Microbial etiology of pneumonia in patients with decreased renal function

Background

Patients with renal impairment have altered immunity, which might cause vulnerability to specific pathogens and worsen pneumonia-related outcomes. Nonetheless, the microbiological features of pneumonia in patients with decreased renal function remain unknown.

Methods

Therefore, we conducted a retrospective cohort study enrolling adult patients hospitalized with pneumonia to assess this knowledge gap. The baseline estimated glomerular filtration rate (eGFR) and first sputum microbiology during hospitalization were used for statistical analyses.

Results

Overall, 1554 patients hospitalized with pneumonia (mean age, 76.1 ± 16.7) were included, and 162 patients had died at the end of hospitalization. The cutoff eGFR value predicting mortality was <55 mL/min/1.73 m², which defined decreased renal function in this study. Patients with decreased renal function demonstrated a significantly higher risk of fungi and Staphylococcus aureus (S. aureus) infection. On the other hand, this group of patients showed significantly higher neutrophil-to-lymphocyte ratio (NLR), which associated with higher mortality. Additionally, patients with S. aureus had a significantly lower eGFR, lymphocyte count and a higher NLR.

Conclusions

These findings suggested the altered immunity and vulnerability to S. aureus infection in patients with decreased renal function, which may be the underlying cause of worse outcomes of pneumonia in this group of patients.

Ventilator-Associated Pneumonia Patients who Do Not Reduce Bacteria from the Lungs have a Worse Prognosis

The authors determined the significance of serial semi-quantitative bronchoalveolar lavage (BAL) culture results in patients undergoing therapy for ventilator-associated pneumonia. A total of 32 patients underwent at least 2 nonbronchoscopic BAL studies. Fourteen patients had methicillin-resistant Staphylococcus aureus(MRSA). Of these, 11 had more than 100 colony-forming units (cfu) of MRSA/mL of BAL from the follow-up BAL. Eighteen patients had an organism other than MRSA, and 7 of these patients had > 100 cfu of bacteria/mL of BAL from the follow-up BAL. Of the 18 patients with > 100 cfu of bacteria/mL of BAL at follow-up, 14 (79%) died, whereas only 5 of 14 (36%) patients who cleared their bacteria at follow-up died within 28 days. The inability to reduce the bacterial burden from the lower respiratory tract within the first few days of therapy for ventilator-associated pneumonia was associated with increased mortality.

Linezolid Versus Vancomycin in the Empiric Treatment of Nosocomial Pneumonia: A Cost-Utility Analysis Incorporating Results from the ZEPHyR Trial

OBJECTIVE

To examine the cost-effectiveness of vancomycin versus linezolid in the empiric treatment of nosocomial pneumonias incorporating results from a recent prospective, double-blind, multicenter, controlled trial in adults with suspected methicillin-resistant Staphylococcus aureus (MRSA) nosocomial pneumonia.

METHODS

A decision-analytic model examining the cost-effectiveness of linezolid versus vancomycin for the empiric treatment of nosocomial pneumonia was created. Publicly available cost, efficacy, and utility data populated relevant model variables. A probabilistic sensitivity analysis varied parameters in 10,000 Monte-Carlo simulations, and univariate sensitivity analyses assessed the impact of model uncertainties and the robustness of our conclusions.

RESULTS

Results indicated that the cost per quality-adjusted life-year (QALY) increased 6% ($22,594 vs. $23,860) by using linezolid versus vancomycin for nosocomial pneumonia. The incremental cost per QALY gained by using linezolid over vancomycin was $6,089, and the incremental cost per life saved was $68,615 with the use of linezolid. Vancomycin dominated linezolid in the subset of patients with documented MRSA. The incremental cost per QALY gained using linezolid if no mortality benefit exists between agents or a 60-day time horizon was analyzed was $19,608,688 and $443,662, respectively.

CONCLUSIONS

Linezolid may be a cost-effective alternative to vancomycin in the empiric treatment of patients with suspected MRSA nosocomial pneumonia; however, results of our model were highly variable on a number of important variables and assumptions including mortality differences and time frame analyzed.

Bacteriology of aspiration pneumonia in patients with acute coma

Loss of protective airway reflexes in patients with acute coma puts these patients at risk of aspiration pneumonia complicating the course of the primary disease. Available data vary considerably with regard to bacteriology, role of anaerobic bacteria, and antibiotic treatment. Our objective was to research the bacteriology of aspiration pneumonia in acute coma patients who were not pre-treated with antibiotics or hospitalized within 30 days prior to the event. We prospectively analyzed 127 patient records from adult patients admitted, intubated and ventilated to a tertiary medical intensive care unit with acute coma. Bacteriology and antibiotic resistance testing from tracheal aspirate sampled within 24 h after admission, blood cultures, ICU scores (APACHE II, SOFA), hematology, and clinical chemistry were assessed. Patients were followed up until death or hospital discharge. The majority of patients with acute coma suffered from acute cardiovascular disorders, predominantly myocardial infarction, followed by poisonings, and coma of unknown cause. In a majority of our patients, microaspiration resulted in overt infection. Most frequently S. aureus, H. influenzae, and S. pneumoniae were isolated. Anaerobic bacteria (Bacteroides spec., Fusobacteria, Prevotella spec.) were isolated from tracheal aspirate in a minority of patients, and predominantly as part of a mixed infection. Antibiotic monotherapy with a 2nd generation cephalosporin, or a 3rd generation gyrase inhibitor, was most effective in our patients regardless of the presence of anaerobic bacteria.

