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M S Niederman

Publications and source records attributed to M S Niederman.

At least 37 records · Page 2Linked to original sources
PubMed1999

Treatment cost of acute exacerbations of chronic bronchitis.

In 1994, the National Center for Health Statistics estimated that more than 14 million people (54 per thousand) had chronic bronchitis and sought treatment for 90.9% of their acute episodes. However, few studies have been done on the treatment cost of chronic bronchitis using national data. We conducted a retrospective analysis of claims for patients treated for acute exacerbations of chronic bronchitis (AECB) to assess the frequency of services rendered and the costs to the health care system. Records were selected for the study based on a primary diagnosis of AECB according to the International Classification of Diseases, Ninth Revision, code. Medicare was the primary source of data on patients aged > or =65 years; data from the National Healthcare and Cost Utilization Project, the National Ambulatory Medical Care Survey, and the National Hospital Ambulatory Medical Care Survey were used for patients aged <65 years. We calculated a total treatment cost of $1.2 billion for patients aged > or =65 years and $419 million for patients aged <65 years. These calculations were based on the following: 280,839 hospital discharges resulting in hospital costs of $1.1 billion for the 207,540 patients aged > or =65 years, and $408 million for the 73,299 patients aged <65 years. The mean hospital length of stay was 6.3 days with a mean cost of $5497 for patients aged > or =65 years and 5.8 days with a mean cost of $5561 for younger patients. Room and board represented the largest percentage of the mean hospital costs of AECB. Inpatient physician services cost $32 million and $11 million for the 2 age groups, respectively. Diagnosis-specific data for outpatient services were found to be less reliable than inpatient data, possibly due to diagnostic coding omissions; 331,000 outpatient office visits for AECB were found for those aged > or =65 years and 237,000 visits for those aged <65 years, resulting in respective total outpatient costs of $24.9 million and $15.1 million. If the number of outpatient visits remain consistent with 1994 levels, there would be 5.8 million visits annually for those aged > or =65 years and 4.2 million visits for those aged <65 years; total outpatient costs would be $452 million and $317 million, respectively. Because the treatment costs of AECB are largely the costs of hospitalization, any new therapy that allows more patients to be treated in the outpatient setting is likely to generate significant savings.

Aged↗
PubMed1999

Blood cultures have limited value in predicting severity of illness and as a diagnostic tool in ventilator-associated pneumonia.

STUDY OBJECTIVES: To define the usefulness of blood cultures for confirming the pathogenic microorganism and severity of illness in patients with ventilator-associated pneumonia (VAP). DESIGN: Prospective observational study using BAL and blood cultures collected within 24 h of establishing a clinical diagnosis of VAP. SETTING: A 15-bed medical and surgical ICU. PATIENTS: One hundred and sixty-two patients receiving mechanical ventilation hospitalized for > 72 h who had new or progressive lung infiltrate plus at least two of three clinical criteria for VAP. INTERVENTIONS: BAL and blood culture performed within 24 h of establishing a clinical diagnosis of VAP. MEASUREMENTS AND RESULTS: Ninety patients were BAL positive (BAL+), satisfying a microbiological definition of VAP (>/= 10(4) cfu/mL), 72 patients were BAL negative (BAL-). Bacteremia was diagnosed when at least two sets of blood cultures yielded a microorganism or when only one set was positive, but the same bacteria was present at a concentration >/= 10(4) cfu/mL in the BAL fluid. Bacteremia was significantly more frequent in the BAL+ than in the BAL- group (22/90 patients vs 5/72 patients; p = 0.006). In 6 of 22 BAL+ patients with bacteremia, an extrapulmonary site of infection was the source of bacteremia. Sensitivity of blood culture for disclosing the pathogenic microorganism in BAL+ patients was 26%, and the positive predictive value to detect the pathogen was 73%. Factors associated with mortality were age > 50 years, simplified acute physiology score > 14, prior inadequate antibiotic therapy, PaO(2)/fraction of inspired oxygen < 205, and use of H(2) blockers. By multivariate analysis, only the use of prior inadequate antimicrobial therapy (odds ratio [OR], 6.47) and age > 50 years (OR, 5.12) were independently associated with higher mortality. The rate of complications was not different in patients with bacteremia. CONCLUSIONS: Blood cultures have a low sensitivity for detecting the same pathogenic microorganism as BAL culture in patients with VAP. The presence of bacteremia does not predict complications, it is not related to the length of stay, and it does not identify patients with more severe illness. Inadequacy of prior antimicrobial therapy and age > 50 years were the only factors associated with mortality in a multivariate analysis. Blood cultures in patients with VAP are clearly useful if there is suspicion of another probable infectious condition, but the isolation of a microorganism in the blood does not confirm that microorganism as the pathogen causing VAP.

