Interventional Ultrasound in the ICU
Gisela I. Banauch
Adam W. Katz
I. ULTRASOUND-GUIDED VASCULAR ACCESS
A. General principles.
1. Avoid injury to adjacent structures through real-time ultrasound (US) imaging/guidance.
B. Indications.
1. Venous cannulation.
a. Internal jugular vein (IJV).
b. Subclavian vein (ScV).
c. Femoral vein.
d. Peripheral veins (piv).
2. Arterial cannulation.
a. Radial artery.
b. Brachial artery.
c. Femoral artery.
C. Procedure.
1. Include both clinical considerations and US imaging in site selection.
2. Identify both vessels of vascular bundle with cross-sectional US prior to needle insertion (exceptions: piv, radial artery). US features suggesting arterial vessel are
a. Pulsation (requires steady US image, possibly absent in hypotension).
b. Less compressibility than accompanying vessel.
c. No respiratory variation.
d. No venous valves.
3. US imaging excludes local contraindications.
a. For venous targets, serial cross-sectional compressions throughout vessel’s course proximal to insertion site with fully compressible vein on US indicate absence of thrombi.
b. A vein that collapses with respiration is not accessible to cannulation and often indicates significant intravascular hypovolemia.
c. Arterial aneurysmal dilation contraindicates puncture at that site.
4. US machine position should require only up/down movement to look from sterile field to US screen.
a. IJV: ipsilateral upper chest.
b. ScV: contralateral upper chest.
c. Femoral vessels/radial artery: contralateral lower flank.
d. Brachial artery: contralateral upper chest.
e. Piv: ipsilateral lateral/upper arm.
5. US screen tilt should minimize screen glare.
6. Assure orientation marker is on left side of ultrasound screen.
7. Sterile equipment must include sterile ultrasound transducer cover.
8. Standardize direction of ultrasound transducer marker.
a. For cross-sectional needle guidance, direct marker to operator’s left side. (Ensures that needle movement direction is same on sterile field and on ultrasound screen).
b. For longitudinal needle guidance, direct marker toward operator. (Ensures that needle insertion occurs on ultrasound screen’s left side).
9. Real-time US guidance for vessel puncture.
a. US imaging plane cross sectional to vessel long axis.
i. With vessel’s cross section in center of ultrasound screen, operator inserts the needle a small distance (e.g., 0.5 cm) as close as possible to ultrasound transducer face long axis’ center.
ii. Sweep transducer cross sectionally along needle long axis and distal to it; then sweep back proximally till needle is again recaptured on US image. The distal/proximal transducer sweep that ends with needle image recaptured assures that needle tip, rather than cross section of more proximal portions of needle shaft, is in scanning plane prior to further advancing the needle.
iii. Move needle side to side with respect to target vessel’s long axis to enhance US visualization of needle.
iv. Once needle tip is identified on US, assess whether needle direction requires adjustment, then adjust, and insert, similar to Section C.9.a.i. Repeat Sections C.9.a.i to iv till vessel is punctured.
b. US imaging plane parallel to vessel long axis.
i. Identify vessel cross sectionally. Prepare sterile needle/syringe.
ii. Turn transducer to achieve longitudinal vessel image.
iii. Insert needle while imaging entire extent of needle longitudinally throughout insertion. Pay special attention to maintaining vessel squarely in US image while needle is advanced. It is easy to slide off target vessel onto accompanying vessel without realizing this because US image depicts one vessel only. If this error is not recognized, operator will proceed to puncture the wrong vessel without realizing this.
c. Longitudinal technique achieves less acute puncture angle—better for deeper vessels.
10. Site-specific considerations.
a. IJV.
