Is it possible to predict which patients with mild pneumonias will develop hypoxemia?

Prospective observational study of Trichomonas tenax infection in patients with pneumonia

Trichomonas tenax, an oral commensal parasite commonly found in the human mouth, is associated with periodontitis and poor oral hygiene. However, it has also been identified in the bronchoalveolar lavage fluid (BALF) of individuals with lung diseases. Notably, significant quantities of T. tenax have been isolated following bronchoscopy in cases of empyema and acute respiratory distress syndrome (ARDS). Furthermore, research has demonstrated its ability to induce inflammation in pulmonary epithelial cells. To comprehend the potential role of T. tenax in pneumonia, it is crucial to elucidate the relationship between the parasite and the disease. We investigated the clinical factors associated with T. tenax infection in patients with pneumonia. Employing nested polymerase chain reactions, we amplified nucleic acids from BALF and analyzed the relationships between T. tenax and various clinical factors. Our data revealed a significant association between T. tenax and bacterial infections, high pneumonia severity index (PSI) scores, nasogastric tube feeding, and pulmonary complications. Logistic regression analyses also showed strong associations between T. tenax and these clinical factors in pneumonia patients. These findings suggest that T. tenax infection in pneumonia is accompanied by bacterial infection and severe clinical manifestations.

Nicardipine-induced acute respiratory failure: Case report and literature review

Hypoxic pulmonary vasoconstriction (HPV) is a major physiological mechanism that prevents the development of hypoxemia secondary to a regional decrease in the ventilation-perfusion ratio (the intrapulmonary shunt effect). Calcium plays a critical role in the cellular response to hypoxia and the regulation of the pulmonary vascular tone. Therefore, calcium channel antagonists such as nicardipine have the potential to interfere with the pulmonary response to hypoxia, increasing intrapulmonary blood shunt and thus worsening underlying hypoxemia. This article reports the case of a 40-year-old man suffering from lobar pneumonia, who developed a rapidly progressing hypoxemia after starting nicardipine infusion for blood pressure control. After ruling out all major causes of hypoxemic respiratory failure, the involvement of the calcium channel antagonist was strongly suspected. Hypoxemia caused by HPV release is an underreported side effect of calcium channel blockers. There are few clinical reports that describe the occurrence of this adverse event, and to our knowledge, only one other publication describes a patient suffering from infectious pneumopathy. In this article, we discuss the cellular mechanisms behind the HPV, as well as the pharmacology of calcium channel antagonists and their involvement in the development of acute respiratory failure. The purpose of this report is to remind clinicians dealing with patients affected by acute hypoxemia that pharmacologic HPV inhibition should be considered as part of the differential diagnosis, thus avoiding unnecessary costly and time-consuming assessments.

Discordance of physician clinical judgment vs. pneumonia severity index (PSI) score to admit patients with low risk community-acquired pneumonia: a prospective multicenter study

BACKGROUND

The relationship between clinical judgment and the pneumonia severity index (PSI) score in deciding the site of care for patients with community-acquired pneumonia (CAP) has not been well investigated. The objective of the study was to determine the clinical factors that influence decision-making to hospitalize low-risk patients (PSI ≤2) with CAP.

METHODS

An observational, prospective, multicenter study of consecutive CAP patients was performed at five hospitals in Spain. Patients admitted with CAP and a PSI ≤2 were identified. Admitting physicians completed a patient-specific survey to identify the clinical factors influencing the decision to admit a patient. The reason for admission was categorized into 1 of 6 categories. We also assessed whether the reason for admission was associated with poorer clinical outcomes [intensive care unit (ICU) admission, 30-day mortality or readmission].

RESULTS

One hundred and fifty-five hospitalized patients were enrolled. Two or more reasons for admission were seen in 94 patients (60.6%), including abnormal clinical test results (60%), signs of clinical deterioration (43.2%), comorbid conditions (28.4%), psychosocial factors (28.4%), suspected H1N1 pneumonia (20.6%), and recent visit to the emergency department (ED) in the past 2 weeks (7.7%). Signs of clinical deterioration and abnormal clinical test results were associated with poorer clinical outcomes (P<0.005).

CONCLUSIONS

Low-risk patients with CAP and a PSI ≤2 are admitted to the hospital for multiple reasons. Abnormal clinical test results and signs of clinical deterioration are two specific reasons for admission that are associated with poorer clinical outcomes in low risk CAP patients.

The potential role of 13-valent pneumococcal conjugate vaccine in preventing respiratory complications in bacteraemic pneumococcal community-acquired pneumonia

INTRODUCTION

Pneumococcal 13-valent vaccine (PCV-13) has a potential role in preventing bacteraemic pneumococcal pneumonia and its complications, but little is known about its ability to specifically prevent respiratory complications. Our aim were to analyse the pneumococcal serotypes associated with the development of respiratory complications and the potential role of PCV-13 in preventing respiratory complications in bacteraemic pneumococcal pneumonia.

