The radiographic resolution of Streptococcus pneumoniae pneumonia

Acute organ injury and long-term sequelae of severe pneumococcal infections

Streptococcus pneumoniae (Spn) is a major public health problem, as it is a main cause of otitis media, community-acquired pneumonia, bacteremia, sepsis, and meningitis. Acute episodes of pneumococcal disease have been demonstrated to cause organ damage with lingering negative consequences. Cytotoxic products released by the bacterium, biomechanical and physiological stress resulting from infection, and the corresponding inflammatory response together contribute to organ damage accrued during infection. The collective result of this damage can be acutely life-threatening, but among survivors, it also contributes to the long-lasting sequelae of pneumococcal disease. These include the development of new morbidities or exacerbation of pre-existing conditions such as COPD, heart disease, and neurological impairments. Currently, pneumonia is ranked as the 9^th leading cause of death, but this estimate only considers short-term mortality and likely underestimates the true long-term impact of disease. Herein, we review the data that indicates damage incurred during acute pneumococcal infection can result in long-term sequelae which reduces quality of life and life expectancy among pneumococcal disease survivors.

Persistent Lung Inflammation After Clinical Resolution of Community-Acquired Pneumonia as Measured by 18FDG-PET/CT Imaging

BACKGROUND

Survivors of community-acquired pneumonia (CAP) are at increased risk of cardiovascular disease, cognitive and functional decline, and death, but the mechanisms remain unknown.

RESEARCH QUESTION

Do CAP survivors have evidence of increased inflammatory activity in their lung parenchyma on 2-deoxy-2-[¹⁸F]fluoro-d-glucose (¹⁸FDG)-PET/CT imaging after clinical resolution of infection?

STUDY DESIGN AND METHODS

We obtained ¹⁸FDG-PET/CT scans from 22 CAP survivors during their hospitalization with pneumonia (acute CAP) and 30 to 45 days after hospital discharge (post-CAP). In each set of scans, we assessed the lungs for foci of increased ¹⁸FDG uptake by visual interpretation and by total pulmonary glycolytic activity (tPGA), a background-corrected measure of total metabolic activity (as measured by ¹⁸FDG uptake). We also measured, post-CAP, the glycolytic activity of CAP survivor lung areas with volumes similar to the areas in 28 matched historical control subjects without pneumonia.

RESULTS

Overall, 68% of CAP survivors (95% CI, 45%-85%) had distinct residual areas of increased ¹⁸FDG uptake in their post-CAP studies. tPGA decreased from 821.5 (SD, 1,140.2) in the acute CAP period to 80.0 (SD, 81.4) in the post-CAP period (P = .006). The tPGA post-CAP was significantly higher than that in lung areas of similar volume in control subjects (80.0 [SD, 81.4] vs -19.4 [SD, 5.9]; P < .001).

INTERPRETATION

An important proportion of CAP survivors have persistent pulmonary foci of increased inflammatory activity beyond resolution of their infection. As inflammation contributes to cardiovascular disease, cognitive decline, functional waning, and mortality risk in the general population, this finding provides a plausible mechanism for the increased morbidity and mortality that have been observed post-CAP.

Prediction model for pneumonia in primary care patients with an acute respiratory tract infection: role of symptoms, signs, and biomarkers

BACKGROUND

Diagnosing pneumonia can be challenging in general practice but is essential to distinguish from other respiratory tract infections because of treatment choice and outcome prediction. We determined predictive signs, symptoms and biomarkers for the presence of pneumonia in patients with acute respiratory tract infection in primary care.

METHODS

From March 2012 until May 2016 we did a prospective observational cohort study in three radiology departments in the Leiden-The Hague area, The Netherlands. From adult patients we collected clinical characteristics and biomarkers, chest X ray results and outcome. To assess the predictive value of C-reactive protein (CRP), procalcitonin and midregional pro-adrenomedullin for pneumonia, univariate and multivariate binary logistic regression were used to determine risk factors and to develop a prediction model.

RESULTS

Two hundred forty-nine patients were included of whom 30 (12%) displayed a consolidation on chest X ray. Absence of runny nose and whether or not a patient felt ill were independent predictors for pneumonia. CRP predicts pneumonia better than the other biomarkers but adding CRP to the clinical model did not improve classification (- 4%); however, CRP helped guidance of the decision which patients should be given antibiotics.

CONCLUSIONS

Adding CRP measurements to a clinical model in selected patients with an acute respiratory infection does not improve prediction of pneumonia, but does help in giving guidance on which patients to treat with antibiotics. Our findings put the use of biomarkers and chest X ray in diagnosing pneumonia and for treatment decisions into some perspective for general practitioners.

Clinical presentations and outcome of severe community-acquired pneumonia

Background

Severe community-acquired pneumonia (SCAP) represents a frequent and potentially life-threatening condition. About 10% of all hospitalized patients with CAP require admission to the intensive care unit (ICU), and the mortality of these patients reaches 20–50%.

Objective

To evaluate the clinical presentation, bacteriological profile and outcome of severe community-acquired pneumonia (SCAP).

Patients and methods

54 patients presented by symptoms and sign of severe community acquired pneumonia who were admitted to respiratory care unit of Alhussein, Al-Azhar University Hospital from August 2015 to March 2016 were subjected to full clinical examination, chest X ray, complete blood picture, sputum and blood culture, PCR for suspected cases of Influenza H1N1 and MERS-COV, treatment, follow up, data collections and statistical analysis.

