Pulmonary Source Of Infection Research Articles

844. Nosocomial Pseudomonas aeruginosa Blood-Stream Infections; Susceptibility Pattern and Mortality at a Tertiary Care Centre in Edmonton, Alberta, Canada

Background Pseudomonas aeruginosa is one of the leading gram negative nosocomial pathogens, causing severe infections including blood-stream infections (BSI) with high mortality rates. (1). Multi-drug resistant P. aeruginosa (MDRPA) infection rates are reported to be increasing (2) and have been associated with increased mortality (3). This study aims to review the susceptibility pattern and trend of P. aeruginosa BSIs and mortality and identify patients at increased risk of BSI with a resistant P. aeruginosa isolate. This data has important treatment implications.MethodsCases of nosocomial P. aeruginosa bacteremia were prospectively identified at the University of Alberta, Edmonton, Alberta, Canada by the infection prevention and control surveillance program between January 1, 2007 and December 31, 2018. Patient charts were retrospectively reviewed to collect microbiological, clinical, and epidemiological information.Results148 cases of P. aeruginosa BSI were identified over a 12-year period between January 2007 and December 2018. There were 19 cases of MDRPA BSI and 9 cases of XDRPA BSI. The incidence of P. aeruginosa BSI was 0.47 per 10,000 patient days and remained relatively stable over the study period. 66.9% of cases occurred in men. The mean age was 60 years. The average length of stay prior to bacteremia was 42 days. The overall 30-day mortality following P. aeruginosa BSI was 36.4%. Risk factors for increased 30-day mortality included: pulmonary source of infection (OR 4.26, p < 0.001), bacteremia with extremely drug resistant Pseudomonas aeruginosa (XDRPA) (p < 0.0001), and diabetes (OR 2.24, p < 0.05). BSI with MDRPA was not an independent risk factor for increased mortality. Significant risk factors for bacteremia with an MDRPA or XDRPA were length of stay > 28 days (OR 4.22, p < 0.001) and hemodialysis (OR 8.92, p < 0.000001).Annual hospital acquired P. aeruginosa blood-stream infections from 2007-2018 Antibiogram of P. aeruginosa blood-stream isolates from 2007-2018 ConclusionThe incidence of P. aeruginosa BSI as well as the rate of MDRPA and XDRPA BSI have remained stable at our centre between 2007 and 2018. We found that BSI with XDRPA but not MDRPA alone was a significant risk factor for mortality. Risk factors for BSI with a resistant P. aeruginosa strain may be considered to guide empiric therapy.Disclosures All Authors: No reported disclosures

Outcomes of Adult Patients With Septic Shock Undergoing Extracorporeal Membrane Oxygenation Therapy

Extracorporeal membrane oxygenation (ECMO) has been shown to provide benefits in children, but not adults, with septic shock. This study described the clinical outcomes of adults in septic shock who underwent ECMO. This study retrospectively investigated adults who were supported on venoarterial or venovenous modes of ECMO and who had septic shock at the time of cannulation from January 1, 2009 to December 31, 2016 at a quaternary medical center in the United States. The primary outcomes were rate of survival to hospital discharge and time to survival using Kaplan-Meier survival estimates. This study analyzed survival by mode, previous cardiac arrest, and timing of cannulation (<96 and ≥96 hours after admission to the intensive care unit). Secondary outcomes were complications and days of ECMO support, length of stay in the intensive care unit, and hospitalization days. Of 243 patients supported on ECMO during this 7-year period, 32 met the criteria for septic shock, and the majority had a pulmonary source of infection (72%). The most common mode of support was venovenous ECMO (65%), and median ejection fraction was 51%. Median time on ECMO was 5.8 days (interquartile range, 2.6, 11.3 days). Survival to hospital discharge was 13 of 32 (41%), whereas median survival was 14.5 days (interquartile range, 5.2, 23.7 days). There was no statistically significant difference in survival by subgroup, including ECMO mode. Health care-associated infections were frequent (25%). This cohort of patients undergoing ECMO had equivalent median survival compared with literature-based estimates of other cohorts of patients with septic shock.

A pulmonary source of infection in patients with sepsis-associated acute kidney injury leads to a worse outcome and poor recovery of kidney function.