A novel treatment option for MRSA pneumonia: ceftaroline fosamil-yielding new hope in the fight against a persistent infection

Methicillin-resistant Staphylococcus aureus (MRSA) hospital-acquired pneumonia (HAP) and healthcare-associated pneumonia (HCAP) patients treated with current antibiotic therapies have exhibited poor outcomes, increased hospital length of stay, and higher costs of care. The optimal management of these infections is undetermined; thus, it is critical to look at ways to improve outcomes in these patients. There is insufficient data on clinical efficacy in patients with MRSA HAP or HCAP infection treated with ceftaroline-fosamil. In a recent pilot study, nearly 90% of patients treated with ceftaroline-fosamil survived, despite the difficulties associated with administrating bactericidal antimicrobial therapy for this increasingly resistant pathogen. These data suggest a possible benefit in the use of ceftaroline-fosamil for MRSA pneumonia. Presently, we have identified cases over a two-year period treated with ceftaroline-fosamil, and will conduct a comparative analysis to controls (those treated with vancomycin and/or cefepime, and linezolid) to determine optimal therapeutic agents; these findings will have important implications for control of further spread of infection, recurrence, readmission, and mortality attributable to MRSA HAP and HCAP.

Epidemiology and prevention of nosocomial pneumonia associated with Panton-Valentine Leukocidin (PVL) producing Staphylococcus aureus in Departmental Hospital Centre of Zou Collines in Benin

BACKGROUND

An eight (8) months prospective study was carried out to control an outbreak of nosocomial pneumonia due to a Panton-Valentine Leukocidin (PVL) producing Staphylococcus aureus, in the paediatrics' unit at the Zou/Collines Departmental Hospital (CHDZ/C), (Benin).

METHODS

Between 1(st) September 2004 and 30(th) May 2005 an investigation was conducted that involved the screening of all patients suspected to have nosocomial pneumonia, hospital environment sampling and the follow-up of cases until the end of hospital admission period. Isolates were identified, tested for antimicrobial susceptibility and analysed for PVL production. The study period was divided into Period I, corresponding to the outbreak period and Period II, after the complete renovation of the Unit along with hand washing promotion.

RESULTS

A total of 453 patients were admitted during the period of the study; (235 during Period I and 218 during Period II) in the malnourished children sector. Twenty eight (28) cases of pneumonia due to S. aureus were discovered and PVL-producing S. aureus constituted 61% (17/28) of identified cases. The mortality rate among the PVL- producing strains was 15/17 (88%) while it was 1/11 (9%) among non PVL-producing strains. Enhanced hygiene measures helped to terminate the outbreak.

CONCLUSIONS

This study showed that PVL was strongly linked to nosocomial pneumonia. PVL-producing S aureus can be controlled in the hospital by a combination of the promotion of preventive measures, decontamination of the environment and the early use of the correct antibiotic at the appropriate dose and for an adequate duration.

Comparative in vivo efficacies of epithelial lining fluid exposures of tedizolid, linezolid, and vancomycin for methicillin-resistant Staphylococcus aureus in a mouse pneumonia model

The antibacterial efficacies of tedizolid phosphate (TZD), linezolid, and vancomycin regimens simulating human exposures at the infection site against methicillin-resistant Staphylococcus aureus (MRSA) were compared in an in vivo mouse pneumonia model. Immunocompetent BALB/c mice were orally inoculated with one of three strains of MRSA and subsequently administered 20 mg/kg TZD every 24 hours (q24h), 120 mg/kg linezolid q12h, or 25 mg/kg vancomycin q12h over 24 h. These regimens produced epithelial lining fluid exposures comparable to human exposures observed following intravenous regimens of 200 mg TZD q24h, 600 mg linezolid q12h, and 1 g vancomycin q12h. The differences in CFU after 24 h of treatment were compared between control and treatment groups. Vehicle-dosed control groups increased in bacterial density an average of 1.1 logs. All treatments reduced the bacterial density at 24 h with an average of 1.2, 1.6, and 0.1 logs for TZD, linezolid, and vancomycin, respectively. The efficacy of TZD versus linezolid regimens against the three MRSA isolates was not statistically different (P > 0.05), although both treatments were significantly different from controls. In contrast, the vancomycin regimen was significantly different from TZD against one MRSA isolate and from linezolid against all isolates. The vancomycin regimen was less protective than either the TZD or linezolid regimens, with overall survival of 61.1% versus 94.7% or 89.5%, respectively. At human simulated exposures to epithelial lining fluid, vancomycin resulted in minimal reductions in bacterial counts and higher mortality compared to those of either TZD or linezolid. TZD and linezolid showed similar efficacies in this MRSA pneumonia model.

Ventilator-associated pneumonia due to meticillin-resistant Staphylococcus aureus: risk factors and outcome in a large general hospital

BACKGROUND

Data about risk factors and impact on outcome of methicillin-resistant S. aureus (MRSA) in unselected patients with ventilator-associated pneumonia (VAP) are limited.

AIM

To assess predisposing factors and outcome of VAP due to MRSA in a large teaching institution.

METHODS

Prospective study carried out over four years in the three adult ICUs of our hospital. Patients with MRSA-VAP were compared with those with bacterial VAP due to other microorganisms.

FINDINGS

Overall, 474 episodes of bacterial VAP were collected. Significant differences between MRSA-VAP (111) and VAP due to other microorganisms (363) were found for median age (68 vs. 62 years), median APACHE II score (12 vs. 11), neurosurgery (5.4% vs. 13.8%), abdominal surgery (35% vs. 19%), prior treatment with any antibiotic (82.9% vs. 64.5%) and with imipenem (24% vs. 11%) at present admission before VAP, and pleural effusion (12% vs. 5%). Multivariate analysis adjusted for confounding factors showed that higher APACHE II score, prior treatment with any antibiotic and pleural effusion were independent risk factors for MRSA. As for treatment and outcome, the differences between MRSA-VAP and other VAP were inadequate empiric treatment (70% vs. 53%), median cost of antibiotics per episode (€974 vs. €726), and in-hospital mortality (60% vs. 47%). At multivariate analysis, however, MRSA was not found to be an independent risk factor for mortality.

CONCLUSION

MRSA is a common cause of VAP. Underlying conditions predispose to its high mortality.

