Peripheral Venous Access - PEARLS
PEARLS
Peripheral venous cannulation is actually harder than central venous cannulation even with the aid of PoCUS. There are three parameters that can be optimized to improve success rates:
1. "Ideal" Peripheral Vein
2. Choosing an Angiocath
Peripheral venous cannulation is actually harder than central venous cannulation even with the aid of PoCUS. There are three parameters that can be optimized to improve success rates:
1. "Ideal" Peripheral Vein
2. Choosing an Angiocath
1. "Ideal" Peripheral Vein
Before needling a vein, assess the following parameters to screen for a vein that will be least troublesome to cannulate:
Before needling a vein, assess the following parameters to screen for a vein that will be least troublesome to cannulate:
- Depth: How deep is the vein?
- Diameter: How big is the vein?
- Patency: Is there something inside it (eg. thrombus)?
- Trajectory: Is it relatively straight, or it runs a winding course?
The ideal vein for cannulation has had been defined as the survival rates of the IV access. In this particular study, whether the vessel was in the forearm or brachial region, and whether the vessel was superficial or deeper were studied to see if these factors would affect the longevity of the IV access. The survival curves of these IVs cannulated at these different sites show that the deeper the vein, the less likely it will last. Also, the ones inserted into the brachial region do not tend to last long as well.
In this study, Witting et al showed that the if the peripheral vein is too deep (>1.4cm) or too shallow (<0.3cm), success rates fall. Presumably:
- Too shallow: US cannot see needle - no need for US anyways
- Too deep: insufficient length of the catheter will be situated in the lumen for anchoring
- Too small for the angiocath's diameter
- Easily collapsible
To summarize, choose a vein with these parameters to improve your cannulation success rates.
2. Choosing an Angiocath
As eluded above, vein Depth and Diameter both influence the successes and failures of peripheral venous cannulations, so it is important to choose an angiocath with the appropriate length and diameter -- particularly length.
The BD Instyte Autoguard BC is the angiocath that is utilized at my institution. The ones enveloped by the blue rectangle are the specific model in stock. Note their respective Lengths and Outer Diameter (Catheter OD).
Usually these parameters are detailed on the packaging.
As eluded above, vein Depth and Diameter both influence the successes and failures of peripheral venous cannulations, so it is important to choose an angiocath with the appropriate length and diameter -- particularly length.
The BD Instyte Autoguard BC is the angiocath that is utilized at my institution. The ones enveloped by the blue rectangle are the specific model in stock. Note their respective Lengths and Outer Diameter (Catheter OD).
Usually these parameters are detailed on the packaging.
Key Message:
- The "ideal" vein:
- not too deep, or too shallow
- big diameter
- patent
- trajectory is relatively straight
- Need a respectively compatible Angiocath - length and diameter - to the chosen vein