Improving Outcomes in Nosocomial Pneumonia: Recent Evidence and More Challenges.

Nosocomial pneumonia (NP) represents a leading nosocomial infection and results in substantial morbidity and cost. Over the last several years, the evidence has evolved which directs our approach to NP. Specifically, the definition of NP and classification of its various subtypes has expanded to capture nuances among various phenotypes of this syndrome. For example, segregating those with hospital-acquired pneumonia (HAP) based on whether they subsequently require mechanical ventilation has been shown to be important. Likewise, newer data indicate the true economic cost of NP and underscore the diverse range of pathogens that can cause NP. Moreover, multidrug-resistant (MDR) bacteria have become a major threat in NP. Fortunately, newer simple preventive strategies have been tested and found to be effective at reducing the incidence of NP. Should prevention fail, a range of new antibiotics have been formally studied in NP and found to be effective. Some of these novel agents have relatively broad ranges of activity and are in vitro active against select MDR organisms. Others, however, are narrower in spectrum and directed against specific problem bacteria. In short, the literature in the field of NP has progressed rapidly, and clinicians require a clear appreciation of these changes so as to improve patient outcomes.

At the Intersection of Critical Care and Infectious Diseases: The Year in Review.

Severe infection represents a leading reason for admission to the intensive care unit (ICU) while nosocomial infection can arise as a complication of care in the ICU. The mortality and morbidity of such infections are substantial. These processes also put economic strain on the healthcare system. Additionally, the continued spread of antimicrobial resistance has made it more challenging both to prevent and treat severe infection. Until recently, there were few well-done trials addressing infection among the critically ill. However, over the last year, six important randomized studies have dealt with a range of topics at the intersection of infectious diseases and critical care. Our goal is to review these reports in order to clarify their major findings, significance, strengths, weaknesses, and clinical applications. Specifically, we explore and discuss six trials conducted in the areas of (1) prevention, (2) the present use of standard antimicrobials, and (3) novel adjunctive and antibiotic treatments. Through highlighting these trials, we hope to help clinicians apply their important findings in an evidence-based fashion at the bedside. It is through the application of key evidence that both infectious disease practitioners and intensivists can improve patient outcomes.

Bloodstream Infection in the Intensive Care Unit: Evolving Epidemiology and Microbiology.

Bloodstream infections (BSIs) arising in the intensive care unit (ICUs) present a significant challenge and we completed a narrative review of the emerging literature on this issue. Multiple reports document that these infections are associated with substantial morbidity and mortality. Also, they can be caused by a variety of pathogens. Generally classified as either community or hospital in onset, or as either primary or secondary in origin, the microbiology of ICU BSIs varies across the globe. Gram-positive pathogens predominate in certain regions such as the United States while Gram-negative organisms occur more frequently in Europe, Asia, and Latin America. The incidence of ICU BSIs climbed during the recent pandemic. BSIs complicating the care of persons suffering from Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection significantly heighten the risk for death compared to patients who develop ICU BSIs but who are not infected with SARS-CoV-2. Furthermore, rates of antimicrobial resistance are generally increasing in ICU BSIs. This fact complicates attempts to ensure that the patient receives initially appropriate antimicrobial therapy and is of particular concern in Methicillin-resistant Staphylococcus aureus, Carbapenem-resistant Enterobacterales, and Acinetobacter baumannii. Fortunately, with respect to clinical application, preventive measures exist, and recent analyses suggest that increased collaboration between infectious disease specialists and intensivists can improve patient outcomes.

Examining the Burden of Potentially Avoidable Heart Failure Hospitalizations.

