Effects of selective decontamination of digestive tract on mortality and acquisition of resistant bacteria in intensive care: a randomised controlled trial

Selective decontamination of the digestive tract in burn patients: Protocol for a systematic review

BACKGROUND

Nosocomial infections contribute significantly to mortality and morbidity in burn patients. Selective decontamination of the digestive tract is an infection prevention measure that has been shown to improve survival in mechanically ventilated intensive care unit (ICU) patients. It has been hypothesized that burn patients may benefit from selective decontamination of the digestive tract.

METHODS/DESIGN

We will conduct a systematic review with meta-analysis and trial sequential analysis of randomized clinical trials (RCTs) assessing the patient-important effects of selective decontamination of the digestive tract in burn patients, as compared with placebo or no intervention/standard of care. The primary outcome will be 30-day mortality. Secondary outcomes include serious adverse events, anti-microbial resistance, pneumonia, blood stream infections, ICU- and hospital-free days and 90-day mortality. We will search the following databases: CENTRAL, MEDLINE, EMBASE, BIOSIS, Web of Science and CINAHL and follow the recommendations provided by the Cochrane Collaboration and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The certainty of evidence will be assessed according to the GRADE approach: Grading of Recommendations Assessment, Development and Evaluation.

DISCUSSION

There is clinical equipoise about the use of selective decontamination of the digestive tract in burn patients. In the outlined systematic review and meta-analysis, we will assess the desirable and undesirable effects of selective decontamination of the digestive tract in burn patients.

Selective Digestive Decontamination: A Comprehensive Approach to Reducing Nosocomial Infections and Antimicrobial Resistance in the ICU

Background/Objective: Multidrug-resistant (MDR) bacteria pose a significant threat to global health, especially in intensive care units (ICUs), where high antibiotic consumption drives antimicrobial resistance. Selective digestive decontamination (SDD) is a strategy designed to prevent nosocomial infections and colonization by MDR pathogens. This study aimed to evaluate the impact of implementing an SDD protocol on antibiotic consumption and colonization by carbapenemase-producing Enterobacterale (CPE) in a specific ICU setting. Methods: This quasi-experimental study was conducted in the ICU of a university hospital from June 2021 to June 2023. Patients were divided into two groups: pre-intervention (before SDD) and post-intervention (after SDD implementation). Data on antibiotic consumption (expressed as defined daily doses (DDDs) per 100 stays), nosocomial infections, colonization rates, and the incidence of MDR bacteria were collected. A statistical analysis was conducted to compare the pre- and post-intervention groups. Results: A total of 3266 patients were included, with 1532 in the pre-intervention group and 1734 in the post-intervention group. The implementation of the SDD protocol resulted in a significant reduction in total antibiotic consumption (p = 0.028), with notable decreases in carbapenem use (p < 0.01) and colonization by CPE (p = 0.0099). The incidence of nosocomial infections also decreased in the post-SDD group, although this reduction was not statistically significant. Conclusions: The implementation of the SDD protocol in this ICU setting significantly reduced antibiotic consumption and colonization by CPE. These findings suggest that SDD may be a valuable tool in managing antimicrobial resistance in critical care settings, without contributing to the development of MDR bacteria.

Relationship between SARS-CoV-2 infection and ICU-acquired candidemia in critically ill medical patients: a multicenter prospective cohort study

BACKGROUND

While SARS-CoV2 infection has been shown to be a significant risk-factor for several secondary bacterial, viral and Aspergillus infections, its impact on intensive care unit (ICU)-acquired candidemia (ICAC) remains poorly explored.

METHOD

Using the REA-REZO network (French surveillance network of ICU-acquired infections), we included all adult patients hospitalized for a medical reason of admission in participating ICUs for at least 48 h from January 2020 to January 2023. To account for confounders, a non-parsimonious propensity score matching was performed. Rates of ICAC according to SARS-CoV2 status were compared in matched patients. Factors associated with ICAC in COVID-19 patients were also assessed using a Fine-Gray model.

RESULTS

A total of 55,268 patients hospitalized at least 48 h for a medical reason in 101 ICUs were included along the study period. Of those, 13,472 were tested positive for a SARS-CoV2 infection while 284 patients developed an ICAC. ICAC rate was higher in COVID-19 patients in both the overall population and the matched patients' cohort (0.8% (107/13,472) versus 0.4% (173/41,796); p < 0.001 and 0.8% (93/12,241) versus 0.5% (57/12,241); p = 0.004, respectively). ICAC incidence rate was also higher in those patients (incidence rate 0.51 per 1000 patients-days in COVID-19 patients versus 0.32 per 1000 patients-days; incidence rate ratio: 1.58 [95% CI:1.08-2.35]; p = 0.018). Finally, patients with ICAC had a higher ICU mortality rate (49.6% versus 20.2%; p < 0.001).

CONCLUSION

In this large multicenter cohort of ICU patients, although remaining low, the rate of ICAC was higher among COVID-19 patients.

Effect of opioids on constipation in critically ill patients: A meta-analysis

OBJECTIVES

This meta-analysis evaluated the effect of opioids on constipation in ICU patients.

REVIEW METHOD USED

Systematic review and meta-analysis.

DATA SOURCES

PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), and Wanfang DATA databases.

REVIEW METHODS

Random or fixed-effects meta-analyses were used. Subgroup analysis was performed according to the definition of constipation (three vs. six days), opioids (fentanyl vs. morphine), study design (prospective vs. retrospective), adjustment of confounders (No vs. Yes), and patient's age (adults vs. children). We used sensitivity analysis to test the robustness of results with significant statistical heterogeneity.

RESULTS

Seven studies (2264 patients) were included. Opioid use in ICU patients was associated with an increased risk of constipation (relative risk [RR]=1.14; 95% confidence interval [CI]=1.05 to 1.24; I2=49.8%). Subgroup analysis further showed that adjustment form, category of opioid, study design, and patient's age significantly influenced the relationship between opioid use and the risk of constipation. Sensitivity analysis confirmed the robustness of pooled results.

CONCLUSION

Opioids significantly increase the risk of constipation in critically ill patients, especially children. It is worth noting that the adjustment of the constipation definition used for ICU significantly influenced the relationship between opioid use and the risk of constipation. Therefore, It is necessary to clearly define ICU constipation and conduct time-based layered treatment. Additional prospective studies are needed to investigate the consistent definition of ICU constipation.

Association between selective digestive decontamination and decreased rate of acquired candidemia in mechanically ventilated ICU patients: a multicenter nationwide study

BACKGROUND

Candidemia is a high-risk complication among intensive care unit (ICU) patients. While selective digestive decontamination (SDD) has been shown to be effective in preventing ICU-acquired bacterial secondary infection, its effects on ICU-acquired candidemia (ICAC) remain poorly explored. Therefore, we sought to assess the effects of SDD on ICAC.

METHOD

Using the REA-REZO network, we included adult patients receiving mechanical ventilation for at least 48 h from January 2017 to January 2023. Non-parsimonious propensity score matching with a 1:1 ratio was performed to investigate the association between SDD and the rate of ICAC.

RESULTS

A total of 94 437 patients receiving at least 48 h of mechanical ventilation were included throughout the study period. Of those, 3 001 were treated with SDD and 651 patients developed ICAC. The propensity score matching included 2 931 patients in the SDD group and in the standard care group. In the matched cohort analysis as well as in the overall population, the rate of ICAC was lower in patients receiving SDD (0.8% versus 0.3%; p = 0.012 and 0.7% versus 0.3%; p = 0.006, respectively). Patients with ICAC had higher mortality rate (48.4% versus 29.8%; p < 0.001). Finally, mortality rates as well as ICU length of stay in the matched populations did not differ according to SDD (31.0% versus 31.1%; p = 0.910 and 9 days [5-18] versus 9 days [5-17]; p = 0.513, respectively).

CONCLUSION

In this study with a low prevalence of ICAC, SDD was associated with a lower rate of ICAC that did not translate to higher survival.

Indirect (herd) effects of topical antibiotic prophylaxis and oral care versus non-antimicrobial methods increase mortality among ICU patients: realigning Cochrane review data to emulate a three-tier cluster randomised trial

OBJECTIVE

This study aimed to estimate the direct effects to recipients and indirect (herd) effects to non-recipients of each of topical antibiotic prophylaxis (TAP) and oral care methods on patient mortality within randomised concurrent controlled trials (RCCT) using Cochrane review data.

DESIGN

Control and intervention groups from 209 RCCTs of TAP (tier 3), oral care (tier 2) each versus non-antimicrobial (tier 1) ventilator-associated pneumonia (VAP) prevention interventions arranged to emulate a three-tiered cluster randomised trial (CRT). Eligible RCCTs were those including ICU patients with >50% of patients receiving >24 hours of mechanical ventilation (MV) with mortality data available as abstracted in 13 Cochrane reviews.

EXPOSURES

Direct and indirect exposures to either TAP or oral care within RCCTs versus non-antimicrobial VAP prevention interventions.

MAIN OUTCOMES AND MEASURES

The ICU mortality within control and intervention groups, respectively, within RCCTs of either TAP or oral care versus that within non-antimicrobial VAP prevention RCCTs serving as benchmark.

RESULTS

The ICU mortality was 23.9%, 23.0% and 20.3% for intervention groups and 28.7%, 25.5% and 19.5% for control groups of RCCTs of TAP (tier 1), oral care (tier 2) and non-antimicrobial (tier 3) methods of VAP prevention, respectively. In a random effects meta-regression including late mortality data and adjusting for group mean age, year of study publication and MV proportion, the direct effect of TAP and oral care versus non-antimicrobial methods were 1.04 (95% CI 0.78 to 1.30) and 1.1 (95% CI 0.77 to 1.43) whereas the indirect effects were 1.39 (95% CI 1.03 to 1.74) and 1.26 (95% CI 0.89 to 1.62), respectively.