Health care-associated pneumonia (HCAP): empiric antibiotics targeting methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa predict optimal outcome

Inappropriate initial antimicrobial therapy (IIAT) has been associated with decreased survival in patients with health care-associated pneumonia (HCAP). We performed a study to determine whether empiric HCAP antibiotic regimens targeting methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa are associated with greater appropriate therapy. A retrospective cohort study of culture-positive HCAP over 6 years (January 2003-December 2008) was performed at Barnes-Jewish Hospital, a 1200-bed urban teaching hospital. We identified 757 consecutive patients with HCAP. IIAT was administered to 213 (28%) patients. The pathogens most frequently associated with IIAT included P. aeruginosa (n=60, 28%), MRSA (n=58, 27%), and Acinetobacter species (n=32, 15%).Multivariate logistic regression analysis demonstrated that empiric anti-pseudomonal antibiotics (adjusted odds ratio [AOR], 1.75; 95% confidence interval [CI], 1.34-2.29; p=0.036), empiric anti-MRSA antibiotics (AOR, 1.71; 95% CI, 1.36-2.14; p=0.018), infection with Streptococcus pneumoniae (AOR, 2.82; 95% CI, 2.03-3.91; p=0.002), absence of Acinetobacter species infection (AOR, 10.57; 95% CI, 7.29-15.33; p<0.001), absence of P. aeruginosa infection (AOR, 1.69; 95% CI, 1.36-2.05; p=0.014), and absence of Stenotrophomonas maltophilia infection (AOR, 20.43; 95% CI, 9.35-44.66; p<0.001) are independent predictors of appropriate therapy for HCAP. Our study suggests that initial therapy for HCAP should include antibiotics targeting MRSA and P. aeruginosa in order to provide appropriate initial therapy. However, the selection of individual antibiotic agents should be based on local patterns of infection and adjusted when microbiology results become available.

[Analysis of risk factors related to mortality of patients with community-acquired pneumonia due to methicillin-resistant Staphylococcus aureus]

OBJECTIVE

To describe the clinical features of reported cases of community-acquired pneumonia (CAP) due to methicillin-resistant Staphylococcus aureus (MRSA), and to evaluate the risk factors related to outcome.

METHODS

A systematic search of databases from January 1995 to December 2009 was performed. Baseline characteristics of survivors and non-survivors in the hospital were compared with the chi2 test for categorical variables. Variables with P<0.2 were entered in Logistic regression. Survival analysis was estimated by the Kaplan-Meier method according to use of antimicrobials inhibiting toxin production.

RESULTS

Fifty-two articles were identified reporting data on 74 patients, with 41.1% of total mortality, short duration of symptom onset to death [(6.1+/-11.0) days], and prolonged hospital admissions [(28.6+/-29.1) days]. Logistic regression analysis showed that influenza like symptoms (P=0.04), hemoptysis (P<0.01), leucopenia (P<0.01) were the risk factors associated with death, and using clindamycin or linezolid which could inhibit the Panton-Valentine leukocidin (PLV, P<0.01) was the factor associated with survival. Kaplan-Meier analysis indicated that the antibiotic therapies inhibiting toxin production were associated with improved outcome in these cases (chi2=21.59, P<0.01).

CONCLUSION

CAP due to MRSA is a severe disease with significant lethality. Empiric therapy of severe CAP with flu-like symptoms, hemoptysis and leucopenia should include coverage for MRSA. Targeted treatment with antimicrobials inhibiting toxin production appear to be more appropriate selection.

Comparison of community-acquired pneumonia due to methicillin-resistant and methicillin-susceptible Staphylococcus aureus producing the Panton-Valentine leukocidin

OBJECTIVE

To investigate the clinical features and prognosis of patients with methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) community-acquired pneumonia (CAP) producing the Panton-Valentine leukocidin (PVL).

METHODS

PubMed and Scopus were searched. Inclusion was stratified according to S. aureus susceptibility and clinical, microbiological and outcome data of patients with S. aureus CAP; both primary and secondary cases of CAP (hematogenous spread from other sites of infection) were included.

RESULTS

We identified 71 articles reporting data on patients with MRSA (n = 76) and MSSA (n = 31) PVL-positive CAP. There were no differences in demographics and history among patients with MRSA and MSSA CAP. Features associated with MRSA CAP were gastrointestinal tract symptoms (P = 0.016) and unilobar infiltrates (P = 0.043). Features associated with MSSA CAP were airway hemorrhage (P = 0.01), multilobar infiltrates (P = 0.043) and acute respiratory distress syndrome (ARDS, P = 0.023). Although MSSA patients were more likely to receive initial appropriate antimicrobial therapy (P < 0.001), there was no difference in mortality between the two groups (P = 0.919). Univariate analysis showed that influenza-like symptoms (P < 0.001), multi-organ failure (P < 0.001), admission to the intensive care unit (P < 0.001), mechanical ventilation (P < 0.001), leucopenia (P < 0.001), shock (P = 0.001), development of complications (P = 0.003), vein thrombosis (P < 0.001), disseminated intravascular coagulation (P = 0.03), acidosis (P = 0.012), rash (P = 0.024), ARDS (P = 0.021), necrotizing pneumonia (P = 0.026), and use of macrolides after culture results (P = 0.011) were factors associated with death.

CONCLUSIONS

Patients with MRSA PVL-positive CAP did not have higher rates of mortality than patients with MSSA PVL-positive CAP.

Predictors of mortality for methicillin-resistant Staphylococcus aureus health-care-associated pneumonia: specific evaluation of vancomycin pharmacokinetic indices

OBJECTIVE

The goal of this investigation was to determine whether vancomycin pharmacokinetic indexes (eg, serum trough concentrations or area under the concentration curve [AUC] values) were associated with mortality for patients with health-care-associated pneumonia (HCAP) attributed to methicillin-resistant Staphylococcus aureus (MRSA).

DESIGN

A retrospective, single-center, observational cohort study.

