Central Venous Catheters - developinganaesthesia



CENTRAL VENOUS CATHETERS

The “Gokstad” Longboat, late 9th Century (left) and the “Osberg” Longboat, early 9th Century, Vikingskipshuset Museum Oslo, Norway. Center panel shows a fearsome array of late 9th Century, Viking weaponry unearthed during the construction of the Great Southern Railway, Ireland in the early 19th Century.

“I Aethelred, in the company of the priests of God and our counselors, contemplating with the pacific gaze of a religious mind and with good will, the anger of God raging with ever increasing savagery against us, have decreed that he shall be appeased with the unremitting performance of good works and that there shall be no desisting from his praises. And since in our days we suffer the fires of war and the plundering of our riches, and from the cruel depredations of barbarian enemies engaged in ravaging our country and from the manifold sufferings inflicted on us by pagan races threatening us with extermination we perceive that we live in perilous times…it greatly behoves us…to give the utmost care and attention to the profit of our souls”

So wrote King Aethelred of Wessex in the year 1005, reflecting the terror felt by his subjects to the increasingly violent attacks of the “Norsemen” who had first arrived “en masse” in 865 AD and subsequently occupied large tracts of the British Isles known as the “Danelaw”. From that time they had been held in check only by the payment of vast amounts of tribute known as the “Danegeld” However by Aethelred’s time they were no longer satisfied with tribute, they were after further conquest.

The Modern 21st Century medical professions of Emergency and Intensivist physicians also enjoy attacking their “victims” with a fearsome array of sharp instruments and like the Danegeld may exact a very high cost for their services so rendered! Patients should be reassured, however that the modern methods of applying sharp instruments though still expensive are somewhat more refined than those of the ninth century.

CENTRAL VENOUS CATHETERS

Introduction

There are three types:

● Subclavian

● Internal Jugular

● Femoral

Each has its own advantages and disadvantages.

Subclavian lines

These are the most difficult and time consuming to perform and carry significant risk of pneumothorax.

Pneumothorax will be a significant complication in patients with respiratory compromise.

They are more comfortable for the patient, however and easier to manage from a nursing perspective.

Femoral lines

These are often the best option in emergency resuscitation situations.

They are the easiest to perform quickly and have less serious complications.

They have a higher rate of infection, however than internal jugular or subclavian lines, especially if the inguinal region is already contaminated.

Internal jugular

These lines carry a risk of damage to the carotid artery and because of the shorter distance to the heart carry a greater risk of guidewire induced arrhythmias.

Indications

1. Long term IV access.

2. Monitoring of the CVP.

● Note that the values obtained from CVCs provide only a rough guide to the true CVP.

● Values obtained will not only be influenced by the degree of “filling” of the circulation, but also cardiac contractility. Femoral lines may not be as good a guide as internal jugular or subclavian lines of the true CVP, but nonetheless in a supine patient will still give a reasonable indication. Note that the trend of values obtained for “central” pressures is more important than absolute numbers.

3. Administration of phlebitic drug infusions or hypertonic solutions.

4. For urgent venous access in cases of failed peripheral access.

5. Insertion of a transvenous pacemaker or Swan Ganz Catheter.

Contraindications

1. Infection or cellulitis over the proposed insertion site.

2. Coagulopathy is a relative contraindication.

● A femoral CVC is usually the best option here.

Internal jugular lines may result in local hematomas with compression of, or damage to the carotid artery. Sublcavian lines are best avoided, as direct compression of the artery is not possible should significant bleeding occur.

3. Uncooperative patient

Complications

1. Sepsis, (Femoral > internal jugular > subclavian)

● Local

● Systemic in longer term

2. Damage to adjacent structures:

Internal jugular lines:

● Carotid artery

Subclavian lines:

● Subclavian artery

● Pneumothorax

● Laceration of thoracic duct, (left subclavian lines) with subsequent chylothorax.

Femoral lines:

● Femoral artery

3. Arrhythmias:

● In cases of internal jugular lines (more likely) and subclavian (less likely).

● These are generally resistant to drug therapy but respond to withdrawal of the catheter/guidewire.

4. Hydro/Hemothorax:

● This may occur with penetration of the catheter tip through the wall of the subclavian vein or SVC.

5. Hydro/Hemopericardium:

● May occur with penetration of the catheter tip through the wall of the right atrium.

