Central Line Question

Central Venous Catheters (CVC) placed in the internal jugular and subclavian veins must terminate within the vicinity or right at the caval-atrial junction (our policy is plus or minus 2 cm per the chest x-ray read). This is a widely acceptable location to measure CVP.

Some clinicians feel that lines placed in the femoral vein though considered CVC are not accurate for measuring CVP but some studies do show some correlation with numbers taken from catheters with tips right at the caval-atrial junction in certain conditions.

Multi-lumen Access Catheters and Introducer Catheters (i.e., MAC, Cordis) are shorter in length and typically terminate farther from the caval-atrial junction so these are also sometimes not considered accurate for CVP measurement depending on who you ask.

Can Central Venous Pressure Be Measured with a Femoral Line? - NEJM Journal Watch

Critical Care | Full text | Central venous pressure in a femoral access: a true evaluation?

Is the central venous pressure reading equally reliable if the central line is inserted via the femoral vein

That is odd. I'd be interested to see where the tip terminates on the chest film. I place lines at work as an NP and I've seen line tips do odd things (i.e., SC line coiling up to the IJ, IJ lines taking an angle to the SC, IJ lines coiling back up within the IJ). Sometimes there are preexisting thrombus that block the natural course of the catheter and in those situations, the provider should place a new line in another site and remove the malpositioned catheter.

It all depends on where the tip of that catheter is. The rule is if the tip terminates close to the caval-atrial junction, then the CVP would be "accurate". That is, as long as the transducer is positioned and zeroed in relation to the level of the R atrium is followed. I typed accurate in quotation marks because there are multiple studies that show that CVP really is a wild card - it is an inconsistent number that varies widely and should not be the only number used to assess intravascular volume.

PA catheters used to be common in ICU's but they have lost favor because through the years studies have shown no mortality benefit nor improved length of stay with patients who had one placed. Having said that, clinicians still agree that the numbers obtained from a Swan-Ganz catheter are helpful in assessing the overall picture of fluid volume status and R sided heart function.

In most places, they are used in circumstances when the clinical picture is confusing in terms of what direction to take in treating patients. Some patient populations benefit from their use - patients in cardiac surgery, lung transplant surgery, and cardiogenic shock states. I think they still have a place in critical care but certainly not how they were initially used which was placing them randomly and leaving them in indefinitely.

More recently, ultrasound technology has gained an increase in utilization in critical care. More and more ICU's are purchasing portable ultrasound equipment with a cardiac probe and you'll see them as part of the ICU providers' armamentarium of equipments. Intensivists are learning to use ultrasound to perform cardiac evaluations to assess heart function (similar to a formal echocardiogram).

Fluid volume status can also be assessed by looking at the size and compressibility of the inferior vena cava by ultrasound. There are also limitations to this approach one of which is operator skillset but one should also consider the effect of positive pressure ventilation on IVC appearance which unfortunately many patients in the ICU are mechanically ventilated.

For further reading about Swan-Ganz and the studies done on them, see: JAMA Network | JAMA | Impact of the Pulmonary Artery Catheter in Critically Ill Patients: Â*Meta-analysis of Randomized Clinical Trials