Background: Two-thirds of the 1 million annual US CHF hospitalizations are for diuresis only; some may be avoidable. We describe a population of low-severity short-stay (2. We compared baseline characteristics, processes of care, and outcomes in low-severity (CHF-L) to CHF-H. Results: Among 301,672 short-stay CHF patients, 135,304 (44.8%) were CHF-L. Compared to CHF-H, CHF-L was younger (70.5 ± 14.1 vs 72.1 ± 13.6 years, p < 0.001), more commonly female (48.6% vs 45.8%, p < 0.001), and more likely to receive IV ACE-I/ARB agents (0.5% vs 0.4%, p = 0.003). Most other IV medications were more common in CHF-H, and anticoagulation was the most prevalent non-diuretic IV therapy in both groups (23.8% vs 33.3%, p < 0.001). Hospital mortality (0.2% vs 1.5%, p < 0.001) and CHF-related 30-day readmissions (8.1% vs 10.5%, p < 0.001) were lower in CHF-L than CHF-H. Conclusion: Among short-stay CHF patients, nearly ½ meet criteria for CHF-L, and are mainly admitted for fluid management. Avoiding these admissions could result in substantial savings.

Respiratory Viruses in Nosocomial Pneumonia: An Evolving Paradigm.

Nosocomial pneumonia (NP) represents a leading cause of morbidity and mortality in hospitalized patients. Historically, clinicians have considered hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP), which comprise NP, to be essentially bacterial processes. As such, patients suspected of having either HAP or VAP are initially treated with broad-spectrum antibiotics, and few clinicians search for a possible culprit virus. Recent reports which build on earlier studies, however, indicate that viruses likely play an important role in NP. Studies employing viral diagnostics as part of the evaluation for NP indicate that common respiratory viruses can spread nosocomially and lead to HAP and VAP. Similarly, studies of the general epidemiology of respiratory viral infections, such as influenza, respiratory syncytial virus, adenovirus, and rhinovirus, confirm that these pathogens are important causes of NP, especially among immunosuppressed and pediatric patients. More importantly, these more contemporary analyses reveal that one cannot, based on clinical characteristics, distinguish a viral from a bacterial cause of NP. Additionally, viral HAP and VAP result in crude mortality rates that rival or exceed those reported in bacterial NP. Rigorous prospective, multicenter trials are needed to confirm the significance of respiratory viruses in NP, as are studies of novel therapeutics for these viral infections.

Healthcare Trajectories and Outcomes in the First Year After Tracheostomy Based on Patient Characteristics.

OBJECTIVES: To define healthcare trajectories after tracheostomy to inform shared decision-making efforts for critically ill patients. DESIGN: Retrospective epidemiologic cohort study. SETTING: California Patient Discharge Database 2018-2019. PATIENTS: Patients who received a tracheostomy. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We tracked 1-year outcomes after tracheostomy, including survival and time alive in and out of a healthcare facility (HCF. Patients were stratified based on surgical status (did the patient require a major operating room procedure or not), age (65 yr old or older and less than 65 yr), pre-ICU comorbid states (frailty, chronic organ dysfunction, cancer, and robustness), and the need for dialysis during the tracheostomy admission. We identified 4,274 nonsurgical adults who received a tracheostomy during the study period with 50.9% being 65 years old or older. Among adults 65 years old or older, median survival after tracheostomy was less than 3 months for individuals with frailty, chronic organ dysfunction, cancer, or dialysis. Median survival was 3 months for adults younger than 65 years with cancer or dialysis. Most patients spent the majority of days alive after a tracheostomy in an HCF in the first 3 months. Older adults had very few days alive and out of an HCF in the first 3 months after tracheostomy. Most patients who ultimately died in the first year after tracheostomy spent almost all days alive in an HCF. CONCLUSIONS: Cumulative mortality and median survival after a tracheostomy were very poor across most ages and groups. Older adults and several subgroups of younger adults experienced high rates of prolonged hospitalization with few days alive and out of an HCF. This information may aid some patients, surrogates, and providers in decision-making.

Participant- and Disease-Related Factors as Independent Predictors of Treatment Outcomes in the RESTORE-IMI 2 Clinical Trial: A Multivariable Regression Analysis.

