Ultrasound diagnosis of alveolar consolidation in the critically ill

Objective. Alveolar consolidation is a basic concern in critically ill patients. Radiography is not a precise tool, and referral to CT raises problems (transport, irradiation). The aim of this study was to assess the utility of ultrasound in the diagnosis of alveolar consolidation. Design. Prospective clinical study. Setting. The medical ICU of a university-affiliated teaching hospital. Patients. A total of 65 cases of alveolar consolidation proven on CT were compared to 53 CT controls. Measurements. Alveolar consolidation was defined as a tissue-like pattern visible at the chest wall, arising from the pleural line and devoid of centrifugal inspiratory dynamics. Results. Feasibility was 99%. In 65 cases of alveolar consolidation, ultrasound was positive in 59 and negative in 6. In 52 analyzable controls, ultrasound was negative in 51 and positive in 1. Sensitivity of ultrasound was 90% and specificity 98%. A concordance test showed a Kappa coefficient of 0.89. Among 62 posterior locations on CT, ultrasound showed posterior consolidation patterns in 56 cases and was negative in 6. Ultrasound showed anterior involvement in all 3 cases of whole lung consolidation. Conclusions. Ultrasound provides a reliable non-invasive, bedside method for accurate detection and location of alveolar consolidation in critically ill patients.