Diagnostic point-of-care ultrasound: applications in obstetric anaesthetic management

Complications during pregnancy are not frequent, but may occur abruptly. Point-of-care ultrasound is a non-invasive, non-ionising diagnostic tool that is available at the bed-side when complications occur. This review covers the use of ultrasound in various clinical situations. Gastric ultrasound can identify stomach contents that put the woman at risk for pulmonary aspiration. In the future, this tool will probably be used routinely before induction of anaesthesia to determine the presence of stomach contents above a particular risk threshold. Difficult tracheal intubation, and the potential for 'can't intubate, can't oxygenate', is more frequent in pregnant women. Point-of-care ultrasound of the airway allows accurate identification of the cricothyroid membrane, permitting rapid and safer establishment of front-of-neck airway access. Combined cardiac and lung ultrasound can determine the potential risk:benefit of fluid administration in the pregnant patient. Such prediction is of critical importance, given the tendency of pregnant women to develop pulmonary oedema. Combined echocardiography and lung ultrasound can be combined with ultrasound of the leg veins to differentiate between the various causes of acute respiratory failure, and guide treatment in this situation. Finally, as shown in the general population, multi-organ point-of-care ultrasound allows early diagnosis of the main causes of circulatory failure and cardiac arrest at the bed-side. As the importance of point-of-care ultrasound in critical patients is increasingly recognised, it is emerging as an important tool in the therapeutic armoury of obstetric anaesthetists.