SETTING

Barnes-Jewish Hospital, a 1,200-bed urban teaching facility.

PATIENTS

Adult patients requiring hospitalization who were identified as having HCAP attributed to MRSA by BAL semi-quantitative cultures.

INTERVENTIONS

Retrospective data collection from automated hospital, microbiology, and pharmacy databases.

MEASUREMENTS AND MAIN RESULTS

One hundred two patients with MRSA HCAP were identified over a 6.5-year period. Thirty-two patients (31.4%) died during their hospitalization. The mean (+/- SD) vancomycin trough concentrations (13.6 +/- 5.9 vs 13.9 +/- 6.7 microg/mL, respectively; p = 0.866) and AUC values (351 +/- 143 vs 354 +/- 109 microg/h/mL, respectively; p = 0.941) did not differ between survivors and nonsurvivors. The stratification of the vancomycin trough concentrations and AUC values yielded no relationship with hospital mortality.

CONCLUSIONS

We found no evidence that greater vancomycin trough concentrations or AUC values correlated with hospital outcome. Based on these results, aggressive dosing strategies for vancomycin (eg, trough concentrations of > 15 microg/mL) may not offer any advantage over traditional dose targets (range, 5 to 15 microg/mL).

[Severe community acquired pneumonia due to Staphylococcus aureus in children. About two cases]

The staphylococcal pneumonia is the prerogative of the infant but rare cases were observed in the childhood. We report the observation of two children aged respectively of six years and three years and a half having presented a particular form of severe staphylococcal pneumonia apart from any context of immunodepression. The identification of the particular strains producing toxins Like the Panton and Valentine leukocidin constitutes the first stage of the comprehension of this atypical form of pneumonia. Through these observations and with a review of literature we underline the specific clinical and biological aspects of this form.

Hospital-acquired pneumonia in the 21st century: a review of existing treatment options and their impact on patient care

Hospital-acquired pneumonia is a common nosocomial infection, with significant morbidity and mortality, and represents a major therapeutic challenge to clinicians. The therapeutic approach must be patient-oriented and institution-specific. The specific risk factors of each patient, such as previous antibiotic exposure, underlying diseases, length of hospital stay and the local patterns of antimicrobial resistance, should guide physicians in their decision of the initial optimal empirical therapy. Delays in the initiation or inappropriate/inadequate initial therapy are related to increased mortality and worse outcomes. In responding patients, as soon as culture data are available, efforts should be made to change the initial broad spectrum antibiotic regimen to a more targeted one (de-escalation). The optimal duration of treatment is a matter of debate, but courses longer than 1 week are rarely justified.

Morbidity and cost burden of methicillin-resistant Staphylococcus aureus in early onset ventilator-associated pneumonia

Introduction

To gain a better understanding of the clinical and economic outcomes associated with methicillin-resistant Staphylococcus aureus (MRSA) infection in patients with early onset ventilator-associated pneumonia (VAP), we retrospectively analyzed a multihospital US database to identify patients with VAP over a 24 month period (2002–2003).

Method

Data recorded included physiologic, laboratory, culture, and other clinical variables from 59 institutions. VAP was defined as new positive respiratory culture after at least 24 hours of mechanical ventilation (MV) and the presence of primary or secondary ICD-9-CM diagnosis codes of pneumonia. Outcomes measures included in-hospital morbidity and mortality for the population overall and after onset of VAP (duration of MV, intensive care unit [ICU] stay, in-hospital stay, and case mix and severity-adjusted operating cost). The overall cost was calculated at the hospital level using the Center for Medicare and Medicaid Services Cost/Charge Index for each calendar year.

Results

A total of 499 patients were identified as having VAP. S. aureus was the leading organism (31% of isolates). Patients with MRSA were significantly older than patients with methicillin-sensitive Staphylococcus aureus (MSSA; median age 74 versus 67 years, P < 0.05) and more likely to be medical patients. Compared with MSSA patients, MRSA patients on average consumed excess resources of 4.4 (95% confidence interval 0.6–8.2) overall MV days, 3.8 (-0.5 to +8.0) days of inpatient length of stay (LOS), 5.3 (1.0–9.7) ICU days, and US$7731 (-US$8393 to +US$23,856) total cost after controlling for case mix and other factors. Furthermore, MRSA patients needed excess resources after the onset of VAP (4.5 [95% confidence interval 1.0–8.1] MV days, 3.7 [-0.5 to +8.0] inpatient days, and 4.4 [0.4–8.4] ICU days) after controlling for the same case mix and admission severity covariates.

Conclusion

S. aureus remains a common cause of VAP. VAP due to MRSA was associated with increased overall LOS, ICU LOS, and attributable ICU LOS compared with MSSA-related VAP. Although not statistically significant because of small sample size and large variation, the attributable excess costs of MRSA amounted to approximately US$8000 per case after controlling for case mix and severity.

Is Methicillin Resistance Associated with a Worse Prognosis in Staphylococcus aureus Ventilator-Associated Pneumonia?

BACKGROUND

Excess mortality associated with methicillin resistance in patients with Staphylococcus aureus ventilator-associated pneumonia (SA-VAP), taking into account such confounders as treatment adequacy and time in the intensive care unit (ICU), have not been adequately estimated.

METHODS

One hundred thirty-four episodes of SA-VAP entered in the Outcomerea database were studied. Patients from whom methicillin-resistant S. aureus (MRSA) was recovered were compared with those from whom methicillin-susceptible S. aureus (MSSA) was recovered, stratified for duration of stay in the ICU at the time of VAP diagnosis and adjusted for confounders (severity at admission, characteristics at VAP diagnosis, and treatment adequacy).