Results

The present study included 54 patients 26 males and 28 females with SCAP who were admitted to respiratory care unit of Alhussein, Al-Azhar University Hospital. The most common comorbidities were diabetes mellitus and hypertension. The most common presentations were fever, cough, dyspnea and hypoxemia. Two patients developed renal failure and 4 patients developed septic shock. The most common isolated organism was Streptococcus pneumoniae, Influenza H1N1, and Staphylococcus aureus. Mortality was 24% and it was common in patients with comorbidity than in patients without comorbidities.

Conclusion

SCAP occurs more frequently in those with comorbidities. The most frequent isolated causative organism of SCAP is S. pneumoniae, Influenza H1N1 and S. aureus. SCAP is associated with significant mortality, early recognition and prompt treatment may improve outcome.

Accuracy of Point-of-care Lung Ultrasonography for Diagnosis of Acute Chest Syndrome in Pediatric Patients with Sickle Cell Disease and Fever

OBJECTIVES

The objective was to determine the test performance characteristics for point-of-care lung ultrasonography (LUS) performed by pediatric emergency medicine (PEM) physicians compared with radiographic diagnosis of acute chest syndrome (ACS) in patients with sickle cell disease (SCD) and fever.

METHODS

This was a prospective study of patients up to 21 years with SCD and fever requiring chest X-ray (CXR) evaluation for ACS. Before obtaining CXR, a blinded PEM physician performed LUS using a standardized scanning protocol. Positive LUS for ACS was defined as lung consolidation. All patients received CXR and follow-up. The criterion standard for ACS was consolidation on CXR as determined by a blinded radiologist. LUS clips were reviewed by a blinded expert PEM sonologist.

RESULTS

A total of 116 febrile events from 91 patients with a median age of 5.7 years were enrolled by 15 PEM sonologists. CXR was positive for ACS in 15 (13%) patients, and LUS was positive for ACS in 19 (16%) patients. Positive LUS had a sensitivity of 87% (95% confidence interval [CI] = 62% to 96%), specificity of 94% (95% CI = 88% to 97%), positive likelihood ratio of 14.6 (95% CI = 6.5 to 32.5), and negative likelihood ratio of 0.14 (95% CI = 0.04 to 0.52) for ACS. The interobserver agreement (kappa) was 0.77. There were two missed cases of ACS on LUS.

CONCLUSIONS

LUS may be sensitive and specific for diagnosis of ACS in pediatric patients with SCD and fever. LUS may reduce the need for routine CXR and associated ionizing radiation exposure in this population.

Haemorrhagic pneumonia in sled dogs caused by Streptococcus equi subsp. zooepidemicus - one fatality and two full recoveries: a case report

In spite of yearly vaccination, outbreaks of canine infectious respiratory disease are periodically seen amongst domestic dogs. These infections compromise host defense mechanisms, and, when combined with other stressful events, allow opportunistic pathogens like Streptococcus equi subsp. zooepidemicus to create serious disease. Early recognition and treatment are tremendously important for a successful outcome in these cases. A polyvalent vaccine was given to 22 racing dogs three days after a competition, followed by two days of rest, and then the dogs were returned to regular training. Coughing was noticed among the dogs four days after immunisation. Three days after this outbreak one of the dogs was unusually silent and was found dead the next morning. Simultaneously two other dogs developed haemorrhagic expectorate, depression and dyspnea and were brought in to the veterinary hospital. Streptococcus equi subsp. zooepidemicus was isolated in pure culture from all three cases. They were treated and rehabilitated successfully, and won a sledge race three months later. This paper discusses the necropsy results, treatment regime, rehabilitation and the chronology of vaccination, stressful events and disease.

An Elderly Man with Non-Resolving Fever and a Pulmonary Infiltrate

A 62-year-old Pakistani man presented with fever and chest pain of five-day duration. He was non-smoker and he had no history of hemoptysis, wheezing, loss of weight or exposure to tuberculosis. Other history was unremarkable. Physical examination revealed a heart rate of 116 beats/min, BP of 121/ 58 mm Hg, temperature of 38.5°C, and a room air oxygen saturation of 92 %. There was no cervical, axillary, or inguinal lymphadenopathy. Chest examination revealed bronchial breath sounds in the right middle and lower zones. Cardiac examination revealed tachycardia with no gallops or murmurs. Abdomen was nontender without hepatosplenomegaly. Extremities were free of cyanosis, edema, and clubbing. There were no skin lesions

Patterns of Resolution of Chest Radiograph Abnormalities in Adults Hospitalized with Severe Community-Acquired Pneumonia

BACKGROUND

Timing of follow-up chest radiographs for patients with severe community-acquired pneumonia (CAP) is difficult, because little is known about the time to resolution of chest radiograph abnormalities and its correlation with clinical findings. To provide recommendations for short-term, in-hospital chest radiograph follow-up, we studied the rate of resolution of chest radiograph abnormalities in relation to clinical cure, evaluated predictors for delayed resolution, and determined the influence of deterioration of radiographic findings during follow-up on prognosis.

METHODS

A total of 288 patients who were hospitalized because of severe CAP were followed up for 28 days in a prospective multicenter study. Clinical data and scores for clinical improvement at day 7 and clinical cure at day 28 were obtained. Chest radiographs were obtained at hospital admission and at days 7 and 28. Resolution and deterioration of chest radiograph findings were determined.

