5 Minute Journal: The effect of vessel depth, diameter, and location on ultrasound-guided peripheral intravenous catheter longevity

Author: Dr. Evelyn Schraft, PGY1

Study Title: The effect of vessel depth, diameter, and location on ultrasound-guided peripheral intravenous catheter longevity

Citation:

Fields, Jason & Dean, Anthony & Todman, Raleigh & Au, Arthur & Anderson, Kenton & Ku, Bon & Pines, Jesse & Panebianco, Nova. (2011). The effect of vessel depth, diameter, and location on ultrasound-guided peripheral intravenous catheter longevity. The American Journal of Emergency Medicine. 30. 1134-40. 10.1016/j.ajem.2011.07.027.

Clinical Question: Do vessel characteristics predict the longevity of ultrasound guided PIV catheters (USGPIV)?

Background:

Twenty-seven percent of ED visits require IV placement. In patients with difficult IV access, ultrasound-guided peripheral IVs are an alternative method but have a failure rate of up to 8 percent in the first hour and 47 percent within the first 24 hours. These failure rates are higher than traditionally placed PIVs. It is possible that USGPIVs fail more often due to proximal access through more subcutaneous tissue leading to kinks or dislodgement.

Methods:

The database was originally obtained for a separate study. This prior database was used to examine the success of initial USGPIV placement related to vessel depth and diameter. It was then combined with retrospective chart review for the PIV outcomes.

1. Study Type: Retrospective chart review
2. Patient Allocation: Patients with difficult IV access were enrolled in prior study
3. Location of Study: size of hospital(s): Urban, tertiary academic hospital with Ultrasound fellowship
4. Inclusion Criteria: Successful USGPIV placement of a 20-gauge 48-mm long Angiocath in the ED in a patient with difficult IV access (DIVA) defined as two failed peripheral IV attempts or a history of DIVA with inability to visualize or palpate a vein
5. Exclusion Criteria: Unsuccessful PIV placement, insufficient documentation, or reviewer disagreement of IV outcome
6. Study Design:  The database of 183 patients with USGPIV placed by three residents and one fellow was reviewed for PIV characteristics including depth, diameter, and proximal versus distal upper-extremity placement. On chart review by two blinded reviewers, the PIV outcomes were examined in terms of failure (early removal due to PIV infiltration, dislodgement, or patient discomfort), routine discontinuation, or survival at 48 hours after placement. Univariate analysis was performed on the vessel characteristics.

Results:

1. Sample Size: 151 (183 prior to exclusions)
2. Excluded Patients:32 patients were excluded for failure to establish a PIV (18), lack of charting to determine outcome of line (12), or reviewer disagreement of outcome(2)
3. Primary Outcome: Vessel shallow depth and distal location predicted survival of the USGPIV with statistical significance. The vessel diameter had no significant difference.

• Secondary Outcome:

For each increase of 0.2cm in depth, the odds of failure at 48 hours increased by a hazard ratio of 1.36 (1.15-1.61). Placement of proximal versus distal location increases the odds of failure by a hazard ratio of 2.76 (1.25-6.09). The patient characteristics of PIVs that failed and those that survived were similar.

Discussion:

1. Study Deductions: Depth is the strongest predictor of survival and should therefore be the main consideration if a PIV is needed for a brief period of time. Vessels greater than 1.2 cm deep should be avoided due to high immediate failure rate.
2. Strengths:
   1. The urban academic tertiary ED patient population represents a generalizable DIVA population.
   1. Two independent reviewers were used for the retrospective chart review.
   1. Improving USGPIVs’ survival has good clinical significance as the procedure is routinely performed.
3. Weaknesses/Limitations:
   1. The study underestimates the failure of PIVs because catheters may be documented as “removed” to avoid appearance of an adverse outcome, if they were no longer needed, or if realization of PIV failure was delayed or poorly documented.
   1. Potential confounding variables of catheter length/gauge, type of fixation device, frequency of IV access, and type of infusion were not assessed.
   1. The target vessel depth is measured, but the final vessel depth is not confirmed after PIV placement.
   1. The study is well powered.
   1. PIVs that were removed due to patient discomfort were included in failure group, which should not be considered a failure of PIV performance.
   1. The deep vessel (>1.2 cm) group with an n=23 is not large enough to make strong statements like deep vessels should be avoided without further study.
   1. Trained physician sonographers may not represent the population of providers placing USGPIVs.
   1. Retrospective data gathering increases potential bias.
   1. Single center study also limits generalizability.

Conclusion: Ultrasound-guided peripheral IV catheters are an excellent tool for patients with difficult IV access. Sonographers should choose a vein that is as shallow and distal as possible when performing an USGPIV to promote PIV survival. An alternate access via midline catheter, intraosseous line, or central venous cannulation should be considered if an optimal vessel cannot be found. Further studies may explore different catheter lengths, fixation devices, and IV success at depths greater than 1.2 cm with a greater power.