CONCLUSIONS

Indirect (herd) effects from TAP and oral care methods on mortality are stronger than the direct effects as made apparent by the three-tiered CRT. These indirect effects, being harmful to concurrent control groups by increasing mortality, perversely inflate the appearance of benefit within RCCTs.

Positive single-center randomized trials and subsequent multicenter randomized trials in critically ill patients: a systematic review

BACKGROUND

It is unclear how often survival benefits observed in single-center randomized controlled trials (sRCTs) involving critically ill patients are confirmed by subsequent multicenter randomized controlled trials (mRCTs). We aimed to perform a systemic literature review of sRCTs with a statistically significant mortality reduction and to evaluate whether subsequent mRCTs confirmed such reduction.

METHODS

We searched PubMed for sRCTs published in the New England Journal of Medicine, JAMA, or Lancet, from inception until December 31, 2016. We selected studies reporting a statistically significant mortality decrease using any intervention (drug, technique, or strategy) in adult critically ill patients. We then searched for subsequent mRCTs addressing the same research question tested by the sRCT. We compared the concordance of results between sRCTs and mRCTs when any mRCT was available. We registered this systematic review in the PROSPERO International Prospective Register of Systematic Reviews (CRD42023455362).

RESULTS

We identified 19 sRCTs reporting a significant mortality reduction in adult critically ill patients. For 16 sRCTs, we identified at least one subsequent mRCT (24 trials in total), while the interventions from three sRCTs have not yet been addressed in a subsequent mRCT. Only one out of 16 sRCTs (6%) was followed by a mRCT replicating a significant mortality reduction; 14 (88%) were followed by mRCTs with no mortality difference. The positive finding of one sRCT (6%) on intensive glycemic control was contradicted by a subsequent mRCT showing a significant mortality increase. Of the 14 sRCTs referenced at least once in international guidelines, six (43%) have since been either removed or suggested against in the most recent versions of relevant guidelines.

CONCLUSION

Mortality reduction shown by sRCTs is typically not replicated by mRCTs. The findings of sRCTs should be considered hypothesis-generating and should not contribute to guidelines.

Selective decontamination of the digestive tract: concept and application

Selective digestive decontamination (SDD) is a prophylactic strategy aimed at preventing or eradicating bacterial overgrowth in the intestinal flora that precedes the development of most infections in the Intensive Care Unit. SDD prevents serious infections, reduces mortality, is cost-effective, has no adverse effects, and its short- or long-term use is not associated with any significant increase in antimicrobial resistance. SDD is one of the most widely evaluated interventions in critically ill patients, yet its use is not widespread. The present article offers a narrative review of the most relevant evidence and an update of the pathophysiological concepts of infection control supporting the use of SDD.

Prevention of ICU-acquired infection with decontamination regimen in immunocompromised patients: a pre/post observational study

PURPOSE

Although the proportion of immunocompromised patients admitted to the ICU is increasing, data regarding specific management, including acquired infection (ICU-AI) prophylaxis, in this setting are lacking. We aim to investigate the effect of multiple-site decontamination regimens (MSD) in immunocompromised patients.

METHODS

We conducted a prospective pre-/post-observational study in 2 ICUs in Bretagne, western France. Adults who required mechanical ventilation for 24 h or more were eligible. During the study period, MSD was implemented in participating ICUs in addition to standard care. It consists of the administration of topical antibiotics (gentamicin, colistin sulfate, and amphotericin B), four times daily in the oropharynx and the gastric tube, 4% chlorhexidine bodywash once daily, and a 5-day nasal mupirocin course.

RESULTS

Overall, 295 immunocompromised patients were available for analysis (151 in the post-implementation group vs 143 in the pre-implementation group). Solid organ cancer was present in 77/295 patients while immunomodulatory treatments were noticed in 135/295. They were 35 ICU-AI in 29/143 patients in the standard-care group as compared with 10 ICU-AI in 9/151 patients in the post-implementation group (p < 0.001). In a multivariable Poisson regression model, MSD was independently associated with a decreased incidence of ICU-AI (incidence rate ratio = 0.39; 95%CI [0.20-0.87] p = 0.008). There were 35/143 deaths in the standard-care group as compared with 22/151 in the post-implementation group (p = 0.046), this difference remained in a multivariable Cox model (HR = 0.58; 95CI [0.34-0.95] p = 0.048).

CONCLUSION

In conclusion, MSD appeared to be associated with improved outcomes in critically ill immunocompromised patients.

Eudragit® FS Microparticles Containing Bacteriophages, Prepared by Spray-Drying for Oral Administration

Phage therapy is recognized to be a promising alternative to fight antibiotic-resistant infections. In the quest for oral dosage forms containing bacteriophages, the utilization of colonic-release Eudragit^® derivatives has shown potential in shielding bacteriophages from the challenges encountered within the gastrointestinal tract, such as fluctuating pH levels and the presence of digestive enzymes. Consequently, this study aimed to develop targeted oral delivery systems for bacteriophages, specifically focusing on colon delivery and employing Eudragit^® FS30D as the excipient. The bacteriophage model used was LUZ19. An optimized formulation was established to not only preserve the activity of LUZ19 during the manufacturing process but also ensure its protection from highly acidic conditions. Flowability assessments were conducted for both capsule filling and tableting processes. Furthermore, the viability of the bacteriophages remained unaffected by the tableting process. Additionally, the release of LUZ19 from the developed system was evaluated using the Simulator of the Human Intestinal Microbial Ecosystem (SHIME^®) model. Finally, stability studies demonstrated that the powder remained stable for at least 6 months when stored at +5 °C.

Multiple-site decontamination to prevent acquired infection in patients with veno-venous ECMO support

BACKGROUND

Acute distress respiratory syndrome (ARDS) patients with veno-venous extra corporeal membrane oxygenation (ECMO) support are particularly exposed to ECMO-associated infection (ECMO-AI). Unfortunately, data regarding AI prophylaxis in this setting are lacking. Selective decontamination regimens decrease AI incidence, including ventilator-associated pneumonia (VAP) and bloodstream infection (BSI) in critically ill patients. We hypothesized that a multiple-site decontamination (MSD) regimen is associated with a reduction in the incidence of AI among VV-ECMO patients.

METHODS

We conducted a retrospective observational study in three French ECMO referral centers from January 2010 to December 2021. All adult patients (> 18 years old) who received VV-ECMO support for ARDS were eligible. In addition to standard care (SC), 2 ICUs used MSD, which consists of the administration of topical antibiotics four times daily in the oropharynx and the gastric tube, once daily chlorhexidine body-wash and a 5-day nasal mupirocin course. AIs were compared between the 2 ICUs using MSD (MSD group) and the last ICU using SC.

RESULTS

They were 241 patients available for the study. Sixty-nine were admitted in an ICU that applied MSD while the 172 others received standard care and constituted the SC group. There were 19 ECMO-AIs (12 VAP, 7 BSI) in the MSD group (1162 ECMO-days) compared to 143 AIs (104 VAP, 39 BSI) in the SC group (2376 ECMO-days), (p < 0.05 for all infection site). In a Poisson regression model, MSD was independently associated with a lower incidence of ECMO-AI (IRR = 0.42, 95% CI [0.23-0.60] p < 0.001). There were 30 multidrug resistant microorganisms (MDRO) acquisition in the SC group as compared with two in the MSD group (IRR = 0.13, 95% CI [0.03-0.56] p = 0.001). Mortality in ICU was similar in both groups (43% in the SC group vs 45% in the MSD group p = 0.90). Results were similar after propensity-score matching.

CONCLUSION

In this cohort of patients from different hospitals, MSD appeared to be safe in ECMO patients and may be associated with improved outcomes including lower ECMO-AI and MDRO acquisition incidences. Since residual confounders may persist, these promising results deserve confirmation by randomized controlled trials.

Target attainment and pharmacokinetics of cefotaxime in critically ill patients undergoing continuous kidney replacement therapy

OBJECTIVES

Limited data exist about the antimicrobial target attainment and pharmacokinetics of cefotaxime in critically ill patients in the ICU undergoing continuous kidney replacement therapy (CKRT). We conducted a prospective observational study in two large teaching hospitals [Isala Hospital (IH) and Zwolle and Maasstad Hospital (MH)] to investigate target attainment and pharmacokinetics of cefotaxime in patients undergoing CKRT.

PATIENTS AND METHODS

Patients aged ≥18 years admitted to the ICU treated with IV cefotaxime 1000 mg three times daily (IH) or 4 times daily (MH) were included. Fifteen patients were enrolled in total. Per patient eight cefotaxime plasma and eight ultrafiltrate samples were drawn in IH and four plasma samples in MH on Day 2 of treatment. In ICU patients the recommended antimicrobial target of cefotaxime is a plasma concentration 100% of the time above the MIC.

RESULTS

In IH 10/11 patients had higher plasma trough concentrations than the MIC breakpoint of Enterobacterales of 1 mg/L (clinical breakpoint for susceptible strains) and 9/11 patients had concentrations above 2 mg/L (clinical breakpoint for resistant strains). All patients (4/4) in MH had higher plasma trough concentrations than 2 mg/L. A sieving coefficient of 0.74 was identified, with a median amount of 40% of cefotaxime eliminated by CKRT.