RESULTS

At day 7, 57 (25%) of the patients had resolution of chest radiograph abnormalities, whereas 127 (56%) had clinical improvement (mean difference, 31%; 95% confidence interval, 25%-37%). At day 28, 103 (53%) of the patients had resolution of chest radiograph abnormalities, and 152 (78%) had clinical cure (mean difference, 25%; 95% confidence interval, 19%-31%). Delayed resolution of radiograph abnormalities was independently associated with multilobar disease (odds ratio, 2.87; P < or = .01); dullness to percussion at physical examination (odds ratio, 6.94; P < or = .01); high C-reactive protein level, defined as >200 mg/L (odds ratio, 4.24; P < or = .001); and high respiratory rate at admission, defined as >25 breaths/min (odds ratio, 2.42; P < or = .03). There were no significant differences in outcome at day 28 between patients with and patients without deterioration of chest radiograph findings during the follow-up period (P > .09).

CONCLUSIONS

Routine short-term follow-up chest radiographs (obtained <28 days after hospital admission) of hospitalized patients with severe CAP seem to provide no additional clinical value.

[Follow-up criteria for community acquired pneumonias and acute exacerbations of chronic obstructive pulmonary disease]

The follow-up of Community Acquired Pneumonias (CAP) and Acute Exacerbations of Chronic Obstructive Pulmonary Diseases (AECOPD) differs with the setting of care, but overall calls upon the same investigations as the initial evaluations. In the event of initial ambulatory care, the evaluation is carried out primarily on clinical data, at the 2 or 3rd day for the CAP, at the 2nd to 5th day for the AECOPD. In the event of unfavourable evolution, or from the start in the most severe cases, the follow-up is carried out in hospital; clinical evaluation is readily daily, and all the more frequent that the clinical condition is worrying because of the severity or risk factors. The investigations will be limited to those initially abnormal in the event of favourable evolution; on the contrary, unfavourable evolution can justify new investigations which depend on clinical characteristics. Remotely, i.e. 4 to 8 weeks later, must be checked the return at the baseline clinical state, a chest X-ray (CAP), spirometry and arterial blood gas (AECOPD), even bronchoscopy and thoracic CT-scan.

Pneumonia in hospitalized children

Pneumonia is one of the most common infections in the pediatric age group and one of the leading diagnoses that results in overnight hospital admission for children. Various micro-organisms can cause pneumonia, and etiologies differ by age. Clinical manifestations vary, and diagnostic testing is frequently not standardized. Hospital management should emphasize timely diagnosis and prompt initiation of antimicrobial therapy when appropriate. Issues of particular relevance to inpatient management are emphasized in this article.

Nonresolving Pneumonia

Uncertainty over the expected clinical course of a community-acquired or nosocomial pneumonia is a common reason for pulmonary consultation. Determining which patients with prolonged pneumonia and at what point during therapy they should undergo further evaluation can be challenging. This article reviews "normal" resolution times for the most common pneumonias, risk factors for delayed resolution, and infectious and noninfectious conditions that can cause nonresolving pneumonia. An approach to the evaluation of the patient with this common problem is described.

Nonresponses and treatment failures with conventional empiric regimens in patients with community-acquired pneumonia

Although most patients with suspected CAP respond to empiric therapy,a small number of patients do not respond in the expected fashion. Age and underlying comorbid conditions have a strong influence on the course of illness. Less common causes of treatment failures include overwhelming infection, antimicrobial resistance, and misdiagnosis. It is a common practice for empiric antimicrobial treatment of CAP to be initiated without microbiologic studies. Clinicians carefully should observe these patients for unusual or slow responses and should be ready to pursue a more extensive search for the cause of treatment failure.

Anti-inflammatory effects of macrolides—an underappreciated benefit in the treatment of community-acquired respiratory tract infections and chronic inflammatory pulmonary conditions?

BACKGROUND

It has been recognized for more than 20 years that the macrolides have immunomodulatory effects that are beneficial for those suffering from chronic pulmonary inflammatory syndromes, such as diffuse panbronchiolitis, cystic fibrosis, asthma and bronchiectasis. The macrolides have consistently been associated with decreased length of stay and mortality when used alone or in combination with beta-lactam antibiotics. This effect can be demonstrated against combinations consisting of beta-lactams and other antibiotics active against 'atypical chest pathogens' when treating community-acquired pneumonia (CAP) in hospitalized patients. As such, it appears that the macrolides' effects in CAP patients are more than just antibacterial in nature. AIMS OF THIS REVIEW: This review aims: to give the reader information on the background areas described, as well as related areas; to review the CAP benefits with macrolides and how they may be related to the immunomodulatory properties they demonstrate, albeit in a shorter period of time than previously demonstrated with chronic pulmonary disorders; to use ex vivo data to support these extrapolations.

LITERATURE SEARCH

A literature search using Medline was conducted from 1966 onwards, searching for articles with relevant key words such as macrolide, diffuse panbronchiolitis, community-acquired pneumonia, biofilm, immunomodulation, cystic fibrosis, erythromycin, clarithromycin, roxithromycin and azithromycin, bronchiectasis and asthma. When appropriate, additional references were found from the bibliographies of identified papers of interest. Any relevant scientific conference proceedings or medical texts were checked when necessary.

CONCLUSIONS

(1) Research into macrolide immunomodulation for chronic pulmonary disorders demonstrates consistent positive effects, although of types other than seen with diffuse panbronchiolitis. These effects, together with their inhibitory activity on biofilms, have the potential to make them a useful option. (2) The benefits for CAP are consistent, and higher when a macrolide is given with another atypical agent than if the other atypical agent is given alone, suggesting a non-antibacterial benefit. (3) Recent research of the immunomodulatory properties of azithromycin imply that azithromycin may have a previously unknown short-term biphasic effect on inflammation modulation: enhancement of host defence mechanisms shortly after initial administration followed by curtailment of local infection/inflammation in the following period. (4) Additional in vivo research is needed prior to developing any firm conclusions.

