There are several large bore vascular access devices available for rapid fluid and blood administration in trauma and resuscitation settings, and depending on which country you are in, and where you work, these devices may be referred to by different names.
In this post we’ll take a look at some of the different devices, what they are used for, and some practical tips if you decide to put one in.
DISCLAIMER: I have absolutely no financial or other interest in any of the brands or products mentioned in this post.
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1) Sheath introducers:
Commonly referred to as:
- Swann sheath
- Angiography sheath
Sheath introducers are long, very wide bore, single lumen catheters with a wide plastic hub on the proximal end, which has a central smaller hole (one-way-valved to prevent back-flow of blood), through which various other vascular catheters can be inserted, including triple-lumen central lines, Swann-Ganz catheters (hence the name “Swann sheath”), temporary external pacing wires and coronary angiography catheters.
They act as a “sheath” around these other catheters, providing a clean path and protected portal for these catheters to enter a vessel, whilst allowing simultaneous administration of fluid via the side-port or side-catheter, which runs perpendicular to the sheath, and has standard luer-lock connections to which IV giving sets can be connected. (Giving sets cannot be connected to the main sheath hub).
During procedures like coronary angiography, many angiography and stenting catheters are inserted and withdrawn through the sheath. During Swann Ganz catheter insertion it is sometimes necessary to move the catheter in or out to position it correctly. Using a sheath prevents multiple punctures of the skin, and it also prevents skin bacteria being carried into the vessel as long catheters are advanced and withdrawn.
In ED resuscitation settings, sheath introducers can be used alone for rapid fluid administration. IV fluid can only be administered via the side port tubing via a luer lock connection. Fluid cannot be administered via the main hub.
Common brands of sheath introducer include Cordis, Arrow and Oscor. It seems our American colleagues have appropriated the name “Cordis” to refer to any sheath introducer. In Australia, many people refer to them as “Swann sheaths” (as they are used for Swann-Ganz or Pulmonary Artery catheters). These terms all refer to the same device!
Depending on the brand, these sheaths come in multiple diameters and lengths, ranging from 4Fr right up to the vein-busting 11Fr (i.e. very large!), and sheath lengths from from 5.5cm to 23cm.
A mid-range size of 8Fr would suffice in trauma resuscitation.
It is difficult to find documentation of the diameter of the side port tubing, or the connection point where the tubing joins the hub, and flow rates are not published. One would assume that the internal diameter of the side port is the same as the sheath, and that no narrowing would occur where the side port tubing joins the hub, but this is not clear.
Of some concern are these studies from the 1980’s:
These articles look into flow rates through the side ports of sheaths. Whilst one would hope the designs have improved in the last 30 years, the article raises the issue that the point of connection of the side port tubing to the hub may be a point of narrowing, and therefore reduction in flow rate.
Due to their large size, sheath introducers should only be inserted into compressible, large veins (as they leave a large hole when removed that will require external compression to achieve post-removal haemostasis). These include:
- External jugular vein
- Internal jugular vein
- Femoral vein
During angiography procedures, these may be inserted into the radial or femoral arteries, however this is not done in the Emergency Department!
Seldinger technique, with the dilator pre-loaded inside the sheath prior to starting, which allows for smooth insertion of the dilator-sheath complex in one movement, followed by removal of the wire and dilator.
Here’s Scott Weingart from EMCrit showing how to insert a “Cordis” (although it’s an Arrow branded line!)
UPDATE: Looks like Scott has deleted this video. D’oh!
- Very large access with very high flow rates possible
- It is actually very hard/impossible to find accurate product information on the actual diameter of the side-port tubing, and flow rates achievable through these devices
- Flow is reduced if another catheter is placed through the hub into the sheath (e.g. a CVC or PA catheter)
- Post removal complications:
- Air embolism
- Inadvertent large-bore arterial puncture (although these are inserted into arteries for angiographic procedures)
As with any central access device, the potential complications include:
- vessel wall perforation
- pleural and mediastinal injuries
- air embolism
- sheath embolism
- thoracic duct laceration
- inadvertent arterial puncture
- nerve damage
This is a real risk with these catheters. Air can enter the central haemostasis valve while in-situ, or the puncture site post removal. This can be avoided by keeping the haemostasis valve/hub covered with an “obturator” (the blue twist-lock cap), a sterile gloved finger, or by inserting another catheter (e.g. Swann/CVC). Also having the patient head-down during insertion/removal via jugular veins, or supine during insertion/removal via femoral vein will minimse the risk. An airtight/occlusive dressing should be applied for 24-72 hours post removal, as air can enter until the hole in the vein is sealed.