RESULTS

Treatment was adequate within 24 h after VAP diagnosis for 86% of the 65 MSSA-infected patients and 77% of the 69 MRSA-infected patients (P = .2). Polymicrobial VAP was more commonly associated with MSSA than with MRSA (49.2% vs. 25.7%; P = .01). MRSA infection was associated with a lower prevalence of coma at hospital admission and a higher rate of use of central venous lines and fluoroquinolones during the first 48 h of the ICU stay. The rates of shock, recurrence, and superinfection were similar in both groups. The crude hospital mortality rate was higher for MRSA-infected patients than for MSSA-infected patients (59.4% vs. 40%; P = .024). This difference disappeared after controlling for time in the ICU before VAP and parameters imbalanced at ICU admission (odds ratio [OR], 1.23; 95% confidence interval [CI], 0.49-3.12; P = .7) and remained unchanged after further adjustments for initial treatment adequacy and polymicrobial VAP (OR, 0.98; 95% CI, 0.36-2.66).

CONCLUSIONS

Differences in patient characteristics, initial ICU treatment, and time in the ICU confounded estimates of excess death due to MRSA VAP. After careful adjustment, methicillin resistance did not affect ICU or hospital mortality rates.

Pneumonia caused by oxacillin-resistant Staphylococcus aureus treated with glycopeptides*

OBJECTIVE

To determine whether ventilator-associated pneumonia caused by oxacillin-resistant Staphylococcus aureus (VAP-ORSA) treated with glycopeptides is associated with an increased mortality rate.

DESIGN

Retrospective matched cohort study.

SETTING

Four intensive care units in teaching hospitals.

PATIENTS

Seventy-five patients were matched to 75 controls.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

All adult intensive care unit patients with microbiologically documented VAP-ORSA were matched to intubated controls who did not develop VAP-ORSA, based on disease severity (Acute Physiology and Chronic Health Evaluation II score) at admission (+/-3 points), diagnostic category, and length of stay before pneumonia onset. Population characteristics and intensive care unit mortality rates of patients with VAP-ORSA and their controls without pneumonia were compared. Attributable mortality was determined by subtracting the crude mortality rate of controls from the crude mortality rate of VAP-ORSA patients. Thirty-six of the 75 matched VAP-ORSA patients died, representing a crude mortality rate of 48%, whereas 19 of the 75 controls died, a crude mortality rate of 25.3% (p < .01). Excess mortality was estimated to be 22.7% (95% confidence interval, 2.4-42.9%). Median length of intensive care unit stay in the surviving pairs was 33 days (interquartile range, 25-75%: 25-45 days) for VAP-ORSA patients and 21 days (interquartile range, 25-75%: 15-34.75 days) days for controls (p = .054).

CONCLUSIONS

Despite appropriate glycopeptide therapy, there is an increased attributable mortality for pneumonia by ORSA, after careful adjustment for disease severity and diagnostic category.

Impact of Methicillin Resistance on Outcome ofStaphylococcus aureusVentilator-associated Pneumonia

The impact of methicillin resistance on morbidity and mortality of patients suffering from severe Staphylococcus aureus infections remains highly controversial. We analyzed a retrospective cohort of 97 patients with methicillin-susceptible and 74 patients with methicillin-resistant Staphylococcus aureus ventilator-associated pneumonia (VAP). Initial empiric antibiotic therapy was appropriate for every patient. Patients with methicillin-resistant Staphylococcus aureus VAP were older, had higher disease-severity scores, and had been on mechanical ventilation longer at onset of VAP. Factors associated with 28-day mortality retained by multivariate logistic regression analysis were: age (odds ratio [OR] = 1.05, 95% confidence interval [CI], 1.02-1.08, p = 0.001) and Day 1 organ dysfunctions or infection (ODIN) score (OR = 1.90, 95% CI, 1.31-2.78, p = 0.001), but not methicillin resistance (OR = 1.72, 95% CI, 0.73-4.05, p = 0.22). The percentages of infection relapse or superinfection did not differ significantly between the two patient groups. In conclusion, after controlling for clinical and physiologic heterogeneity between groups, methicillin resistance did not significantly affect 28-day mortality of patients with Staphylococcus aureus VAP receiving appropriate antibiotics.

Staphylococcus aureus bacteremic pneumonia: differences between community and nosocomial acquisition

OBJECTIVE

The aim of the study was to ascertain the clinical and epidemiologic characteristics of patients with nosocomial or community-acquired Staphylococcus aureus bacteremic pneumonia.

METHODS

A prospective study of 134 cases diagnosed between January 1990 and December 1995 was performed.

RESULTS

Fifty cases involved primary bacteremic pneumonias, of which 80% were nosocomial (the majority, 72%, in intensive care unit patients, of whom 57% were post-surgery). Of the 84 cases of secondary pneumonia, 36 were non-intravenous drug users (78% nosocomial, of whom 43% were in the intensive care unit), and 48 cases were intravenous drug users (98% community-acquired).

CONCLUSIONS

Nosocomial S. aureus bacteremic pneumonia was especially frequent in intensive care unit patients (68.1%), and community-acquired pneumonia in intravenous drug users (72.3%). In non-intravenous drug users, clinical outcome and mortality were similar for nosocomial and community-acquired pneumonia.

[Fatal pneumonia in an adolescent due to community-acquired methicillin-resistant Staphylococcus aureus positive for Panton-Valentine-leukocidin]

A 15-year-old girl developed a severe Staphylococcus aureus pneumonia following an influenza virus infection. The patient was admitted to a paediatric intensive-care facility because of respiratory and circulatory failure. Despite aggressive therapy, she died on the third day following admission to the intensive care unit due to secondary hypoxic-ischaemic encephalopathy. Blood and respiratory aspirate cultures showed community-acquired methicillin-resistant S. aureus (CA-MRSA) with a normal antibiotic sensitivity except for betalactam antibiotics. PCR-based methods demonstrated that the isolate possessed the Panton-Valentine-leukocidin (PVL) gene, encoding an S. aureus exotoxin that is associated with fulminant necrotising pneumonia. This case shows that clinicians in the Netherlands should also be aware of the possibility of CA-MRSA in patients without risk factors for MRSA carriage. Especially in children and adolescents with an influenza virus infection, pneumonia due to PVL-positive S. aureus strains may be life-threatening.