Imagerie moderne des pneumonies infectieuses aiguës

Les pneumonies infectieuses aiguës constituent un problème de santé publique important, car elles sont une cause majeure de morbidité et de mortalité chez l’adulte. Si les données cliniques et radiographiques permettent le plus souvent de faire le diagnostic de pneumonie infectieuse, le diagnostic étiologique est plus difficile. En effet, de nombreux agents pathogènes peuvent être responsables de pneumonie et la réaction du parenchyme pulmonaire est peu variée, d’où la faible spécificité des lésions radiologiques observées en dehors de quelques cas particuliers. C’est pourquoi la compréhension des mécanismes physiopathologiques permet d’expliquer certains aspects radiologiques. De même, la connaissance des bases anatomocliniques et radiologiques autorise la reconnaissance de trois aspects radiographiques principaux. Quant à l’appréciation des contextes épidémiologique et immunitaire, ils peuvent permettre également d’approcher le germe en cause.

Radiographic Resolution of Community-Acquired Bacterial Pneumonia in the Elderly

OBJECTIVES

To investigate the radiographic clearance of proven community-acquired nontuberculous bacterial pneumonia in nonimmunocompromised older patients to provide working estimates of the rate of radiographic resolution as a function of the patient cumulative comorbidities, extent of initial radiographic involvement, functional status, and causative pathogens.

DESIGN

A prospective study.

PARTICIPANTS

Seventy-four patients aged 70 and older, consecutively admitted to a hospital for community-acquired bacterial pneumonia.

SETTING

A university-affiliated teaching hospital.

MEASUREMENTS

Chest radiographs were performed every 3 weeks from the date of admission for a total period of 12 weeks or until all radiographic abnormalities had resolved or returned to baseline.

RESULTS

Sixty-four patients (86%) completed the study. The rate of radiographic clearance was estimated at 35.1% within 3 weeks, 60.2% within 6 weeks, and 84.2% within 12 weeks. Radiographic resolution was significantly slower for those with high comorbidity index, bacteremia, multilobar involvement, and enteric gram-negative bacilli pneumonias. Multivariate regression analysis demonstrated that the comorbidity index (relative risk for clearance=0.67 per class index, P<.001) and multilobar disease (relative risk for clearance=0.24 for more than one lobe, P<.001) had independent predictive value (Cox proportional hazards regression model) on the rate of resolution.

CONCLUSION

The radiographic resolution of nontuberculous bacterial pneumonia in the elderly should take into account the extent of lobar disease and the burden of underlying illnesses. A waiting period of 12 to 14 weeks is recommended for slowly resolving pneumonia to be considered nonresolving.

The challenge of nonresolving pneumonia. Knowing the norms of radiographic resolution is key

Pneumonia that fails to resolve after 10 to 14 days of antibiotic therapy can lead physicians to call for consultation or unnecessary invasive diagnostic procedures. Understanding the infectious and noninfectious causes of pneumonia and their normal times to resolution is enormously helpful in the judicious evaluation of and timely intervention in this very challenging condition.

Anti-inflammatory lipid mediators and insights into the resolution of inflammation

The pro-inflammatory signalling pathways and cellular mechanisms that initiate the inflammatory response have become increasingly well characterized. However, little is known about the mediators and mechanisms that switch off inflammation. Recent data indicate that the resolution of inflammation is an active process controlled by endogenous mediators that suppress pro-inflammatory gene expression and cell trafficking, as well as induce inflammatory-cell apoptosis and phagocytosis, which are crucial determinants of successful resolution. This review focuses on this emerging area of inflammation research and describes the mediators and mechanisms that are currently stealing the headlines.

Nonresolving pneumonia and mimics of pneumonia

Physicians caring for patients with community-acquired pneumonia are often faced with the dilemma of how to approach a patient with slowly resolving or even nonresolving pneumonia. When the radiograph has failed to resolve by 50% in 2 weeks or completely in 4 weeks, the pneumonia should be considered to be nonresolving or slowly resolving. The causes of a nonresolving pneumonia and an approach to the work-up are presented.

What factors influence physicians' decisions to switch from intravenous to oral antibiotics for community-acquired pneumonia?

OBJECTIVE

One of the major factors influencing length of stay for patients with community-acquired pneumonia is the timing of conversion from intravenous to oral antibiotics. We measured physician attitudes and beliefs about the antibiotic switch decision and assessed physician characteristics associated with practice beliefs.

DESIGN

Written survey assessing attitudes about the antibiotic conversion decision.

SETTING

Seven teaching and non-teaching hospitals in Pittsburgh, Pa.

PARTICIPANTS

Three hundred forty-five generalist and specialist attending physicians who manage pneumonia in 7 hospitals.

MEASUREMENTS AND RESULTS

Factors rated as "very important" to the antibiotic conversion decision were: absence of suppurative infection (93%), ability to maintain oral intake (79%), respiratory rate at baseline (64%), no positive blood cultures (63%), normal temperature (62%), oxygenation at baseline (55%), and mental status at baseline (50%). The median thresholds at which physicians believed a typical patient could be converted to oral therapy were: temperature < or =100 degrees F (37.8 degrees C), respiratory rate < or =20 breaths/minute, heart rate < or =100 beats/minute, systolic blood pressure > or =100 mm Hg, and room air oxygen saturation > or =90%. Fifty-eight percent of physicians felt that "patients should be afebrile for 24 hours before conversion to oral antibiotics," and 19% said, "patients should receive a standard duration of intravenous antibiotics." In univariate analyses, pulmonary and infectious diseases physicians were the most predisposed towards early conversion to oral antibiotics, and other medical specialists were the least predisposed, with generalists being intermediate (P <.019). In multivariate analyses, practice beliefs were associated with age, inpatient care activities, attitudes about guidelines, and agreeableness on a personality inventory scale.