Hospital mortality rates are higher among patients with sepsis-associated acute kidney injury (SA-AKI) than among patients with sepsis. However, the pathogenesis underlying SA-AKI remains unclear. We hypothesized that the source of infection affects development of SA-AKI. We aim to explore the relationship between the anatomical source of infection and outcome in patients with SA-AKI. Between January 2013 and January 2018, 113 patients with SA-AKI admitted to our Emergency Center were identified and divided into two groups: those with pulmonary infections and those with other sources of infection. For each patient, we collected data from admission until either discharge or death. We also recorded the clinical outcome after 90 days for the discharged patients. The most common source of infection was the lung (52/113 cases, 46%), followed by gastrointestinal (GI) (25/113 cases, 22.1%) and urinary (22/113, 19.5%) sources. Our analysis showed that patients with SA-AKI had a significantly worse outcome (30/52 cases, P<0.001) and poorer kidney recovery (P=0.015) with pulmonary sources of infection than those infected by another source. Data also showed that patients not infected by a pulmonary source more likely experienced shock (28/61 cases, P=0.037). This study demonstrated that the source of infection influenced the outcome of SA-AKI patients in an independent manner. Lung injury may influence renal function in an as-yet undetermined manner as the recovery of kidney function was poorer in SA-AKI patients with a pulmonary source of infection.

Predictors of multidrug-resistant Pseudomonas aeruginosa in neutropenic patients with bloodstream infection

ObjectivesTo assess risk factors for multidrug-resistant Pseudomonas aeruginosa (MDR-PA) infection in neutropenic patients. MethodsSingle-centre retrospective analysis of consecutive bloodstream infection (BSI) episodes (2004–2017, Barcelona). Two multivariate regression models were used at BSI diagnosis and P. aeruginosa detection. Significant predictors were used to establish rules for stratifying patients according to MDR-PA BSI risk. ResultsOf 661 Gram-negative BSI episodes, 190 (28.7%) were caused by P. aeruginosa (70 MDR-PA). Independent factors associated with MDR-PA among Gram-negative organisms were haematological malignancy (OR 3.30; 95% CI 1.15–9.50), pulmonary source of infection (OR 7.85; 95% CI 3.32–18.56), nosocomial-acquired BSI (OR 3.52; 95% CI 1.74–7.09), previous antipseudomonal cephalosporin (OR 13.66; 95% CI 6.64–28.10) and piperacillin/tazobactam (OR 2.42; 95% CI 1.04–5.63), and BSI occurring during ceftriaxone (OR 4.27; 95% CI 1.15–15.83). Once P. aeruginosa was identified as the BSI aetiological pathogen, nosocomial acquisition (OR 7.13; 95% CI 2.87–17.67), haematological malignancy (OR 3.44; 95% CI 1.07–10.98), previous antipseudomonal cephalosporin (OR 3.82; 95% CI 1.42–10.22) and quinolones (OR 3.97; 95% CI 1.37–11.48), corticosteroids (OR 2.92; 95% CI 1.15–7.40), and BSI occurring during quinolone (OR 4.88; 95% CI 1.58–15.05) and β-lactam other than ertapenem (OR 4.51; 95% CI 1.45–14.04) were independently associated with MDR-PA. Per regression coefficients, 1 point was assigned to each parameter, except for nosocomial-acquired BSI (3 points). In the second analysis, a score >3 points identified 60 (86.3%) out of 70 individuals with MDR-PA BSI and discarded 100 (84.2%) out of 120 with non-MDR-PA BSI. ConclusionsA simple score based on demographic and clinical factors allows stratification of individuals with bacteraemia according to their risk of MDR-PA BSI, and may help facilitate the use of rapid MDR-detection tools and improve early antibiotic appropriateness.

Epidemiological features and risk factors for mortality in Pseudomonas aeruginosa bacteremia in children.

The objective was to describe the epidemiological, clinical, microbiological, and evolutionary characteristics and the risk factors for mortality. Retrospective, cohort study. A total of 100 patients were included. Of these, 42 (42 %) had septic shock upon admission and 56 (56 %) were admitted to the intensive care unit. Bacteremia was primary in 17 patients (17 %); catheter-related, in 15 (15 %); and secondary, in 68 (68 %). The most common source of infection was the skin and mucous membrane. Resistance to one or more antibiotic groups was 38 %. Thirty-one patients died (31 %). Risk factors for mortality were septic shock (p < 0.0005), admission to the intensive care unit (p < 0.0001), primary bacteremia (p < 0.009) or secondary, non-catheter-related bacteremia (p < 0.003), presence of mucocutaneous or pulmonary source of infection (p < 0.004), and multidrug resistance (p < 0.01) or resistance to carbapenems (p < 0.01).

Risk factors for mortality in patients with acute leukemia and bloodstream infections in the era of multiresistance.