Pulmonary infiltrates in patients receiving long-term glucocorticoid treatment: etiology, prognostic factors, and associated inflammatory response

BACKGROUND

Glucocorticoid treatment alters immunoregulatory defense mechanisms and may therefore favor the development of different pulmonary infections.

METHODS

The etiology, prognostic factors, and associated inflammatory response of pulmonary infiltrates in 33 patients receiving long-term glucocorticoid treatment (LTGCT) were prospectively evaluated.

RESULTS

Aspergillus spp (n = 9, 31%) and Staphylococcus spp (n = 6, 21%) were the most common causative agents. Using different diagnostic techniques, we obtained a specific diagnosis in 28 of 33 episodes (85%) of pulmonary infiltrates. Bronchoscopic techniques provided the diagnosis in 64% of the cases. Crude mortality was 45%. Variables associated with mortality were as follows: age > 64 years, bilateral radiographic involvement, delay in diagnosis, inappropriate empirical treatment, Simplified Acute Physiology Score (SAPS) II > or = 25, and requirement for mechanical ventilation (MV). SAPS II > or = 25 (odds ratio [OR], 16; 95% confidence interval, 1 to 260) and MV requirement (OR, 50; 95% confidence interval, 2 to 360) were also significant on multivariate analysis. Pulmonary infections were associated with an increase in the concentration of relevant inflammatory cytokines such as tumor necrosis factor-alpha and interleukin-6 both in serum and BAL. This local and systemic inflammatory response was attenuated when compared with the response observed in patients with pulmonary infections but without glucocorticoid treatment or receiving glucocorticoids for a short period of time (< 9 days).

CONCLUSIONS

Pulmonary infiltrates in patients receiving LTGCT are often caused by fungi and Gram-positive cocci, and are associated with attenuated local and systemic inflammatory response. Although in most cases, sputum cultures and bronchoscopic techniques are diagnostic, the associated mortality is high, particularly in those requiring MV.

Influence on outcome of ventilator-associated pneumonia in multiple trauma patients with head trauma treated with selected digestive decontamination

OBJECTIVE

Ventilator-associated pneumonia is said to be associated with an increased mortality or a prolonged intensive care unit stay. In multiple trauma, the use of selective digestive decontamination has been reported to decrease morbidity and mortality associated with pneumonia. We performed a study to evaluate the attributable morbidity and mortality of ventilator-associated pneumonia in multiple trauma patients with head trauma treated with selective digestive decontamination.

DESIGN

Prospective, matched-paired, case-control study.

SETTING

Intensive care unit at a tertiary university hospital.

PATIENTS

During a 6-yr period, 324 consecutive multiple trauma patients with head trauma requiring mechanical ventilation for >48 hrs were prospectively followed for the development of VAP. Case-control matching criteria were as follows: 1) age difference within 5 yrs, 2) Glasgow coma scale within five categories, 3) injury severity score within 5 points, 4) APACHE II score within 5 points, 5) ventilation of control patients for at least as long as the cases. The selective digestive decontamination regimen was used in all patients (cases and controls): polymixin E, gentamicin, and amphotericin B. Systemic cefazolin (1 g three times a day) was given for the first 3 days of intensive care unit stay.

MEASUREMENTS AND MAIN RESULTS

Analysis was performed on 58 pairs that were matched with 100% of success The most common isolates recovered were Staphylococcus aureus (39%) and Haemophilus influenzae (22%). High-risk pathogens were rarely isolated: Pseudomonas aeruginosa (5.1%), Acinetobacter species (8.6%), and methicillin-resistant S. aureus (6.7%). The duration of mechanical ventilation and intensive care unit stay were increased in case patients (11.6 +/- 1.7 and 22.7 +/- 2.9 days, respectively) compared with control patients (9.4 +/- 1.3 and 16.8 +/- 2.9 days, respectively; p <.0006). Mortality was similar in both case (17%) and control (24%) patients.

CONCLUSION

Ventilator-associated pneumonia did not seem to increase mortality of multiple trauma patients with head trauma who received selective digestive decontamination. Whether or not this conclusion applied to trauma patients not receiving selective digestive decontamination should be evaluated in further studies.

Association between Staphylococcus aureus strains carrying gene for Panton-Valentine leukocidin and highly lethal necrotising pneumonia in young immunocompetent patients

BACKGROUND

Between 1986 and 1998, eight cases of community-acquired pneumonia due to Staphylococcus aureus strains carrying the gene for the Panton-Valentine leukocidin (PVL) were recorded in France, six of which were fatal. We aimed to assess the clinical features of these eight cases, and those of other cases identified prospectively, and to compare them with the characteristics of patients with pneumonia caused by PVL-negative strains.

METHODS

We compared eight retrospective and eight prospective cases of PVL-positive S aureus pneumonia with 36 cases of PVL-negative S aureus pneumonia. For all patients, we recorded age, length of hospital stay, risk factors for infection, signs and symptoms, laboratory findings, antibiotic treatment, and serial radiological findings.

FINDINGS

Median age was 14.8 years (IQR 5.4-24.0) for the PVL-positive patients and 70.1 years (59.2-81.4) for the others (p=0.001). Influenza-like illness had occurred during the 2 days before admission in 12 of the 16 PVL-positive patients, but in only three of 33 PVL-negative patients (p<0.001). PVL-positive infections were more often marked by: temperature greater than 39 degrees C (p=0.01), heart rate above 140 beats per min (p=0.02), haemoptysis (p=0.005), onset of pleural effusion during hospital stay (p=0.004), and leucopenia (p=0.001). The survival rate 48 h after admission was 63% for the PVL-positive patients and 94% for PVL-negative individuals (p=0.007). Histopathological examination of lungs at necropsy from three cases of necrotising pneumonia associated with PVL-positive S aureus showed extensive necrotic ulcerations of the tracheal and bronchial mucosa and massive haemorrhagic necrosis of interalveolar septa.

