Ultrasound assessment of antibiotic-induced pulmonary reaeration in ventilator-associated pneumonia

Abstract

Objective In this study we assessed lung reaeration by means of bedside chest radiography, lung computed tomography (CT), and lung ultrasound (LUS) in patients with ventilator-associated pneumonia (VAP) treated by antibiotics. Introduction VAP is a subtype of hospital-acquired pneumonia that occurs in patients under mechanical ventilation for at least 48 h and is characterized by the presence of a new or progressive infiltrate, signs of systemic infection (temperature, blood cell count), changes in sputum characteristics, and detection of the causative agent. Ultrasound examination is increasingly being used as a valuable bedside method for the diagnosis of various thoracic conditions in ICUs, including pleural or pericardial effusion, empyema, pneumothorax, pulmonary embolism, and pneumonia. To date, only a few studies have investigated the use of LUS in the diagnosis of pneumonia in the emergency department or in the ICU. In critically ill patients with acute lung injury, pulmonary aeration may be reliably assessed using bedside LUS. Design This is a randomized prospective comparative trial. Setting The study was conducted in the Critical Care Department of Alexandria Main University Hospital. Patients and methods This study was carried out on 60 patients with a preliminary diagnosis of VAP who matched the inclusion and exclusion criteria in the Critical Care Medicine Department in Alexandria University. In all patients chest ultrasound (US),chest radiography, and chest CT (the gold standard) were performed in sequence at day 0 and day 7 after antibiotic administration. Thereafter, all patients were categorized on the basis of the radiological findings and finally the effectiveness of each method was calculated and statistical comparisons were made. Results In our study, we compared lung reaeration by bedside chest radiography, lung CT, and LUS in patients with VAP treated with antibiotics. We included 60 patients with a preliminary diagnosis of VAP (33.3% were male and 16.7% were female); their ages ranged between 31 and 70 years (mean±SD: 48.3±11.063 years). In our study, we found a highly significant correlation between LUS score and CT reaeration findings (P Conclusion This study can affirm the superiority of chest US over chest radiographs for quantifying lung reaeration in patients with VAP who are successfully treated with antibiotics. LUS is a reliable, dynamic, rapid, noninvasive, bedside technique. Thus, considering the benefits of chest US versus the multiple drawbacks of chest CT, such as the requirement for a special request, the dose of radiation, and the major problem of patient transfer, chest US can be reported to be a reasonable substitute, allowing the early detection of antibiotic-induced lung reaeration or the extension of lung infection in cases of antimicrobial therapy failure. Ultrasound can be considered a reasonable bedside ‘gold standard’ in the critically ill.