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Query: UMLS:C0032285 (pneumonia)
 54,520 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Microbial colonization and infection patterns were prospectively evaluated in premature baboons with and without bronchopulmonary dysplasia (BPD) to assess if prolonged hyperoxia would predispose to a different pattern of microbial colonization and/or a higher risk of respiratory infection. Forty baboons were delivered by hysterotomy at 75% of gestation and randomized into two groups. Group I (control or PRN) animals were placed immediately on high-frequency oscillation at 15 Hz; I:E ratio 1:2, and changed to positive-pressure ventilation at 48 to 72 h. They were maintained on clinically appropriate oxygen at minimal ventilator settings for the remainder of the 21-day experimental period. Group II (oxygen-treated or BPD) animals were ventilated with PPV and FIO2 1.0 for 7 days followed by FIO2 0.8 for 14 days. All animals were treated with antibiotics during some portion of the 21-day course. Specimens from nose, oropharynx, trachea, and rectum were cultured for both aerobes and anaerobes throughout the neonatal intensive care unit (NICU) course. A subset of animals from both groups were killed at 21 days and lung, liver, spleen, and gastric contents were cultured quantitatively at autopsy. Findings showed that coagulase-negative staphylococci were the predominant organisms that colonized the neonate in the NICU. Lung infections were seen to evolve through sequential pathogenetic steps: colonization of the upper respiratory tract, with concomitant or subsequent colonization of the trachea with comparable organism and ultimate recovery of the same organisms at autopsy in the lungs of animals with pneumonia.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Bacterial colonization and infection studies in the premature baboon with bronchopulmonary dysplasia. 195 45

The role of gastric microbial colonization in nosocomial infections and endotoxemia was investigated prospectively in 40 neurosurgical patients requiring mechanical ventilation for greater than 48 h. Each was studied up to 7 d. Swabs from the nose and oropharynx were cultured at admission, and aspirates from the stomach and trachea were cultured daily until enteral alimentation was started. Patients were evaluated every second day for endotoxemia and coagulation activation. Of 153 gastric aspirates, 66.7% contained microorganisms at a mean quantity of 10(7) cfu/ml. Nosocomial pneumonia occurred in 15 patients, septicemia in 5, and meningitis in 1. The stomach was the evident source of infection in only 1 patient with pneumonia. Of 140 plasma samples, 12 (8.6%) from 10 patients showed detectable endotoxin levels, but there was no association between endotoxemia or coagulation activation and the presence of microorganisms in the stomach. The stomach was not an important source for nosocomial infections or endotoxemia, even in patients with high gastric pH.
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PMID:Role of gastric colonization in nosocomial infections and endotoxemia: a prospective study in neurosurgical patients on mechanical ventilation. 276 Apr 97

Serious respiratory tract infections are rare in the healthy individual and most of the nuisance morbidity that occurs results from nasopharyngeal viral infections that many people get once or twice a year. The economic impact from these upper respiratory tract infections is appreciable, however, in terms of absenteeism from school or work, but unfortunately there is little that can be done to ward them off in a practical way. Pneumonia is an infrequent lifetime experience for most non-smoking adults and when it occurs, unusual circumstances may pertain--a particularly virulent microorganism is in circulation, or perhaps one has been exposed to a newly recognized germ, such as has occurred with Legionella species in the past 8 years or so. What protects us the great majority of the time is a very effective network of respiratory tract host defenses. These include many mechanical and anatomical barrier mechanisms concentrated in nose and throat; mucociliary clearance, coughing and mucosal immunoglobulins in the conducting airways and in the air-exchange region of the alveolar structures, phagocytes, opsonins, complement, surfactant and many other factors combine to clear infectious agents. The ability to mount an inflammatory response in the alveoli may represent the maximal and ultimate expression of local host defense. In some way these host defenses are combating constantly the influx of micro-organisms, usually inhaled or aspirated into the airways, that try to gain a foothold on the mucosal surface and colonize it. But many general changes in overall health such as debility, poor nutrition, metabolic derangements, bone marrow suppression and perhaps aging promote abnormal microbial colonization and undermine the body's defenses that try to cope with the situation. It is a dynamic struggle. The departure from normal respiratory health may not be obvious immediately to the patient or to the physician and repeated episodes of infection or persisting symptoms of cough, expectoration and sinus or ear infections may develop before serious assessment of the situation is taken and appropriate diagnosis gotten underway. Obvious explanations for respiratory infections may be apparent and, nowadays, side effects from antineoplastic chemotherapy or immunosuppressive therapy for a variety of diseases that create an immunocompromised host are common. In a few subjects, especially young adults who present with a cumulative history of frequent but mild infections in childhood and youth, a subtle deficiency in host defenses may exist and have been partially masked because of attentive pediatric medical care and prompt use of broad spectrum antibiotics.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Respiratory infections may reflect deficiencies in host defense mechanisms. 384 94