Background: In the RESTORE-IMI 2 trial, imipenem/cilastatin/relebactam (IMI/REL) was noninferior to piperacillin/tazobactam in treating hospital-acquired bacterial pneumonia/ventilator-associated bacterial pneumonia. This post hoc analysis was conducted to determine independent predictors of efficacy outcomes in the RESTORE-IMI 2 trial, to assist in treatment decision making. Methods: A stepwise multivariable regression analysis was conducted to identify variables that were independently associated with day 28 all-cause mortality (ACM), favorable clinical response at early follow-up (EFU), and favorable microbiologic response at end of treatment (EOT). The analysis accounted for the number of baseline infecting pathogens and in vitro susceptibility to randomized treatment. Results: Vasopressor use, renal impairment, bacteremia at baseline, and Acute Physiologic Assessment and Chronic Health Evaluation (APACHE) II scores ≥15 were associated with a greater risk of day 28 ACM. A favorable clinical response at EFU was associated with normal renal function, an APACHE II score <15, no vasopressor use, and no bacteremia at baseline. At EOT, a favorable microbiologic response was associated with IMI/REL treatment, normal renal function, no vasopressor use, nonventilated pneumonia at baseline, intensive care unit admission at randomization, monomicrobial infections at baseline, and absence of Acinetobacter calcoaceticus-baumannii complex at baseline. These factors remained significant after accounting for polymicrobial infection and in vitro susceptibility to assigned treatment. Conclusions: This analysis, which accounted for baseline pathogen susceptibility, validated well-recognized patient- and disease-related factors as independent predictors of clinical outcomes. These results lend further support to the noninferiority of IMI/REL to piperacillin/tazobactam and suggests that pathogen eradication may be more likely with IMI/REL. Clinical Trials Registration: NCT02493764.

Bloodstream Infection and Gram-Negative Resistance: The Role for Newer Antibiotics.

Gram-negative resistance remains a major challenge. Rates of in vitro resistance to commonly utilized antibiotics have skyrocketed over the last decade. Clinicians now encounter multidrug-resistant organisms routinely. Fortunately, newer agents, such as ceftazidime-avibactam, ceftolozone-tazobactam, meropenem-vaborbactam, and cefiderocol, have been developed and are now available for use against these pathogens. Clinical trials with these novel therapies have focused on multiple infection types ranging from complicated urinary tract infections to nosocomial pneumonia. Nonetheless, there remains little information about the efficacy of these drugs for bacteremia. To better appreciate the types and limitations of the evidence supporting the role for these unique molecules in bloodstream infection, one requires an appreciation of the initial clinical trials supporting the regulatory approval of these antibiotics. Furthermore, physicians must understand the subsequent case series and reports specifically focusing on outcomes for patients with bacteremia treated with these drugs. Despite the limitations of the data and reports relating to treatment for bacteremia with these antibiotics, each agent appears to be efficacious and can provide good outcomes in bloodstream infections due to resistant pathogens.

Efficacy and safety of sulbactam-durlobactam versus colistin for the treatment of patients with serious infections caused by Acinetobacter baumannii-calcoaceticus complex: a multicentre, randomised, active-controlled, phase 3, non-inferiority clinical trial (ATTACK).