CONCLUSIONS

We conclude that cefotaxime 1000 mg 3-4 times daily gives adequate plasma concentrations in patients with anuria or oliguria undergoing CKRT. The 1000 mg four times daily dosage is recommended in patients undergoing CKRT with partially preserved renal function to achieve the target.

Effect of Selective Decontamination of the Digestive Tract on Hospital Mortality in Critically Ill Patients Receiving Mechanical Ventilation: A Randomized Clinical Trial

Importance

Whether selective decontamination of the digestive tract (SDD) reduces mortality in critically ill patients remains uncertain.

Objective

To determine whether SDD reduces in-hospital mortality in critically ill adults.

Design, Setting, and Participants

A cluster, crossover, randomized clinical trial that recruited 5982 mechanically ventilated adults from 19 intensive care units (ICUs) in Australia between April 2018 and May 2021 (final follow-up, August 2021). A contemporaneous ecological assessment recruited 8599 patients from participating ICUs between May 2017 and August 2021.

Interventions

ICUs were randomly assigned to adopt or not adopt a SDD strategy for 2 alternating 12-month periods, separated by a 3-month interperiod gap. Patients in the SDD group (n = 2791) received a 6-hourly application of an oral paste and administration of a gastric suspension containing colistin, tobramycin, and nystatin for the duration of mechanical ventilation, plus a 4-day course of an intravenous antibiotic with a suitable antimicrobial spectrum. Patients in the control group (n = 3191) received standard care.

Main Outcomes and Measures

The primary outcome was in-hospital mortality within 90 days. There were 8 secondary outcomes, including the proportion of patients with new positive blood cultures, antibiotic-resistant organisms (AROs), and Clostridioides difficile infections. For the ecological assessment, a noninferiority margin of 2% was prespecified for 3 outcomes including new cultures of AROs.

Results

Of 5982 patients (mean age, 58.3 years; 36.8% women) enrolled from 19 ICUs, all patients completed the trial. There were 753/2791 (27.0%) and 928/3191 (29.1%) in-hospital deaths in the SDD and standard care groups, respectively (mean difference, -1.7% [95% CI, -4.8% to 1.3%]; odds ratio, 0.91 [95% CI, 0.82-1.02]; P = .12). Of 8 prespecified secondary outcomes, 6 showed no significant differences. In the SDD vs standard care groups, 23.1% vs 34.6% had new ARO cultures (absolute difference, -11.0%; 95% CI, -14.7% to -7.3%), 5.6% vs 8.1% had new positive blood cultures (absolute difference, -1.95%; 95% CI, -3.5% to -0.4%), and 0.5% vs 0.9% had new C difficile infections (absolute difference, -0.24%; 95% CI, -0.6% to 0.1%). In 8599 patients enrolled in the ecological assessment, use of SDD was not shown to be noninferior with regard to the change in the proportion of patients who developed new AROs (-3.3% vs -1.59%; mean difference, -1.71% [1-sided 97.5% CI, -∞ to 4.31%] and 0.88% vs 0.55%; mean difference, -0.32% [1-sided 97.5% CI, -∞ to 5.47%]) in the first and second periods, respectively.

Conclusions and Relevance

Among critically ill patients receiving mechanical ventilation, SDD, compared with standard care without SDD, did not significantly reduce in-hospital mortality. However, the confidence interval around the effect estimate includes a clinically important benefit.

Trial Registration

ClinicalTrials.gov Identifier: NCT02389036.

Association Between Selective Decontamination of the Digestive Tract and In-Hospital Mortality in Intensive Care Unit Patients Receiving Mechanical Ventilation: A Systematic Review and Meta-analysis

Importance

The effectiveness of selective decontamination of the digestive tract (SDD) in critically ill adults receiving mechanical ventilation is uncertain.

Objective

To determine whether SDD is associated with reduced risk of death in adults receiving mechanical ventilation in intensive care units (ICUs) compared with standard care.

Data Sources

The primary search was conducted using MEDLINE, EMBASE, and CENTRAL databases until September 2022.

Study Selection

Randomized clinical trials including adults receiving mechanical ventilation in the ICU comparing SDD vs standard care or placebo.

Data Extraction and Synthesis

Data extraction and risk of bias assessments were performed in duplicate. The primary analysis was conducted using a bayesian framework.

Main Outcomes and Measures

The primary outcome was hospital mortality. Subgroups included SDD with an intravenous agent compared with SDD without an intravenous agent. There were 8 secondary outcomes including the incidence of ventilator-associated pneumonia, ICU-acquired bacteremia, and the incidence of positive cultures of antimicrobial-resistant organisms.

Results

There were 32 randomized clinical trials including 24 389 participants in the analysis. The median age of participants in the included studies was 54 years (IQR, 44-60), and the median proportion of female trial participants was 33% (IQR, 25%-38%). Data from 30 trials including 24 034 participants contributed to the primary outcome. The pooled estimated risk ratio (RR) for mortality for SDD compared with standard care was 0.91 (95% credible interval [CrI], 0.82-0.99; I2 = 33.9%; moderate certainty) with a 99.3% posterior probability that SDD reduced hospital mortality. The beneficial association of SDD was evident in trials with an intravenous agent (RR, 0.84 [95% CrI, 0.74-0.94]), but not in trials without an intravenous agent (RR, 1.01 [95% CrI, 0.91-1.11]) (P value for the interaction between subgroups = .02). SDD was associated with reduced risk of ventilator-associated pneumonia (RR, 0.44 [95% CrI, 0.36-0.54]) and ICU-acquired bacteremia (RR, 0.68 [95% CrI, 0.57-0.81]). Available data regarding the incidence of positive cultures of antimicrobial-resistant organisms were not amenable to pooling and were of very low certainty.

Conclusions and Relevance

Among adults in the ICU treated with mechanical ventilation, the use of SDD compared with standard care or placebo was associated with lower hospital mortality. Evidence regarding the effect of SDD on antimicrobial resistance was of very low certainty.

Multiple-site decontamination regimen decreases acquired infection incidence in mechanically ventilated COVID-19 patients

Background

Among strategies that aimed to prevent acquired infections (AIs), selective decontamination regimens have been poorly studied in the COVID-19 setting. We assessed the impact of a multiple-site decontamination (MSD) regimen on the incidence of bloodstream infections (BSI) and ventilator-associated pneumonia (VAP) in COVID-19 patients receiving mechanical ventilation.

Methods

We performed an ancillary analysis of a multicenter retrospective observational study in 15 ICUs in western France. In addition to standard-care (SC), 3 ICUs used MSD, a variant of selective digestive decontamination, which consists of the administration of topical antibiotics four times daily in the oropharynx and the gastric tube, chlorhexidine body wash and a 5-day nasal mupirocin course. AIs were compared between the 3 ICUs using MSD (MSD group) and the 12 ICUs using SC.

Results

During study period, 614 of 1158 COVID-19 patients admitted in our ICU were intubated for at least 48 h. Due to missing data in 153 patients, 461 patients were finally included of whom 89 received MSD. There were 34 AIs in the MSD group (2117 patient-days), as compared with 274 AIs in the SC group (8957 patient-days) (p < 0.001). MSD was independently associated with a lower risk of AI (IRR = 0.56 [0.38–0.83]; p = 0.004) (Table 2). When the same model was used for each site of infection, MSD remained independently associated with a lower risk of VAP (IRR = 0.52 [0.33–0.89]; p = 0.005) but not of BSI (IRR = 0.58, [0.25–1.34], p = 0.21). Hospital mortality was lower in the MSD group (16.9% vs 30.1%, p = 0.017).

Conclusions

In ventilated COVID-19 patients, MSD was independently associated with lower AI incidence.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-022-01057-x.

Tackling recalcitrant Pseudomonas aeruginosa infections in critical illness via anti-virulence monotherapy

Intestinal barrier derangement allows intestinal bacteria and their products to translocate to the systemic circulation. Pseudomonas aeruginosa (PA) superimposed infection in critically ill patients increases gut permeability and leads to gut-driven sepsis. PA infections are challenging due to multi-drug resistance (MDR), biofilms, and/or antibiotic tolerance. Inhibition of the quorum-sensing transcriptional regulator MvfR(PqsR) is a desirable anti-PA anti-virulence strategy as MvfR controls multiple acute and chronic virulence functions. Here we show that MvfR promotes intestinal permeability and report potent anti-MvfR compounds, the N-Aryl Malonamides (NAMs), resulting from extensive structure-activity-relationship studies and thorough assessment of the inhibition of MvfR-controlled virulence functions. This class of anti-virulence non-native ligand-based agents has a half-maximal inhibitory concentration in the nanomolar range and strong target engagement. Using a NAM lead in monotherapy protects murine intestinal barrier function, abolishes MvfR-regulated small molecules, ameliorates bacterial dissemination, and lowers inflammatory cytokines. This study demonstrates the importance of MvfR in PA-driven intestinal permeability. It underscores the utility of anti-MvfR agents in maintaining gut mucosal integrity, which should be part of any successful strategy to prevent/treat PA infections and associated gut-derived sepsis in critical illness settings. NAMs provide for the development of crucial preventive/therapeutic monotherapy options against untreatable MDR PA infections.

Pseudomonas aeruginosa infections are increasingly difficult to treat due to the development of antimicrobial resistance. Here, the authors describe the synthesis, characterisation and efficacy of a quorum sensing inhibitor.

