Daily Respiratory Research Analysis
Three impactful clinical studies advance respiratory care: (1) higher ventilator driving pressures in ARDS independently predict subsequent acute kidney injury with a threshold near 15 cm H2O; (2) in immunocompromised adults hospitalized with community-acquired pneumonia, empiric broad-spectrum antibiotics did not reduce mortality and were associated with harm; and (3) SGLT-2 inhibitors in patients with COPD and type 2 diabetes were associated with lower all-cause mortality, fewer hospitalizatio
Summary
Three impactful clinical studies advance respiratory care: (1) higher ventilator driving pressures in ARDS independently predict subsequent acute kidney injury with a threshold near 15 cm H2O; (2) in immunocompromised adults hospitalized with community-acquired pneumonia, empiric broad-spectrum antibiotics did not reduce mortality and were associated with harm; and (3) SGLT-2 inhibitors in patients with COPD and type 2 diabetes were associated with lower all-cause mortality, fewer hospitalizations, and fewer exacerbations.
Research Themes
- Ventilator strategy and kidney protection in ARDS
- Antimicrobial stewardship in immunocompromised pneumonia
- Cardiometabolic therapies improving respiratory outcomes
Selected Articles
1. Association Between Driving Pressure and Subsequent Development of Acute Kidney Injury in Acute Respiratory Distress Syndrome.
In a secondary analysis of 2,960 ARDS patients from seven RCTs, each 1 SD increase in baseline driving pressure increased the odds of late AKI by 35%, with a threshold near 15 cm H2O. Findings were robust across multiple sensitivity analyses.
Impact: Links a modifiable ventilator parameter to kidney injury, expanding the concept of ventilator-induced organ injury beyond the lung and providing a tangible target for prevention.
Clinical Implications: Consider targeting driving pressure ≤15 cm H2O in ARDS to mitigate kidney injury risk, integrating renal protection into lung-protective ventilation strategies.
Key Findings
- Among 2,960 ARDS patients, late AKI occurred in 33.8% between days >2 and ≤7 after ARDS onset.
- Each 1 SD increase in baseline driving pressure increased odds of late AKI by 35% (OR 1.35; 95% CI 1.15–1.58).
- A driving pressure threshold around 15 cm H2O was identified for AKI risk; results were consistent in sensitivity analyses.
Methodological Strengths
- Individual patient-level secondary analysis pooling seven randomized trials
- Adjusted models with multiple sensitivity analyses demonstrating robustness
Limitations
- Observational secondary analysis cannot prove causality
- Baseline driving pressure may not reflect time-varying ventilator dynamics
Future Directions: Prospective interventional trials testing kidney-protective ventilation targets (e.g., driving pressure ≤15 cm H2O) and mechanistic studies of lung–kidney cross-talk.
OBJECTIVES: Although preclinical evidence indicates that injurious mechanical ventilation may lead to acute kidney injury (AKI), relevant clinical evidence is limited. We aimed to investigate the association of driving pressure (a marker of injurious mechanical ventilation) with subsequent development of AKI in patients with acute respiratory distress syndrome (ARDS). DESIGN: Secondary analysis of individual patient-level data from seven ARDS Network and Prevention and Early Treatment of Acute Lung Injury (PETAL) Network randomized controlled clinical trials. SETTING: Adult ICUs participating in the ARDS Network and PETAL Network trials. PATIENTS: After exclusion of patients with early AKI (i.e., those who met AKI criteria within the first 2 d following ARDS onset), we classified the study population into two groups: "late AKI" and "no AKI." The "late AKI" group included patients who developed AKI more than 2 days but no longer than 7 days following ARDS onset. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of 5367 patients with ARDS initially enrolled in trials, 2960 patients were included in the main analysis. Late AKI developed in 1000 patients (33.8%). After controlling for confounders, baseline driving pressure was independently associated with development of late AKI (each 1 sd increase in driving pressure was associated with a 35% increase in the odds of late AKI [odds ratio, 1.35; 95% CI, 1.15-1.58]). This result persisted in the sensitivity analysis, which did not exclude patients with early AKI, and in the sensitivity analysis, which included patients who developed AKI later than 7 days following ARDS onset. There was a threshold of driving pressure equal to 15 cm H 2 O for its association with development of late AKI. CONCLUSIONS: Driving pressure was associated with subsequent development of AKI in patients with ARDS suggesting that injurious mechanical ventilation may lead to AKI.
2. The clinical effectiveness of sodium-glucose co-transporter-2 inhibitors on prognosis of patients with chronic obstructive pulmonary disease and diabetes.
Across multiple countries and institutions, SGLT-2 inhibitor initiation in patients with COPD and type 2 diabetes was associated with reduced all-cause mortality (HR 0.757), hospitalizations, exacerbations, respiratory infections, and major cardiovascular events versus DPP-4 inhibitors.
Impact: Provides strong real-world evidence that a cardiometabolic therapy improves hard outcomes in COPD with diabetes, supporting broader therapeutic integration beyond glycemic control.
Clinical Implications: For COPD patients with type 2 diabetes, consider SGLT-2 inhibitors to reduce mortality, hospitalizations, exacerbations, and respiratory infections, while individualizing therapy and monitoring for known class effects.
Key Findings
- SGLT-2 inhibitors reduced all-cause mortality vs DPP-4 inhibitors (HR 0.757; 95% CI 0.716–0.801).