MATERIAL AND METHODS

We analysed demographic characteristics, comorbidities, antibiotic resistances and the outcomes of a cohort of 65 vaccine-naïve bacteraemic pneumococcal pneumonias, stratified by the pneumococcal serotypes included in PCV13 vs. those not included. Complications were clustered as follows: respiratory complications (hypoxemic respiratory failure; mechanical ventilation), systemic complications (septic shock; multiorgan failure), suppurative complications (empyema; pleural effusion; lung abscess).

RESULTS

From a population of 65 CAP-SP, 47.7% of the isolates belonged to PCV-13 serotypes group. No differences in comorbidities or clinical manifestations were found between groups. With regard to biochemical parameters, we found more profound hypoxemia levels in PCV-13 serotypes group comparing to non-vaccine group [PaO2/FiO2 209 (63) vs. 268 (57); p=0.007]. Global complications were identified in 69.2% (45 patients), and the most frequent were respiratory complications, found in 47.7%. Respiratory complications were detected more frequently in PCV-13 groups compared to non-vaccine groups (61.3% vs. 35.3%; p=0.036). Overall 30-day mortality was 30.8%. Mortality was similar between both groups (25.8% vs. 35.3%; p=0.408).

CONCLUSIONS

Pneumococcal 13-valent conjugate vaccine includes the serotypes which cause more respiratory complications in our series; these serotypes were not associated with higher mortality in our series. PCV-13 may have a potential role in preventing respiratory complications due to bacteraemic pneumonoccal pneumonia.

Community-acquired pneumonia team decreases length of stay in hospitalized, low-risk patients with pneumonia

BACKGROUND

Team-focused intervention to improve the care of low-risk patients with community-acquired pneumonia (CAP) is a matter of controversy. Our aim was to determine if a community-acquired pneumonia team (CAPT) would shorten hospital length of stay (LOS) and improve health care utilization in low-risk patients with CAP compared with management by a general pulmonary team (GPT).

METHODS

We performed a prospective cohort study of hospitalized, low-risk patients with CAP (Pneumonia Severity Index [PSI] score class I or II) at a single tertiary hospital from June 2007 to June 2008. Study patients were stratified to management by the CAPT treating group (n = 35), following the Infectious Diseases Society of America (IDSA) and American Thoracic Society (ATS) CAP guideline recommendations, or to management by the GPT (n = 30) following the standard of care. Primary outcome measure for comparison of the efficacy of the 2 different team-focused interventions was hospital LOS for patients with CAP. Secondary study outcome measures included patient 30- and 90-day all-cause readmission rate, rate of mortality at 30 and 90 days, antibiotic-treatment duration, time to switch patient from intravenous (IV) to oral antibiotic treatment, and time to achieve clinical stability for patients.

RESULTS

Hospitalized, low-risk patients with CAP, who were assisted by a CAPT were more likely to have a shorter hospital stay (9 days less; P < 0.001), shorter time to switch from IV to oral antibiotic therapy (8 days less; P <0.001), and total shorter duration of antibiotic treatment (6 days less; P <0.001), when compared with low-risk patients with CAP who were assisted by a GPT. In addition, for both groups of assisted patients, there were no differences in the time to achieve clinical stability, use of guideline-concordant antibiotic therapy, rate of mortality, or rate of readmissions at 30 and 90 days.

CONCLUSIONS

Management by a dedicated CAPT reduced patient hospital LOS, time to switch from IV to oral antibiotic therapy, and duration of antibiotic treatment, without causing adverse events, compared with standard of care, in low-risk patients with CAP.

Hypoxia and fungal pathogenesis: to air or not to air?

Over the last 3 decades, the frequency of life-threatening human fungal infections has increased as advances in medical therapies, solid-organ and hematopoietic stem cell transplantations, an increasing geriatric population, and HIV infections have resulted in significant rises in susceptible patient populations. Although significant advances have been made in understanding how fungi cause disease, the dynamic microenvironments encountered by fungi during infection and the mechanisms by which they adapt to these microenvironments are not fully understood. As inhibiting and preventing in vivo fungal growth are main goals of antifungal therapies, understanding in vivo fungal metabolism in these host microenvironments is critical for the improvement of existing therapies or the design of new approaches. In this minireview, we focus on the emerging appreciation that pathogenic fungi like Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus are exposed to oxygen-limited or hypoxic microenvironments during fungal pathogenesis. The implications of these in vivo hypoxic microenvironments for fungal metabolism and pathogenesis are discussed with an aim toward understanding the potential impact of hypoxia on invasive fungal infection outcomes.