BACKGROUND: An urgent need exists for antibiotics to treat infections caused by carbapenem-resistant Acinetobacter baumannii-calcoaceticus complex (ABC). Sulbactam-durlobactam is a ß-lactam-ß-lactamase inhibitor combination with activity against Acinetobacter, including multidrug-resistant strains. In a phase 3, pathogen-specific, randomised controlled trial, we compared the efficacy and safety of sulbactam-durlobactam versus colistin, both in combination with imipenem-cilastatin as background therapy, in patients with serious infections caused by carbapenem-resistant ABC. METHODS: The ATTACK trial was done at 59 clinical sites in 16 countries. Adults aged 18 years or older with ABC-confirmed hospital-acquired bacterial pneumonia, ventilator-associated bacterial pneumonia, ventilated pneumonia, or bloodstream infections were randomised 1:1 using a block size of four to sulbactam-durlobactam (1·0 g of each drug in combination over 3 h every 6 h) or colistin (2·5 mg/kg over 30 min every 12 h) for 7-14 days. All patients received imipenem-cilastatin (1·0 g of each drug in combination over 1 h every 6 h) as background therapy. The primary efficacy endpoint was 28-day all-cause mortality in patients with laboratory-confirmed carbapenem-resistant ABC (the carbapenem-resistant ABC microbiologically modified intention-to-treat population). Non-inferiority was concluded if the upper bound of the 95% CI for the treatment difference was less than +20%. The primary safety endpoint was incidence of nephrotoxicity assessed using modified Risk, Injury, Failure, Loss, End-stage renal disease criteria measured by creatinine level or glomerular filtration rate through day 42. This trial is registered at ClinicalTrials.gov, NCT03894046. FINDINGS: Between Sep 5, 2019, and July 26, 2021, 181 patients were randomly assigned to sulbactam-durlobactam or colistin (176 hospital-acquired bacterial pneumonia, ventilator-associated bacterial pneumonia, or ventilated pneumonia; and five bloodstream infections); 125 patients with laboratory-confirmed carbapenem-resistant ABC isolates were included in the primary efficacy analysis. 28-day all-cause mortality was 12 (19%) of 63 in the sulbactam-durlobactam group and 20 (32%) of 62 in the colistin group, a difference of -13·2% (95% CI -30·0 to 3·5), which met criteria for non-inferiority. Incidence of nephrotoxicity was significantly (p<0·001) lower with sulbactam-durlobactam than colistin (12 [13%] of 91 vs 32 [38%] of 85). Serious adverse events were reported in 36 (40%) of 91 patients in the sulbactam-durlobactam group and 42 (49%) of 86 patients in the colistin group. Treatment-related adverse events leading to study drug discontinuation were reported in ten (11%) of 91 patients in the sulbactam-durlobactam group and 14 (16%) of 86 patients in the colistin group. INTERPRETATION: Our data show that sulbactam-durlobactam was non-inferior to colistin, both agents given in combination with imipenem-cilastatin, for the primary endpoint of 28-day all-cause mortality. Sulbactam-durlobactam was well tolerated and could be an effective intervention to reduce mortality from serious infections caused by carbapenem-resistant ABC, including multidrug-resistant strains. FUNDING: Entasis Therapeutics and Zai Lab.

Descriptive Epidemiology and Outcomes of Patients with Short Stay Hospitalizations for the Treatment of Congestive Heart Failure in the US.

Background: Congestive heart failure (CHF) hospitalizations cost the US $35 billion annually. Two-thirds of these admissions, generally requiring 3 days (long, LLOS) in a cross-sectional multicenter analysis within the 2018 National Inpatient Sample. We applied complex survey methods to calculate nationally representative results. Results: Among 4,979,350 discharges with any CHF code, 1,177,910 (23.7%) had CHF-PD, of whom 511,555 (43.4%) had SLOS. Patients with SLOS were younger (>/=65 years: 68.3% vs 71.9%), less likely covered by Medicare (71.9% vs 75.4%), and had a lower comorbidity burden (Charlson: 3.9 [2.1] vs 4.5 [2.2) than patients with LLOS; they less frequently developed acute kidney injury (0.4% vs 2.9%) or a need for mechanical ventilation (0.7% vs 2.8%). A higher proportion with SLOS than with LLOS underwent no procedures (70.4% vs 48.4%). Mean LOS (2.2 [0.8] vs 7.7 [6.5]), direct hospital costs ($6150 [$4413]) vs $17,127 [$26,936]), and aggregate annual hospital costs $3,131,560,372 vs $11,359,002,072) were all lower with SLOS than LLOS. All comparisons reached alpha = 0.001. Conclusion: Among patients admitted for CHF, nearly ½ have LOS

Outcomes in participants with ventilated nosocomial pneumonia and organ failure treated with ceftolozane/tazobactam versus meropenem: a subset analysis of the phase 3, randomized, controlled ASPECT-NP trial.