Adult↗
PubMed1999

[Clinical contribution of the newer fluoroquinolones in acute bacterial exacerbation of chronic bronchitis].

Acute exacerbations occur frequently in patients with chronic bronchitis and the majority of these patients benefit from antimicrobial therapy. The ideal antimicrobial agent for the management of acute exacerbations of chronic bronchitis (AECB) should have good activity against the common bacterial pathogens associated with these exacerbations (non-typable Haemophilus influenzae, Moraxella catarrhalis and pneumococci); it should be resistant to bacterial betalactamases; penetrate well into pulmonary tissues and secretions; kill bacteria without inducing excessive airway inflammation; be easy to take (given once or twice a day) in order to ensure high patient compliance, and be cost-effective. Fluoroquinolone antibiotics have demonstrated efficacy in the treatment of AECB, but because of the limited activity of certain older agents in this class when administered in standard doses against Streptococcus pneumoniae, they have not be extensively used for this indication. Newer agents including levofloxacin, grepafloxacin, sparfloxacin and trovafloxacin have excellent activity against both Gram positive and Gram negative pathogens likely to be involved in AECB. These agents can be administered once daily, making patient compliance and a successful therapeutic outcome more likely. The new quinolones offer promising alternatives for antimicrobial therapy in outpatients with AECB, particularly those with underlying co-morbidity and severe obstruction.

Acute Disease↗
PubMed1998

Community-acquired pneumonia.

Community-acquired pneumonia (CAP) is a significant cause of morbidity and mortality in all age groups, especially the elderly, which is a patient population that continues to grow. Recently the spectrum and clinical picture of pneumonia has been changing as a reflection of this aging population; this requires a reassessment of and a new approach to the patient with pneumonia. Currently, pneumonia patients are classified as having either community-acquired or hospital-acquired infection rather than typical versus atypical. Patients who have CAP are categorized by age, presence of a coexisting medical illness, and the severity of the pneumonia. The rationale behind categorizing patients is to stratify them in terms of mortality risk to help determine the location of therapy (e.g., outpatient, inpatient, intensive care unit) and focus the choice of initial antimicrobial therapy. Once the decision to hospitalize a patient with pneumonia is made, the next step is to decide on an appropriate diagnostic evaluation and antibiotic therapy. Both decisions have evolved over the last several years since the publication of the American Thoracic Society's CAP guidelines. The current approach to the diagnostic work-up of pneumonia stresses a limited role of diagnostic tests and procedures. The antimicrobial regimen has now evolved into one that is empiric in nature and based on the age of the patient, the presence of coexisting medical disease, and the overall severity of the pneumonia. This process is a dynamic once because bacterial resistance to commonly used antibiotics can further complicate the course of pneumonia therapy, but the impact of resistance on outcome is less clear. Resistance of Streptococcus pneumoniae to penicillin is a prime example of this growing problem, and adjustment to pneumonia therapy may be required. A difficult but not uncommon problem in pneumonia patients is slow recovery and delayed resolution of radiographic infiltrates. Factors that impact negatively on pneumonia resolution include advanced age and the presence of serious comorbid illnesses such as diabetes mellitus, renal disease, or chronic obstructive pulmonary disease. In addition, certain organism factors (e.g., intrinsic virulence) may interact with host factors and advanced age to delay pneumonia resolution. For example, 50% of patients with pneumococcal pneumonia have radiographic clearing at 5 weeks, and the majority clear within 2 to 3 months. Recent data demonstrate that radiographic resolution of CAP is most influenced by the number of lobes involved and the age of the patient. Radiographic clearance of CAP decreases by 20% per decade after age 20, and patients with multilobar infiltrates take longer to clear than those with unilobar disease. In general, when approaching slowly resolving infiltrates after pneumonia, bronchoscopic evaluation and lung biopsy are more likely to yield a specific diagnosis if the patient is a nonsmoker younger than 55 years old with multilobar disease. If the patients has either no identifiable factors associated with prolonged pneumonia resolution or the repeat chest radiograph at 1 month shows no appreciable change, further diagnostic testing is indicated. The route and duration of antibiotic therapy, another detail of the management of CAP patients that has changed recently, is complicated by the fact that the majority of patients with CAP have no pathogen identified. Therefore, in most instances the physician initiates empiric antibiotics on the basis of epidemiologic data. If an etiologic pathogen is identified (either initially or at a later time), then the antibiotic spectrum can be narrowed. When no pathogen is discovered, broad-spectrum empiric antibiotics are continued. (ABSTRACT TRUNCATED)

Aged↗
PubMed1998

A "closed" medical intensive care unit (MICU) improves resource utilization when compared with an "open" MICU.

