Physiologic and Clinical Principles behind Noninvasive Resuscitation Techniques and Cardiac Output Monitoring

Table 1

Central venous pressure by ultrasonography of the inferior vena cava.

IVC diameter (cm)	Respiratory collapse	RA pressure (mmHg)*
<1.5	Total Collapse	0–5
1.5–2.5	>50% Collapse	5–10
1.5–2.5	<50% Collapse	10–15
>2.5	<50% Collapse	15–20
>2.5	No Collapse	>20

IVC: inferior vena cava, RA: right atrial.