ARDS: inflammation, infections, and corticosteroids

Pharmacologic therapies of ARDS: From natural herb to nanomedicine

Acute respiratory distress syndrome (ARDS) is a common critical illness in respiratory care units with a huge public health burden. Despite tremendous advances in the prevention and treatment of ARDS, it remains the main cause of intensive care unit (ICU) management, and the mortality rate of ARDS remains unacceptably high. The poor performance of ARDS is closely related to its heterogeneous clinical syndrome caused by complicated pathophysiology. Based on the different pathophysiology phases, drugs, protective mechanical ventilation, conservative fluid therapy, and other treatment have been developed to serve as the ARDS therapeutic methods. In recent years, there has been a rapid development in nanomedicine, in which nanoparticles as drug delivery vehicles have been extensively studied in the treatment of ARDS. This study provides an overview of pharmacologic therapies for ARDS, including conventional drugs, natural medicine therapy, and nanomedicine. Particularly, we discuss the unique mechanism and strength of nanomedicine which may provide great promises in treating ARDS in the future.

Acute lung injury/acute respiratory distress syndrome (ALI/ARDS): the mechanism, present strategies and future perspectives of therapies

Acute lung injury/acute respiratory distress syndrome (ALI/ARDS), which manifests as non-cardiogenic pulmonary edema, respiratory distress and hypoxemia, could be resulted from various processes that directly or indirectly injure the lung. Extensive investigations in experimental models and humans with ALI/ARDS have revealed many molecular mechanisms that offer therapeutic opportunities for cell or gene therapy. Herein the present strategies and future perspectives of the treatment for ALI/ARDS, include the ventilatory, pharmacological, as well as cell therapies.

Pharmacologic adjuncts to mechanical ventilation in acute respiratory distress syndrome

This article reviews pharmacologic approaches to treating acute respiratory distress syndrome (ARDS). The authors discuss the therapeutic effects of ketoconazole, antioxidants, corticosteroids, surfactant, ketanserin, pentoxifylline, bronchodilators, and almitrine in ARDS. Current animal data and proposed mechanics which may foster future pharmacologic therapies are also examined.

The role of gallium-67 scintigraphy in diagnosing sources of fever in ventilated patients

OBJECTIVE

To evaluate the diagnostic value of gallium-67 scintigraphy in febrile ventilated patients by correlating the findings of 67Ga scintigraphy to sources of fever and pulmonary density, as determined by a comprehensive protocolized diagnostic evaluation.

DESIGN

Prospective observational study.

PATIENTS

Thirty-two intubated patients on mechanical ventilation for > or = 3 days with fever (> or = 38.3 degrees C) and a new or progressive density on chest radiograph. Twenty patients (21 tests) had adult respiratory distress syndrome (ARDS).

INTERVENTION

Diagnostic evaluation for fever included bronchoscopy with protected specimen brushing and (protected) bronchoalveolar lavage (BAL); computed tomography (CT) of sinuses; cultures of blood, urine, and central lines; and CT of the abdomen in high-risk patients.

MEASUREMENTS AND RESULTS

Uptake of 67Ga was reported as either focal or diffuse pulmonary uptake and extrapulmonary uptake. The combined causes of fever were pneumonia (9), fibroproliferation of late ARDS (7), abdominal process (4), sinusitis (4), urinary tract infection (3), and others (6). Causes of the pulmonary densities were pneumonia (9), ARDS (13), atelectasis (7), congestive heart failure (3), and empyema (1). Marked and diffuse pulmonary uptake was found only in patients with ARDS; however, it was not useful in discriminating those patients with pulmonary fibroproliferation as the sole cause of fever (p = 0.167) from those with infection. 67Ga scintigraphy was inadequate for detecting pneumonia but valuable in identifying extrapulmonary sites of infection in patients with ARDS (p = 0.021).

CONCLUSIONS

67Ga scintigraphy should be considered only as an adjunct diagnostic test in the febrile, ventilated patient who has no obvious source of fever, despite a negative evaluation that includes testing for pneumonia, sinusitis, and urinary tract infection, conditions that are rarely detected by 67Ga scintigraphy.

Diagnostic imaging of idiopathic adult respiratory distress syndrome (ARDS)/diffuse alveolar damage (DAD) histopathological correlation with radiological imaging

In ten patients with idiopathic adult respiratory distress syndrome (ARDS) who had histopathologically diffuse alveolar damage (DAD), and who did not have specific underlying diseases, we compared the histopathological findings with their radiographic images in order to study the detail analysis of radiographic images and the clinical courses. These patients were roughly classified as having the interstitial pneumonia dominant type (type IP) of idiopathic ARDS, in which alveolar septal thickening, alveolitis, or both were the predominant histological findings and images showed increasing attenuation of lung fields with small honeycomb lung, or the organizing pneumonia dominant type (type OP), in which organizing exudate predominantly filled the alveoli histologically and images showed consolidation shadows with some air. Hyaline membrane was seen very frequently in patients with a short clinical course, and in accordance with a longer clinical course, widespread fibrosis and honeycomb lung covered by organizing hyaline membrane was seen with both types. Patients with type OP in whom collapse of the normal pulmonary structure was less and for whom changes on radiographic images were larger seemed to respond relatively favorably to steroid treatment, as judged from pulmonary function and radiographic images.