CONCLUSIONS

Physicians believed that patients could be switched to oral antibiotics once vital signs and mental status had stabilized and oral intake was possible. However, there was considerable variation in several antibiotic practice beliefs. Guidelines and pathways to streamline antibiotic therapy should include educational strategies to address some of these differences in attitudes.

Diagnosis of pneumonia and monitoring of infection eradication

Pneumonia can be classified as community-acquired (CAP) or hospital-acquired (nosocomial). Both are frequent infections that demand a great amount of medical resources. The diagnosis of CAP is based on clinical signs and the presence of a pulmonary infiltrate visible on chest radiograph. For practical purposes, CAP has been classified as typical, with an acute onset in which the most representative microorganism is Streptococccus pneumoniae, and atypical, with a subacute onset (Mycoplasma pneumoniae). Nevertheless, so far no studies have clearly demonstrated the utility of this classification in predicting the aetiology. Guidelines on CAP recommend associating the aetiology of CAP with comorbidity, age and severity. The microbiological diagnosis relies mainly on Gram stain and sputum culture, but this technique has disadvantages such as frequent contamination of the sample with oropharyngeal commensal flora, frequent sterile cultures associated with previous antibiotic treatment, and the fact that approximately 40% of patients are not able to expectorate. Other diagnostic techniques such as blood cultures, serological tests and fibreoptic bronchoscopy must be reserved for patients who are hospitalised, especially if they need admission to an intensive care unit. Compared with CAP, nosocomial pneumonia has major diagnostic problems due to the presence of other diseases able to mimic pneumonia and frequent bacterial colonisation of the lower respiratory tract. Most of the diagnostic techniques produce a high percentage of false-negative and false-positive results. This is especially true for ventilator-associated pneumonia. There is controversy over using a comprehensive aetiological work-up based on bronchoscopic techniques or only on quantitative culture of endotracheal aspiration. By contrast, there is consensus about the importance of the adequacy of empirical antibiotic treatment, since mortality rates are higher in patients who are inadequately treated. Once treatment of pneumonia has begun, it must be maintained for 48 to 72 hours because this is the minimum time to evaluate a clinical response. Antibacterial agents have to be adjusted according to microbiological findings. In nonresponding patients, pneumonia-related complications and the presence of multiresistant micro-organisms or non-covered pathogens must be ruled out.

Slowly resolving and nonresolving pneumonia. Questions to ask when response is delayed

What is the proper course of action when pneumonia symptoms seem to linger? Is the disease running a typical course, or is further evaluation needed? Dr Johnson addresses these important questions with an outline of risk factors for delayed resolution and a detailed listing of diagnostic considerations. He also discusses reasonable timing of further studies and the usefulness of radiography and fiberoptic bronchoscopy.

Risk factors for community-acquired pneumonia diagnosed upon hospital admission. British Thoracic Society Pneumonia Study Group

A case-control study of risk factors for community-acquired pneumonia in adults admitted to hospital is reported. Cases were surviving patients (n = 178) admitted to 14 hospitals in England. Controls were individuals (n = 385) randomly selected from the electoral registers of the areas served by the hospitals. The two groups were compared with regard to risk factors for pneumonia using a standardized postal questionnaire. Independent risk factors associated with cases in log-linear regression analysis were age, heart disease (as indicated by congestive heart failure and/or digitalis treatment), lifetime smoking history, chronic airway disease (chronic bronchitis and/or asthma), occupational dust exposure, pneumonia as a child, single marital status and unemployment. Corticosteroid and bronchodilator therapy were also independent risk factors in the log-linear regression analysis, but may reflect the severity of underlying lung disease for which these drugs were prescribed. These data suggest that cigarette smoking is the major avoidable risk factor for acute pneumonia in adults.

Community-acquired pneumonia in the elderly

Pneumonia in the elderly is a common and serious problem with a clinical presentation that can differ from that in younger patients. Older patients with pneumonia complain of significantly fewer symptoms than do younger patients, and delirium commonly occurs. Indeed, delirium may be the only manifestation of pneumonia in this group of patients. Alcoholism, asthma, immunosuppression, and age >70 years are risk factors for community-acquired pneumonia in the elderly. Among nursing home residents, the following are risk factors for pneumonia: advanced age, male sex, difficulty in swallowing, inability to take oral medications, profound disability, bedridden state, and urinary incontinence. Streptococcus pneumoniae is the most common cause of pneumonia among the elderly. Aspiration pneumonia is underdiagnosed in this group of patients, and tuberculosis always should be considered. In this population an etiologic diagnosis is rarely available when antimicrobial therapy must be instituted. Use of the guidelines for treatment of pneumonia issued by the Infectious Diseases Society of America, with modification for treatment in the nursing home setting, is recommended.

