A-lines and B-lines: lung ultrasound as a bedside tool for predicting pulmonary artery occlusion pressure in the critically ill.

Background: The risk of pulmonary edema is the main limiting factor in fluid therapy in the critically ill. Interstitial edema is a subclinical step that precedes alveolar edema. This study assesses a bedside tool for detecting interstitial edema, lung ultrasound.

Mechanical ventilation and lung infection in the genesis of air-space enlargement.

Introduction: Air-space enlargement may result from mechanical ventilation and/or lung infection. The aim of this study was to assess how mechanical ventilation and lung infection influence the genesis of bronchiolar and alveolar distention.

Methods: Four groups of piglets were studied: non-ventilated-non-inoculated (controls, n = 5), non-ventilated-inoculated (n = 6), ventilated-non-inoculated (n = 6), and ventilated-inoculated (n = 8) piglets.

Lung deposition of continuous and intermittent intravenous ceftazidime in experimental Pseudomonas aeruginosa bronchopneumonia.

Objective: Lung tissue deposition of intravenous ceftazidime administered either continuously or intermittently was compared in ventilated piglets with experimental bronchopneumonia.

Design: Prospective experimental study

Animals: Eighteen anesthetized and ventilated piglets

Interventions: Bronchopneumonia was produced by the intrabronchial inoculation of Pseudomonas aeruginosa characterized by an impaired sensitivity to ceftazidime (MIC 16 mg/l). Ceftazidime was administered either through a continuous infusion of 90 mg/kg per 24 h after a bolus of 30 mg/kg or by an intermittent infusion of 30 mg/kg per 8 h.

Novel and innovative strategies to treat ventilator-associated pneumonia: optimizing the duration of therapy and nebulizing antimicrobial agents.

Ventilator-associated pneumonia (VAP) is responsible for approximately half of the infections acquired in the intensive care unit (ICU) and represents one of the principal reasons for prescribing antibiotics in this setting. Because unnecessary prolongation of antimicrobial therapy and insufficient dosing of antibiotics at the site of infection in patients with true bacterial infection may lead to the selection of multidrug-resistant microorganisms without improving clinical outcome, efforts to reduce the duration of therapy and optimize pulmonary penetration of antimicrobial agents are warranted. An 8-day regimen can probably be standard for patients with VAP.

Ultrasound diagnosis of occult pneumothorax.

Objectives: Pneumothorax can be missed by bedside radiography, and computed tomography is the current alternative. We asked whether lung ultrasound could be of any help in this situation.

Design: Retrospective study.

Intravenous versus nebulized ceftazidime in ventilated piglets with and without experimental bronchopneumonia: comparative effects of helium and nitrogen.

Background: Lung deposition of intravenous cephalosporins is low. The lung deposition of equivalent doses of ceftazidime administered either intravenously or by ultrasonic nebulization using either nitrogen-oxygen or helium-oxygen as the carrying gas of the aerosol was compared in ventilated piglets with and without experimental bronchopneumonia.

Methods: Five piglets with noninfected lungs and 5 piglets with Pseudomonas aeruginosa experimental bronchopneumonia received 33 mg/kg ceftazidime intravenously.

Comparative diagnostic performances of auscultation, chest radiography, and lung ultrasonography in acute respiratory distress syndrome.

Background: Lung auscultation and bedside chest radiography are routinely used to assess the respiratory condition of ventilated patients with acute respiratory distress syndrome (ARDS). Clinical experience suggests that the diagnostic accuracy of these procedures is poor.

Methods: This prospective study of 32 patients with ARDS and 10 healthy volunteers was performed to compare the diagnostic accuracy of auscultation, bedside chest radiography, and lung ultrasonography with that of thoracic computed tomography.

Experimental ventilator-associated pneumonia: distribution of lung infection and consequences for lung aeration.

Ventilator-associated pneumonia (VAP) has been described in humans and in experimental animals. The most severe lesions are located in dependent lung segments along a sterno-vertebral axis, however the cephalocaudal distribution of lung infection remains unknown. We used an experimental model to evaluate the distribution of lung infection, considering its anteroposterior and cephalocaudal gradient, and its impact on lung aeration.

Lung deposition and efficiency of nebulized amikacin during Escherichia coli pneumonia in ventilated piglets.

Lung tissue deposition and antibacterial efficiency of nebulized and intravenous amikacin (AMK) were compared in anesthetized and ventilated piglets suffering from a bronchopneumonia produced by the intrabronchial inoculation of Escherichia coli. AMK was administered 24 hours after the inoculation either through an ultrasonic nebulizer (45 mg x kg-1, n = 10) or by intravenous infusion (15 mg x kg-1, n = 8). Piglets were killed 1 hour after a second AMK administration performed 24 hours after the first one, and lung tissue concentrations of AMK and lung bacterial burden were assessed on multiple lung specimens.

Influence of lung aeration on pulmonary concentrations of nebulized and intravenous amikacin in ventilated piglets with severe bronchopneumonia.

Background: Pulmonary concentrations of aminoglycosides administered intravenously are usually low in the infected lung parenchyma. Nebulization represents an alternative to increase pulmonary concentrations, although the obstruction of bronchioles by purulent plugs may impair lung deposition by decreasing lung aeration.

Methods: An experimental bronchopneumonia was induced in anesthetized piglets by inoculating lower lobes with a suspension of 10(6) cfu/ml Escherichia coli.