BACKGROUND: The pivotal ASPECT-NP trial showed ceftolozane/tazobactam was non-inferior to meropenem for the treatment of ventilated hospital-acquired/ventilator-associated bacterial pneumonia (vHABP/VABP). Here, we evaluated treatment outcomes by degree of respiratory or cardiovascular dysfunction. METHODS: This was a subset analysis of data from ASPECT-NP, a randomized, double-blind, non-inferiority trial (ClinicalTrials.gov NCT02070757). Adults with vHABP/VABP were randomized 1:1 to 3 g ceftolozane/tazobactam or 1 g meropenem every 8 h for 8-14 days. Outcomes in participants with a baseline respiratory component of the Sequential Organ Failure Assessment (SOFA) score (R-SOFA) ≥ 2 (indicative of severe respiratory failure), cardiovascular component of the SOFA score (CV-SOFA) ≥ 2 (indicative of shock), or R-SOFA ≥ 2 plus CV-SOFA ≥ 2 were compared by treatment arm. The efficacy endpoint of primary interest was 28-day all-cause mortality. Clinical response, time to death, and microbiologic response were also evaluated. RESULTS: There were 726 participants in the intention-to-treat population; 633 with R-SOFA ≥ 2 (312 ceftolozane/tazobactam, 321 meropenem), 183 with CV-SOFA ≥ 2 (84 ceftolozane/tazobactam, 99 meropenem), and 160 with R-SOFA ≥ 2 plus CV-SOFA ≥ 2 (69 ceftolozane/tazobactam, 91 meropenem). Baseline characteristics, including causative pathogens, were generally similar in participants with R-SOFA ≥ 2 or CV-SOFA ≥ 2 across treatment arms. The 28-day all-cause mortality rate was 23.7% and 24.0% [difference: 0.3%, 95% confidence interval (CI) - 6.4, 6.9] for R-SOFA ≥ 2, 33.3% and 30.3% (difference: - 3.0%, 95% CI - 16.4, 10.3) for CV-SOFA ≥ 2, and 34.8% and 30.8% (difference: - 4.0%, 95% CI - 18.6, 10.3), respectively, for R-SOFA ≥ 2 plus CV-SOFA ≥ 2. Clinical cure rates were as follows: 55.8% and 54.2% (difference: 1.6%, 95% CI - 6.2, 9.3) for R-SOFA ≥ 2, 53.6% and 55.6% (difference: - 2.0%, 95% CI - 16.1, 12.2) for CV-SOFA ≥ 2, and 53.6% and 56.0% (difference: - 2.4%, 95% CI - 17.6, 12.8), respectively, for R-SOFA ≥ 2 plus CV-SOFA ≥ 2. Time to death was comparable in all SOFA groups across both treatment arms. A higher rate of microbiologic eradication/presumed eradication was observed for CV-SOFA ≥ 2 and R-SOFA ≥ 2 plus CV-SOFA ≥ 2 with ceftolozane/tazobactam compared to meropenem. CONCLUSIONS: The presence of severe respiratory failure or shock did not affect the relative efficacy of ceftolozane/tazobactam versus meropenem; either agent may be used to treat critically ill patients with vHABP/VABP. TRIAL REGISTRATION: ClinicalTrials.gov NCT02070757. Registered 25 February 2014, https://clinicaltrials.gov/ct2/show/NCT02070757.

The importance of viruses in ventilator-associated pneumonia.

