Sinusite sous ventilation mécanique : diagnostic et apport de l'échographie

In intubated patients undergoing mechanical ventilation, maxillary sinusitis is a frequent complication and may play a role in nosocomial pneumonia and severe sepsis. Moreover, the occurrence of ventilator-associated pneumonia can be prevented by the systematic search and treatment of nosocomial sinusitis. However, nosocomial sinusitis in intensive care unit is often underestimated and frequently under-diagnosed. In fact, its diagnosis in intensive care unit is difficult and based on the presence of radiological maxillary sinusitis obtained from computerized tomography (CT) and the isolation of organisms from culture of purulent material obtained after transnasal puncture. Controversy exists regarding the best method of confirming a suspected diagnosis of sinusitis. CT scan is the modality of choice, but this procedure requires the transportation of critically ill patients and serial examinations are virtually impossible. The property of ultrasound to cross a bone may appear paradoxical, but experience shows that flat bones made up only of compact tissue, such as the anterior wall of the maxillary sinus, are not a hindrance. The image defined as normal is an acoustic shadow arising from the front wall. Two levels of positive echography are described: an incomplete sinusogram is defined as the visualization only of the hyperechogenic posterior wall of the sinus and a complete sinusogram is defined as the hyperechogenic visualization of the posterior wall and the extension by the internal wall of the sinus outlining the hypoechogenic sinus cavity. We fully confirmed the basic importance of ultrasound in this field and showed that ultrasound accuracy for all lesions was improved in the semi-erect patient with a sensitivity of 100%, and a specificity of 96.7%. Moreover, ultrasound sinusitis evidence seems to be of value to indicate and perform a transnasal puncture directly, avoiding CT exam. Sinus ultrasound in critically ill patients is a noninvasive, and painless examination, with easily movable equipment. It represents a rapid, easily reproducible means of monitoring at the bedside and may be proposed as the first line for diagnosis.