Comparison of A-mode ultrasound and computed tomography: Detection of secretion in maxillary and frontal sinuses in ventilated patients

Objective: To study the accuracy of A-mode ultrasonography (A-MU) in detecting secretion in maxillary and frontal sinuses in critically ill, intubated patients undergoing mechanical ventilation. Design: Open study in mechanically ventilated, comatose patients. Setting: Medical-surgical intensive care unit in the General Hospital of Rovigo. Patients: 50 consecutive, mechanically ventilated, critically ill patients. All patients were in a coma and needed cerebral computed tomography (CT) for a diagnosis. Measurements and results: The A-MU technique gave 100 images of maxillary and frontal sinuses. The images were read blindly and classified into five categories: definitely normal, definitely abnormal, probably normal, questionable, and probably abnormal. CT findings were considered to be the ''gold standard''. The specificity of echo images varied from 72 to 98% and the sensitivity from 63 to 86% for maxillary sinuses. For frontal sinuses, the specificity varied from 96 to 99% and the sensitivity from 14 to 57%. The area under the receiver-operating characteristic curve was found to be 0.89 and 0.76 for maxillary and frontal sinuses, respectively. Conclusions: The A-MU technique is an accurate tool for detecting secretion in the maxillary sinuses in intubated patients. More investigations are necessary in order to evaluate its usefulness in the frontal sinuses.