Effect of Probiotics on Incident Ventilator-Associated Pneumonia in Critically Ill Patients: A Randomized Clinical Trial.

Importance: Growing interest in microbial dysbiosis during critical illness has raised questions about the therapeutic potential of microbiome modification with probiotics. Prior randomized trials in this population suggest that probiotics reduce infection, particularly ventilator-associated pneumonia (VAP), although probiotic-associated infections have also been reported. Objective: To evaluate the effect of Lactobacillus rhamnosus GG on preventing VAP, additional infections, and other clinically important outcomes in the intensive care unit (ICU). Design, Setting, and Participants: Randomized placebo-controlled trial in 44 ICUs in Canada, the United States, and Saudi Arabia enrolling adults predicted to require mechanical ventilation for at least 72 hours. A total of 2653 patients were enrolled from October 2013 to March 2019 (final follow-up, October 2020). Interventions: Enteral L rhamnosus GG (1 × 1010 colony-forming units) (n = 1321) or placebo (n = 1332) twice daily in the ICU. Main Outcomes and Measures: The primary outcome was VAP determined by duplicate blinded central adjudication. Secondary outcomes were other ICU-acquired infections including Clostridioides difficile infection, diarrhea, antimicrobial use, ICU and hospital length of stay, and mortality. Results: Among 2653 randomized patients (mean age, 59.8 years [SD], 16.5 years), 2650 (99.9%) completed the trial (mean age, 59.8 years [SD], 16.5 years; 1063 women [40.1%.] with a mean Acute Physiology and Chronic Health Evaluation II score of 22.0 (SD, 7.8) and received the study product for a median of 9 days (IQR, 5-15 days). VAP developed among 289 of 1318 patients (21.9%) receiving probiotics vs 284 of 1332 controls (21.3%; hazard ratio [HR], 1.03 (95% CI, 0.87-1.22; P = .73, absolute difference, 0.6%, 95% CI, -2.5% to 3.7%). None of the 20 prespecified secondary outcomes, including other ICU-acquired infections, diarrhea, antimicrobial use, mortality, or length of stay showed a significant difference. Fifteen patients (1.1%) receiving probiotics vs 1 (0.1%) in the control group experienced the adverse event of L rhamnosus in a sterile site or the sole or predominant organism in a nonsterile site (odds ratio, 14.02; 95% CI, 1.79-109.58; P < .001). Conclusions and Relevance: Among critically ill patients requiring mechanical ventilation, administration of the probiotic L rhamnosus GG compared with placebo, resulted in no significant difference in the development of ventilator-associated pneumonia. These findings do not support the use of L rhamnosus GG in critically ill patients. Trial Registration: ClinicalTrials.gov Identifier: NCT02462590.

Using bioimpedance analysis to assess intensive care unit patients with sepsis in the post-resuscitation period: a prospective multicentre observational study.

PURPOSE: Clinicians lack well-validated, non-invasive, objective tools to guide volume management in the post-resuscitative period. Bioimpedance analysis (BIA) represents a novel method for guiding fluid management. We studied the relationship of BIA vector length (VL), an indicator of volume status, to the need for mechanical ventilation in patients with sepsis. METHODS: This is a multicentre prospective observational study at four Canadian ICUs. We examined adult patients admitted to the ICU within 72 hr of a sepsis diagnosis. Patients underwent daily BIA measurements for 30 days, until discharge from the ICU, or until death. Our primary outcome was the ongoing need for invasive mechanical ventilation, and we examined the association with VL using a generalized estimating equation. Our secondary analyses were targeted to determine an association between VL and other measures of volume status and acute kidney injury (AKI). RESULTS: We enrolled 159 patients from four centres over 27 months. The mean (standard deviation [SD]) age was 64 (15) yr with a mean (SD) APACHE (acute physiology, age, chronic health evaluation) II score of 25 (10); 57% (n = 91) were male. A 50-unit (ohm·m) increase in VL over any time period was associated with a 30% decrease in the probability of requiring invasive mechanical ventilation (P < 0.03). Volume expansion, indicated by a shorter VL, correlated with higher edema scores (r = - 0.31; P < 0.001) and higher net 24-hr fluid balance (r = - 0.27, P < 0.001). Patients with AKI had a shorter overall VL (r = - 0.23; P = 0.003). CONCLUSIONS: An increase in VL over time is associated with a decrease in probability of requiring invasive mechanical ventilation. Vector length correlates with other commonly used volume assessment methods in post-resuscitation patients with sepsis.