INTERPRETATION

PVL-producing S aureus strains cause rapidly progressive, haemorrhagic, necrotising pneumonia, mainly in otherwise healthy children and young adults. The pneumonia is often preceded by influenza-like symptoms and has a high lethality rate.

Severe community acquired pneumonia: a one-year analysis in a tertiary referral intensive care unit

AIMS

To define outcomes, characteristics, microbiology and salient prognostic factors of patients admitted to our intensive care unit (ICU) with severe community acquired pneumonia, over a one year period.

METHODS

All adult patients with severe community acquired pneumonia admitted between July 1997 and July 1998 were studied. Data were extracted by retrospective chart review. Variables assessed included underlying conditions and baseline physical parameters. Evolutionary variables eg, septic shock and laboratory data including microbiology and arterial blood gas determinants were also assessed. Prognostic factors were determined by comparison of the above variables between survivors and non-survivors. The prognostic value of the British Thoracic Society discriminant 'rule one' was assessed. Results. 32 patients were assessed. ICU mortality was 31%. 84% of patients had co-morbidity. The average age was 58.5 (SD 17.4) years and the average APACHE 11 score was 20.37 (SD 9.12). A microbiological diagnosis was made in 40%. Mortality was not increased in those in whom a bacterial diagnosis was not made. Commonest pathogens isolated were Streptococcus pneumoniae (46%), gram negative organisms (29%) and Staphylococcus aureus (23%). Prognostic factors on and during ICU admission were the need for mechanical ventilation (p=0.0003), septic shock (p=0.02), inotrope requirement (p=0.003), low serum albumin (p=0.041), base deficit (p=0.04), INR (p=0.02) and inspired oxygen concentration (p=0.003). On initial admission to hospital the presence of bilateral pneumonia was the only variable correlated with outcome (p=0.01). The British Thoracic Society 'rule one' did not correlate with death either on admission to hospital or ICU.

CONCLUSIONS

Severe community acquired pneumonia carries a high mortality despite ICU management. Bacterial diagnostic rate was low but made no difference to mortality. Streptococcus pneumoniae was the commonest causative pathogen. The development of septic shock, requirement for mechanical ventilation and bilateral disease are important adverse prognostic indicators.

Lower respiratory tract infections following cardiac arrest and cardiopulmonary resuscitation

All episodes of lower respiratory tract infection that developed among 96 patients surviving for > 24 hours after cardiac arrest were prospectively studied over an 18-month period. Pneumonia developed in 23 (24.0%) of patients after a mean of 7 days (SD, +/- 6.2 days). The development of four superinfections raised the cumulative incidence to 28.1%. Purulent tracheobronchitis was diagnosed in three instances. The causative agent of pneumonia was identified in 18 episodes, three of which were polymicrobial. Gram-positive cocci represented 57.1% of isolates, and Staphylococcus aureus--the most frequently isolated microorganism in this population--accounted for two-thirds of all gram-positive cocci. Pseudomonas aeruginosa was isolated in six episodes, five of which were associated with previous antibiotic use. Nine (39.1%) of the 23 patients in the group with pneumonia died, but only one of these deaths was considered to be directly related to pneumonia. In conclusion, pneumonia is a common complication of patients surviving cardiac arrest, but, with adequate treatment, its influence on outcome is marginal. Gram-positive cocci are the predominant pathogens, although infection with P. aeruginosa should be considered among patients receiving antibiotics.

Staphylococcal pneumonia in childhood: will early surgical intervention lower mortality?

Staphylococcus aureus pneumonia (SAP) continues to be a serious bacterial infection which is associated with a high incidence of complications. We retrospectively reviewed the case records of 36 infants and children admitted with SAP to the Sophia Children's Hospital between 1970 and 1992 to analyse changes over time in the clinical presentation, diagnostic work-up, management and complications. Fifteen of these 36 children (42%) were less than 1 year old. Fever (97%) and respiratory distress (83%) were the most common symptoms at the initial presentation. Chest X-ray findings on admission or during hospitalisation included pleural effusion (75%), pneumothorax (47%), and abscess and/or pneumatocele (39%). Diagnostic and/or therapeutic thoracentesis of pleural fluid was performed in 17 of the 36 patients (47%). Twenty-one patients (58%) needed chest tube drainage. Twelve had a thoracotomy (33%). Artificial ventilation was needed in 13 of the patients (36%). Extrapulmonary complications included convulsions in 6 patients (17%) and osteomyelitis in 2 children (6%). The mean duration of hospitalization was 36 days. Two of the 36 children died (6%). The low mortality rate in this study may be the result of the relatively high rate of thoracotomy and of improvements in supportive treatment.

Ventilator-associated pneumonia by Staphylococcus aureus. Comparison of methicillin-resistant and methicillin-sensitive episodes

All episodes of ventilator-associated pneumonia (VAP) caused by Staphylococcus aureus were prospectively analyzed for a 30-mo period. Methicillin-sensitive S. aureus (MSSA) was isolated in 38 episodes and methicillin-resistant S. aureus (MRSA) in 11 others. The two groups were similar regarding sex, severity of underlying diseases, prior surgery, and presence of renal failure, diabetes, cardiopathy, and coma. MRSA-infected persons were more likely to have received steroids before developing infection (relative risk [RR] = 3.45, 95% confidence interval [CI] = 1.38-8.59), to have been ventilated > 6 d (RR = 2.03, 95% CI = 1.36-3.03), to have been older than 25 yr (RR = 1.50, 95% CI = 1.09-2.06), and to have had preceding chronic obstructive pulmonary disease (RR = 2.76, 95% CI = 0.89-8.56) than MSSA-infected patients. MSSA-infected persons were more likely than MRSA-infected patients to have cranioencephalic trauma (RR = 1.94, 95% CI = 1.22-3.09). All patients with MRSA VAP had previously received antibiotics, compared with only 21.1% of those with MSSA infection (p < 0.000001). The incidence of empyema was similar in both groups; nevertheless, the presence of bacteremia and septic shock was more frequent in the MRSA group. Finally, mortality directly related to pneumonia was significantly higher among patients with MRSA episodes (RR = 20.72, 95% CI = 2.78-154.35). This analysis was repeated for monomicrobial episodes, and the difference remained statistically significant. We conclude that MRSA and MSSA strains infect patients with different demographic profiles; previous antibiotic therapy is the most important risk factor for developing MRSA infection.(ABSTRACT TRUNCATED AT 250 WORDS)

