Respiratory tract colonization and incidence of secondary infection during hospital treatment of community-acquired pneumonia

Upper respiratory tract colonization by gram-negative rods in patients with chronic lymphocytic leukemia: analysis of risk factors

The aim of the study was to assess the frequency and predisposing factors of colonization of upper respiratory tract by Gram-negative rods (GNRs) in chronic lymphocytic leukemia (CLL) patients. Antimicrobial susceptibility of the isolated strains was determined. A significantly higher frequency of GNR colonization in CLL patients was observed (36.7%) in comparison to healthy volunteers (8.3%). GNR isolates mainly belonged to the Enterobacteriaceae family. Three isolates of GNR demonstrating presence of AmpC β-lactamases and one ESBL-producing strain were obtained from CLL patients. GNR colonization rate was higher among CLL patients with lower level of IgG in serum (P = 0.017), with higher number of neutrophils (P = 0.039) or higher number of lymphocytes in serum (P = 0.053). The longer the time elapsed since diagnosis, the higher the frequency of GNR colonization observed. Multivariate analysis showed importance of the Rai stage, number, and type of infections as independent predictors of GNR colonization in CLL patients.

Pneumonia in older people

The incidence of pneumonia is higher in older than younger people, due to both an increase in factors facilitating entry of infectious agents into the lungs, and attenuated functioning of the immune system. Classic features of presentation of pneumonia may be absent. The most common signs of pneumonia in old age are tachypnoea and tachycardia. Aetiology is established in only 50% of older patients. The empirical treatment of community-aquired pneumonia (CAP) should be aimed at its most common cause,Streptococcus pneumoniae. The empirical treatment of health care-associated pneumonia (HCAP) should be targeted at Gram-negative agents. Choice of antibiotic must include consideration of potential drug interactions.

Patterns and density of early tracheal colonization in intensive care unit patients

OBJECTIVE

The study aimed to describe the patterns and density of early tracheal colonization among intubated patients and to correlate colonization status with levels of antimicrobial peptides and inflammatory cytokines.

DESIGN

The was a prospective cohort study.

SETTING

The study was conducted in medical and cardiovascular intensive care units of a tertiary referral hospital.

PATIENTS

Seventy-four adult patients admitted between March 2003 and May 2006 were recruited for the study.

INTERVENTIONS

Tracheal aspirates were collected daily for the first 4 days of intubation using standardized, sterile technique and sent for quantitative culture and cytokines, lactoferrin and lysozyme measurements.

MEASUREMENTS AND MAIN RESULTS

The mean acute physiology and chronic health evaluation (APACHE II) score in this cohort was 24 +/- 7. Proportion of subjects colonized by any microorganism increased over the first 4 days of intubation (47%, 60%, 70%, 70%, P = .08), but density of colonization for bacteria or yeast did not change significantly. No known risk factors predicted tracheal colonization on day 1 of intubation. Several patterns of colonization were observed (persistent, transient, new colonization, and clearance of initial colonization).The most common organisms cultured were Candida albicans and coagulase-negative Staphylococcus. Levels of cytokines, lactoferrin, or lysozyme did not change over time and were not correlated with tracheal colonization status. Four subjects (6%) had ventilator-associated pneumonia.

CONCLUSIONS

The density of tracheal colonization did not change significantly over the first 4 days of intubation in medical intensive care unit patients. There was no correlation between tracheal colonization and the levels of antimicrobial peptides or cytokines. Several different patterns of colonization may have to be considered while planning interventions to reduce airway colonization.

Tracheobronchitis in the Intensive Care Unit

Tracheobronchitis can be broadly defined as inflammation of the airways between the larynx and the bronchioles. Clinically, this syndrome is recognized by an increase in the volume and purulence of the lower respiratory tract secretions and is frequently associated with signs of variable airflow obstruction. In the intensive care unit (ICU), tracheobronchitis is a relatively common problem with an incidence as high as 10.6% [1]. Although tracheobronchitis is associated with a significantly longer length of ICU stay and a prolonged need for mechanical ventilation, it has not been shown to increase mortality. These outcomes can be improved through the use of antimicrobial agents [1].

Antimicrobial treatment failures in patients with community-acquired pneumonia: causes and prognostic implications

The aim of the study was to determine the causes and prognostic implications of antimicrobial treatment failures in patients with nonresponding and progressive life-threatening, community-acquired pneumonia. Forty-nine patients hospitalized with a presumptive diagnosis of community-acquired pneumonia during a 16-mo period, failure to respond to antimicrobial treatment, and documented repeated microbial investigation >/= 72 h after initiation of in-hospital antimicrobial treatment were recorded. A definite etiology of treatment failure could be established in 32 of 49 (65%) patients, and nine additional patients (18%) had a probable etiology. Treatment failures were mainly infectious in origin and included primary, persistent, and nosocomial infections (n = 10 [19%], 13 [24%], and 11 [20%] of causes, respectively). Definite but not probable persistent infections were mostly due to microbial resistance to the administered initial empiric antimicrobial treatment. Nosocomial infections were particularly frequent in patients with progressive pneumonia. Definite persistent infections and nosocomial infections had the highest associated mortality rates (75 and 88%, respectively). Nosocomial pneumonia was the only cause of treatment failure independently associated with death in multivariate analysis (RR, 16.7; 95% CI, 1.4 to 194.9; p = 0.03). We conclude that the detection of microbial resistance and the diagnosis of nosocomial pneumonia are the two major challenges in hospitalized patients with community-acquired pneumonia who do not respond to initial antimicrobial treatment. In order to establish these potentially life-threatening etiologies, a regular microbial reinvestigation seems mandatory for all patients presenting with antimicrobial treatment failures.

