Procedure.

VIEWS

Once you have identified an appropriate vessel, there are two views that can be used on the ultrasound machine for peripheral IV placement: out-of-plane/short axis (transverse) view or in-plane/long axis (longitudinal) view. The equipment needed is the same for either method.

EQUIPMENT

·       High frequency linear ultrasound probe

·       Sterile gel/lubricant

·       Adhesive dressing (e.g., Tegaderm®)

·       IV catheter (ideally longer than 1.16 inches)

·       Tourniquet

·       Antiseptic solution

In-plane / Long Axis / Longitudinal Approach.

The aim of an In-plane, longitudinal approach is to visualize the entire needle during the whole procedure, minimizing the chances of losing track of the needle itself.

1.     Use the same technique as described in steps 1-4 of the short axis approach above.

2.     Place the ultrasound probe on the skin parallel to the axis of the previously identified vein with the probe indicator facing towards the patient’s head.

3.     Pierce the skin between 30 and 45 degrees angles just distal to the ultrasound probe with the needle at the centre of the probe.

4.     Identify the hyperechoic needle on the right side of the screen.

5.     Advance the needle tip until you visualize it piercing the wall of the vessel on the screen.

6.     Thread the catheter in the usual fashion and secure the catheter to the skin with adhesive.

7.     The IV should now flush easily and painlessly if placed correctly.

Pitfalls.

The 5 Most Common (and correctable) Pitfalls of Ultrasound-Guided IV Placement [14] 

1. Failure of positioning

·       Mistake: The ultrasound screen is positioned in such a way that the provider has to turn significantly to see the screen, or has to lean over such that they are looking up at the screen, resulting in challenging ergonomics.

·       Fix: Elevate the bed to the proper height with the patient’s arm extended outwards onto a table, with the ultrasound screen positioned over the patient’s shoulder in line with the arm. The provider, the patient’s arm, and the ultrasound screen should form one straight axis.

Pitfall #1 is the easiest to correct. It involves no physical skills, and depends only on the provider to fight the natural urge to skip basic steps. A moment of preparation will likely save time in the end.

2. Failure to identify vein location and course 

·       Mistake: The provider correctly identifies a vein, but lacks the 3-dimensional knowledge of where it is and its path relative to the ultrasound probe and probe marker. After skin puncture, they realize their needle tip is not close to the target.

·       Fix: Turn on the ultrasound reference lines to indicate the midline of the probe and deliberately note the vessel depth. With 30 seconds of scanning, a vein can be easily mapped in three-dimensional space.

Pitfall #2 is likely to be overcome naturally with experience using ultrasound. Encourage trainees to do all superficial ultrasound with their non-dominant hand so that they are accustomed to manipulating the linear array probe. Ultrasound ambidexterity will confer benefit for other procedures (e.g. central venous line placement, arthrocentesis, etc).

3. Last-minute adjustments in position

·       Mistake: The provider holds the needle above the skin. When looking up at the screen at the time of skin puncture, they make a minor unintentional movement just prior to insertion. As a result, the needle (and its subsequent course) is considerably off-target.

·       Fix: Rest the needle on the skin, ensuring the midline markers line up with vessel.

Pitfall #3 is subtle, but common and easily correctable. Remind the trainee that simply resting the needle on the skin in the correct position will not hurt the patient.

4. Failure to advance to adequate depth

·       Mistake: The initial puncture is too superficial. If the first movement ends at only superficial depth, the needle must then traverse a significant vertical distance during which time there is a high risk of losing the tip. Furthermore, this gentle and prolonged dissection of tissue is painful (and stressful)!

·       Fix: Deliberately insert and advance the needle to 80% of the vessel depth.

Pitfall #4 is the most common. Although a sense of depth will come naturally over time, it is greatly accelerated by explicit mindfulness of the target depth. Frequently, the tip will become lost and subsequent attempts to locate the tip are either unsuccessful or unsalvageable due to hematoma formation. Consider practicing by inserting an angiocath into gauze at specific depths.

5. Looking for a flash

·       Mistake: The innate – seemingly unavoidable - tendency is to look down at the hub to check for a flash. Looking away from the screen causes subtle movements of one or both hands, leading to loss of the needle tip and inadvertent advancement of the catheter.

·       Fix: Do not look away from screen until the catheter has been fully advanced inside the vessel and you are ready to put down the ultrasound probe. Identifying a flash is not part of successful USPIV placement.

Pitfall #5 is an exercise in fighting instinct. The urge to look for a flash is nearly universal, likely because of experience with placing standard peripheral IVs. In the event that a flash is identified, the celebratory moment ends when attention is redirected to the screen and the target sign has vanished due to a subtle inadvertent movement of the probe. If no flash was present, the needle tip is usually buried in the vessel wall creating a hematoma. Instead, encourage learners to pursue "ultrasonic flash" (the target sign) and then continue with advancement without taking their attention from the screen until the catheter has been fully advanced. Even when reminded mid-procedure to never look down, trainees find it nearly irresistible. Continual reminders are needed to overcome this temptation.