Your new angiocath will not relieve tension pneumothorax

Conventional teaching for treatment of confirmed or suspected tension pneumothorax in an unstable patient is immediate chest decompression with a large bore angiocatheter [1]. New generation angiocaths feature blood control technology, which allows a flash of blood to rise into the hub but will not transmit that blood out the end, which increases safety and decreases messes. Half of the departments I work in now stock blood control angiocaths; since this device is more expensive than its predecessors, you can expect all american hospitals will soon move to them.

Notice the blood control valve, which adds length to the hub compared to the same catheter without this feature.

BC Valve

 

2016-04-21 06.47.58

 

The blood control valve prevents blood from flowing out the hub but also prevents any other fluid from flowing through the catheter, including air. So stabbing your pneumothorax patient with this device will not decompress the chest.

Fortunately the valve opens permanently when it is pushed down by IV tubing, or by attaching a syringe.

valve is closed

attach syringe

now valve is opened

 

So place the angiocath as usual, then take a syringe, pull out the plunger, and twist it firmly onto the hub, until you hear your rush of air.

There are all sorts of problems with using any needle or angiocath to decompress pneumothorax, especially if you use the usual anterior approach, and you are better off in most cases performing a finger thoracostomy or quickly placing a chest tube. But if you do use an angiocath, be mindful of blood control technology, because if you place a catheter thinking you’ve relieved tension but you haven’t, now you’ve made a real mess.

BC angiocath in package

 

[1] See chapter ten of the sixth edition of Roberts and Hedges.

[2] I’ve pictured the Becton Dickinson device but many angiocath manufacturers offer the same feature under a variety of names.

A Better Central Line Technique: Wire Through Catheter

Most of us were taught to place central lines using the wire through needle Seldinger technique, but using the introduction catheter instead of the needle makes successful wire insertion more likely and facilitates venous confirmation. A 7 minute screencast.

on vimeo

operating room video of wire through catheter technique. recommend viewing at 2x speed.

Update 1 Lee 2015 compares wire through needle and wire through catheter and shows that wire through needle is (slightly) better. The operators were anesthesiologists very experienced in central line insertion, which may account for their results. In the less controlled ED environment, with providers who don’t place a lot of lines (especially learners), the tendency of the needle to move before the wire can be transmitted may be more important. Also they did not confirm venous location in this study, which should be done whenever feasible and is greatly facilitated by the wire through catheter technique. Still, I’m aware of no data comparing the two techniques other than this (which appeared a few weeks after I posted the video), so though my success rate is definitely higher since I switched to wire through catheter, your mileage may vary.

Update 2  There are two advantages of the wire through needle (conventional approach): the needle is functionally slightly longer than the catheter, and the needle doesn’t kink. Neither of these advantages make a difference at the IJ site, and where I work almost all lines are IJ, so I didn’t mention this in the video. Based on feedback, I am surprised (and pleased) at how many non-IJ lines are being placed out there. If there is a lot of flesh in between the skin and the vein, for example at the femoral site in an obese person, the catheter can kink. This can be managed by keeping the pannus out of the way and keeping the skin taut throughout the procedure (flabby groin tissue can interfere with wire advancement as well, regardless of which technique you use to transmit the wire), but this requires an extra set of hands. At the subclavian site, the problem is not flesh but distance–sometimes you enter the vein relatively far away from where you enter the skin, and in this case the couple of millimeter difference between the wire and the catheter can be relevant. You can overcome this problem, in cases where you have to hub the catheter to get into the vein, by applying gentle continuous forward pressure on the hub until the wire is in the vein.

 

Peripheral line in central vein

Does a 48 mm single-lumen angiocath in a central vein assume the infection risk of a central line or a peripheral line? Stated differently, does the infection risk of a central line stem from the line itself, the vein, or some other factor? Many of us who trained without ultrasound are very adept at cannulating the subclavian vein by landmarks. To be able to place a simple angiocath into a central vein in non-sterile fashion would be very convenient in difficult access patients. I can’t advocate for this unproven maneuver at large, but it may have a role in patients who need vascular access expediently but don’t need a central line, perhaps as a bridge to a conventional peripheral line or a formal central line.

pIV in central vein JEM Nov 2009.pdf (1 page)

Journal of Emergency Medicine 37:4 p419

Confirmation of placement of central line: artery vs. vein

Excerpted from MSSM M&M teaching points:

* Accidental arterial cannulation is usually benign but should be detected before dilation to avoid significant vessel injury. When performing an ultrasound-guided central line, the point where the needle tip enters the vein must be in the visualized ultrasound field. This may be accomplished by entering the skin with the needle a short distance away from the probe, rather than immediately adjacent to the probe, which will lead to the tip entering the vein out of the vertical plane visualized on the screen. Alternatively, the tip of the needle can be tracked into the vein by sliding the probe along the skin as the needle tip approaches the vein, keeping the tip in the visualized ultrasound field.

