Lung ultrasound in anaesthesia and critical care medicine

Lung ultrasound (respiratory or thoracic ultrasound) has traditionally been used for evaluation and guidance of drainage of pleural effusion, where it has been shown to reduce iatrogenic injuries from intercostal catheter insertion into adjacent organs. Only recently has its use in bedside diagnosis of respiratory disease become popular. Lung ultrasound is more accurate than chest radiography and approaches the accuracy of computed tomography in diagnosis of pleural effusion, pneumothorax, pulmonary oedema, consolidation and collapse, abscess, emphysema, and even pulmonary embolus. Improved accuracy and speed of diagnosis may also reduce the need for chest radiography and CT, reducing exposure of patients and staff to ionising radiation and the requirement to transport the critically ill. This useful technique is becoming incorporated into clinical practice and training in emergency and critical care medicine, where it has been shown to be effective in rapid diagnosis of the cause of respiratory distress. Additional potential uses for in anaesthetic practice include preoperative assessment in patients with dyspnoea, and rapid assessment of respiratory failure that may occur intra or postoperatively, for example from pneumothorax, acute pulmonary oedema and massive atelectasis or consolidation. Rapid bedside exclusion of pneumothorax may be useful after insertion of central line or paravertebral catheter, or prior to or during mechanical ventilation. There is also an emerging role of lung ultrasound in guidance of endotracheal and subglottic airway management. Lung ultrasound is relatively easy to learn using portable ultrasound machines and can be integrated into routine clinical ‘ultrasound-assisted examination’.