OBJECTIVE: Ventilator-associated pneumonia (VAP) remains a challenge. The importance of viruses in VAP is not established. We sought to determine the prevalence of viruses in VAP and the outcomes of viral VAP. DESIGN: Retrospective study of VAP over 3 years. The frequency of a viral process represented the primary endpoint. Clinical outcomes served as secondary endpoints. We identified variables independently associated with a virus and conducted sensitivity analyses to assess the interaction between type of infection and patient characteristics. SETTING: Tertiary-care referral center. PATIENTS: The final cohort consisted of 710 patients and a virus was isolated in 5.1%. INTERVENTIONS: None. RESULTS: The most common viruses included: rhinovirus, influenza A, and cytomegalovirus. Baseline characteristics were similar between those with and without viral infections. In logistic regression, immunosuppression (adjusted odds ratio [aOR], 2.97; 95% confidence interval [CI], 1.44-6.14) and stem-cell transplantation (SCT, aOR, 3.58; 95% CI, 1.17-10.99) were independently associated with a virus. The presence of either variable performed poorly as a screening test for a virus. In-hospital (22.4% vs 21.6%; P = .869) and 30-day (32.8% vs 27.9%; P = .448) mortality rates were similar between the cohorts, respectively. Sensitivity analyses restricted to patients without a mixed viral and bacterial infection or those who were immunocompetent yielded similar results. CONCLUSION: Although infrequent, a range of viruses may cause VAP. Viruses more often complicate SCT and immunosuppression, but one can isolate viruses in immunocompetent subjects. Viral VAP produces severe infection and results in high mortality rates. Clinical features do not differentiate viral from nonviral VAP.

Descriptive epidemiology of hospitalized patients with bacterial nosocomial pneumonia who experience 30-day readmission in the US, 2014-2019.

INTRODUCTION: Nosocomial pneumonia (NP) remains associated with excess morbidity and mortality. The effect of NP on measures such as re-admission at 30 days remains unclear. Moreover, differing types of NP may have varying impacts on re-admissions. METHODS: We conducted a multicenter retrospective cohort study within the Premier Research database, a source containing administrative, pharmacy, and microbiology data. We compared NP patients readmitted with pneumonia (RaP) as the principal diagnosis to those readmitted for other reasons (RaO) with respect to the type of NP (ventilator-associated bacterial pneumonia [VABP], ventilated hospital-acquired bacterial pneumonia [vHABP], and non-ventilated HABP [nvHABP]), and characteristics and outcomes of the index hospitalization. RESULTS: Among 17,819 patients with NP, 14,123 (79.3%) survived to discharge, of whom 2,151 (15.2%) required an acute readmission within 30 days of index discharge. Of these, 106 (4.9%) were RaP, and the remainder were RaO. At index hospitalization, RaP patients were older (mean age [SD] 67.4 (13.9] vs. 63.0 [15.2] years), more likely medical (44.3% vs. 36.7%), and less chronically ill (median [IQR] Charlson scores (3 [2-5] vs. 4 [2-5]) than persons with RaO. Bacteremia (10.4% vs. 17.5%), need for vasopressors (15.1% vs. 20.0%), dialysis (9.4% vs. 16.5%), and/or sepsis (9.4% vs. 16.5%) or septic shock 14.2% vs. 17.1%) occurred less frequently in the RaP group. With respect to NP type, nvHABP was most common in RaP (47.2%) and VABP in RaO (38.1%). CONCLUSIONS: One in seven survivors of a hospitalization complicated by NP requires an acute rehospitalization within 30 days. However, few of these readmissions had a principal diagnosis of pneumonia, irrespective of NP type. Of the 5% of NP subjects with RaP, the plurality initially suffered from nvHABP.

Going Viral-RSV as the Neglected Adult Respiratory Virus.

Human respiratory syncytial virus (RSV) is increasingly recognized as a significant viral pathogen in adults with acute respiratory illness, particularly in the elderly, the immunocompromised, and those with underlying cardiopulmonary disease. Although long acknowledged as one of the most common causes of upper respiratory tract infections (URI) in children since its discovery in 1956, the true burden of disease in adults is likely significantly under-recognized. The emerging evidence of RSV as a driver of morbidity and mortality in elderly and immunocompromised patients has sparked advances in vaccine development and renewed interest in quantifying the true burden of disease. This review attempts to summarize the findings of the most recent evidence investigating the burden of RSV related disease in adults and to highlight where future research is needed.

