In previous pearls we have discussed the many limitations of central venous pressure as an accurate marker of volume status.
Importantly, the focus of volume assessment should be on determining which patients are likely to augment their cardiac output in response to additional IVFs, i.e. 'preload responsive'.
Ultrasound can be used in the ED to assist in identifying which patients are preload responsive.
In general, a 15% variation in the inferior vena cava diameter with respiration predicts response to additional fluids.
References
Boyd JH, Walley KR. The role of echocardiography in hemodynamic monitoring. Curr Opin Crit Care 2009;15:1-5.
