial stewardship programme interventions reduce the rate of and protect against Clostridium difficile infection?

OBJECTIVES: Antimicrobial stewardship programmes (ASPs) have often been recommended as a viable solution to minimise the incidence of Clostridium difficile infection (CDI), which can be life-threatening. This study aimed to evaluate whether ASP interventions have contributed to reducing CDI rates. METHODS: A retrospective review of ASP interventions issued from January 2013 to April 2014 was performed using data from the ASP database of Singapore General Hospital, a 1600-bed tertiary-care hospital in Singapore. A total of 283 interventions satisfied the inclusion criteria, of which commonly audited antibiotics were piperacillin/tazobactam (41.3%) and carbapenems (54.8%). Comparisons were made at 30days post-intervention between those with accepted or rejected interventions. The primary outcome was CDI incidence; secondary outcomes included length of hospitalisation post-intervention, 30-day mortality and CDI recurrence rate. RESULTS: Whilst the median duration of antibiotic therapy was reduced by 2days (6days vs. 4 days; P<0.001), acceptance of ASP interventions did not alter primary CDI incidence at 30days (P=0.644) post-intervention. However, reduced CDI recurrence rates were observed for patients positive for CDI in the accepted patient group compared with the rejected group (0% vs. 37.5%; P=0.03), with no difference in CDI 30-day mortality between the two groups. CONCLUSION: Intervention acceptance did not contribute to a significant reduction in CDI incidence but may be associated with lower recurrence rates, although further studies are required.

Optimisation of antimicrobial dosing based on pharmacokinetic and pharmacodynamic principles.

While suboptimal dosing of antimicrobials has been attributed to poorer clinical outcomes, clinical cure and mortality advantages have been demonstrated when target pharmacokinetic (PK) and pharmacodynamic (PD) indices for various classes of antimicrobials were achieved to maximise antibiotic activity. Dosing optimisation requires a good knowledge of PK/PD principles. This review serves to provide a foundation in PK/PD principles for the commonly prescribed antibiotics (ß-lactams, vancomycin, fluoroquinolones and aminoglycosides), as well as dosing considerations in special populations (critically ill and obese patients). PK principles determine whether an appropriate dose of antimicrobial reaches the intended pathogen(s). It involves the fundamental processes of absorption, distribution, metabolism and elimination, and is affected by the antimicrobial's physicochemical properties. Antimicrobial pharmacodynamics define the relationship between the drug concentration and its observed effect on the pathogen. The major indicator of the effect of the antibiotics is the minimum inhibitory concentration. The quantitative relationship between a PK and microbiological parameter is known as a PK/PD index, which describes the relationship between dose administered and the rate and extent of bacterial killing. Improvements in clinical outcomes have been observed when antimicrobial agents are dosed optimally to achieve their respective PK/PD targets. With the rising rates of antimicrobial resistance and a limited drug development pipeline, PK/PD concepts can foster more rational and individualised dosing regimens, improving outcomes while simultaneously limiting the toxicity of antimicrobials.

A multidisciplinary antimicrobial stewardship programme safely decreases the duration of broad-spectrum antibiotic prescription in Singaporean adult renal patients.

Patients with chronic kidney disease have increased risk of infections. Thus, physicians may favour prolonged broad-spectrum antibiotic use. Studies focused on antimicrobial stewardship programmes (ASPs) in renal patients are currently lacking. Here we describe the role of a multidisciplinary ASP and the impact of ASP interventions in renal patients. A multidisciplinary ASP was initiated at a tertiary hospital in Singapore. Patients prescribed broad-spectrum parenteral antibiotics were identified daily and were subjected to prospective review with immediate concurrent feedback. ASP data from January 2010 to December 2011 were analysed for all renal patients. Outcome measures included the duration and appropriateness of antibiotics, intervention acceptance rates, cost savings and safety outcomes. A total of 2084 antibiotic courses were reviewed, of which 24% were inappropriate, with meropenem most commonly prescribed inappropriately (31.0%). The commonest reasons for inappropriate use were wrong choice (51.0%) and wrong duration (21.4%). In total, 634 recommendations were made, with high acceptance rates (73.3%). Recommendations to discontinue antibiotics (33.4%) and to optimise doses (17.2%) comprised the bulk of ASP work. A mean reduction of -1.28 days of antibiotic use was observed among patients with interventions accepted versus those rejected (P<0.001), with direct cost savings of SGD$90,045. No difference in 30-day mortality (P=0.91) was observed between the accepted and rejected intervention groups. In conclusion, a multidisciplinary ASP resulted in a shorter duration of antibiotic use without compromising safety in renal patients. Continued effort is needed to produce a long-term impact on antibiotic prescription and resistance.

Impact of Antimicrobial Stewardship Program (ASP) on Outcomes in Patients with Acute Bacterial Skin and Skin Structure Infections (ABSSSIs) in an Acute-Tertiary Care Hospital.

INTRODUCTION: Acute bacterial skin and skin structure infections (ABSSSIs) are among the most common infections treated in hospitals, but to date, there has been little information with regards to the implementation of Antimicrobial Stewardship Programs (ASPs) for patients with ABSSSIs. Hence, we aim to evaluate the impact of ASPs on the following outcomes in patients with ABSSSIs: duration of therapy and hospital stay, 14-day reinfection, infection-related readmissions and mortality. METHODS: A retrospective review of the ASP database was conducted, focusing on selected outcomes (as above) among all patients in whom the institution's ASP recommended a change in antibiotic regimen-de-escalation of the antibiotic based on culture results; discontinuation of the antibiotic; narrowing of the empirical coverage; and intravenous-to-oral (i.v.-to-p.o.) switch between September 2009 and December 2012. Data were expressed as mean ± standard deviation for continuous variables, and unpaired Student's t test was performed to determine intergroup differences between mean values. For categorical variables, data were presented as number and percentage and analyzed using the χ (2) test or Fisher's exact test, as appropriate. RESULTS: ASP recommended 407 interventions with an overall acceptance rate of 66.8%. ASP interventions significantly reduced median duration of therapy by 2 [from a median (interquartile range, IQR) of 8 (6-12) days to 6 (4-9) days] and median length of stay by 5 days [from median (IQR) of 12 (5-32) days to 7 (3-18) days]. This led to an estimated total cost avoidance of USD 0.7 million. There were no significant differences in the 14-day reinfection, infection-related readmission and mortality rates between patients whose physicians accepted and those who rejected ASP interventions. CONCLUSION: Interventions recommended by the ASP in Singapore General Hospital were safe and associated with a significant reduction in duration of therapy and hospital stay. The results of our study have affirmed the role of ASP in optimizing the care of patients with ABSSSI.