The risk of inappropriate empiric treatment and its outcomes based on pathogens in non-ventilated (nvHABP), ventilated (vHABP) hospital-acquired and ventilator-associated (VABP) bacterial pneumonia in the US, 2012-2019.

BACKGROUND: Inappropriate empiric antimicrobial treatment (IET) contributes to worsened outcomes. While IET's differential impact across types of nosocomial pneumonia (NP: non-ventilated [nvHABP], ventilated [vHABP] hospital-acquired and ventilator-associated [VABP] bacterial pneumonia) is established, its potential interaction with the bacterial etiology is less clear. METHODS: We conducted a multicenter retrospective cohort study in the Premier Healthcare Database using an administrative algorithm to identify NP. We paired respective pathogens with empiric treatments. Antimicrobial coverage was appropriate if a drug administered within 2 days of infection onset covered the recovered organism(s). All other treatment was IET. RESULTS: Among 17,819 patients with NP, 26.5% had nvHABP, 25.6% vHABP, and 47.9% VABP. Gram-negative (GN) organisms accounted for > 50% of all infections. GN pathogens were ~ 2 × as likely (7.4% vHABP to 10.7% nvHABP) to engender IET than Gram-positive (GP, 2.9% vHABP to 4.9% nvHABP) pathogens. Although rare (5.6% nvHABP to 8.3% VABP), GN + GP infections had the highest rates of IET (6.7% vHABP to 12.9% nvHABP). Carbapenem-resistant GNs were highly likely to receive IET (33.8% nvHABP to 40.2% VABP). Hospital mortality trended higher in the IET group, reaching statistical significance in GN + GP vHABP (47.8% IET vs. 29.3% non-IET, p = 0.016). 30-day readmission was more common with IET (16.0%) than non-IET (12.6%, p = 0.024) in GN VABP. Generally post-infection onset hospital length of stay and costs were higher with IET than non-IET. CONCLUSIONS: IET is ~ 2 × more common in GN than GP infections. Although the magnitude of its impact varies by NP type, IET contributes to worsened clinical and economic outcomes.

Novel agents in development for multidrug-resistant Gram-negative infections: potential new options facing multiple challenges.

PURPOSE OF REVIEW: To review novel antiinfective agents in development for multidrug-resistant (MDR) Gram-negative bacterial infections. RECENT FINDINGS: Four novel agents are in various phases of development (tebipenem, durlobactam-sulbactam, cefepime-taniborbactam, and xeruborbactam). Tebpipenem is an oral carbapenem with a recently completed phase III trial for complicated urinary tract infections while durlobactam-sulbactam represents a potential alternative for drug-resistant Acinetobacter baumannii . Cefepime-taniborbactam possesses in-vitro potency against a range of troubling pathogens and we await further information on a recently completed study on complicated urinary tract infection. Finally, xeruborbactam is an ultrabroad beta-lactamase inhibitor that can be paired with a range of intravenous and oral agents. It exhibits enhanced in-vitro activity against many MDR pathogens, including those resistant to newer, broader spectrum options. Data in humans with xeruborbactam are limited. SUMMARY: Each of the newer options reviewed possesses a unique range of in-vitro activity against select, challenging pathogens with some narrowly tailored and other broader in activity. Several have both oral and intravenous formulations. Two agents have presented data from recent phase III trials, whereas two are not as advanced in their clinical programs.

Inappropriate Empiric Therapy Impacts Complications and Hospital Resource Utilization Differentially Among Different Types of Bacterial Nosocomial Pneumonia: A Cohort Study, United States, 2014-2019.

