Learning Objectives

Anatomy & Ultrasound Viewing of Vessels:

 

  • Recall the vascular anatomy of the 2 major sites of central line placement, the internal jugular & carotid as well as the femoral artery and vein

 

  • Distinguish arterial vessels from venous vessels using multiple modalities: including appearance, location, compressibility, pulsatile movement, doppler flow (audio and waveform), and response to positioning or vagal maneuvers

 

  • Acknowledge the incredible variety of human anatomy, in deviation from textbook figures, and independently identify each target vessel, surrounding structures, and anatomical boundaries for each patient prior to each central line

 

  • Assess the shape, depth, pathway of each target vein through both short and long axis views, to general a mental map of the pathway it courses in 3 dimensions

 

  • Identify easy and difficult approaches based on depth/angle/direction of then target vein, proximity to muscles/nerves/arteries & prescribe steps that can be taken to optimize the view and approach

 

  • Recognize good patient positioning as well as poor positioning, along with the complications foreseeable with poor positioning

 

Indications & Consequences:

 

  • Appreciate the severe consequences of failure in this procedure & what are considered catastrophic events: losing the wire into the body, dilating into an artery – and understand how these errors occur through case examples

 

  • Appreciate the minor risks and harms that occur more commonly, but are avoidable all the same with careful and deliberate practice: pain, infection, bleeding, pneumothorax

 

  • Recognize the function and benefit of each type of central access: double/triple lumens, introducers, trialysis catheters

 

  • Remember to do post procedural confirmation with x-ray, and for crash central lines ultrasound

 

  • Acknowledge that crash central lines happen, when the risk/benefit ratio of sterility are traded for imminent life threats that are best served through central access – and for which IOs are inadequate or unavailable & appreciate the potential harm of infection and need for rapid replacement when stability is achieved

 

  • Recall the fundamental importance of hand washing prior to procedure start as a major preventable source of line infections

 

 

Materials:

 

  • Identify categories of core equipment:

    • sterile field (hair cover, mask, gown, gloves, drape, clorhexadine)

    • ultrasound (machine, linear probe, gel, sterile cover/gel)

    • central line kit & it’s core items

      • large gauge needle & syringe

      • guide wire

      • scalpel

      • dilator

      • catheter

      • securing equipment (suture, clips)

    • accessories often not in central line kit

      • 3x needleless access points – aka Q-Sytes

      • 3x sterile flushes

      • Lidocaine

 

Technique:

 

  • Understand the basic features of an ultrasound including left/right distinction, depth setting and gain – which a focus on acquiring optimal view of the target vessel in question in both short and long axis

 

  • Understand that a linear probe is the best probe for shallow viewing of high detail features; and should be used for line placement exclusively

 

  • Experience various placements of the screen relative to your body and target workspace – too appreciate the discomfort and difficulty with extreme misalignment of these 3 objects

 

  • Appreciate that deliberate practice is required for mastery of a 2 handed procedure, and that without conscious effort errors will occur

 

  • Recall basic geometry, that is that a needle entering at 45 degrees with travel to a depth equal to the distance away from the probe when it appears on the screen – and that the length of needle required to hit that target can be approximated as 1.5x the depth to the target (and distance from the probe)

 

  • Conceptualize the pathway a needle might take, based on ultrasound, as well as the final central line, at various angles & the values and drawbacks of shallow and deep angled approaches

 

  • Conceptualize the placement of the needle, bevel up, as cutting a narrow channel through tissue to a target space – and each subsequent step as dilating and preserving that channel while minimizing trauma to tissue and surrounding vessels/nerves/muscles

 

  1. Entry of needle into space

  2. Passage of wire into space through needle

  3. Removal of needle

  4. Dilation of skin and tissue with scalpel & dilator

  5. Placement of central access

  6. Preliminary confirmation (via drawback of dark blood and easy flushing)

  7. Securement of central access

  8. Final confirmation of central access with x-ray

 

  • Anticipate the common pitfalls & their preventative or correctional actions:

  • Punching through the vein’s deep wall (through & through)

  • Moving the needle when removing the syringe & losing access

  • Moving your non-dominant hand unconsciously (the ultrasound probe) while you are moving the dominant hand (the needle) – often paired with holding your ultrasound probe in the air (floating) without a fixation point

  • Failure to dilate adequately via scalpel or dilation tool

  • Excessive force application of the dilator, often when proximally holding the dilator, that results in kinking of the wire