Well functioning host defenses in the respiratory tract effectively remove microbes and other debris that reach the conducting airways and alveoli, and this usually prevents infections. People with acute and chronic illnesses can experience failure of any number of these defense mechanisms that allow pneumonia (and bacteremia) to occur, often with considerable morbidity and mortality. People with alcohol-related illnesses are a susceptible group for infections, and many strategies are needed to help them such as moderating alcohol abuse and dependence, providing timely immunizations to create antibody against encapsulated bacteria, anticipating microbial colonization of mucosal areas that can promote infection, giving excellent supporting medical care in crisis situations, and prescribing appropriate antibiotics. New approaches to boosting inflammatory reactions to control lung infections better with cytokines and new immunomodulator therapies must be investigated now.
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PMID:Pulmonary host defenses. 777 64

The microbial colonization and the associated risk of respiratory infection during the application of a multiple-use closed-system suction catheter (CSSC) and a single-use open-system suction catheter (OSSC) on liver transplant patients was evaluated in this preliminary study. The cost differential for the two systems was also compared. Twenty post-orthotopic liver transplant (OLTx) patients who were mechanically ventilated via an endotracheal (ET) tube were studied. Ten subjects were randomly allocated ET suction by the CSSC and 10 with OSSC. Both groups were similar according to age, sex, clinical severity, presence of a naso-gastric tube, use of H2 antagonists and antibiotics used. Standard protocols were followed to intubate and suction the patients and to change ventilatory equipment. Suctioning performed with the CSSC did not significantly increase the risk of microbial colonization of the respiratory tract. Similarly there was no apparent difference in the incidence of nosocomial pneumonia between the two suction systems, based on the microbiological and clinical data. The mean daily cost of using the CSSC compared to the OSSC was 11.6 times higher. This may be balanced by a reduction in nursing time and reduced risk of spread of infection associated with the CSSC.
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PMID:Microbial colonization of closed-system suction catheters used in liver transplant patients. 918 Apr 92

Pasteurella haemolytica is an important respiratory pathogen of cattle that incites extensive infiltrates of neutrophils into the lung. In addition to the parenchymal damage caused by factors released by P. haemolytica, neutrophils contribute to the pathologic changes in the lungs. Molecules which mediate neutrophil infiltration into the lungs during P. haemolytica pneumonia are poorly characterized. To determine whether the CD18 family (beta2-integrin) of leukocyte adhesion molecules mediates initial passage of neutrophils into the pulmonary bronchi and bronchioles of lungs infected with P. haemolytica, three Holstein calves homozygous for bovine leukocyte adhesion deficiency (BLAD) (CD18-deficient neutrophils), and three age- and breed-matched control calves (normal CD18 expression) were inoculated with P. haemolytica A1 via a fiberoptic bronchoscope and euthanized at 2 h postinoculation. Sections of lung were stained for neutrophils, and the intensity of neutrophilic infiltration was determined by computerized image analysis. Significantly fewer (P < 0.05) neutrophils infiltrated the lumen, epithelium, and adventitia of bronchioles and bronchi in lungs of calves with BLAD compared to normal calves, which had dense infiltrates within these sites at 2 h postinoculation. The reduced infiltration in calves with BLAD occurred despite the presence of an extremely large number of neutrophils in peripheral blood that is typical for these calves. The large number of neutrophils in the blood of calves with BLAD is probably a physiologic response that can occur without microbial colonization, since one calf with BLAD that was raised under germ-free conditions had large numbers of neutrophils in the blood that were similar to those in a calf with BLAD that was raised conventionally. Neutrophil counts in the germ-free and conventionally reared calves with BLAD were much higher than those in the three normal calves raised under germ-free conditions. The work in this study demonstrates that during the initial inflammatory response, neutrophils with normal CD18 expression pass more readily than CD18-deficient neutrophils into the walls and lumen of bronchi and bronchioles. It suggests that CD18 is needed for initial passage through the extensive extracellular matrix of the bronchi and bronchioles. This has potential importance for the development of therapies to direct or inhibit neutrophil infiltration into conducting airways rather than alveolar spaces.
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PMID:Induction of CD18-mediated passage of neutrophils by Pasteurella haemolytica in pulmonary bronchi and bronchioles. 991 73

The present article reviews the association between microbial colonization of the oral cavity and the lungs in critically ill patients that develop ventilator-associated pneumonia (VAP) in the intensive care unit (ICU) setting. The risk factors and microorganisms associated with VAP are presented. The role of oral colonization of VAP-associated pathogens (VAP-AP) in the development of VAP is examined. We explore the potential factors involved in oral colonization of VAP-AP, which are atypical bacteria for the oral cavity. Strategies for the prevention or moderation of oral colonization of VAP-AP have had limited success. We need a deeper understanding of the pathophysiology of VAP in order to reduce the morbidity, mortality, and cost from this common complication in ICU medicine and surgery.
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PMID:The role of oral microbial colonization in ventilator-associated pneumonia. 1558 38