COVID-19 Secondary Infections in ICU Patients and Prevention Control Measures: A Preliminary Prospective Multicenter Study

The incidence of secondary infections in critically ill coronavirus disease 2019 (COVID-19) patients is worrisome. We investigated whether selective digestive decontamination (SDD) added to infection control measures during an intensive care unit (ICU) stay modified these infection rates. Methods: A retrospective observational cohort study was carried out in four ICUs in Spain. All consecutive ventilated patients with a SARS-CoV-2 infection engaged in national infection control programs between 1 March and 10 December 2020 were investigated. Patients were grouped into two cohorts according to the site of ICU admission. Secondary relevant infections were included. Infection densities corresponding to ventilator-associated pneumonia (VAP), catheter bacteremia, secondary bacteremia, and multi-resistant germs were obtained as the number of events per 1000 days of exposure and were compared between SDD and non-SDD groups using Poisson regression. Factors that had an independent association with mortality were identified using multidimensional logistic analysis. Results: There were 108 patients in the SDD cohort and 157 in the non-SDD cohort. Patients in the SDD cohort showed significantly lower rates (p < 0.001) of VAP (1.9 vs. 9.3 events per 1000 ventilation days) and MDR infections (0.57 vs. 2.28 events per 1000 ICU days) and a non-significant reduction in secondary bacteremia (0.6 vs. 1.41 events per 1000 ICU days) compared with those in the non-SDD cohort. Infections caused by MDR pathogens occurred in 5 patients in the SDD cohort and 21 patients in the non-SDD cohort (p = 0.006). Differences in mortality according to SDD were not found. Conclusion: The implementation of SDD in infection control programs significantly reduced the incidence of VAP and MDR infections in critically ill SARS-CoV-2 infected patients.

A prospective matched case-control study on the genomic epidemiology of colistin-resistant Enterobacterales from Dutch patients

Background

Colistin is a last-resort treatment option for infections with multidrug-resistant Gram-negative bacteria. However, colistin resistance is increasing.

Methods

A six-month prospective matched case-control study was performed in which 22 Dutch laboratories with 32 associated hospitals participated. Laboratories were invited to send a maximum of five colistin-resistant Escherichia coli or Klebsiella pneumoniae (COLR-EK) isolates and five colistin-susceptible isolates (COLS-EK) to the reference laboratory, matched for patient location, material of origin and bacterial species. Epidemiological/clinical data were collected and included in the analysis. Characteristics of COLR-EK/COLS-EK isolates were compared using logistic regression with correction for variables used for matching. Forty-six ColR-EK/ColS-EK pairs were analysed by next-generation sequencing (NGS) for whole-genome multi-locus sequence typing and identification of resistance genes, including mcr genes. To identify chromosomal mutations potentially leading to colistin resistance, NGS reads were mapped against gene sequences of pmrAB, phoPQ, mgrB and crrB.

Results

In total, 72 COLR-EK/COLS-EK pairs (75% E. coli and 25% K. pneumoniae) were included. Twenty-one percent of COLR-EK patients had received colistin, in contrast to 3% of COLS-EK patients (OR > 2.9). Of COLR-EK isolates, five contained mcr-1 and two mcr-9. One isolate lost mcr-9 after repeated sub-culturing, but retained colistin resistance. Among 46 sequenced COLR-EK isolates, genetic diversity was large and 19 (41.3%) isolates had chromosomal mutations potentially associated with colistin resistance.

Conclusions

Colistin resistance is present but uncommon in the Netherlands and caused by the mcr gene in a minority of COLR-EK isolates. There is a need for surveillance of colistin resistance using appropriate susceptibility testing methods.

Tales of the unexpected in antibiotic resistance

Since the 1990s few new antibiotics have become available; during the same period the appearance and spread of bacteria no longer susceptible to first- and second-line antibiotics has accelerated; indeed some bacterial infections untreatable with existing antibiotics. Control of antibiotic resistance is multifactorial, and includes restrictive antibiotic use and good infection control. The 2021 Lowbury lecture addresses three aspects of antibiotic resistance, with reference to the Netherlands, that illustrate the complexity of antibiotic resistance epidemiology. Initially selective decontamination of the digestive tract (SDD) was not adopted in the Netherlands because of concern about antibiotic resistance. However, three trials showed that SDD regimens, including 4 days of systemic cephalosporins, gave better clinical outcomes with no effect on antibiotic-resistant bacteria. Many predictions have been made about the impact of infections with antibiotic-resistant bacteria on human health. However, the situation is complex, because the risk factors for infection with multidrug-resistant bacteria are also risk factors for poor clinical outcome. A study in 8 Dutch hospitals estimated the mortality attributable to antibiotic resistance as close to zero. Concern about the emergence of resistance in Staphyloocccus aureus has limited the universal use of mupirocin to prevent surgical site infections. However, the risk may have been overstated, and universal decolonisation with mupirocin and chlorhexidine has now become standard of care in patients undergoing cardiothoracic or orthopaedic surgery in many Dutch hospitals. Prophylactic antibiotics can improve patient outcomes with acceptable risks of promoting resistance.

Croix CM, Watkins SC, Wenzel SE, Mallampalli RK, Greenberger JS, Bayır H, Kagan VE, Tyurina YY. P. aeruginosa augments irradiation injury via 15-lipoxygenase-catalyzed generation of 15-HpETE-PE and induction of theft-ferroptosis

Total body irradiation (TBI) targets sensitive bone marrow hematopoietic cells and gut epithelial cells, causing their death and inducing a state of immunodeficiency combined with intestinal dysbiosis and nonproductive immune responses. We found enhanced Pseudomonas aeruginosa (PAO1) colonization of the gut leading to host cell death and strikingly decreased survival of irradiated mice. The PAO1-driven pathogenic mechanism includes theft-ferroptosis realized via (a) curbing of the host antiferroptotic system, GSH/GPx4, and (b) employing bacterial 15-lipoxygenase to generate proferroptotic signal - 15-hydroperoxy-arachidonoyl-PE (15-HpETE-PE) - in the intestines of irradiated and PAO1-infected mice. Global redox phospholipidomics of the ileum revealed that lysophospholipids and oxidized phospholipids, particularly oxidized phosphatidylethanolamine (PEox), represented the major factors that contributed to the pathogenic changes induced by total body irradiation and infection by PAO1. A lipoxygenase inhibitor, baicalein, significantly attenuated animal lethality, PAO1 colonization, intestinal epithelial cell death, and generation of ferroptotic PEox signals. Opportunistic PAO1 mechanisms included stimulation of the antiinflammatory lipoxin A4, production and suppression of the proinflammatory hepoxilin A3, and leukotriene B4. Unearthing complex PAO1 pathogenic/virulence mechanisms, including effects on the host anti/proinflammatory responses, lipid metabolism, and ferroptotic cell death, points toward potentially new therapeutic and radiomitigative targets.

The role of the microbiota in the management of intensive care patients

The composition of the gut microbiota is highly dynamic and changes according to various conditions. The gut microbiota mainly includes difficult-to-cultivate anaerobic bacteria, hence knowledge about its composition has significantly arisen from culture-independent methods based on next-generation sequencing (NGS) such as 16S profiling and shotgun metagenomics. The gut microbiota of patients hospitalized in intensive care units (ICU) undergoes many alterations because of critical illness, antibiotics, and other ICU-specific medications. It is then characterized by lower richness and diversity, and dominated by opportunistic pathogens such as Clostridioides difficile and multidrug-resistant bacteria. These alterations are associated with an increased risk of infectious complications or death. Specifically, at the time of writing, it appears possible to identify distinct microbiota patterns associated with severity or infectivity in COVID-19 patients, paving the way for the potential use of dysbiosis markers to predict patient outcomes. Correcting the microbiota disturbances to avoid their consequences is now possible. Fecal microbiota transplantation is recommended in recurrent C. difficile infections and microbiota-protecting treatments such as antibiotic inactivators are currently being developed. The growing interest in the microbiota and microbiota-associated therapies suggests that the control of the dysbiosis could be a key factor in the management of critically ill patients. The present narrative review aims to provide a synthetic overview of microbiota, from healthy individuals to critically ill patients. After an introduction to the different techniques used for studying the microbiota, we review the determinants involved in the alteration of the microbiota in ICU patients and the latter's consequences. Last, we assess the means to prevent or correct microbiota alteration.

Zinc Exposure Promotes Commensal-to-Pathogen Transition in Pseudomonas aeruginosa Leading to Mucosal Inflammation and Illness in Mice

The opportunistic pathogen Pseudomonas aeruginosa (P. aeruginosa) is associated gastrointestinal (GI) inflammation and illness; however, factors motivating commensal-to-pathogen transition are unclear. Excessive zinc intake from supplements is common in humans. Due to the fact that zinc exposure enhances P. aeruginosa colonization in vitro, we hypothesized zinc exposure broadly activates virulence mechanisms, leading to inflammation and illness. P. aeruginosa was treated with excess zinc and growth, expression and secretion of key virulence factors, and biofilm production were determined. Effects on invasion, barrier function, and cytotoxicity were evaluated in Caco-2 cells co-cultured with P. aeruginosa pre-treated with zinc. Effects on colonization, mucosal pathology, inflammation, and illness were evaluated in mice infected with P. aeruginosa pre-treated with zinc. We found the expression and secretion of key virulence factors involved in quorum sensing (QS), motility (type IV pili, flagella), biosurfactants (rhamnolipids), toxins (exotoxin A), zinc homeostasis (CzcR), and biofilm production, were all significantly increased. Zinc exposure significantly increased P. aeruginosa invasion, permeability and cytotoxicity in Caco-2 cells, and enhanced colonization, inflammation, mucosal damage, and illness in mice. Excess zinc exposure has broad effects on key virulence mechanisms promoting commensal-to-pathogen transition of P. aeruginosa and illness in mice, suggesting excess zinc intake may have adverse effects on GI health in humans.

