Subclavian line insertion

Insertion of a subclavian line with a landmark technique is a potentially life saving option in a particular cohort of critically unwell trauma patients – specifically those patient who are either periarrest or in actual cardiac arrest due to severe haemorrhagic shock where no other large bore IV access has been achieved.

 

 

 

Why the subclavian vein?

 

From: Thoracic upper limb veins by OpenStax College, licenced under CC-BY-3.0

 

The subclavian vein is a continuation of the axillary vein which passes over the 1st rib, lying anterior to scalene tubercle. It runs parallel to the subclavian artery but is separated from it by scalenus anterior muscle. It is covered in its entire course by the clavicle, costo-clavicular ligament and subclavius muscle. Held in position (and thus patency remained) by fascia colli media. It remains patulous and undisplaced even in the hypovolaemic patient.

Generally the right side is the preferred site of subclavian access. Significant degloving injury, suspected vascular injury to ipsilateral subclavian vessels or ipsilateral clavicle fracture can all prompt use of the opposite side. A pre-existent pneumothorax makes insertion of the line on the ipsilateral side the preferred site.

 

By comparison, the internal jugular vein (IJV) is less suitable during trauma resuscitation due to its collapsibility in hypovolaemia and the need to remove cervical splinting and rotate a potentially injured cervical spine.

The femoral route is a viable alternative but its main drawbacks include:

• inappropriate siting for patients with significant abdominal or pelvic trauma with concerns for downstream venous injury
• collapse with hypovolaemia

Intraosseous access (preferably in the humeral site in a shocked trauma patient) is an option of course, but the flow rates achievable are much less than with a large bore central line even with a pressure bag – approx 100 ml/minute compared to up to 500 ml/min. They are also prone to displacement with arm movement which often occurs in a trauma resuscitation to facilitate procedures such as thoracostomy.

 

PROCEDURE – INSERTION OF SUBCLAVIAN LINE

Indications

 

Subclavian trauma lines are intended for adult patients (over 16 yo) who are the victim of hypovolaemia secondary to trauma or in traumatic cardiac arrest plus with inadequate IV access and requiring time critical intervention.

In most cases it is anticipated that other forms of access have failed or are insufficient for patient need. A 12Fr triple lumen line can achieve flow rates of 500ml/min.

 

 

 

Risks:

• Pneumothorax 2.5-4%
• Haemothorax 0.4-5%
• Subclavian artery puncture
• Thoracic duct injury (if left sided insertion)
• Phrenic/recurrent laryngeal nerve injury

 

Equipment

 

Personal protective equipment:

• sterile gloves
• mask
• safety glasses/face shield

 

Cleaning equipment:

NOTE: AS THIS IS AN EMERGENCY PROCEDURE AND THE PATIENT IS LIKELY HAVING OTHER INTERVENTIONS UNDERTAKEN, FULL CLAB DRAPING OF THE ENTIRE BODY MIGHT NOT BE POSSIBLE

• chlorhexidine wipe
• drape

 

The CVL kit: 

• Needle with syringe Wire
• Dilator Scalpel
• 12Fr triple lumen line

 

Securing: 

• 1-0 silk suture
• GRIP-LOK device Tegaderm

 

Landmarks

 

While ultrasound is utilised for subclavian line insertion in medically well patients, in the crashing trauma patient use of USS is likely to cause a significant time delay unless used by practitioners that are highly skilled in ultrasound guided subclavian line insertion. We are therefore advocating a landmark approach for the majority of users.

The landmark for needle insertion is 1cm inferior to the junction of the middle and medial 1/3 of the clavicle

This corresponds to being 1cm inferior to the deltopectoral groove and one fingerbreadth lateral to the angle of the clavicle if these landmarks are palpable.

 

Point of puncture is 1-2cm inferior to junction of the middle and medial thirds of the clavicle. Aim directly across to the point at the top of the sternal notch (put your index finger there). The angle of needle insertion should be shallow and flat to prevent puncturing the lung

 

Technique

 

The steps for performing the infra-clavicular approach are as follows:

 

1. Clean the skin and place drape
2. Define clavicle and find the junction of the middle 1/3 and medial 1/3. Insert needle 1cm inferior to this landmark
3. Skirt under clavicle – press down on shaft of needle to facilitate passage under clavicle with fingers of open non-operating hand
4. Advance needle parallel to underside of clavicle aiming for sternal notch with repeated gentle aspiration of syringe plunger. It is imperative to keep tip of needle as anterior as possible by keeping palmar aspect operating as flush to chest as possible (this prevents posterior angulation of needle and consequent pleural injury / arterial injury). Gentle caudal traction on ipsilateral arm may improve alignment of clavicle to facilitate needle insertion
5. Once blood is aspirated, advance the needle a further 0.5cm and rotate the bevel of the needle downwards (towards the heart).
6. After successful venous puncture – thread guidewire (arrhythmia unlikely – patient may or may not be on ECG monitoring. Observe for wire related arrhythmia)
7. Now perform a small scalpel incision 2-3mm wide to permit dilator. The dilator should be inserted at the same angle as the originally introduced needle. Twist the dilator slightly to decrease friction as you apply firm, constant smooth pressure to advance the dilator. Insert enough of the dilator to enter the vein, which is almost always less than half the length of the dilator. Be careful not to apply so much pressure that you kink the wire. Remove dilator keeping wire held in position. Be ready to hold gauze over the insertion site as soon as the dilator is out, as the patient will bleed.
8. Insert the triple lumen catheter over the wire. Unclamp the brown port as the wire will come out through this port. Once you have a hold of the wire through the brown port, slide the catheter through the skin. You may have to pull the wire a few centimetres out of the patient in order for it come out of the end of the CVC. Failure of this step can result in the wire being lost intravascularly into the patient.
9. Secure line in position with 1-0 silk suture x A GRIP-LOK device can be used in addition to secure the device. Tegaderm dressing provided to cover device

 

Troubleshooting

 

Wire kinking

Continuously pull back the wire to maintain tension on the wire as the dilator is advances. This will prevent the wire from kinking. The guidewire and dilator should never be advanced as a single unit. The wire should serve as an fixed monorail over which the dilator (or catheter) slides.

 

Difficulty advancing the dilator

 If you have difficulty advancing the dilator due to poor skin turgor (aka floppy skin), have an assistant hold tension on the skin to prevent sliding of the subcutaneous tissue.

Difficulty advancing the dilator may be due to a small uncut skin-tag between the wire and your skin nick.

Another possibility for difficulty in advancing the dilator may be due to the wire being kinked or the wire having been pushed out of proper alignment. With the tip of the dilator in the subcutaneous tissue, gently pull the wire out of the patient 1-2cm.

 

Video

The following video demonstrates the insertion of a subclavian line using a landmark technique. It also includes an introduction to CVLs and the seldinger technique. For those familiar with this, skip to 5:41 for a demonstration of the landmarks and 9:03 for the insertion technique.

 

SUBCLAVIAN CENTRAL VENOUS CATHETERIZATION Theory & Practice