Risk factors for community-acquired pneumonia diagnosed by general practitioners in the community

The purpose of this study was to identify risk factors for pneumonia diagnosed in the community by general practitioners, using a case control study in 29 general practices in Nottingham, U.K. Patients with radiographically confirmed pneumonia were compared with adults randomly selected from electoral registers corresponding to the catchment areas of the general practices taking part in the study. Sixty-six cases and 489 controls participated. Significant risk factors in univariate analysis included age, chronic obstructive pulmonary disease, congestive heart failure and lifetime consumption of cigarettes. Multiple logistic regression analysis of these four variables showed that age [adjusted odds ratio = 2.69 (for 30 year increment), 95%CI = 1.66-4.35] and chronic obstructive pulmonary disease (adjusted odds ratio= 1.99, 95%CI = 1.15-3.45) were independent risk factors. Only age and chronic obstructive pulmonary disease were independent risk factors for pneumonia in this study. Since cigarette smoking is the major cause of chronic obstructive pulmonary disease, these data suggest that cigarette smoking is the main avoidable risk factor for community-acquired pneumonia in adults.

Treatment guideline for nursing home-acquired pneumonia based on community practice

OBJECTIVES

To describe the findings of a retrospective study of the treatment of nursing home-acquired pneumonia (NHAP) in 11 nursing homes in one community and the development of a treatment guideline for NHAP using data from the retrospective study.

DESIGN

A retrospective chart review of 239 episodes of NHAP occurring between November 1, 1997, and April 30, 1998, was performed. Data regarding antibiotic treatment of NHAP were used to revise a treatment guideline developed by the authors. Further refinements of the guideline were made based on small group discussions with physicians and nurse practitioners caring for the study population.

SETTING

Residents with NHAP were identified among the populations of 11 nursing homes in the metropolitan Buffalo, New York area (Erie county). These 11 nursing homes had a total of 2375 beds, comprising nearly one-third of all nursing home beds in the county.

PARTICIPANTS

Nursing home residents with chest X-rays showing infiltrates and signs and symptoms of pneumonia.

MEASUREMENTS

Antibiotic treatment (drug used, route of administration, and duration of treatment), location of initial treatment (nursing home or hospital), and status (alive or dead) of each resident were recorded 30 days after diagnosis of NHAP.

RESULTS

Of the 239 episodes of NHAP, 171 (72%) were initially treated in nursing homes. Of these 171 patients, 105 (61%) were treated only with an oral regimen, whereas 66 (39%) were treated initially with an intramuscular antibiotic and subsequently with an oral regimen. There was no significant difference in 30-day mortality rates between those initially treated in nursing homes (22%) and those initially treated in hospitals (31%; P = .15) or between those initially treated with an oral regimen in nursing homes (21%) and those initially treated with an intramuscular antibiotic in nursing homes (25%; P = .56). There was no consistency in how physicians made the choice to use intramuscular antibiotics in nursing homes, and a logistic model for predicting this approach could explain very little. The frequency of the prescription of various antibiotic agents in nursing homes and in hospitals was tabulated as well as the duration of treatment; specific attention was paid to the timing of the switch to an oral agent among episodes initially treated with a parenteral agent. These data were used in the guideline to make specific recommendations regarding which agent to prescribe, the duration of parenteral therapy, the timing of the switch to an oral regimen, and the duration of treatment. In the setting of informal small groups, the guideline was discussed with physicians who cared for residents with NHAP in the study nursing homes. Revisions made to the guideline were based on these discussions.

CONCLUSIONS

A treatment guideline for NHAP was developed primarily on the basis of the practices of geriatricians in one community. These treatment practices were similar to those reported in the literature in terms of the proportion of patients treated in nursing homes and the antibiotics prescribed. The guideline also provided specific recommendations for timing of the switch to an oral agent after parenteral therapy and for duration of treatment. Studies are in progress to determine if use of this guideline will reduce some of the variation observed in the treatment of NHAP.

A multicenter study of grepafloxacin and clarithromycin in the treatment of patients with community-acquired pneumonia

STUDY OBJECTIVES

To compare the efficacies of 10-day regimens of grepafloxacin (GFX) (Raxar or Vaxar; Glaxo Wellcome; Greenford, UK), 600 qd, and clarithromycin (CLA) (Klacid, Biaxin, or Klaracid; Abbott Laboratories; Chicago, IL), 500 mg bid, in patients with community-acquired pneumonia (CAP), on the basis of clinical response, including radiographic evidence, and bacteriologic efficacy.

DESIGN

Phase IIIb, double-blind, double-dummy, randomized, prospective, parallel-group, comparative study conducted at 58 centers in 11 countries.

PATIENTS AND SETTING

Adult patients with signs and symptoms of CAP that was confirmed by radiographic evidence and who did not require parenteral therapy were included in the study.

ASSESSMENTS

Patients were assessed before treatment, during treatment, after treatment, and at follow-up (28 to 35 days after treatment completion). Clinical response was evaluated. Blood and sputum samples were cultured for bacterial pathogens, and serology testing was performed to detect atypical pneumonia.

RESULTS

A total of 504 patients were enrolled into the trial: 251 were randomly assigned to receive GFX and 253 to receive CLA. In patients able to be clinically evaluated, clinical success rates at follow-up were 147 of 163 patients (90%) in the GFX group and 148 of 167 patients (89%) in the CLA group (95% confidence interval, -6% to 9%). Pretreatment pathogens were confirmed in 131 of 504 patients (26%), either by culture or serology testing, the primary pathogens being Streptococcus pneumoniae (22%), Haemophilus influenzae (17%), Mycoplasma pneumoniae (25%), and Chlamydia pneumoniae (11%). For patients able to be evaluated who had typical pathogens, bacteriologic success was achieved in 92% of the patients in each treatment group. For patients able to be evaluated who had atypical pathogens, 18 of 18 patients (100%) in the GFX and 23 of 26 patients (88%) in the CLA group had a successful clinical outcome. There were similar rates of adverse events in each group, resulting in </= 7% withdrawal from treatment; gastrointestinal events were the most common.