Management of pneumonia in critically ill patients

Severe pneumonia is associated with high mortality (short and long term), as well as pulmonary and extrapulmonary complications. Appropriate diagnosis and early initiation of adequate antimicrobial treatment for severe pneumonia are crucial in improving survival among critically ill patients. Identifying the underlying causative pathogen is also critical for antimicrobial stewardship. However, establishing an etiological diagnosis is challenging in most patients, especially in those with chronic underlying disease; those who received previous antibiotic treatment; and those treated with mechanical ventilation. Furthermore, as antimicrobial therapy must be empiric, national and international guidelines recommend initial antimicrobial treatment according to the location's epidemiology; for patients admitted to the intensive care unit, specific recommendations on disease management are available. Adherence to pneumonia guidelines is associated with better outcomes in severe pneumonia. Yet, the continuing and necessary research on severe pneumonia is expansive, inviting different perspectives on host immunological responses, assessment of illness severity, microbial causes, risk factors for multidrug resistant pathogens, diagnostic tests, and therapeutic options.

Selective Intestinal Decontamination as a Method for Preventing Infectious Complications (Review)

Infectious complications are the most common cause of death in patients with severe burns. To date, there is no generally accepted method for preventing such complications in burn injury. One of the possible prevention options is selective intestinal decontamination (SID). This method is based on the enteral administration of non-absorbable antimicrobial agents. The preventive effect of SID involves inhibition of intestinal microflora translocation through the mucous membranes, inasmuch as studies demonstrate that endogenous opportunistic microorganisms are a common cause of infectious complications in various critical conditions.

The SID method was originally developed in the Netherlands for patients suffering from mechanical injury. Antimicrobial drugs were selected based on their high activity in relation to the main endogenous opportunistic pathogens and minimal activity against normal intestinal microflora components. The combination of polymyxin (B or E), tobramycin, and amphotericin B with intravenous cefotaxime was chosen as the first SID regimen. Other regimens were proposed afterwards, and the application field of the method was expanded. In particular, it became the method of choice for prevention of infectious complications in patients with severe burn injury.

Clinical studies demonstrate efficacy of some SID regimens for preventing infectious complications in patients with thermal injury. Concomitant administration of SID and systemic preventive antibiotics and addition of oropharyngeal decontamination increases the method efficacy. SID is generally well-tolerated, but some studies show an increased risk of diarrhea with this preventive option. In addition, SID increases the risk of developing antibiotic resistance like any other antibiotic regimens.

Modelling and Simulation of the Effect of Targeted Decolonisation on Incidence of Extended-Spectrum Beta-Lactamase-Producing Enterobacterales Bloodstream Infections in Haematological Patients

Introduction

Haematological patients are at higher risk of bloodstream infections (BSI) after chemotherapy. The aim of this study was to develop a simulation model assessing the impact of selective digestive decontamination (SDD) of haematological patients colonised with extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E) on the incidence of ESBL-E BSI after chemotherapy.

Methods

A patient population was created by a stochastic simulation model mimicking the patients’ states of colonisation with ESBL-E during hospitalisation. A systematic literature search was performed to inform the model. All ESBL-E carriers were randomised (1:1) to either the intervention (targeted SDD) or the control group (placebo). ESBL-E BSI incidence was the outcome of the model. Sensitivity analyses were performed by prevalence of ESBL-E carriage at hospital admission (low: < 10%, medium: 10–25%, high: > 25%), duration of neutropenia after receiving chemotherapy, administration of antibiotic prophylaxis with quinolones, and time interval between SDD and chemotherapy.

Results

The model estimated that the administration of targeted SDD before chemotherapy reduces the incidence of ESBL-E BSI in the hospitalised haematological population up to 27%. The greatest benefit was estimated in high-prevalence settings, regardless of the duration of neutropenia, the time interval before chemotherapy, and the administration of antibiotic prophylaxis with quinolones (p < 0.05). In medium-prevalence settings, SDD was effective in patients receiving quinolone prophylaxis, with either 1-day time interval before chemotherapy and a neutropenia duration > 6 days (p < 0.05) or 7-day time interval before chemotherapy and a neutropenia duration > 9 days (p < 0.05). No benefit was observed in low-prevalence settings.

Conclusions

Our model suggests that targeted SDD could decrease the rate of ESBL-E BSI in haematological carriers before chemotherapy in the setting of high ESBL-E prevalence at hospital admission. These estimates require confirmation by well-designed multicentre RCTs, including the assessment of the impact on resistance/disruption patterns of gut microbiome.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-021-00550-3.

Inhaled amikacin versus placebo to prevent ventilator-associated pneumonia: the AMIKINHAL double-blind multicentre randomised controlled trial protocol

INTRODUCTION

Pre-emptive inhaled antibiotics may be effective to reduce the occurrence of ventilator-associated pneumonia among critically ill patients. Meta-analysis of small sample size trials showed a favourable signal. Inhaled antibiotics are associated with a reduced emergence of antibiotic resistant bacteria. The aim of this trial is to evaluate the benefit of a 3-day course of inhaled antibiotics among patients undergoing invasive mechanical ventilation for more than 3 days on the occurrence of ventilator-associated pneumonia.

METHODS AND ANALYSIS

Academic, investigator-initiated, parallel two group arms, double-blind, multicentre superiority randomised controlled trial. Patients invasively ventilated more than 3 days will be randomised to receive 20 mg/kg inhaled amikacin daily for 3 days or inhaled placebo (0.9% Sodium Chloride). Occurrence of ventilator-associated pneumonia will be recorded based on a standardised diagnostic framework from randomisation to day 28 and adjudicated by a centralised blinded committee.

ETHICS AND DISSEMINATION

The protocol and amendments have been approved by the regional ethics review board and French competent authorities (Comité de protection des personnes Ouest I, No.2016-R29). All patients will be included after informed consent according to French law. Results will be disseminated in international scientific journals.

TRIAL REGISTRATION NUMBERS

EudraCT 2016-001054-17 and NCT03149640.

Microevolution of acquired colistin resistance in Enterobacteriaceae from ICU patients receiving selective decontamination of the digestive tract

BACKGROUND

Colistin is an antibiotic that targets the LPS molecules present in the membranes of Gram-negative bacteria. It is used as a last-resort drug to treat infections with MDR strains. Colistin is also used in selective decontamination of the digestive tract (SDD), a prophylactic therapy used in patients hospitalized in ICUs to selectively eradicate opportunistic pathogens in the oropharyngeal and gut microbiota.

OBJECTIVES

To unravel the mechanisms of acquired colistin resistance in Gram-negative opportunistic pathogens obtained from SDD-treated patients.

RESULTS

Routine surveillance of 428 SDD-treated patients resulted in 13 strains with acquired colistin resistance (Escherichia coli, n = 9; Klebsiella aerogenes, n = 3; Enterobacter asburiae, n = 1) from 5 patients. Genome sequence analysis showed that these isolates represented multiple distinct colistin-resistant clones but that colistin-resistant strains within the same patient were clonally related. We identified previously described mechanisms that lead to colistin resistance, i.e. a G53 substitution in the response regulator PmrA/BasR and the acquisition of the mobile colistin resistance gene mcr-1.1, but we also observed novel variants of basR with an 18 bp deletion and a G19E substitution in the sensor histidine kinase BasS. We experimentally confirmed that these variants contribute to reduced colistin susceptibility. In a single patient, we observed that colistin resistance in a single E. coli clone evolved through two unique variants in basRS.

CONCLUSIONS

We show that prophylactic use of colistin during SDD can select for colistin resistance in species that are not intrinsically colistin resistant. This highlights the importance of continued surveillance for strains with acquired colistin resistance in patients treated with SDD.

Protocol summary and statistical analysis plan for the Selective Decontamination of the Digestive Tract in Intensive Care Unit Patients (SuDDICU) crossover, cluster randomised controlled trial

Background: It is unclear whether the use of selective decontamination of the digestive tract (SDD) improves outcomes in ventilated patients in intensive care units (ICUs) and whether SDD is associated with the development of antibiotic resistance. Objective: To describe the study protocol and statistical analysis plan for the Selective Decontamination of the Digestive Tract in Intensive Care Unit Patients (SuDDICU) trial. Design, setting, participants and intervention: SuDDICU is an international, crossover, cluster randomised controlled trial of mechanically ventilated patients in ICUs using two 12-month trial periods. For each period, participating ICUs will implement SDD plus standard care or standard care alone. The SuDDICU drug intervention is an oral paste and gastric suspension of three antibiotics combined with a 4-day course of intravenous antibiotics. Observational ecological assessments will be conducted during five surveillance periods. The trial will be conducted in 19 ICUs in Australia and ten ICUs in Canada and the United Kingdom, and will recruit 15 000-17 000 patients. Recruitment commenced in Australia in 2017. Main outcome measures: The primary outcome is all-cause hospital mortality. Secondary outcomes include: duration of ventilation, ICU stay and hospital stay; incidence of new antibiotic-resistant organisms during the index ICU admission; changes in antibiotic-resistant organism rates; incidence of new Clostridioides difficile infections; and total use of antibiotics. Results and conclusions: SuDDICU will determine whether the use of SDD plus standard care is associated with a reduction in hospital mortality in ventilated ICU patients compared with standard care alone. It will also quantify the impact of the use of SDD on the development of antibiotic resistance. Trial registration: Australian New Zealand Clinical Trials Registry (ACTRN12615000411549) and ClinicalTrials.gov (NCT02389036).

