How to Become Flow Righteous: The 1-2-3 Elements of SuccessNancy Moureau, RN, PhD, CRNI, CPUI, VA-BC PICC Excellence, Inc.

Presented atAssociation for Vascular Access Annual Scientific Meeting | October 2020

PURPOSE & BACKGROUND

Veins, valves, velocity, volume of blood flow, i.e. 4Vs, and hemodilution all play an important role in the safe delivery of medications. Optimal peripheral intravenous catheter (PIVC) site selection relies on 4V knowledge. Thus, the Vascular Access Specialist (VAS) offers unique expertise to optimize the patient’s PIVC result.

In one study, a multi-modal strategy (Table 1. The PIV5Rights Bundle) was used to achieve both a high first-stick success rate and longer lasting dwell time with reduced complications.6 This PIV5Rights study leveraged a systematic review of over 100 studies to create a best practice bundle. This bundle resulted in significant clinical and economic improvement (Table 2).6

According to Gagne,1 successful PIVCs are those that function to both infuse fluids and aspirate blood for the duration of a patient’s need. Premature catheter failure rates reported in the literature range as high as 63%.2 Newer evidence suggests that a longer catheter placed in the cephalic forearm may improve longevity.3,4,5,6

AUTHOR N RESULTS

Maurer et al3 3,723 93% Success

Moretti4 3,500 90% Success

Rickard5 5,376 Optimal

Steere6 207 89% Success

1. Proficient, trained and educated clinician

Right Training2. Insertion and use of ultrasound for assessment, selection

Right Insertion3. Selection and use of the best vein and catheter

Right Vein and Catheter4. Supplies included; PIVC start kit, longer catheter, anti-reflux needleless connector, and antimicrobial dressing

Right Supplies and Technology5. Assessment performed by a proficient nurse and documented with photo in an iPad app

Right Review and Assessment

Table 1. The PIV5Rights Bundle

Table 2. Results from the PIV5Rights study6The Results

Variable Current State(n=94)

PIV5R(n=113)

Dwell Time, Hours(mean ± SD, P<0.001)

Complication Rate(%, P<0.001)

Cost/Bed/Year(2018 USD)

Saving/Bed/Year(2018 USD) – $3,376

Success Rate(therapy completed)

29.6 ± 18.0 71.4 ± 58.8

40% 11%

$4,781 $1,405

15% 89%

HEMODILUTION

Roethlisberger and associates, in 2017, established a dilution ratio for vein protection to buffer pH and osmolarity of solutions.7 The hemodilution ratio should be >3 mL/minute for any patient receiving IV medications. Foor et al conducted a duplex mapping study and hemodilution calculations for 10 healthy human volunteers to better understand why the forearm cephalic was an optimal PIVC placement site.8

4VS: VEINS & VALVES

Vein: Returns blood to the heart from all organs of the body. Vein diameter, valve function and location, and blood flow velocity are important characteristics for catheter site selection.

Valve: Maintains the direction of the blood flow to the heart. Valve function and proximity to the catheter tip are important.

4VS: VELOCITY & VOLUME

CONCLUSIONS

FLOW RIGHTEOUS TARGET ZONES

Roethlisberger established a parametric approach, comparing it with conventional and experimental approaches, to determine the Maximum volume of infusion, the Dilution ratio at the point of infusion, according to Infusion time.7 Intravenous parenteral solutions and medications should aim toward being isotonic and euhydric, in other words establishing a physiological pH when infused into blood. Yet, due to other considerations, this goal is often not reasonable or doable. There are no clear allowable ranges related to pH and osmolality. However, because many factors play a role in terms of the level of irritation and local tolerance of the vein – such as administration site and route of administration, vein selected, related venous blood flow, injection volume, infusion time, infusion – no well-defined and generally recognized pH, buffer strength, or hemodilution limits have been established.

Roethlisberger’s Formula7 for:• Maximum volume of infusion• Dilution ratio at the point of infusion• Infusion time

Velocity: Speed of blood flowing in the vein measured in centimeters per second.

Volume: Amount of blood flowing through the vein. Blood flow volume is calculated by using vein diameter in centimeters and velocity in centimeters per second.

