I love your blog! I was wondering if you could tell me when doctors would use an IV versus a central line in a trauma situation?
Hiiiiiiii! Awesome question! IV access is actually apersonal favorite topic of mine, which is good, because we sure put in a lot ofthem!
First, let’s define a “central line”, which is an IV with along catheter that sits in the great veins, the Vena Cavae, just outside theheart. They’re used for patients who need a LOT of resuscitative efforts. They’replaced at one of three sites: under the clavicle (subclavian), in the groin(femoral), or in the neck (internal jugular, or IJ).
This is an illustration of a central line, specifically a right subclavian:
Image by Blausen.com staff (Wikimedia commons,permitted for all use).
Central lines can have devastating effects if they’re doneimproperly or managed poorly, so docs are relatively hesitant to use them; abroken arm won’t get a central line. In general, central lines are reserved forthose in shock, those expected to require multiple agents (such as sedation andantibiotics and pressors and…), and those who are simply critically ill.
Severe shock. Ongoing bleeding. Internal bleeding. That’sthe kind of indication we’re looking at here.
But in the critically ill, especially if someone is expectedto need vasopressors like norepinephrine or dobutamine for whatever reason,they’re absolutely essential.
That’s because, while data is becoming available on usingvasopressors in PIVs (peripheral IVs, like ones in the hard on arm),
This paragraph is nerdy and unnecessary, butI’m keeping it: CVCs (Central Venous Catheters) are also slightly differentfrom Pulmonary Artery Catheters, based on where they sit. CVCs sit in the venacava, the great vein either below (Inferior, or IVC) or above (Superior, orSVC) the heart. However, PACs are threaded throughthe heart to monitor pressures in the pulmonary artery. PACs are also known as Swan-Ganz catheters;when you hear someone on TV saying to “float a swan”, they’re talking aboutputting in a PAC. Swans are falling out of favor, and they’re not done so muchin the ER, but they’re worth a mention in any post on CVCs.
The location selected for a central line also will varybased on where the character is injured. For example, a patient with trauma inthe abdomen won’t get a femoral line (an IV in the groin) if there is damagesuspected to the great veins, because the medications or fluids infused maysimply just bleed out of the damaged vessel and into the abdomen.
Meanwhile, someone with a collapsed lung may actually get a subclavianon the affected side. That’s because one of the side effects ofplacing a subclavian is the possibility of deflating the lung by causing apneumothorax. If the lung is already deflated, that’s basically a “freebie”.(This was actually a question on my flight medic exam!)
So I hope you really really wanted a 400-word article oncentral lines, because that is what you got!!
If you want to see a video of one being placed in a dummy, check this page right yurr: http://emcrit.org/central-lines/
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