Anti-infectious decontamination strategies in Dutch intensive care units: A survey study on contemporary practice and heterogeneity

PURPOSE

Despite increasing evidence and updated national guidelines, practice of anti-infectious strategies appears to vary in the Netherlands. This study aimed to determine the variation of current practices of anti-infectious strategies in Dutch ICUs.

MATERIALS AND METHODS

In 2018 and 2019 an online survey of all Dutch ICUs was conducted with detailed questions on their anti-infectious strategies.

RESULTS

89% (63 of 71) of the Dutch ICUs responded to the online survey. The remaining ICUs were contacted by telephone. 47 (66%) of the Dutch ICUs used SDD, 14 (20%) used SOD and 10 (14%) used neither SDD nor SOD. Within these strategies considerable heterogeneity was observed in the start criteria of SDD/SOD, the regimen adjustments based on microbiological surveillance and the monitoring of the interventions.

CONCLUSIONS

The proportion of Dutch ICUs applying SDD or SOD increased over time. Considerable heterogeneity in the regimens was reported. The impact of the observed differences within SDD and SOD practices on clinical outcome remains to be explored.

Rescuing the Last-Line Polymyxins: Achievements and Challenges

Antibiotic resistance is a major global health challenge and, worryingly, several key Gram negative pathogens can become resistant to most currently available antibiotics. Polymyxins have been revived as a last-line therapeutic option for the treatment of infections caused by multidrug-resistant Gram negative bacteria, in particular Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacterales. Polymyxins were first discovered in the late 1940s but were abandoned soon after their approval in the late 1950s as a result of toxicities (e.g., nephrotoxicity) and the availability of "safer" antibiotics approved at that time. Therefore, knowledge on polymyxins had been scarce until recently, when enormous efforts have been made by several research teams around the world to elucidate the chemical, microbiological, pharmacokinetic/pharmacodynamic, and toxicological properties of polymyxins. One of the major achievements is the development of the first scientifically based dosage regimens for colistin that are crucial to ensure its safe and effective use in patients. Although the guideline has not been developed for polymyxin B, a large clinical trial is currently being conducted to optimize its clinical use. Importantly, several novel, safer polymyxin-like lipopeptides are developed to overcome the nephrotoxicity, poor efficacy against pulmonary infections, and narrow therapeutic windows of the currently used polymyxin B and colistin. This review discusses the latest achievements on polymyxins and highlights the major challenges ahead in optimizing their clinical use and discovering new-generation polymyxins. To save lives from the deadly infections caused by Gram negative "superbugs," every effort must be made to improve the clinical utility of the last-line polymyxins. SIGNIFICANCE STATEMENT: Antimicrobial resistance poses a significant threat to global health. The increasing prevalence of multidrug-resistant (MDR) bacterial infections has been highlighted by leading global health organizations and authorities. Polymyxins are a last-line defense against difficult-to-treat MDR Gram negative pathogens. Unfortunately, the pharmacological information on polymyxins was very limited until recently. This review provides a comprehensive overview on the major achievements and challenges in polymyxin pharmacology and clinical use and how the recent findings have been employed to improve clinical practice worldwide.

Reducing the dosing frequency of selective digestive tract decontamination to three times daily provides effective decontamination of Gram-negative bacteria

This study evaluated the effectiveness of selective digestive tract decontamination (SDD) application three times daily (t.i.d.) compared to the standard four times daily (q.i.d.). Retrospective equivalence (combined non-inferiority and non-superiority design) study with a before-and-after design on a tertiary ICU in which the SDD frequency was reduced from q.i.d. to t.i.d. All patients with ICU admissions ≥72h and with ≥2 surveillance cultures collected on different dates were included in this study. We compared successful decontamination of Gram-negative bacteria (GNB). Furthermore, time to decontamination, ICU-acquired GNB bacteraemia and 28-day mortality were compared between the two groups. In total 1958 ICU admissions (1236 q.i.d., 722 t.i.d). Decontamination was achieved during the first week of admission in 77% and 76% of patients receiving SDD q.i.d and t.i.d., respectively. Successful decontamination within 14 days (without consecutive acquisition of Gram-negative bacteria) was achieved in 69.3% of the admissions with q.i.d. versus 66.8% in t.i.d. SDD (p-value = 0.2519). The proportions of successful decontamination of GNB were equivalent in both groups (−0.025, 98% CI: −0.087; 0.037). There was no significant difference in time to decontamination between the two regimens (log-rank test p-value = 0.55). Incidence (episodes/1000 days) of ICU-acquired GNB bacteraemia was 0.9 in both groups, and OR for death at day 28 in the t.i.d. group compared to the q.i.d. group was 0.99 (95% confidence interval, 0.80–1.21). This study shows that a t.i.d. application regimen achieves similar outcomes to the standard q.i.d. regime, for both microbiological and clinical outcome measures.

Topical antibiotic prophylaxis to reduce respiratory tract infections and mortality in adults receiving mechanical ventilation

BACKGROUND

Patients treated with mechanical ventilation in intensive care units (ICUs) have a high risk of developing respiratory tract infections (RTIs). Ventilator-associated pneumonia (VAP) has been estimated to affect 5% to 40% of patients treated with mechanical ventilation for at least 48 hours. The attributable mortality rate of VAP has been estimated at about 9%. Selective digestive decontamination (SDD), which consists of the topical application of non-absorbable antimicrobial agents to the oropharynx and gastroenteric tract during the whole period of mechanical ventilation, is often used to reduce the risk of VAP. A related treatment is selective oropharyngeal decontamination (SOD), in which topical antibiotics are applied to the oropharynx only. This is an update of a review first published in 1997 and updated in 2002, 2004, and 2009.

OBJECTIVES

To assess the effect of topical antibiotic regimens (SDD and SOD), given alone or in combination with systemic antibiotics, to prevent mortality and respiratory infections in patients receiving mechanical ventilation for at least 48 hours in ICUs.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), which contains the Cochrane Acute Respiratory Infections (ARI) Group's Specialised Register, PubMed, and Embase on 5 February 2020. We also searched the WHO ICTRP and ClinicalTrials.gov for ongoing and unpublished studies on 5 February 2020. All searches included non-English language literature. We handsearched references of topic-related systematic reviews and the included studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and cluster-RCTs assessing the efficacy and safety of topical prophylactic antibiotic regimens in adults receiving intensive care and mechanical ventilation. The included studies compared topical plus systemic antibiotics versus placebo or no treatment; topical antibiotics versus no treatment; and topical plus systemic antibiotics versus systemic antibiotics.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included a total of 41 trials involving 11,004 participants (five new studies were added in this update). The minimum duration of mechanical ventilation ranged from 2 (19 studies) to 6 days (one study). Thirteen studies reported the mean length of ICU stay, ranging from 11 to 33 days. The percentage of immunocompromised patients ranged from 0% (10 studies) to 22% (1 study). The reporting quality of the majority of included studies was very poor, so we judged more than 40% of the studies as at unclear risk of selection bias. We judged all studies to be at low risk of performance bias, though 47.6% were open-label, because hospitals usually have standardised infection control programmes, and possible subjective decisions on who should be tested for the presence or absence of RTIs are unlikely in an ICU setting. Regarding detection bias, we judged all included studies as at low risk for the outcome mortality. For the outcome RTIs, we judged all double-blind studies as at low risk of detection bias. We judged five open-label studies as at high risk of detection bias, as the diagnosis of RTI was not based on microbiological exams; we judged the remaining open-label studies as at low risk of detection bias, as a standardised set of diagnostic criteria, including results of microbiological exams, were used. Topical plus systemic antibiotic prophylaxis reduces overall mortality compared with placebo or no treatment (risk ratio (RR) 0.84, 95% confidence interval (CI) 0.73 to 0.96; 18 studies; 5290 participants; high-certainty evidence). Based on an illustrative risk of 303 deaths in 1000 people this equates to 48 (95% CI 15 to 79) fewer deaths with topical plus systemic antibiotic prophylaxis. Topical plus systemic antibiotic prophylaxis probably reduces RTIs (RR 0.43, 95% CI 0.35 to 0.53; 17 studies; 2951 participants; moderate-certainty evidence). Based on an illustrative risk of 417 RTIs in 1000 people this equates to 238 (95% CI 196 to 271) fewer RTIs with topical plus systemic antibiotic prophylaxis. Topical antibiotic prophylaxis probably reduces overall mortality compared with no topical antibiotic prophylaxis (RR 0.96, 95% CI 0.87 to 1.05; 22 studies, 4213 participants; moderate-certainty evidence). Based on an illustrative risk of 290 deaths in 1000 people this equates to 19 (95% CI 37 fewer to 15 more) fewer deaths with topical antibiotic prophylaxis. Topical antibiotic prophylaxis may reduce RTIs (RR 0.57, 95% CI 0.44 to 0.74; 19 studies, 2698 participants; low-certainty evidence). Based on an illustrative risk of 318 RTIs in 1000 people this equates to 137 (95% CI 83 to 178) fewer RTIs with topical antibiotic prophylaxis. Sixteen studies reported adverse events and dropouts due to adverse events, which were poorly reported with sparse data. The certainty of the evidence ranged from low to very low.

AUTHORS' CONCLUSIONS

Treatments based on topical prophylaxis probably reduce respiratory infections, but not mortality, in adult patients receiving mechanical ventilation for at least 48 hours, whereas a combination of topical and systemic prophylactic antibiotics reduces both overall mortality and RTIs. However, we cannot rule out that the systemic component of the combined treatment provides a relevant contribution in the observed reduction of mortality. No conclusion can be drawn about adverse events as they were poorly reported with sparse data.