ObjectivesWe assess the epidemiology and risk factors for mortality of bloodstream infection (BSI) in patients with acute leukemia (AL).MethodsProspectively collected data of a cohort study from July 2004 to February 2016. Multivariate analyses were performed.Results589 episodes of BSI were documented in 357 AL patients, 55% caused by gram-positive bacteria (coagulase-negative staphylococci 35.7%, Enterococcus spp 10.8%) and 43.5% by gram-negative bacteria (E. coli 21%, PA 12%). We identified 110 (18.7%) multidrug-resistant (MDR) microorganisms, especially MDR-Pseudomonas aeruginosa (7%) and extended-spectrum beta-lactamase producing Enterobacteriaceae (7%). The 30-day mortality was 14.8%. Age (OR 3.1; 95% CI 1.7–5.7); chronic lung disease (4.8; 1.1–21.8); fatal prognosis according to McCabe index (13.9; 6.4–30.3); shock (3.8; 1.9–7.7); pulmonary infection (3.6; 1.3–9.9); and MDR-PA infections with inappropriate treatment (12.8; 4.1–40.5) were related to mortality. MDR-PA BSI was associated to prior antipseudomonal cephalosporin use (9.31; 4.38–19.79); current use of betalactams (2.01; 1.01–4.3); shock (2.63; 1.03–6.7) and pulmonary source of infection (9.6; 3.4–27.21).ConclusionsMDR organisms were commonly isolated in BSI in AL. Inappropriate empiric antibiotic treatment for MDR-PA is the primary factor related to mortality that can be changed. New treatment strategies to improve the coverage of MDR-PA BSI should be considered in those patients with risk factors for this infection.

Early risk factors and the role of fluid administration in developing acute respiratory distress syndrome in septic patients

Background Sepsis is a major risk factor for acute respiratory distress syndrome (ARDS). However, there remains a paucity of literature examining risk factors for ARDS in septic patients early in their course. This study examined the role of early fluid administration and identified other risk factors within the first 6 h of hospital presentation associated with developing ARDS in septic patients.MethodsThis was a secondary analysis of septic adult patients presenting to the Emergency Department or being admitted for high-risk elective surgery from the multicenter observational cohort study, US Critical Injury and Illness trial Group-Lung Injury Prevention Study 1 (USCIITG-LIPS 1, NCT00889772). Multivariable logistic regression was performed to identify potential early risk factors for ARDS. Stratified analysis by shock status was performed to examine the association between early fluid administration and ARDS.ResultsOf the 5584 patients in the original study cohort, 2534 (45.4%) met our criteria for sepsis. One hundred and fifty-six (6.2%) of these patients developed ARDS during the hospital stay. In multivariable analyses, Acute Physiology and Chronic Health Evaluation (APACHE) II score (OR 1.10, 95% CI 1.07–1.13), age (OR 0.97, 95% CI 0.96–0.98), total fluid infused in the first 6 h (in liters) (OR 1.15, 95% CI 1.03–1.29), shock (OR 2.57, 95% CI 1.62–4.08), pneumonia as a site of infection (OR 2.31, 95% CI 1.59–3.36), pancreatitis (OR 3.86, 95% CI 1.33–11.24), and acute abdomen (OR 3.77, 95% CI 1.37–10.41) were associated with developing ARDS. In the stratified analysis, total fluid infused in the first 6 h (in liters) (OR 1.05, 95% CI 0.87–1.28) was not associated with the development of ARDS in the shock group, while there was an association in the non-shock group (OR 1.21, 95% CI 1.05–1.38).ConclusionsIn septic patients, the following risk factors identified within the first 6 h of hospital presentation were associated with ARDS: APACHE II score, presence of shock, pulmonary source of infection, pancreatitis, and presence of an acute abdomen. In septic patients without shock, the amount of fluid infused during the first 6 h of hospital presentation was associated with developing ARDS.

Identifying critically ill patients at risk for inappropriate antibiotic therapy: a pilot study of a point-of-care decision support alert.

To develop an automated alert aimed at reducing inappropriate antibiotic therapy of serious healthcare-associated infections. Single-center cohort study from November 2011 to November 2012. Barnes-Jewish Hospital (1,250-bed academic hospital). A total of 3,616 critically ill patients receiving treatment with antibiotics targeting healthcare-associated infections due to Gram-negative bacteria. Upon antibiotic order entry in the ICU for a Gram-negative antibiotic, the antibiotic and microbiologic history for each patient was electronically queried in real time across all 13 BJC HealthCare hospitals. Patients were assigned to the alert group if they had exposure to the same antibiotic class currently being prescribed (cefepime, meropenem, or piperacillin-tazobactam) or had a positive culture isolating a Gram-negative organism with resistance to the prescribed antibiotic in the previous 6 months. Nine hundred patients (24.2%) generated an alert. Alerted patients were significantly more likely to receive inappropriate antibiotic therapy (7.1% vs. 2.9%; p < 0.001). Based on clinical information available in the alert, 34 of 64 of the alerted patients that received inappropriate therapy (53.1%) could have received an alternative β-lactam antibiotic with in vitro susceptibility to the identified pathogen. Independent predictors (adjusted odds ratio [95% CI]) of inappropriate therapy included alert generation (1.788 [1.167-2.740]; p = 0.008), medical ICU patients (1.528 [1.007-2.319]; p = 0.046), and a pulmonary source of infection (2.063 [1.363-3.122]; p = 0.0001). Patients in the alert group had significantly greater hospital mortality (29.9% vs. 23.6%; p < 0.001) and hospital length of stay (median, 13.1 vs. 10.7 d; p < 0.001) compared with nonalert patients. Our results suggest that a simple automated alert could identify more than 40% of critically ill patients prescribed inappropriate antibiotic therapy for healthcare-associated infections. These data suggest that an opportunity exists to employ hospital informatics systems to improve the prescription of antibiotic therapy in ICU patients with suspected healthcare-associated infections.