We hypothesized that a "closed" intensive care unit (ICU) was more efficient that an "open" one. ICU admissions were retrospectively analyzed before and after ICU closure at one hospital; prospective analysis in that ICU with an open ICU nearby was done. Illness severity was gauged by the Mortality Prediction Model (MPM0). Outcomes included mortality, ICU length of stay (LOS), hospital LOS, and mechanical ventilation (MV). There were no differences in age, MPM0, and use of MV. ICU and hospital LOS were lower when "closed" (ICU LOS: prospective 6.1 versus 12.6 d, p < 0.0001; retrospective 6.1 versus 9.3 d, p < 0.05; hospital LOS: prospective 19.2 versus 33.2 d, p < 0.008; retrospective 22.2 versus 31.2 d, p < 0.02). Days on MV were lower when "closed" (prospective 2.3 versus 8.5 d, p < 0.0005; retrospective 3.3 versus 6.4 d, p < 0.05). Pooled data revealed the following: MV predicted ICU LOS; ICU organization and MPM0 predicted days on MV; MV and ICU organization predicted hospital LOS; mortality predictors were open ICU (odds ratio [OR] 1.5, p < 0.04), MPM0 (OR 1.16 for MPM0 increase 0.1, p < 0.002), and MV (OR 2.43, p < 0.0001). We conclude that patient care is more efficient with a closed ICU, and that mortality is not adversely affected.

Adolescent↗
PubMed1998

Severe community-acquired pneumonia. Assessment of severity criteria.

The purpose of the study was to validate the criteria used in the guidelines of the American Thoracic Society (ATS) for severe community-acquired pneumonia (CAP). Severe pneumonia was defined as admission to the intensive care unit (ICU). Overall 331 nonsevere (84%) and 64 severe cases (16%) of CAP were prospectively studied. Mortality was 19 of 395 (5%) and 19 of 64 (30%), respectively. Single severity criteria as well as the ATS definition of severe pneumonia were assessed calculating the operative indices. A modified prediction rule including minor (baseline) and major (baseline or evolutionary) criteria was derived. Single minor criteria at admission had a low sensitivity and positive predictive value. Defining severe pneumonia according to the ATS guidelines had a high sensitivity (98%). However, specificity and positive predictive value were low (32% and 24%, respectively). A modified prediction rule (presence of two or three minor criteria [systolic blood pressure < 90 mm Hg, multilobar involvement, PaO2/FIO2 < 250] or one of two major criteria [requirement of mechanical ventilation, presence of septic shock]) had a sensitivity of 78%, a specificity of 94%, a positive predictive value of 75%, and a negative predictive value of 95%. The ATS definition of severe pneumonia was highly sensitive but insufficiently specific and had a low positive predictive value. Our suggested modified rule had a more balanced performance and, if validated in an independent population, may represent a more accurate definition of severe CAP.

APACHE↗
PubMed1998

Community-acquired pneumonia: a North American perspective.

The North American guidelines for pneumonia generally show agreement in both the Canadian and American approaches. However, much new data have appeared since the original recommendations, and revisions are needed. The general approach to empiric therapy that has been proposed in both the Canadian and American Thoracic Society documents does appear to be valid, and future recommendations will probably use the original approach as a framework for a more refined approach.

Canada↗
PubMed1998

Infective exacerbations of chronic bronchitis: relation between bacteriologic etiology and lung function.