Selective Decontamination of the Digestive Tract to Prevent Postoperative Pneumonia and Anastomotic Leakage after Esophagectomy: A Retrospective Cohort Study

Infectious complications occur frequently after esophagectomy. Selective decontamination of the digestive tract (SDD) has been shown to reduce postoperative infections and anastomotic leakage in gastrointestinal surgery, but robust evidence for esophageal surgery is lacking. The aim was to evaluate the association between SDD and pneumonia, surgical-site infections (SSIs), anastomotic leakage, and 1-year mortality after esophagectomy. A retrospective cohort study was conducted in patients undergoing Ivor Lewis esophagectomy in four Dutch hospitals between 2012 and 2018. Two hospitals used SDD perioperatively and two did not. SDD consisted of an oral paste and suspension (containing amphotericin B, colistin, and tobramycin). The primary outcomes were 30-day postoperative pneumonia and SSIs. Secondary outcomes were anastomotic leakage and 1-year mortality. Logistic regression analyses were performed to determine the association between SDD and the relevant outcomes (odds ratio (OR)). A total of 496 patients were included, of whom 179 received SDD perioperatively and the other 317 patients did not receive SDD. Patients who received SDD were less likely to develop postoperative pneumonia (20.1% vs. 36.9%, p < 0.001) and anastomotic leakage (10.6% vs. 19.9%, p = 0.008). Multivariate analysis showed that SDD is an independent protective factor for postoperative pneumonia (OR 0.40, 95% CI 0.23–0.67, p < 0.001) and anastomotic leakage (OR 0.46, 95% CI 0.26–0.84, p = 0.011). Use of perioperative SDD seems to be associated with a lower risk of pneumonia and anastomotic leakage after esophagectomy.

Do probiotics help prevent ventilator-associated pneumonia in critically ill patients? A systematic review with meta-analysis

BACKGROUND

Probiotic treatments might contribute to the prevention of ventilator-associated pneumonia (VAP). Due to its unclear clinical effects, here we intend to assess the preventive effect and safety of probiotics on intensive care unit (ICU) patients.

METHODS

Eligible randomised controlled trials were selected in databases until 30 September 2019. The characteristics of the studies were extracted, including study design, definition of VAP, probiotics intervention, category of included patients, incidence of VAP, mortality, duration of mechanical ventilation (MV) and ICU stay. Heterogeneity was evaluated by Chi-squared and I2 tests.

RESULTS

15 studies involving 2039 patients were identified for analysis. The pooled analysis suggests significant reduction on VAP (risk ratio, 0.68; 95% Cl, 0.60 to 0.77; p<0.00001) in a fixed-effects model. Subgroup analyses performed on the category of clinical and microbiological criteria both support the above conclusion; however, there were no significant differences in duration of MV or length of ICU stay in a random-effects model. Also, no significant differences in total mortality, overall mortality, 28-day mortality or 90-day mortality were found in the fixed-effects model.

CONCLUSIONS

The probiotics helped to prevent VAP without impacting the duration of MV, length of ICU stay or mortality.

Current progress of research on intestinal bacterial translocation

Under normal conditions, the intestinal flora and the body are in dynamic equilibrium. When the barrier function of the intestinal tract is damaged due to various reasons, changes in the number and proportion of bacteria or spatial displacement result in bacterial translocation (BT), which ultimately leads to multiple organ dysfunction syndrome (MODS). Endogenous infections and endotoxemia caused by intestinal flora and endotoxin translocation are the origins of inflammatory responses, and the intestinal tract is the organ in which MODS both initiates and targets. Only by ensuring the integrity of the intestinal mucosal barrier can intestinal BT be effectively prevented. Elimination of the primary disease and maintaining blood and oxygen supply to the intestine is the most basic treatment. Early initiation of the intestinal tract, establishment of enteral nutrition, and selective digestive decontamination are also highly effective treatments. Early diagnosis, intervention, or prevention of BT may be a new avenue or important connection in the treatment of various diseases. The mechanism of BT, detection techniques, prevention and treatment, and its interaction with parenteral diseases were reviewed.

Nutrition and the gut microbiome during critical illness: A new insight of nutritional therapy

Changes in the microbiome in response to environmental influences can affect the overall health. Critical illness is considered one of the major environmental factors that can potentially influence the normal gut homeostasis. It is associated with pathophysiological effects causing damage to the intestinal microbiome. Alteration of intestinal microbial composition during critical illness may subsequently compromise the integrity of the intestinal epithelial barrier and intestinal mucosa absorptive function. Many factors can impact the microbiome of critically ill patients including ischemia, hypoxia and hypotension along with the iatrogenic effects of therapeutic agents and the lack of enteral feeds. Factors related to disease state and medication are inevitable and they are part of the intensive care unit (ICU) exposure. However, a nutritional intervention targeting gut microbiota might have the potential to improve clinical outcomes in the critically ill population given the extensive vascular and lymphatic links between the intestines and other organs. Although nutrition is considered an integral part of the treatment plan of critically ill patients, still the role of nutritional intervention is restricted to improve nitrogen balance. What is dismissed is whether the nutrients we provide are adequate and how they are processed and utilised by the host and the microbiota. Therefore, the goal of nutrition therapy during critical illness should be extended to provide good quality feeds with balanced macronutrient content to feed up the entire body including the microbiota and host cells. The main aim of this review is to examine the current literature on the effect of critical illness on the gut microbiome and to highlight the role of nutrition as a factor affecting the intestinal microbiome-host relationship during critical illness.

Colistin Update on Its Mechanism of Action and Resistance, Present and Future Challenges

Colistin has been extensively used since the middle of the last century in animals, particularly in swine, for the control of enteric infections. Colistin is presently considered the last line of defense against human infections caused by multidrug-resistant Gram-negative organisms such as carbapenemase-producer Enterobacterales, Acinetobacter baumanni, and Pseudomonas aeruginosa. Transferable bacterial resistance like mcr-genes was reported in isolates from both humans and animals. Researchers actively seek strategies to reduce colistin resistance. The definition of guidelines for colistin therapy in veterinary and human medicine is thus crucial. The ban of colistin use in swine as a growth promoter and for prophylactic purposes, and the implementation of sustainable measures in farm animals for the prevention of infections, would help to avoid resistance and should be encouraged. Colistin resistance in the human-animal-environment interface stresses the relevance of the One Health approach to achieve its effective control. Such measures should be addressed in a cooperative way, with efforts from multiple disciplines and with consensus among doctors, veterinary surgeons, and environment professionals. A revision of the mechanism of colistin action, resistance, animal and human use, as well as colistin susceptibility evaluation is debated here.

Efficacy of a hospital policy of selective digestive decontamination for carbapenem-resistant Enterobacterales carriers: prospective before-after study

A single-centre interrupted time series quasi-experimental study was undertaken to assess whether a hospital policy of selective digestive decontamination (SDD, gentamicin/amikacin with neomycin) administered to carbapenem-resistant Enterobacterales (CRE) carriers would reduce the duration of carriage and contain the spread of CRE. No significant difference in time to CRE eradication was observed between the observation (12 months, 120 patients) and intervention (12 months, 101 patients) periods. No change in the trend of new in-hospital CRE acquisitions or bacteraemia during the intervention was detected. As such, administration of SDD to CRE carriers was not effective for the eradication of carriage or controlling in-hospital CRE transmissions.

Selective digestive decontamination solution used as "lock therapy" prevents and eradicates bacterial biofilm in an in vitro bench-top model

Background

Most preventing measures for reducing ventilator-associated pneumonia (VAP) are based mainly on the decolonization of the internal surface of the endotracheal tubes (ETTs). However, it has been demonstrated that bacterial biofilm can also be formed on the external surface of ETTs. Our objective was to test in vitro the efficacy of selective digestive decontamination solution (SDDs) onto ETT to prevent biofilm formation and eradicate preformed biofilms of three different microorganisms of VAP.

Methods

We used an in vitro model in which we applied, at the subglottic space of ETT, biofilms of either P. aeruginosa ATCC 15442, or E. coli ATCC 25922, or S. aureus ATCC 29213, and the SDDs at the same time (prophylaxis) or after 72 h of biofilm forming (treatment). ETT were incubated during 5 days with a regimen of 2 h-locks. ETT fragments were analyzed by sonication and confocal laser scanning microscopy to calculate the percentage reduction of cfu and viable cells, respectively.

Results

Median (IQR) percentage reduction of live cells and cfu/ml counts after treatment were, respectively, 53.2% (39.4%—64.1%) and 100% (100%–100.0%) for P. aeruginosa, and 67.9% (46.7%–78.7%) and 100% (100%–100.0%) for E. coli. S. aureus presented a complete eradication by both methods. After prophylaxis, there were absence of live cells and cfu/ml counts for all microorganisms.

Conclusions

SDDs used as “lock therapy” in the subglottic space is a promising prophylactic approach that could be used in combination with the oro-digestive decontamination procedure in the prevention of VAP.

An overview of guidelines for the management of hospital-acquired and ventilator-associated pneumonia caused by multidrug-resistant Gram-negative bacteria

PURPOSE OF REVIEW

Multidrug-resistant (MDR) Gram-negative pathogens in hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) are associated with poor clinical outcomes. These pathogens represent a global threat with few therapeutic options. In this review, we discuss current guidelines for the empiric management of HAP/VAP caused by MDR Gram-negative pathogens.