CONCLUSIONS

GFX, 600 mg qd, was equivalent to CLA, 500 mg bid, in treating adult patients with CAP. Both treatments were well tolerated.

Nonresolving or slowly resolving pneumonia

Given the variability in rate of radiographic resolution, it remains controversial to decide when to initiate an invasive diagnostic work-up for nonresolving or slowly resolving pulmonary infiltrates. In immunocompetent patients who present with classical features of CAP (i.e., fever, chills, productive cough, new pulmonary infiltrate), clinical response to therapy is the most important determinant for further diagnostic studies. Within the first few days, persistence or even progression of infiltrates on chest radiographs is not unusual. Defervescence, diminished symptoms, and resolution of leukocytosis strongly support a response to antibiotic therapy, even when chest radiographic abnormalities persist. In this context, observation alone is reasonable, and invasive procedures can be deferred. Serial radiographs and clinical examinations dictate subsequent evaluation. In contrast, when clinical improvement has not occurred and chest radiographs are unchanged or worse, a more aggressive approach is warranted. In this setting, we advise fiberoptic bronchoscopy with BAL and appropriate cultures for bacteria, legionella, fungi, and mycobacteria. When endobronchial anatomy is normal and there is no purulence to suggest infection, TBBs should be done to exclude noninfectious causes (discussed earlier) or infections attributable to mycobacteria or fungi. An aggressive approach is also warranted in patients who are clinically stable or improving when the rate of radiographic resolution is delayed. As discussed earlier, what constitutes excessive delay is controversial, and depends upon the acuity of illness, specific pathogen, extent of involvement (i.e., lobar versus multilobar), comorbidities, and diverse host factors. Stable infiltrates even 2 to 4 weeks after institution of antibiotic therapy does not mandate intervention provided patients are improving clinically. Invasive techniques can also be deferred when unequivocal, albeit incomplete, radiographic resolution can be demonstrated. Lack of at least partial radiographic resolution by 6 weeks, even in asymptomatic patients, however, deserves consideration of alternative causes (e.g., endobronchial obstructing lesions, or noninfectious causes). Fiberoptic bronchoscopy with BAL and TBBs has minimal morbidity and is the preferred initial invasive procedure for detecting endobronchial lesions or substantiating noninfectious causes. The yield of bronchoscopy depends on demographics, radiographic features, and pre-test likelihood. In the absence of specific risk factors, the incidence of obstructing lesions (e.g., bronchogenic carcinomas, bronchial adenomas, obstructive foreign body) is low. Bronchogenic carcinoma is rare in nonsmoking, young (< 50 years) patients but is a legitimate consideration in older patients with a history of tobacco abuse. Non-neoplastic causes (e.g., pulmonary vasculitis, hypersensitivity pneumonia, etc.) should be considered when specific features are present (e.g., hematuria, appropriate epidemiologic exposures). Ancillary serologic tests or biopsies of extrapulmonary sites are invaluable in some cases. In rare instances, surgical (open or VATS) biopsy is necessary to diagnose refractory or non-resolving "pneumonias."

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)

Measuring symptomatic and functional recovery in patients with community-acquired pneumonia

OBJECTIVE

To determine the rates of resolution of symptoms and return to premorbid health status and assess the association of these outcomes with health care utilization in patients with community-acquired pneumonia.

DESIGN

A prospective, multicenter cohort study.

SETTING

Inpatient and outpatient facilities at three university hospitals, one community hospital, and one staff-model health maintenance organization.

PATIENTS

Five hundred seventy-six adults (aged > or = 18 years) with clinical and radiographic evidence of pneumonia, judged by a validated pneumonia severity index to be at low risk of dying.

MEASUREMENTS AND MAIN RESULTS

The presence and severity of five symptoms (cough, fatigue, dyspnea, sputum, and chest pain) were recorded through questionnaires administered at four time points: 0, 7, 30, and 90 days from the time of radiographic diagnosis of pneumonia. A summary symptom score was tabulated as the sum of the five individual severity scores. Patients also provided responses to the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36) and reported the number of and reason for outpatient physician visits. Symptoms and health status 30 days before pneumonia onset (prepneumonia) were obtained at the initial interview. All symptoms, except pleuritic chest pain, were still commonly reported at 30 days, and the prevalence of each symptom at 90 days was still nearly twice prepneumonia levels. Physical health measures derived from the SF-36 Form declined significantly at presentation but continued to improve over all three follow-up time periods. Patients with elevated symptom scores at day 7 or day 30 were significantly more likely to report pneumonia-related ambulatory care visits at the subsequent day 30 or day 90 interviews, respectively.

CONCLUSIONS

Disease-specific symptom resolution and recovery of the premorbid physical health status requires more than 30 days for many patients with pneumonia. Delayed resolution of symptoms is associated with increased utilization of outpatient physician visits.

Survey of physicians concerning the use of chest radiography in the diagnosis of pneumonia in out-patients

OBJECTIVE

To determine how physicians use chest radiography in the diagnosis of pneumonia in ambulatory patients.

STUDY POPULATION

A convenience sample of 176 Nova Scotia family physicians and internists selected to represent all geographic areas of the province proportional to population. STUDY INSTRUMENT: A 35-item questionnaire covering demographics, experience with out-patients with pneumonia, use of chest radiographs to make this diagnosis and factors that were considered important in the decision to perform initial and follow-up chest radiographs. Two skill-testing questions were also included.