STUDY OBJECTIVE: In patients with severe COPD, acute infective exacerbations are frequent. Streptococcus pneumoniae and Haemophilus influenzae are the most commonly isolated bacteria in sputum cultures from these patients. We hypothesized that in patients with advanced disease, Gram-negative bacteria other than H influenzae play at least an equally important role. METHODS: We evaluated clinical data and sputum culture results from 211 unselected COPD patients admitted to our hospital with an acute infective exacerbation of COPD. One hundred twelve patients fulfilled our protocol criteria of reliable microbiologic results and reproducible lung function tests; the patients were categorized according to the recently published three stages of severity. RESULTS: Lung function tests revealed an FEV1 of > or =50% of the predicted value in 30 patients (stage I), an FEV1 of 35% to <50% of the predicted value in 30 patients (stage II), and an FEV1 of < or =35% of the predicted value in 34 patients (stage III). Bacteria were classified into three groups: group 1 contained S pneumoniae and other Gram-positive cocci; group 2, H influenzae and Moraxella catarrhalis; and group 3, Enterobacteriaceae and Pseudomonas spp. For all patients together, the most frequently isolated bacteria were group 3 organisms (Enterobacteriaceae and Pseudomonas spp, 48.2%), followed by group 1 organisms (S pneumoniae and other Gram-positive cocci, 30.4%), and group 2 organisms (H influenzae and M catarrhalis, 21.4%). In stage I patients, 14 of 30 had bacteria from group 1, seven of 30 had group 2, and nine of 30 had group 3. In stage II patients, eight of 30 had group 1 bacteria, 10 of 30 had group 2, and 12 of 30 had group 3. In stage III patients, 12 of 52 had group 1 bacteria, seven of 52 had group 2, and 22 of 52 had group 3. The three groups of bacteria causing infective exacerbations were unevenly distributed among the three severity stages of lung function (p=0.016). CONCLUSION: There is a correlation between deterioration of lung function and the bacteria isolated from patients with infective exacerbations of COPD. In acute infective exacerbations, Enterobacteriaceae and Pseudomonas spp are the predominant bacteria in patients with an FEV1 < or =35% of the predicted value.

Acute Disease↗
PubMed1998

Strategies for prevention of community-acquired pneumonia.

Our rapidly expanding knowledge of the cause and pathogenesis of Community-acquired pneumonia (CAP) offers new opportunities to prevent this disease. Influenza vaccine is effective for the prevention of respiratory illness, including pneumonia, in the setting of influenza A and B infection. Pneumococcal vaccine is effective for preventing the most common form of bacterial CAP, but it is most effective when administered early in the course of chronic illnesses. Even with the widespread availability and proven efficacy of influenza and pneumococcal vaccines, their use has remained suboptimal. Rimantadine and Amantadine have also been used successfully for prevention of influenza A infection. Further improvement in strategies for the prevention of CAP lies in the development of new and improved vaccines, enhanced environmental control, and general education of physicians and the public, so that new approaches such as hospital-based immunization can be applied.

Amantadine↗
PubMed1997

Survival in patients with nosocomial pneumonia: impact of the severity of illness and the etiologic agent.

OBJECTIVE: To assess the impact of severity of illness at different times, using the Mortality Probability Models (MPM II), and the impact of etiologic agent on survival in patients with nosocomial pneumonia. DESIGN: Retrospective, observational study. SETTING: Fourteen-bed medical-surgical intensive care unit (ICU) in a teaching hospital. PATIENTS: Sixty-two patients with nosocomial pneumonia who were receiving early appropriate antibiotic treatment. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Severity of illness at the time of admission to the ICU (M0), 24 hrs after admission (M24), and at the time of pneumonia diagnosis (M1) was determined using MPM II. Bacteriology was established by quantitative cultures from bronchoscopic samples. The outcome measure was the crude mortality rate. The crude mortality rate in the ICU was 59.7%, compared with average predicted mortality rates of 43.5% (M0), 36.4% (M24), and 52.2% (M1). We observed significant differences in mean MPM II determinations between survivors and nonsurvivors at M1 (39.3% vs. 60.9%, p = .001) but not at M0 and M24. In the univariate analysis, the variables most predictive of mortality were the presence of coma (p = .02), inotropic medication use (p = .001), and an MPM II determination of > 50% (p = .001) when pneumonia was diagnosed (M1). Multivariate analysis showed that, in the absence of Pseudomonas aeruginosa, an MPM II determination of > 50% at M1 was associated with a relative risk of death of 4.8. The presence of P. aeruginosa was associated with an increase in the risk of death of 2.6 and 6.36 in both populations with MPM II determinations at M1 of < or = 50% and > 50%, respectively. CONCLUSIONS: Severity of illness when pneumonia is diagnosed is the most important predictor of survival, and this determination should be used for therapeutic and prognostic stratification. In addition, the presence of P. aeruginosa contributed to an excess of mortality that could not be measured by MPM II alone, suggesting the importance of the pathogen in prognosis.

Aged↗