Ventilator-associated pneumonia (VAP) is the most common nosocomial infection in the intensive care unit and is associated with major morbidity and attributable mortality. Strategies to prevent VAP are likely to be successful only if based upon a sound understanding of pathogenesis and epidemiology. The major route for acquiring endemic VAP is oropharyngeal colonization by the endogenous flora or by pathogens acquired exogenously from the intensive care unit environment, especially the hands or apparel of health-care workers, contaminated respiratory equipment, hospital water, or air. The stomach represents a potential site of secondary colonization and reservoir of nosocomial Gram-negative bacilli. Endotracheal-tube biofilm formation may play a contributory role in sustaining tracheal colonization and also have an important role in late-onset VAP caused by resistant organisms. Aspiration of microbe-laden oropharyngeal, gastric, or tracheal secretions around the cuffed endotracheal tube into the normally sterile lower respiratory tract results in most cases of endemic VAP. In contrast, epidemic VAP is most often caused by contamination of respiratory therapy equipment, bronchoscopes, medical aerosols, water (eg, Legionella) or air (eg, Aspergillus or the severe acute respiratory syndrome virus). Strategies to eradicate oropharyngeal and/or intestinal microbial colonization, such as with chlorhexidine oral care, prophylactic aerosolization of antimicrobials, selective aerodigestive mucosal antimicrobial decontamination, or the use of sucralfate rather than H(2) antagonists for stress ulcer prophylaxis, and measures to prevent aspiration, such as semirecumbent positioning or continuous subglottic suctioning, have all been shown to reduce the risk of VAP. Measures to prevent epidemic VAP include rigorous disinfection of respiratory equipment and bronchoscopes, and infection-control measures to prevent contamination of medical aerosols. Hospital water should be Legionella-free, and high-risk patients, especially those with prolonged granulocytopenia or organ transplants, should be cared for in hospital units with high-efficiency-particulate-arrestor (HEPA) filtered air. Routine surveillance of VAP, to track endemic VAPs and facilitate early detection of outbreaks, is mandatory.
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PMID:The pathogenesis of ventilator-associated pneumonia: its relevance to developing effective strategies for prevention. 1642 68

Ventilator-associated pneumonia (VAP) is the second most common nosocomial infection among children treated in intensive care units. The risk factors for developing this condition are generated by the patient's bedside conditions, the equipment used and the specific treatment administered to the child. Prophylaxis of VAP should necessarily include all measures that have been proven to be efficient in this respect such as rigorous hygiene control of hands and protective clothing of attending staff, changing breathing circuits of ventilators only if they malfunction or if they are visibly contaminated, preference of orotracheal intubation (instead of nasotracheal intubation) and use of endotracheal tubes with dorsal lumens to allow respiratory secretions to drain, and introduction of a uniform approach to patient care and staff training. Prophylaxis of the microbial colonization in children by antibiotics does not reduce the incidence of VAP-causing poly-resistant bacteria. Therapeutic management includes early initiation of broad spectrum empirical antibiotic therapy, the right choice of antibiotic requiring regular monitoring and good knowledge of the antibiotics sensitivity of the most common microbial isolates in the ward.
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PMID:Ventilator-associated pneumonias in children (II)--prophylaxis and treatment. 2290 25

In lung transplant recipients (LTRs), severe clinical complications, such as microbial infections of the lung or transplant rejection, may occur. Surfactant protein D (SP-D) is a C-type lectin that is mainly produced in alveolar type II cells. Plasma SP-D levels are usually low, but may increase when the lung-blood barrier is impaired. In this study, we analyzed whether plasma SP-D concentrations reflect rejection or infection of the lung allograft. An enzyme-linked immunosorbent assay was used to measure SP-D levels in plasma samples from 58 LTRs during intervals without pathologic respiratory findings and during episodes of acute cellular rejection (ACR), microbial colonization, and microbial pneumonia. Median plasma SP-D levels were significantly increased during episodes of microbial pneumonia, but not in the absence of pathologic respiratory findings, during microbial colonization, or during ACR up to grade A2-A3 (P < 0.05). During pneumonia, an increased plasma SP-D level was detected in 60% of LTRs and this was further associated with a significantly higher risk for the patients to develop stage III bronchiolitis obliterans syndrome (BOS III) or to die within the subsequent 6 months after pneumonia (P = 0.0093). All patients with a plasma SP-D level of >300 ng/mL during pneumonia developed BOS III and/or died within 6 months of follow-up (P = 0.001). The determination of SP-D levels in plasma during pneumonia in LTRs may be of prognostic value and warrants further evaluation.
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PMID:Analysis of plasma surfactant protein D levels in lung transplant recipients. 2402 2


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