RECENT FINDINGS

The incidence of MDR Gram-negative bacteria is rising among cases of nosocomial pneumonia, such that it is now becoming a significant challenge for clinicians. Adherence to international guidelines may ensure early and adequate antimicrobial therapy, guided by local microbiological data and awareness of the risk factors for MDR bacteria.

SUMMARY

Due to the increasing prevalence of HAP/VAP caused by MDR Gram-negative pathogens, management should be guided by the local ecology and the patient's risk factors for MDR pathogens. The main risk factors are prior hospitalization for at least 5 days, prior use of broad-spectrum antibiotics, prior colonization with resistant pathogens, admission to hospital settings with high rates of MDR pathogens, and septic shock at the time of diagnosis with nosocomial pneumonia.

Impact of microbiome-based interventions on gastrointestinal pathogen colonization in the intensive care unit

In the intensive care unit (ICU), colonization of the gastrointestinal tract by potentially pathogenic bacteria is common and often precedes clinical infection. Though effective in the short term, traditional antibiotic-based decolonization methods may contribute to rising resistance in the long term. Novel therapies instead focus on restoring gut microbiome equilibrium to achieve pathogen colonization resistance. This review summarizes the existing data regarding microbiome-based approaches to gastrointestinal pathogen colonization in ICU patients with a focus on prebiotics, probiotics, and synbiotics.

Microbiological profile of nosocomial infections following cardiac arrest: Insights from the targeted temperature management (TTM) trial

AIMS

Infectious complications frequently occur in intensive care unit patients admitted after out-of-hospital cardiac arrest. There is debate on the effects of temperature management on the incidence of infections, as well as on the efficacy and choice of antibiotic prophylaxis. In this substudy of the targeted temperature management (TTM) trial, we describe the microbiological profile of infectious complications in patients with cardiac arrest and examined the impact of TTM at 33 °C compared to TTM at 36 °C. Furthermore we aimed to determine the association between antibiotic prophylaxis and the incidence of infections.

METHODS

This is a posthoc analysis of the TTM cohort. Microbiological data was retrospectively collected for the first 14-days of ICU-admission. Logistic regression was used to determine the relationship between antibiotic prophylaxis and pneumonia adjusted for mortality.

RESULTS

Of 696 patients included in this analysis, 158 (23%) developed pneumonia and 28 (4%) had bacteremia with a clinically relevant pathogen. Staphylococcus aureus was the most common pathogen isolated in patients with pneumonia (23%) and in patients with bacteremia (24%). Gram-negative pathogens were most common overall. TTM did not have an impact on the microbiological profile. The use of antibiotic prophylaxis was significantly associated with a reduced risk of infection (OR 0.59, 95%CI 0.43-0.79, p = 0.0005). This association remained significant after correcting for confounders (OR 0.64, 95%CI 0.46-0.90; p = 0.01). The association is not present in a model after correction for clustering within centers (aOR 0.55, 95%CI 0.20-1.47, p = 0.22). Adjustment for mortality did not influence the outcome.

CONCLUSION

Gram-negative pathogens are the most common causes of nosocomial infections following cardiac arrest. TTM does not impact the microbiological profile. It remains unclear whether patients in ICUs using antibiotic prophylaxis have a reduced risk of pneumonia and bacteremia that is unrelated to center effects.

Attenuation of MODS-related and ARDS-related mortality makes infectious complications a remaining challenge in the severely injured

Introduction

The recent decrease in multiple organ dysfunction syndrome (MODS)-associated and adult respiratory distress syndrome (ARDS)-associated mortality could be considered a success of improvements in trauma care. However, the incidence of infections remains high in patients with polytrauma, with high morbidity and hospital resources usage. Infectious complications might be a residual effect of the decrease in MODS-related/ARDS-related mortality. This study investigated the current incidence of infectious complications in polytrauma.

Methods

A 5.5-year prospective population-based cohort study included consecutive severely injured patients (age >15) admitted to a (Level-1) trauma center intensive care unit (ICU) who survived >48 hours. Demographics, physiologic and resuscitation parameters, multiple organ failure and ARDS scores, and infectious complications (pneumonia, fracture-related infection, meningitis, infections related to blood, wound, and urinary tract) were prospectively collected. Data are presented as median (IQR), p<0.05 was considered significant.

Results

297 patients (216 (73%) men) were included with median age of 46 (27–60) years, median Injury Severity Score was 29 (22–35), 96% sustained blunt injuries. 44 patients (15%) died. One patient (2%) died of MODS and 1 died of ARDS. 134 patients (45%) developed 201 infectious complications. Pneumonia was the most common complication (50%). There was no difference in physiologic parameters on arrival in emergency department and ICU between patients with and without infectious complications. Patients who later developed infections underwent more often a laparotomy (32% vs 18%, p=0.009), had more often pelvic fractures (38% vs 25%, p=0.02), and received more blood products <8 hours. They had more often MODS (25% vs 13%, p=0.005), stayed longer on the ventilator (10 (5–15) vs 5 (2–8) days, p<0.001), longer in ICU (11 (6–17) vs 6 (3–10) days, p<0.001), and in hospital (30 (20–44) vs 16 (10–24) days, p<0.001). There was however no difference in mortality (12% vs 17%, p=0.41) between both groups.

Conclusion

45% of patients developed infectious complications. These patients had similar mortality rates, but used more hospital resources. With low MODS-related and ARDS-related mortality, infections might be a residual effect, and are one of the remaining challenges in the treatment of patients with polytrauma.

Level of evidence

Level 3.

Study type

Population-based cohort study.

Selective decontamination of the digestive tract (SDD) in critically ill patients: a narrative review

Selective decontamination of the digestive tract (SDD) is an infection prevention measure for intensive care unit (ICU) patients that was proposed more than 30 years ago, and that is currently considered standard of care in the Netherlands, but only used sporadically in ICUs in other countries. In this narrative review, we first describe the rationale of the individual components of SDD and then review the evidence base for patient-centered outcomes, where we distinguish ICUs with low prevalence of antibiotic resistance from ICUs with moderate–high prevalence of resistance. In settings with low prevalence of antibiotic resistance, SDD has been associated with improved patient outcome in three cluster-randomized studies. These benefits were not confirmed in a large international cluster-randomized study in settings with moderate-to-high prevalence of antibiotic resistance. There is no evidence that SDD increases antibiotic resistance. We end with future directions for research.

Synbiotics for prevention of ventilator-associated pneumonia: a probiotics strain-specific network meta-analysis

Objective

Probiotics may be efficacious in preventing ventilator-associated pneumonia (VAP). The aim of this network meta-analysis (NMA) was to clarify the efficacy of different types of probiotics for preventing VAP.

Methods

This systematic review and NMA was conducted according to the updated preferred reporting items for systematic review and meta-analysis. A systematic literature search of public databases from inception to 17 June 2018 was performed.

Results

NMA showed that “Bifidobacterium longum + Lactobacillus bulgaricus + Streptococcus thermophiles” was more efficacious than “Ergyphilus” in preventing VAP (odds ratio: 0.15, 95% confidence interval: 0.03–0.94). According to pairwise meta-analysis, “B. longum + L. bulgaricus + S. thermophiles” and “Lactobacillus rhamnosus” were superior to placebo in preventing VAP. Treatment rank based on surface under the cumulative ranking curves revealed that the most efficacious treatment for preventing VAP was “B. longum + L. bulgaricus + S. thermophiles” (66%). In terms of reducing hospital mortality and ICU mortality, the most efficacious treatment was Synbiotic 2000FORTE (34% and 46%, respectively).

Conclusions

Based on efficacy ranking, “B. longum + L. bulgaricus + S. thermophiles” should be the first choice for prevention of VAP, while Synbiotic 2000FORTE has the potential to reduce in-hospital mortality and ICU mortality.

Cost-effectiveness of selective digestive decontamination (SDD) versus selective oropharyngeal decontamination (SOD) in intensive care units with low levels of antimicrobial resistance: an individual patient data meta-analysis

OBJECTIVE

To determine the cost-effectiveness of selective digestive decontamination (SDD) as compared to selective oropharyngeal decontamination (SOD) in intensive care units (ICUs) with low levels of antimicrobial resistance.

DESIGN

Post-hoc analysis of a previously performed individual patient data meta-analysis of two cluster-randomised cross-over trials.

SETTING

24 ICUs in the Netherlands.

PARTICIPANTS

12 952 ICU patients who were treated with ≥1 dose of SDD (n=6720) or SOD (n=6232).

INTERVENTIONS

SDD versus SOD.

PRIMARY AND SECONDARY OUTCOME MEASURES

The incremental cost-effectiveness ratio (ICER; ie, costs to prevent one in-hospital death) was calculated by comparing differences in direct healthcare costs and in-hospital mortality of patients treated with SDD versus SOD. A willingness-to-pay curve was plotted to reflect the probability of cost-effectiveness of SDD for a range of different values of maximum costs per prevented in-hospital death.

RESULTS

The ICER resulting from the fixed-effect meta-analysis, adjusted for clustering and differences in baseline characteristics, showed that SDD significantly reduced in-hospital mortality (adjusted absolute risk reduction 0.0195, 95% CI 0.0050 to 0.0338) with no difference in costs (adjusted cost difference €62 in favour of SDD, 95% CI -€1079 to €935). Thus, SDD yielded significantly lower in-hospital mortality and comparable costs as compared with SOD. At a willingness-to-pay value of €33 633 per one prevented in-hospital death, SDD had a probability of 90.0% to be cost-effective as compared with SOD.

CONCLUSION

In Dutch ICUs, SDD has a very high probability of cost-effectiveness as compared to SOD. These data support the implementation of SDD in settings with low levels of antimicrobial resistance.