AVA20 Case Study

Big Vein, Low Velocity, Male, Age 37, 185 lbs, 6'1''

Dilution ratio = =F bl

2v d–2bl

v in

( )π

Ft

inf

X X

By identifying blood velocity in centimeters per minute, an average of 7 to 15 cms per second can be established for veins measuring 0.15 to .035 cms revealing blood flow in milliliters per minute. The ratio of blood flow is divided by the infusion rate, where the flow of blood or fbl is ¼ blood flow in mL/min; the velocity of blood or vbl is ¼ in cm/min; d is ¼ vein diameter in cm, and r is ¼ radius of vein diameter in cms. Parts of Spencer and Mahoney’s 2017 catheter-related thrombosis risk reduction tool were built on components of this same approach.9

Flow-Righteous is the ability of a VAS to select an optimal peripheral catheter site based on specific parameters of the 4-Vs and the patient’s medications with corresponding infusion flow rate.

The goal of Flow Righteous is to achieve a >90% 1st stick success rate and 1-PIVC per patient visit. The 4-Vs of Flow Righteous are designed to help identify the best catheter location for longevity.

Picking the Right Zone

Veins located in the red region are tempting to choose due to their superficial appearance. However, the red zone is not optimal because veins are located in areas of flexion. The hand, specifically, has a low blood flow volume due to small vessel size and vein branches.

Veins located in the yellow region require careful selection, especially on the dorsal side of the wrist in the carpal tunnel region, an area sensitive to pain due to its close proximity to arteries and nerves.

Veins in the green zone represent the optimal placement site. This region has a stable securement location, without a point of flexion, and deeper access veins. Valves and branching are less frequent, and the vein diameter is larger than at the wrist/hand.

The image below represents a Flow Righteous PIVC placement.To watch the video, scan the QR code or visit https://youtu.be/ReMwNGEfPCM

To achieve the goal of Flow Righteous–first stick success and longer PIVC dwell times, considerations for the 4Vs and hemodilution should be included in the VAS assessment. The green target zone, upper forearm cephalic, represents an optimal site.

To watch the video, scan the QR code or visit https://youtu.be/dIGGu0deLoo

RESULTS OF HEMODILUTION STUDY WITH FOREARM CEPHALIC CATHETER PLACEMENT

Observational studies presented via video provided examples of changing dilution ratios based on infusion rates by vein size.

Subject #4 represented the [Minimum] Hemodilution Ratio @ 80 mL/min Infusion Rate

Subject #9 represented the [Mid] Hemodilution Ratio @ 80/125/250 mL/min Infusion Rates

Subject #5 represented the [Maximum] Hemodilution Ratio @ 80/125/250 mL/min Infusion Rate

“Let’s apply this information while looking at the specific subjects and practical applications. When we consider subject #4 vein presentation, we see a young female of average size with no visible superficial veins in the green zone. Without a good pre-assessment, what would a generalist nurse do? Probably insert in the hand, wrist, or dorsal aspect of the wrist. Following an ultrasound assessment on the right cephalic, it was identified with a diameter of 1.2 mm without a tourniquet and 2.0 with. In this case, the starting velocity of 4.3 cm/sec was measured before a 22-gauge catheter was placed. The velocity increased after placement to 6.1 cm/sec. The catheter filled approximately 75% of the vessel and represented a high risk for failure due to the poor catheter-to-vein ratio. The volume of blood moving through this vein was calculated at 4.14 mL/min. A valve is distal to the tip of the catheter without catheter contact. During the flushing process, retrograde blood reflux, turbulence, and vein collapse was noted due to pressure changes. It was determined that this vessel size and velocity was adequate to achieve greater than 3 mL/min of flow. Taking into account a rate of infusion at 80 mL/hour, the hemodilution ratio is optimal at 3:1. But when infusions increased above 80 mL/hour—up to 125 or 250—the ratio of blood flow falls below the optimal 3:1 and down below 2:1. As you can imagine, with larger infusions such as vancomycin requiring 250 mL/hour, this can create a problem for the vein in order to accommodate and reduce irritation to the vein. Pre-assessment of this particular patient could identify this vein as sub-optimal and recognize another option of a larger or upper arm vein that would be a better selection, allowing the patient to avoid multiple attempts by the bedside nurse or emergency department clinician.”