Epidemiology of bloodstream infection in nursing home residents: evaluation in a large cohort from multiple homes.

This study sought to reevaluate the epidemiology of bloodstream infection in nursing home residents. The records of 166 nursing home residents admitted to an urban, public, university-affiliated hospital with 169 episodes of bloodstream infection between January 1997 and April 2000 were retrospectively reviewed. The most common organisms isolated were Escherichia coli (27% of isolates), Staphylococcus aureus (18%; 29% were methicillin-resistant strains), and Proteus mirabilis (13%). There was minimal resistance to quinolones and third-generation cephalosporins among aerobic gram-negative bacilli. The most common sources were the urinary tract (51% of episodes) and the lungs (11%); a source was not identified in 22% of episodes. Hospital mortality was 18%. Independent predictors of hospital mortality were a pulmonary source of infection, systolic blood pressure <90 mm Hg, and leukocytosis >20,000 cells/mm3. Compared with other studies published in the past 2 decades, mortality was lower. The most common resistant organism was methicillin-resistant S. aureus.

Bloodstream infections at a Norwegian university hospital, 1974-1979 and 1988-1989: changing etiology, clinical features, and outcome.

All episodes of bloodstream infection in patients admitted to a Norwegian university hospital in 1974-1979 and in 1988-1989 were analyzed; altogether, there were 1,447 episodes involving 1,286 patients, and 54.3% of all episodes were hospital-acquired. The incidence of bloodstream infection increased between the two periods studied from 4.26/1,000 admissions to 8.71/1,000. Crude mortality rates were 27.6% and 18.8% and attributable mortality rates were 12.3% and 6.9% in the first and second periods, respectively. Patients > 60 years of age accounted for more than half of the bloodstream infections; mortality in this group was significantly higher than that among younger patients (31.4% vs. 13.9%). The frequency of isolation of Enterobacteriaceae decreased from 48% in the first period to 34% in the second, while the rate of isolation of coagulase-negative staphylococci increased from 6.5% to 16.9%. The shift in etiology may be explained in part by the occurrence of significantly more bloodstream infections related to intravascular devices, endocarditis, and skin and wound infections and of significantly fewer episodes related to abdominal or genitourinary disease in the second than in the first period. Almost all isolates of Enterobacteriaceae were susceptible to newer cephalosporins and aminoglycosides. In 1974-1979, 96 (69.1%) of 139 patients with septic shock died; in 1988-1989, the figure was 35 (52.2%) of 67 patients (P = .019). Clinical factors predictive of an adverse outcome were septic shock (odds ratio for first/second period, 12.7/4.6), intensive care treatment (not significant/10.6), malignant disease (4.6/2.6), any underlying disease (4.2/not significant), diabetes mellitus (3.6/not significant), age of > 60 years (not significant/3.0), and pulmonary source of infection (not significant/2.8).

Computed tomography and magnetic resonance imaging of tuberculous meningitis

Tuberculous meningitis usually results from hematogenous seeding of the central nervous system from a primary pulmonary source of infection. Initially, the meningitic process can mimic a flu-like syndrome, followed rapidly by the development of profound neurologic deficits. Computed tomography scanning or magnetic resonance imaging of the head often demonstrates a characteristic pattern of basal cistern involvement with Mycobacterium tuberculosis. The incidence of tuberculous meningitis in the more developed countries has increased during the past 5 years because of the growing number of cases in patients with acquired immunodeficiency syndrome, the spread among the homeless, and the expanding immigrant population. The significant morbidity and mortality rates associated with tuberculous meningitis--generally considered to be a disease of the past--emphasize the need for greater clinical awareness, early diagnosis, and prompt treatment.

Sporothrix schenckii meningitis in a farmer with Hodgkin's disease

A fatal case of chronic meningeal sporotrichosis occurring as an opportunistic infection in a patient with Hodgkin's disease is presented. A pulmonary source of infection was identified at autopsy. The diagnostic importance of the isolation of Sporothrix schenckii from cerebrospinal fluid, even if only from a single specimen, is stressed.