- Lower risks of all-cause hospitalization (HR 0.864; 95% CI 0.845–0.884) and COPD exacerbations (HR 0.924; 95% CI 0.888–0.962).
- Reduced pneumonia, upper respiratory infections, bronchitis, and major cardiovascular events.
Methodological Strengths
- Large, multi-institution, multi-country real-world comparative effectiveness design
- Clinically meaningful endpoints including mortality, hospitalizations, exacerbations
Limitations
- Observational design limits causal inference and may have residual confounding
- Exact sample size and follow-up duration not specified in the abstract
Future Directions: Prospective trials in COPD with diabetes to validate mortality and exacerbation benefits, mechanistic studies on respiratory infection reduction, and head-to-head comparisons with other glucose-lowering agents.
Diabetes is common in patients with chronic obstructive pulmonary disease. Sodium-glucose co-transporter-2 inhibitors are effective in treating type 2 diabetes and provide benefits for conditions like cardiovascular and kidney diseases. We use data from multiple institutions and countries to evaluate their role in patients with chronic obstructive pulmonary disease and diabetes. This study includes chronic obstructive pulmonary disease patients with diabetes who are newly prescribed sodium-glucose co-transporter-2 inhibitors or dipeptidyl peptidase-4 inhibitors between January 1, 2013, and August 25, 2024. The primary outcome is all-cause mortality. The results show that the sodium-glucose co-transporter-2 inhibitors group has a lower risk of all-cause mortality compared to the dipeptidyl peptidase-4 inhibitors group (hazard ratio, 0.757; 95% confidence interval, 0.716-0.801). It also shows significantly lower risks of all-cause hospitalization (hazard ratio, 0.864; 95% confidence interval, 0.845-0.884), exacerbation (hazard ratio, 0.924; 95% confidence interval, 0.888-0.962), pneumonia, upper respiratory infections, bronchitis, and major cardiovascular events.
3. Target Trial Emulation of Empiric Antibiotics on Clinical Outcomes in Moderately Immunocompromised Patients Hospitalized with Pneumonia.
In a target trial emulation of 2,706 moderately immunocompromised adults with CAP and no MDR risk factors, empiric broad-spectrum antibiotics did not reduce mortality but were associated with higher 30-day readmission, ICU transfer, and longer hospital stay.
Impact: Challenges routine broad-spectrum empiric coverage in immunocompromised CAP without MDR risks and quantifies harms, directly informing stewardship and guideline refinement.
Clinical Implications: Avoid routine broad-spectrum empiric therapy in moderately immunocompromised CAP patients lacking MDR risk factors; prioritize guideline-concordant narrow-spectrum therapy and early de-escalation.
Key Findings
- Broad-spectrum empiric antibiotics were used in 59% despite low MDR prevalence (3.5%).
- No mortality benefit with broad-spectrum empiric therapy after adjustment.
- Higher risks: 30-day readmission (aHR 1.32), ICU transfer (aHR 2.65), and longer LOS (aRR 1.14).
Methodological Strengths
- Large multicenter cohort (69 hospitals) with target trial emulation design
- Adjusted analyses with clear predefined outcomes including mortality and readmissions
Limitations
- Observational emulation is subject to residual confounding and treatment selection bias
- Potential misclassification of MDR risk factors and antibiotic exposure windows
Future Directions: Prospective randomized or pragmatic trials in immunocompromised CAP stratified by MDR risk; evaluation of stewardship interventions and rapid diagnostics to guide initial therapy.
BACKGROUND: Immunocompromised patients are often excluded from pneumonia trials, guidelines, and stewardship interventions.The objective of this study was to evaluate whether empiric broad-spectrum antibiotic treatment impacts mortality and other clinical outcomes in moderately immunocompromised patients without risk factors for multidrug-resistant organisms hospitalized with community-acquired pneumonia. METHODS: This was a target trial emulation including moderately immunocompromised (asplenia, hematologic malignancies, solid organ malignancy receiving chemotherapy, kidney transplant >1 year prior, congenital/acquired immunodeficiency and receiving immunosuppressive medications) patients with pneumonia without risk factors for multidrug-resistant organisms at 69 hospitals in the Michigan Hospital Medicine Safety ConsortiumThis study compared the receipt of empiric broad-spectrum antibiotics against antibiotics targeting typical respiratory pathogens on hospital day 1 or 2.The primary outcome was mortality. Secondary outcomes included length of stay, transfer to the intensive care unit and 30-day readmission, emergency department visit, Clostridioides difficile infection and antibiotic-associated adverse events. RESULTS: Of 2706 moderately immunocompromised patients with pneumonia, 59% (N=1596) received empiric broad-spectrum antibiotics. MRSA and resistant gram-negative bacteria were rare (94/2706, 3.5%). After adjustment, empiric broad-spectrum antibiotic treatment was not associated with mortality, but was associated with readmission (adjusted hazard ratio [aHR], 1.32 [1.05-1.66]), transfer to ICU (aHR, 2.65 [1.32-5.30]) and longer hospitalization (adjusted rate ratio [aRR], 1.14 [1.10-1.19]). CONCLUSIONS: Immunocompromised patients hospitalized with pneumonia often receive empiric broad-spectrum antibiotics despite low rates of multidrug-resistant organisms. Empiric broad-spectrum antibiotic use was not associated with mortality, but was associated with harm, including 30-day readmission, transfer to ICU and longer duration of hospitalization.