Review article: Non-invasive assessment of cardiac output with portable continuous-wave Doppler ultrasound


  • Sascha Meyer, MD, Specialist Paediatrician; David Todd, MB BS, PhD, Neonatologist; Ian Wright, FRACP, Senior Staff Specialist; Ludwig Gortner, MD, Specialist Paediatrician; Graham Reynolds, FRACP, Senior Staff Specialist.

Dr Sascha Meyer, The Centre for Newborn Care and The Australian National University, Medical School, The Canberra Hospital, PO Box 11, Woden, ACT 2606, Australia. Email:


Cardiac output is considered an important parameter when assessing the cardiovascular status of a critically ill patient. Both non-invasive (e.g. bioimpedance, echocardiography) and invasive methods (Swan Ganz catheter) have been used to measure cardiac output. The ultrasonic cardiac output monitoring device provides a new method of non-invasively assessing cardiac output in various clinical settings. The ultrasonic cardiac output monitoring device was introduced clinically in 2001, and appears to be a promising adjunct in the assessment of the cardiovascular state in a variety of patient cohorts. In this short review article, we will introduce this new technique, discuss the required skills and compare it with methods already in use. In particular, a critical comparison with the ‘gold standard’, the invasive measurement of cardiac output with the pulmonary artery catheter, will be given.