Nosocomial pneumonia (NP) remains a costly complication of hospitalization fraught with subsequent complications and augmented resource utilization. Consisting of ventilated hospital-acquired bacterial pneumonia (vHABP), nonventilated hospital-acquired bacterial pneumonia (nvHABP), and ventilator-associated bacterial pneumonia (VABP), each may respond differently to inappropriate empiric treatment (IET). We explored whether IET affects the three pneumonia types differently. DESIGN: A multicenter, retrospective cohort study within the Premier Research database. SETTING: Acute care hospitals in the United States. PATIENTS: Patients with three types of NP were identified based on a previously published International Classification of Diseases, 9th Edition/International Classification of Diseases, 10th Edition Clinical Modification algorithm. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We compared the impact of IET on hospital costs, length of stay (LOS), and development of Clostridium difficile infection (CDI), extubation failure (EF), and reintubation (RT). Marginal effects were derived from multivariable regression analyses. IET was present if no drug covering the organism recovered from the index culture was administered within 2 days of the culture date. Among 17,819 patients who met the enrollment criteria, 26.5% had nvHABP, 25.6% vHABP, and 47.9% VABP. Compared with non-IET, IET was associated with increased mean unadjusted hospital LOS across all NP types: nvHABP 12.5 versus 21.1, vHABP 16.7 versus 19.2, and VABP 18.6 versus 21.4 days. The adjusted marginal hospital LOS (4.9 d) and costs ($13,147) with IET were the highest in nvHABP. Incident CDI was rare and similar across NP types (2.4% nvHABP to 3.6% VABP). Both EF and RT were more common with IET in VABP (EF, 15.4% vs 19.2%; RT, 6.2% vs 10.4%), but not vHABP (EF, 15.1% vs 17.7%; RT, 8.1% vs 9.1%). CONCLUSIONS: Although IET is relatively uncommon, it affects resource utilization and the risk of complications differently across NP types. The impact of IET is greatest on both LOS and costs in nvHABP and is greater on VABP than vHABP in terms of EF and RT.

Microbiology, empiric therapy and its impact on the outcomes of nonventilated hospital-acquired, ventilated hospital-acquired, and ventilator-associated bacterial pneumonia in the United States, 2014-2019.

OBJECTIVE: To explore whether microbiology profiles and the impact of inappropriate empiric treatment differ in the setting of hospital-acquired bacterial pneumonia that requires subsequent mechanical ventilation (vHABP) versus one that does not (nvHABP) versus ventilator-associated bacterial pneumonia (VABP). DESIGN: Multicenter retrospective cohort study within Premier Research database, 2014-2019. METHODS: We identified cases based on a previously published International Classification of Disease, Ninth Revision/Tenth Revision Clinical Modification (ICD-9/ICD-10-CM) algorithm, and we compared the 3 groups with respect to the bacterial pathogens isolated from their blood, sputum, or lower airway samples, and their respective rates of exposure to inappropriate empiric treatment. Using regression modeling we computed the effect of inappropriate empiric treatment on outcomes. RESULTS: Among 17,819 patients who met enrollment criteria, 26.5% had nvHABP, 25.6% vHAPB, and 47.9% VABP. S. aureus (majority methicillin-susceptible) was the most frequently isolated organism, followed P. aeruginosa, K. pneumoniae, and E. coli with variations across the conditions. Rates of carbapenem resistance were highest in VABP (9.1%) and to third-generation cephalosporins in vHABP (14.9%). Patients with nvHABP were most likely to receive inappropriate empiric treatment (8.5%). Although inappropriate empiric treatment was associated with an increase in adjusted postinfection-onset hospital length of stay (2.3 days) and cost ($12,142), its greatest magnitude was in the nvHABP group (4.9 days, $13,147). CONCLUSIONS: Substantial microbiologic differences exist among populations who suffer nvHABP, vHABP, and VABP, and inappropriate empiric treatment significantly worsens utilization outcomes. Given the moderate rates of carbapenem resistance and third-generation cephalosporin resistance, all patients require empiric coverage for a range of bacteria, including those targeting extended-spectrum ß-lactamase and carbapenem resistance where appropriate.