Arrow Haemostasis Valve Short Obturator
What if I accidentally put one into an artery?
If you accidentally insert a sheath introducer into an artery, don’t panic, as this is routinely done during coronary angiography procedures (via the femoral or radial artery), however upon removal they require at least 20 minutes (and often longer) of direct pressure, sometimes using a “femostop” direct femoral artery pressure device, and close monitoring for bleeding after this. This is not something you want to be doing during an ED/trauma resuscitation!
Mechanical femoral artery pressure devices:
2) Rapid Infuser Catheter (RIC) Exchange Sets
Commonly referred to as:
- RIC set or RIC line
RIC lines are a superb invention, that allow for rapid upsizing of an IV as small as a 20G (pink) to a very large bore catheter, in a peripheral vein. The main advantages of RIC lines are:
- Can be inserted in peripheral veins
- Can “upsize” an existing IV cannula via seldinger technique using the wire in the kit
- The kit only has 3 items: the RIC line/dilator, a wire, and a small scalpel, so there’s no rummaging around through a tray with lots of unnecessary pieces
As far as I know, Arrow makes the only true RIC set
Image source: ETM Course Manual
The Arrow RIC sets come in:
- 7 Fr (internal diameter) x 2 inch (5.08cm)
- 8.5 Fr (internal diameter) x 2.5 inch (6.35cm)
The smallest IV that you can get the wire through is a 20G (pink).
Image source: ETM Course Manual
In shocked, peripherally shut down trauma patients, it is very hard to get 16G or 14G IV’s into these collapsed veins, but getting a 20G in is much easier. You can then insert the wire, take the 20G cannula out, and seldinger the RIC over the wire in about a minute.
To insert a RIC, you ideally need at least 6-8cm of relatively straight peripheral vein
Common sites include:
- Cubital fossa: cephalic or basilic vein
- Cepahlic vein in forearm
- Saphenous vein
- External jugular vein
Image source: ETM Course Manual
The femoral vein is probably too deep, even in slim patients, for a RIC line. RIC’s are only 5-6cm long, so by the time you’ve gone through a couple of centimetres of subcutaneous fat and entered the femoral triangle, you’ll only have a couple of cm of catheter in the vein – very easy to dislodge. If you want femoral access, go for a sheath introducer or a MAC.
Avoid large bore/rapid infuser catheters in leg veins (e.g. saphenous or femoral) in major pelvic or abdominal injury.
All the infused blood will end up in the peritoneal/pelvic cavity and not in the heart/brain where you want it!
Here’s a video on how to insert a RIC line:
- 8.5Fr RIC likely has the fastest flow rates of available IV access devices
- Relatively cheap compared to sheath/MAC sets
- Easy to insert, only takes about a minute
- Can upsize an existing cannula
- Ultrasound not required
- Sterility can be an issue if upsizing an existing cannula or when inserting under duress in a resus
- Too short for deeper/central veins
Check out our Large bore IV access device showdowns to see just how fast the flow rate through a RIC (and other commonly used devices) is!
3) Emergency Infusion Device
I haven’t seen one of these in use in an Australian ED, so won’t write a detailed comment, but thought I’d mention these for completeness.
They are a cross between a RIC line, and the single piece needle-catheter-sliding-wire arterial line kits, but are designed for venous access.
They comprise a small 20g needle, over which lies a dilator, over which lies the 6 or 8.5Fr catheter
Insertion is via the needle entering the vein, at which point a flashback should occur, the wire can then be advanced into the vein by sliding it down with the small proximal plastic tab. The dilator and catheter can then be fed along the wire.
