Outline the potential roles for the use of ultrasound in the critically ill patient.
College Answer
Roles include –
Cardiac echo – be it transthoracic or transoesophageal looking at structure, function, relationships between the two ventricles and pericardial effusions. Doppler cardiac output monitoring – oesophageal, transthoracic
Vascular – specifically thoracic aorta – but also abdominal aorta. Other vascular include any accessible artery (eg radial, brachial, femoral, carotid etc), grafts for flow assessment, stenosis, patency. Also veins – for thrombosis/patency
Cranial – monitor cerebral blood flow hyperaemia, ischaemia, brain death, detection of vasospasm, fat and other emboli, stroke related artery reperfusion following thrombolysis.
Other –pleural, diaphragm etc
Diagnostic ultrasound, esp abdomen – identify bladder (urinary retention), biliary anatomy, including gallbladder important to mention acalculous cholecystitis, atelectasis, pneumothorax
Ultrasound assisted interventions (drainage of collections)
Vessel identification for line insertion
Discussion
A nice article about the use of ultrasound in the ICU can be found in Continuing Education in Anaesthesia, Critical Care & Pain (Wilson and Mackay, 2012).
This question can be approached systematically; the answer presented below has been modelled on Table 1 from this article, and is organised by body area being examined:
- Head:
- Transcranial doppler in SAH-associated vasospasm and in confirmation of brain death
- Neck
- Central line insertion
- Thoracic
- Identification of pneumothorax
- Localisation and ultrasound-guided aspiration of pleural effusions
- Cardiac
- Echocardiography (structure and function)
- Ultrasound-guided pericardiocentesis
- Abdominal
- FAST
- Solid organ pathology (eg. hydronephrosis, splenomegaly, cirrhosis)
- Renal vascular flow
- Gall bladder pathology
- Portal vein pathology
- Aortic pathology
- Peripheral
- Peripheral venous access
- Peripheral arterial flow assessment
- Assessment of DVTs
References
Wilson, Stephen, and Andrew Mackay. "Ultrasound in critical care." Continuing Education in Anaesthesia, Critical Care & Pain 12.4 (2012): 190-194.