* If venous placement is not certain, verification may be performed using a number of techniques.
**A quick blood gas may be helpful if the PaO2/SaO2 values are conclusive; unfortunately blood gas results may lie in between definitively arterial and venous values.
** Transducing the pressure waveform is effective but takes time to set up.
** A brief and definitive technique uses a quick pressure column setup as follows:

1. Insert the guidewire, remove the needle.
2. Slide the conventional angiocath that comes in all central line kits over the wire, remove the wire.
3. Attach an extension set to the angiocath. An extension set comes in the introducer kit for this purpose. For triple lumen kits, ask the nurse to give you an extension set, or use the circular plastic sheath that stores the guidewire as extension tubing.
4. Keeping the tubing parallel to the floor, allow 20-30 cm of blood to fill the tube.
5. Hold the tube straight up to the ceiling. If the angiocath is in a vein, the column of blood will fall back down to the level of the CVP. If the angiocath is in an artery, the column of blood will continue to rise.
6. If the angiocath is in the vein, thread the guidewire, pull out the angiocath and continue Seldinger technique as usual. If the angiocath is in the artery, either remove the angiocath and hold pressure or call vascular surgery for advice.

** To estimate how low a bag of saline needs to be so that it does not overcome arterial blood pressure, use the formula SBP/2 = height in inches. For example, if the patient has an SBP of 70 mmHg, this corresponds to a height of 35 inches. If the fluid bag is hanging more than 35 inches above a patient with an SBP of 70, it will flow into an artery, fooling the unsuspecting observer into thinking the catheter is in a vein. Therefore, to verify venous placement by attaching a bag of saline, the bag of saline must be lower in inches than half of the patient’s systolic blood pressure.

Demonstrations and discussions of full sterile technique, quick pressure column technique, and a number of other central line-related topics can be found on Haru Okuda and Scott Weingart’s central line project page:

http://ehced.org/howtos/centrallineproject/central-lines.htm

Intraosseous Tips

Agree with previous rave reviews in terms of ease of use, success
rates, reliability.

I would add, as far as pain is concerned, that I have used this device
in quite a few awake infants and young children. We see a tertiary
population, often with underlying disease making PIV access difficult;
I have personally watched the pain response in these patients to PIV
attempts, and have found it much LESS painful to insert an EZ IO in
awake patients. We have done this without local infiltration with
lidocaine. One key is NOT to start and stop the drill as it goes
through the skin – I have seen residents do this and it twists the
skin which hurts. As long as the trigger is held until the needle is
in the bone, patients cry much less than they do with PIV placement.

The caveat, however, is that infusion through the IO definitely
appears painful. We now routinely instill 1cc of 1% lidocaine through
the IO, then wait 2 minutes before pushing fluids (this isn’t
necessary, of course, in an emergent resuscitation of an unconscious
patient). Another technique is to put 2-3 cc of 1% lidocaine in the
bag of IVF that you are infusing which seems to decrease infusion pain
well.

Garth Meckler, MD, MSHS
Fellowship Director and Assistant Section Chief
Pediatric Emergency Medicine
Oregon Health & Science University

 

 

 

  1. For adult patients that respond to painful stimuli, slowly administer 40 mg of lidocaine (2 ml) of 2% lidocaine for cardiac use prior to infusing fluids. This may be titrated as for relief of pain up to a maximum of 100 mg. The initial bolus of lidocaine should be given prior to administration of the 10 ml saline flush. Allow the lidocaine to work for 30 – 60 seconds before administering fluids.

Flow rates of various vascular catheters

standard pink IV:
20 gauge (.8 mm) x 30 mm angiocath
max flow rate = 60 ml / minute

standard green IV:
18 gauge (1 mm) x 30 mm angiocath
max flow rate = 105 ml / minute

standard grey IV:
16 gauge (1.3 mm) x 30 mm angiocath
max flow rate = 220 ml/min

procedural IV:
18 gauge x 64 mm angiocath
max flow rate = 85 ml/min

medial (blue) & proximal (white) lumen of triple lumen catheter:
18 gauge x 190 / 180 mm
max flow rate = 26 ml/min

distal (brown) lumen of triple lumen catheter:
16 gauge x 200 mm
max flow rate = 52 ml/min

cordis / introducer:
8.5 french (2.8 mm) x 100 mm
max flow rate = 126 ml / minute
max flow rate with pressure bag @ 300 mmHg: 333 ml / minute

 

from ETM course large bore IV access showdown

Screenshot 2015-07-28 04.40.56

 

 

 

 

 

 

 

 

 

 

from Traylor 2016 ACEP Abstract

from-traylor-2016-acep-abstract

262. Approach to occluded indwelling catheter / Remove line if local infection? / Why no circumferential bandage or tourniquet or BP cuff on arm with Cimino prosthetic bridge fistula?

emcard0524.jpg

 

blood draws and peripheral lines if necessary distal to a fistula, preferably on hand. from fistulafirst.org:

“I am not aware of any studies dealing with this issue. With respect to the extremity with a functioning access, the general recommended practice by Fistula First is that blood draws should be done in the non-access hand, to preserve veins that may be needed for future access. The next place to consider would be the access extremity hand, or possibly higher but below the access, depending on the circumstances.”