I personally find the arterial line version of these very fidgety to put in. But some people love them. Have a look around your department and let me know if you have them, and what the pros and cons are!
- 6Fr x 1.5in (3.81cm)
- 8.5Fr x 3.5in (8.90cm)
4) Multi-Lumen Access Catheters
Commonly referred to as:
- MAC line
The MAC (Multi-lumen Access Catheter) line is a (relatively, compared to a standard central line) short, 2-lumen line made by Arrow. Like the others it is inserted via seldinger technique. As it’s longer and much thicker than a RIC line, it should be inserted into a large vein.
It has a sheath introducer built in as well as a 9Fr and 12Ga lines. The main benefit of this line is the 9 Fr large lumen, which can be used as a rapid infusion device, while the 2nd 12Ga line can be used for other fluid and drug infusions, including any other incompatible fluids.
So it is essentially the same as a sheath introducer, with the 9Fr side port coming off at a more actute angle, (rather than perpendicular to the sheath, as the standard sheath introducer has) with an additional 12Ga line.
The advantage of having a sheath introducer built in is that a standard triple lumen central line (or the proprietary “MAC Companion single, double or triple lumen 7Fr catheter”) can be placed through the sheath hub, which can then allow for accurate CVP monitoring, and increases the total number of ports up to 5. This may sound excessive, but critically ill trauma patients, for example those with severe head injuries, may easily end up on 5 or more infusions in ICU. This makes the MAC a multi-purpose, resus and ICU line.
A MAC line with a triple lumen CVC through the sheath introducer
The tray for a MAC line – compared to a RIC line there’s a lot
As far as I know, Arrow makes the only commercially available MAC line
The standard Arrow MAC line has 2 usable lumens: 9Fr Side port and a 12Ga line (the sheath introducer is not for fluid administration)
The main body of the catheter is 10cm long.
NB: Technically if you compare the sizes on a standard catheter sizing chart:
9 Fr = 3mm outer diameter
12Ga = 2.769mm outer diameter
i.e They are almost the same!
However once you get to the inside of the main catheter, things change:
This is a cross-section of a MAC line main catheter. It’s unclear what the flow dynamics are through the crescent-shaped 12Ga lumen.
Despite the similarities in the apparent side port external diameters, the flow rate through the 12Ga port is quoted at 11 litres per hour compared to 29+ litres per hour via the 9Fr port (this is for gravity flow rates).
And, just to confuse things, the actual diameter of the main catheter body is 14 Fr!
- External jugular
- Internal Jugular
*Subclavian MAC lines – a cautionary note
Some Australian trauma centres use MAC lines via the subclavian route. This route is generally only preferred if the patient has a concurrent ipsilateral chest injury with an intercostal catheter already.
This is because if there is in inadvertent puncture of the pleura, or intercostal vessel injury during MAC insertion, the subsequent pneumothorax/haemothorax is “already treated”.
However there are other significant risks in placing a subclavian MAC line, mainly that they leave a large hole in non-compressible vessel when removed, which can bleed a lot, and act as a portal for an air embolus.
A recent case a colleague observed highlighted the dangers of subclavian MAC lines:
A man with a right sided chest injury (haemo-pneumothorax) had a right intercostal catheter inserted, and a small to moderate amount of blood drained. He then had a right subclavian MAC line inserted, with aspiration of blood, and a CVP trace was transduced. However the patient remained very unstable, and only partly responded to massive transfusion via the MAC line, whilst the amount of blood draining from the chest drain steadily increased. It was then found that the MAC line was in fact intra-pleural, not intravascular. The “CVP” trace was either correct and the catheter subsequently dislodged, or was in fact an unrecognised intra-pleural pressure trace. The massive transfusion was simply going into the pleural space, and out the chest drain.
These are not benign lines, and are best inserted by those experienced with large bore central venous access, ideally with ultrasound guidance.
So there you have it. A deep dive into the commonly used, very large bore vascular access devices used in trauma.
Do you have any pearls about big lines in trauma? Do you use any different types of lines? Leave a comment below.