RESULTS

One hundred and fourteen of 176 (64.7%) responded; 88% had treated out-patients with pneumonia in the previous three months. Fifty-seven per cent of physicians requested chest radiographs on 90% to 100% of out-patients in whom they had made a clinical diagnosis of pneumonia. These physicians were more likely to be internists and to have graduated before 1970. Factors that ranked most important in the decision to request the initial chest radiograph were clinical appearance, respiratory distress and physical findings, while age and smoking history contributed most to the decision to perform a follow-up chest radiograph.

CONCLUSIONS

There is considerable variability among physicians in requesting chest radiographs on out-patients with a clinical diagnosis of pneumonia. Physician and patient factors contribute to this variability.

Prandial aspiration and pneumonia in an elderly population followed over 3 years

The purpose of our study was to prospectively determine pneumonia frequency and correlate it with prandial liquid aspiration and feeding status in frail elderly nursing home residents. Initially, 152 patients had video swallowing examinations (81 oropharyngeal dysphagia, 19 thoracic dysphagia, 52 without dysphagia). Those diagnosed with oropharyngeal impairment were subsequently managed with swallowing therapy or artificial feeding modalities. Patients were followed for 3 years (unless they expired earlier) and clinical courses were categorized according to the degree of prandial aspiration and feeding (PAF) status. Subjects with new lung infiltrates persisting for at least 5 days with appropriate clinical findings were diagnosed as having pneumonia and were classified according to the PAF status months in which these findings occurred. Fifty-six pneumonias were diagnosed during 4,280 months with the following frequencies: no aspiration months 0.6%; minor aspiration months 0.9%; major aspiration/oral feeding months 1.3%; major aspiration/artificial feeding months 4.4%, p < 0.001. Our results indicate that there is not a simple and obvious relation between prandial liquid aspiration and pneumonia. Artificial feeding does not seem to be a satisfactory solution for preventing pneumonia in elderly prandial aspirators.

Bacteremic pneumococcal pneumonia. A community hospital experience

We reviewed our experience with bacteremic pneumococcal pneumonia (BPP) over a 1-year period at a 600-bed community teaching hospital; 26 cases were identified. The mean age was 57.5 years and there were 12 male and 14 female subjects. Cough, sputum production, fever, and mental status changes were the most frequent symptoms. Risk factors included drug abuse in 10, HIV in 4, current smoking in 7, diabetes in 3, and cancer in 3. The mean PaO2/FIo2 ratio was 274. Radiographic features included a consolidation pattern in 7, bronchopneumonia in 15, combined in 1, and an initial normal film in 3. Average length of stay (LOS) was 11 days with an overall mortality of 11.5%. Four patients required mechanical ventilation, two meeting the criteria for ARDS (if this group were eliminated, LOS would be 8.4 days). Three of these survived. Four patients had organisms resistant to penicillin and all survived. We conclude that (1) BPP remains a serious but treatable infection particularly when utilizing full supportive care; (2) the bronchopneumonia x-ray film pattern was associated with all the mortality; and (3) the occurrence of penicillin resistance did not contribute to the mortality, since early recognition and the use of appropriate antibiotics saved all of these patients.

Pneumonia in the elderly. Special diagnostic and therapeutic considerations

Clinical and radiologic signs and symptoms of gram-negative infections are often muted or obscured by a concurrent disease, and therefore, are not reliable for predicting the infecting organisms. Thus, initial therapy is nearly always empiric and based on the clinician's judgment that a patient's pneumonia is likely to be caused by particular pathogens. The choice of an appropriate regimen requires careful consideration of the extent and severity of coexisting illness and debilitation, the severity of the pneumonia, and the level of care required.

Overview of community-acquired pneumonia. Prognosis and clinical features

Despite the introduction of newer antibiotics, vaccinations, and better supportive care, CAP remains a common, frequently fatal disease. Age and coexisting illness influence which infectious agents are most likely to cause infection. Severity of illness and clinical features are influenced by various host factors and by the virulence of the infectious agent. Mortality and morbidity are reduced by the rapid institution of appropriate antimicrobial therapy. Because of the limitations of presently available diagnostic tests, many patients are begun on empiric regimens, and in up to half of these individuals, a cause is not identified. Although there are a number of potential pathogens, it is possible to identify likely pathogens based on easily identifiable clinical factors (age, presence of coexisting disease, severity of illness at presentation, and the need for hospitalization). Using this approach, CAP in immunocompetent adults may be divided into four categories. Once empiric therapy has been initiated, therapy should be continued for at least 72 hours unless clinical deterioration is noted. Within 4 days, fever and leukocytosis should return to baseline, but abnormal physical findings (i.e., crackles) require longer to resolve, especially with coexisting illness, and chest radiographic findings are the last to return to baseline and are especially delayed if the patient is bacteremic or has structural lung disease. Not all patients respond to initial empiric therapy. Reasons for this include antimicrobial resistance, the presence of nonbacterial pathogens (respiratory viruses), unusual bacterial pathogens, noninfectious causes that may mimic CAP, infectious complications (i.e., empyema), and pneumonia occurring in patients with unrecognized severe immunosuppression. Failure to improve after 72 hours and development of deterioration are indications for repeat diagnostic workup and consideration of alternative diagnoses. More invasive diagnostic tests are appropriate in severely ill patients and in those whose condition is deteriorating rapidly.