Category Archives: Critical Care

Using Ultrasound in Central Line Placement

This week, we have a post from regular contributor Nick Mancuso on how to excel when performing a procedure common in the ED as well as upstairs: ultrasound guided central line placement.

 

The three most common veins used in central line placement are the internal jugular (IJ), subclavian (SV), and femoral (FV). I will focus on IJ placement and the use of dynamic ultrasound.

Procedure:

  • Sterile technique is paramount (if time permits).
  • Linear array probe is used with a sterile probe cover, and sterile gel. A CVC kit is obviously required, along with sterile personal protective equipment. This procedure can be done with one person, but two can be helpful especially during training.
  • Operator on the isiplateral side of the pt, pt in Trendelenburg, probe indicator to the left of operator, in transverse position.
  • Place probe superior to clavicle, IJV usually larger, lateral to carotid artery.
  • The IJV will compress with pressure, vs. the artery. If hypotensive or dehydrated, may disappear with inspiration.
  • Center vein on screen, lidocaine can be used to anesthetize pt. Use center of probe as guide, while not looking at monitor, stick pt skin with entry needle.
  • Look at monitor after puncture. Visualize needle or tissue compression. Puncture vein looking at monitor.
  • If needle can’t be visualized, a long-axis (longitudinal) view can help
  • It is extremely important to visualize the needle tip and not proceed with advancement of the needle without visualization of the tip.  The tip can be followed with slow fanning or sliding of the probe distally as you advance.  The most common mistake is not following the tip of the needle and letting the needle get “ahead of” the probe.  This leads to visualization of the proximal portion of the needle while the tip is in a different location in the neck, possibly causing complication.
Ultrasound visualization of neck vasculature

Ultrasound visualization of neck vasculature (Source)

Top: Internal jugular vein (IJV) and carotid artery (CA) in the transverse view with the transducer held on the skin without pressure (left) and with pressure (right). Note that with pressure, IJV appears compressed while the CA has retained its shape. Bottom: These blood vessels in the longitudinal plane. (Source: http://pie.med.utoronto.ca/OBAnesthesia/OBAnesthesia_content/OBA_ultrasonographyBasics_module.html)

Top: Internal jugular vein (IJV) and carotid artery (CA) in the transverse view with the transducer held on the skin without pressure (left) and with pressure (right). Note that with pressure, IJV appears compressed while the CA has retained its shape. Bottom: These blood vessels in the longitudinal plane. (Source)

Video: Ultrasound Guidance for Central Venous Access – SonoSite

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Disseminated Intravascular Coagulation (DIC)

Pathophys of DIC. Source: Lippincotts

Pathophys of DIC. Source: Lippincotts

DIC is a pathological process where tissue factor or other thromboplastic substances from endothelial cell injury are released into circulation-Leads to paradoxical formation of 1) microthrombi leading to organ failure and 2) hemorrhaging.

 Associated Clinical Causes

-Sepsis
-Trauma (especially neurotrauma)
-Cancer
-Shock
-Major Surgery
-Immunologic (transfusion/transplant reaction)
-Obstetric complications

Diagnosis

Can be complicated by the underlying causes, lab tests indicating DIC:

– Platelets <100,000 or recent rapid large decrease in number
– Prolonged PT and aPTT
– Elevated D-Dimer (>.5ug/ml)
– Schistocytes in blood smear
– Fibrinogen -if obtainable <1g/L (only in ~28% of pts)

A scoring system has been developed (click continued reading)

DDx: DIC, Hemolytic Uremic Syndrome, Liver Disease, Thrombotic Thrombocytopenic Purpura, Heparin-induced thrombocytopenia, HELLP syndrome in pregnancy

Treatment

Treat the underlying cause, platelet and blood factor replacement to treat bleeding can be used but won’t correct DIC. Heparin used when fibrin deposition is excessive and no risk of hemorrhage present (no petechiae or bruising).

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