[Nosocomial pneumonias. The effect of selective intestinal and ventricular decontamination in respirator-treated intensive care patients]

Nosocomial infections, especially pneumonias, are a common problem in Intensive Care Units (ICU) and are a major cause of morbidity and mortality. During the past ten years a new regime, selective decontamination of the digestive tract (SDD) has been introduced to prevent these infections which are often preceded by colonization with aerobic potentially pathogenic microorganisms. Topical antibiotics are applied both orally and by nasogastric tube to prevent secondary endogeneous infections with Gram-negative enteric rods, Staphylococcus aureus and yeasts, in combination with parenteral antibiotics for the treatment of early primarily exogeneous and endogeneous infections. The effect of SDD on morbidity and mortality has been studied in many papers which are very conflicting and their results are difficult to interpret. This article reviews 11 published randomized trials of SDD in ICU among intubated and artificially ventilated adult patients aged more than 15 years. Of the eleven available controlled studies, eight showed a significant reduction of nosocomial pneumonias among patients who received selective decontamination. Only two studies demonstrated a reduction in infection related mortality rates.

Emergency pulmonary resection for pneumonia. High morbidity and mortality

Emergency pulmonary resection was performed because of complicated pneumonia in eight patients (5 pneumonectomies, 2 lobectomies, 1 bilobectomy) over a 2-year period. The patients' age range was 5 months to 43 years. The indications were rapid aggravation of respiratory insufficiency in children with staphylococcal pneumonia and enlarging pneumatoceles, and massive hemoptysis in patients with chronic destructive pneumonia. Two patients died after pneumonectomy, one from contralateral aspiration and one from cardiogenic shock. Postoperative complications occurred in four cases--bronchopleural fistula and pyopneumothorax in three and thoracic empyema with massive chest-wall infection in one. Only two patients had an uneventful postoperative course. Complications of pulmonary necrosis in pneumonia may dictate urgent pulmonary resection, often pneumonectomy. Surgery will be life-saving in most cases, but high morbidity is to be expected.

[The incidence of lung infection in patients with mucoviscidosis and the disease course with various pathogen spectra]

A retrospective review on the frequency of lung infections by the most important organisms Staphylococcus aureus and Pseudomonas aeruginosa in patients with cystic fibrosis in the GDR during the period from 1981 to 1985 revealed an average infectious rate of 58.6 per cent by Staphylococcus and of 26.9 per cent by Pseudomonas respectively. A distinct increase of the infections by Pseudomonas could only be documented from 1981 to 1982, later on the infectious rate remained nearly equal and showed only a peak value of 35.6 per cent in 1983. Thus the frequency of infections by Pseudomonas is significantly lower in the GDR than in most other countries. The comparison of the course of the disease in patients with permanent lung infection during 4 or 5 years established a mortality rate of a double amount in the group of patients with Pseudomonas colonisation versus the group with Staphylococcus colonisation. Otherwise no significant difference could be stated in the mean age of the beginning of lung infection (Staphylococcus = 9.7 years of age - Pseudomonas = 10.1 years of age). Analysing the pulmonary x-ray findings we found a significantly more rapid deterioriation during the follow-up period in patients with permanent Pseudomonas infection than in patients with permanent Staphylococcus infection, whereas the evolution of body height and weight did not take different course.

Adult community-acquired staphylococcal pneumonia in the antibiotic era: a review of 61 cases

We have reviewed the clinical and laboratory features of 61 cases of adult community-acquired staphylococcal pneumonia. A seasonal incidence was found and most cases occurred in April. Clinical and laboratory features were similar to those found in other forms of community-acquired pneumonia. Sputum Gram-stain was positive for staphylococci in 69 per cent of cases and blood cultures were positive in 20 per cent. Evidence of Influenza virus infection was found in 52 per cent of cases. Eighteen patients died (30 per cent). Age greater than 45 years, confusion, reduced conscious level, raised blood urea, acidosis, bacteraemia and admission to the intensive care unit were associated significantly with death. Despite appropriate antibiotic treatment mortality in staphylococcal pneumonia remains high.

Aetiology and outcome of severe community-acquired pneumonia

Between January 1972 and December 1981, 50 patients with severe community-acquired pneumonia were admitted to the intensive care unit of a district general hospital. A causal pathogen was identified in 41 cases (82%). Streptococcus pneumoniae (16 cases), Legionella pneumophila (15 cases) and Staphylococcus aureus (5 cases) were the commonest. Assisted ventilation was required in 44 patients, of whom 25 died (57%). All 5 patients with staphylococcal pneumonia and 12(75%) with pneumococcal pneumonia died. Only 5 (33%) with Legionnaires' disease died. Mortality was significantly associated with age. Recommendations for the management of severe pneumonia are made.

[Staphylococcal pneumonia : a review of 18 cases at Tygerberg Hospital]

A retrospective study of 18 cases of staphylococcal pneumonia is described. The majority of patients were young males without any predisposing factors. A vasculitic rash, three-organ failure and diffuse intravascular coagulation were poor prognostic factors. The value of steroids was doubtful but plasmapheresis probably played a part in the survival of 3 patients with fulminating staphylococcal pneumonia. The case fatality rate for the whole group was 38%. Primary staphylococcal pneumonia probably had a better prognosis but left more residual lung damage than the secondary form of the disease.