Academic and Community ICUs Participating in a Critical Care Randomized Trial: A Comparison of Patient Characteristics and Trial Metrics.

Clinical research in Canada is conducted primarily in "academic" hospitals, whereas most clinical care is provided in "community" hospitals. The objective of this nested observational study was to compare patient characteristics, outcomes, process-of-care variables, and trial metrics for patients enrolled in a large randomized controlled trial who were admitted to academic and community hospitals in Canada. DESIGN: We conducted a preplanned observational study nested within the Probiotics: Prevention of Severe Pneumonia and Endotracheal Colonization Trial (PROSPECT, a randomized controlled trial comparing probiotics to placebo in mechanically ventilated patients) Research Program. SETTING: ICUs. PATIENTS: Mechanically ventilated patients. MEASUREMENTS: We compared patient characteristics, interventions, outcomes, and trial metrics between patients enrolled in PROSPECT from academic and community hospitals. MAIN RESULTS: Participating centers included 34 (82.9%) academic and seven (17.1%) community hospitals, which enrolled 2,203 (86.2%) and 352 (13.8%) patients, respectively. Compared with academic hospitals, patients enrolled in community hospitals were older (mean [sd] 62.7 yr [14.9 yr] vs 59.5 yr [16.4 yr]; p = 0.044), had longer ICU stays (median [interquartile range {IQR}], 13 d [8-23 d] vs 11 d [7-8 d]; p = 0.012) and higher mortality (percentage, [95% CI] in the ICU, 30.4% [25.8-35.4%]vs 20.5% [18.9-11.3%]; p = 0.002) and hospital (40.6% [35.6-45.8%] vs 26.1% [24.3-27.9%]; p < 0.001). Trial metrics, including informed consent rate (85.9% vs 76.3%; p = 0.149), mean (sd) monthly enrolment rate (2.1 [1.4] vs 1.1 [0.7]; p = 0.119), and protocol adherence (90.6% vs 91.6%; p = 0.207), were similar between community and academic ICUs. CONCLUSIONS: Community hospitals can conduct high-quality research, with similar trial metrics to academic hospitals. Patient characteristics differed between community and academic hospitals, highlighting the need for broader engagement of community hospitals in clinical research to ensure generalizability of study results.

Improving sensitivity in chiral supercritical fluid chromatography for analysis of active pharmaceutical ingredients.

Despite its status as the preferred method for routine enantiopurity analysis in pharmaceutical research, supercritical fluid chromatography (SFC) has historically been unsuited for the accurate and precise measurements required for release testing of active pharmaceutical ingredients (APIs) under current good manufacturing processes (cGMPs). Insufficient signal to noise, as compared to HPLC, has heretofore been the major limitation of the chiral SFC approach. We herein describe an investigation into the fundamental limitations and sources of noise in the SFC approach, identifying thermal, electronic, and mechanical sources of noise within the flow cell as key parameters contributing to reduced sensitivity. A variety of instrument modifications are explored, ultimately leading to the development of a new and improved flow cell and other instrument modifications that allow suitable sensitivity and accuracy to carry out GMP release testing for enantiopurity analysis using SFC.

Solving multicomponent chiral separation challenges using a new SFC tandem column screening tool.

A tool for improved tandem column chiral supercritical fluid chromatography (SFC) method development screening was prepared by modification of a commercial analytical SFC instrument with two different software-controllable, six position high-pressure column selection valves, each controlling a bank of five different columns and a pass through line. The resulting instrument, which has the ability to screen 10 different individual columns and 25 different tandem column arrangements, is a useful tool for facilitating the screening of tandem column SFC arrangements for separation of complex mixtures of stereoisomers or other multicomponent mixtures. Strategies for optimal use of the instrument are discussed, and several examples of the use of the instrument in developing tandem SFC methods for resolution of multicomponent mixtures are presented.