Epidemiology of lower respiratory tract infections

The aim of this review is to focus on the epidemiology of lower respiratory tract infections, the etiology, prognosis and risk factors, dividing these problems into the following issues: global impact of these afflictions, community-acquired pneumonia, hospital acquired pneumonia, respiratory infections in surgery, acute bronchitis and exacerbations of chronic bronchitis. Every year about 5 million people die of acute respiratory infections. Among these, pneumonia represents the most frequent cause of mortality, hospitalization and medical consultation. Several factors (age, underlying disease, environment) influence mortality, morbidity and also microbial etiology. The authors also refer to recent data on the most frequently identified antibiotic resistance of respiratory pathogens. The knowledge of such different clinico-epidemiological situations is essential to physicians for an effective approach to treatment of pneumonia and bronchitis.

Changes in symptoms, peak expiratory flow, and sputum flora during treatment with antibiotics of exacerbations in patients with chronic obstructive pulmonary disease in general practice

BACKGROUND

Bacterial infections of the lower airways during an exacerbation in patients with asthma or chronic obstructive pulmonary disease (COPD) may be the cause of an exacerbation or the consequence of a viral infection or an increase in airways limitation. To determine whether bacterial infection is an important component in the pathogenesis of an exacerbation, the effects of antimicrobial treatment must be studied.

METHODS

Patients with asthma or COPD seen in general practice were studied in a double blind randomised manner to investigate whether the antimicrobial drugs amoxicillin (500 mg three times daily), cotrimoxazole (960 mg twice daily), or a placebo, each when added to a short course of oral corticosteroids, can accelerate recovery from exacerbations. Patients were instructed to contact their own physician early in the morning when complaints of increased shortness of breath, wheezing, or exacerbations of cough with or without sputum production occurred. Treatment effects were evaluated over the next 14 days by studying symptom scores (wheeze, dyspnoea, cough with and without mucus production, and awakening with dyspnoea), peak expiratory flow values (PEF, expressed as % predicted), and sublingual temperature. Bacteriological study of the sputum was made at the onset of an exacerbation and 7, 21 and 35 days afterwards.

RESULTS

Of 195 patients enrolled 71 (36%) contacted their physician for symptoms of an exacerbation. Symptoms improved in all three groups, improvements ranging from 0.54 to 0.75 points per day on a four point scale. PEF% predicted showed improvements in the three groups after the exacerbation, ranging from 0.34% to 0.78% predicted per day, finally returning to baseline values. Sublingual temperature did not change. Six of 71 patients consulted their physician because of a relapse between four and 24 days after the start of treatment. In only two of the 50 sputum samples, collected during an exacerbation, and which contained > or = 10(5) bacteria in culture sensitive to the chosen antibiotic given, did any benefit from antimicrobial treatment occur. During the recovery period sputum purulence improved irrespective of antibiotic treatment.

CONCLUSIONS

Antibiotics given with a short course of oral prednisolone during an exacerbation do not accelerate recovery as measured by changes in peak flow and symptom scores in ambulatory patients with mild to moderate asthma or COPD when treated by their general practitioners. Moreover, antibiotics do not reduce the number of relapses after treating an exacerbation.

Factors of importance for the long term prognosis after hospital treated pneumonia

BACKGROUND

Elderly patients admitted to hospital for community acquired pneumonia have a high risk of recurrence of pneumonia and of death during the years after discharge. In this study potential factors of importance for the long term prognosis after hospital treated pneumonia were retrospectively investigated.

METHODS

A total of 241 patients (103 men) with a mean age of 60 (range 18-102) years discharged from hospital after treatment for community acquired pneumonia were studied. After an average follow up period of 31 months, 18 independent variables present during hospital treatment of the initial pneumonia were examined for association with the following end points: recurrence of pneumonia, death from any cause, and death from pneumonia.

RESULTS

Age adjusted analysis showed that systemic treatment with corticosteroids correlated significantly with recurrence of pneumonia and with death. The presence of low serum albumin levels on admission or colonisation of the respiratory tract with Gram negative enteric bacteria seemed to be important negative prognostic factors for the outcome during pneumonia recurrences after discharge.

CONCLUSIONS

Patients who are admitted to hospital with pneumonia are at risk of subsequent pneumonia and death after discharge. This risk seems to be even higher in patients who are treated with corticosteroids systemically, who have a low serum albumin level on admission, or who become colonised in the respiratory tract with Gram negative enteric bacteria during their hospital stay.