6. Venous thrombosis:

● This is a possible later complication, (femoral > internal jugular > subclavian).

7. Air embolism:

● The risk of this can be minimized by maintaining the patient in the Trendelenburg position and maintaining a closed system at all times.

8. Guide wire embolism:

● To avoid this complication always ensure the some portion of the guide wire is visible beyond the introducing needle.

9. Knotting and kinking of the catheter/guidewire:

● The risk of this may be minimized by not using too long a catheter, which may then coil around itself in the atria.

10. Damage to arterial wall, such as dissection.

Equipment

The “Arrow” seldinger guided wire kit.

1. Needle and canula 2. Syringe for aspiration. 3. Guidewire 4. Needle for aspiration 5. Dilator 6. Second needle and canula. 7. Triple lumen catheter. 8. End cap. 9 & 10. Suturable line stays.

Technique

The Seldinger Technique:

All central lines are placed using the seldinger technique, under aseptic conditions, as follows:

1. Introduce needle on syringe into vessel and gently aspirate to confirm placement.

2. Slide guidewire through needle into vessel.

3. Remove needle, leaving the guidewire in place.

4. Insert dilator over guidewire into vessel, then remove, again leaving the guidewire in place.

5. Slide the catheter over the guidewire into the vessel.

6. Remove guidewire, leaving catheter in place.

The seldinger technique

Landmarks for Needle Insertion:

1. Femoral CVC:

● Locate the femoral vein just medial to the artery.

2. Internal Jugular CVC:

● The Internal Jugular Vein lies lateral to the carotid artery.

Supraclavicular Approach:

● Advance the needle at 20 degrees to the skin through the apex of the triangle formed by the 2 heads of the sternomastoid muscle and clavicle as shown in diagram below.

● The ipselateral nipple is aimed for.

● If the first pass is unsuccessful, the needle should be directed slightly more medially on the next insertion attempt.

Midneck Approach:

● Advance the needle 3 fingerbreadths above the clavicle, or roughly at the junction of the posterior border of the sternomastoid and the external jugular vein and just lateral to the carotid artery.

● Aim for the suprasternal notch.

3. Subclavian CVC:

● The subclavian vein lies anterior to and slightly inferior to the subclavian artery.

● The needle is inserted 2-3 cm caudally to the midpoint of the clavicle and is directed just underneath it, toward the suprasternal notch.

● If the first pass is unsuccessful, the needle should be angled in a slightly more cephalad direction on the next insertion attempt.

Average Catheter Insertion Distances in Adults:

From skin entry to junction of right atrium and SCV:

Right Internal Jugular 15cm

Right Subclavian 13cm

Left Internal Jugular 19cm

Left Subclavian 17cm

A CXR SHOULD ALWAYS BE OBTAINED FOLLOWING CVC INSERTION TO CHECK FOR POSITION OR POSSIBLE COMPLICATIONS.

To determine whether the CVC has inadvertently been placed in an artery:

1. Look for typical arterial pulsatile backflow from the catheter.

2. Check the PaO2

3. Connect line to a pressure transducer and look for a typical arterial pressure waveform.

Securing the CVC

Suture the catheter to the skin via the provided plastic “stays”, apply betadine ointment and cover with a tagaderm dressing.

It is important to secure the CVC with 2/0 silk sutures at both the line (or the clamp/clip) as well as the hub, as per the photo, below, (rather than just the clamp/clip alone). If the clamp/clip alone is used there is still potential for line movement.

Catheter Maintenance

Every catheter should be removed as soon as it is no longer needed, since the probability of catheter-related infections increases over time.

The risks of catheter colonization and catheter-related bloodstream infection are low until the fifth to seventh days of catheterization, at which time the risks increase.

Central venous catheters should not be replaced on a routine scheduled basis, as this has not been shown to decrease the rate of catheter-related bloodstream infections and places the patient at increased risk of the mechanical complications of CVC placement.

References:

1. McGee D.C, Gould M.K: Preventing Complications of Central Venous Catheterization, NEJM 2003; 348: March 20, p.1123- 33.

2. Vander Salm TJ, Atlas of Bedside Procedures 2nd ed, 1-4, 35-65.

Dr J Hayes

Reviewed 2 May 2008.

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download