To watch the video, scan the QR code or visit https://youtu.be/f4uOJBvdWpc

To watch the video, scan the QR code or visit https://youtu.be/-wf89hjl6FU

To watch the video, scan the QR code or visit https://youtu.be/tPR-6f2dJyg

“In contrast to the previous cases, this 56-year-old female had vein selection challenges and represented the mid-range of our subjects. In this case, no superficial veins were visible, and likely without an ultrasound would be inserted in the red zone of the hand or the antecubital fossa. Using the zone insertion method for selection is a bit more difficult in this case. In the upper forearm, we do identify veins with ultrasound for the basilic and cephalic having diameters of 3-4 mm. The left upper forearm cephalic was selected with a diameter of 3.5 mm without a tourniquet and 3.7 with. The 22-gauge 1.75-in catheter was inserted. The catheter-to-vein ratio was less than 25%. A valve was present distal to the tip of the catheter and the catheter avoided the valve. Flushing revealed retrograde flow and turbulence. The vein blood velocity was 3.6 cm/sec following catheter placement. The volumetric flow was calculated at 20.78 mL/min and the hemodilution ratio of >3 mL/min. This case had a lower hemodilution ratio, but it was still well within the 3:1 parameters, even at an infusion rate of 250 mL/hour.”

“In this next case, a healthy volunteer, the application of the 4Vs is demonstrated in a 54-year-old, 290-lb male. The veins in this subject are good, representing the upper range of the input data in our study. Observationally, superficial veins are visible in the forearm region. Without ultrasound assessment, a vein would likely be selected in the yellow zone, even though larger veins are present in the green zone. Upon ultrasound assessment, the vein diameter was found to be excellent at 4.1 mm without a tourniquet—even in the lower forearm—and 5.1 mm with a tourniquet. Following placement of a 22-gauge catheter with a 1.75-in length, the catheter-to-vein ratio was identified as taking up 25% and well within the good range for catheter-to-vein ratio. A valve was noted distal to the catheter tip, and the velocity measurements came in at 8.6 cm/sec. The volume measurement was 68.13 mL/min. When applied to the formula for the hemodilution ratio, we find that for an 80 mL/hour infusion, the ratio is quite high at 51:1. As the infusion rate increases to 250 mL/hour, a 16:1 ratio applies. All of these were within the optimal range for hemodilution and best outcomes. This video presented a demonstration of the flushing catheter. The catheter is sub-optimally positioned flat on the bottom of the vein. You can also see retrograde blood reflux, turbulence, and vein collapse that occurred during flushing.”

REFERENCES ADDITIONAL READING

1. Gagne P, Sharma K. Relationship of common vascular anatomy to cannulated catheters. Int J Vasc Med. 2017;5157914.

2. Helm R. Accepted but Unacceptable: Peripheral IV Catheter Failure. J Infus Nurs. 2015;38(3):189-203.

3. Maurer A. A five-year study of reducing the midline occlusion rates. Presented NHS 2016.

4. Moretti M. Vein preservation with extended dwell catheter technology. Presented at the Association for Vascular Access Scientific Meeting. September 2018. Columbus, OH.

5. Rickard CM. Routine versus clinically indicated replacement of peripheral intravenous catheters: a randomized controlled equivalence trial. Lancet. 2012;380(9848):10-66-1074.

6. Steere L, Ficara C, Davis M, Moureau N. Reaching One Peripheral Intravenous Catheter (PIVC) Per Patient Visit with LEAN multimodal strategy: The PIV5Rights™ Bundle. JAVA. 2019;24(3):31-43.

7. Roethlisberger D, Mahler HC, Altenburger U, Pappenberger A. If Euhydric and Isotonic Do Not Work, What Are Acceptable pH and Osmolality for Parenteral Drug Dosage Forms? J Pharm Sci. 2017 Feb;106(2):446-456. doi: 10.1016/j.xphs.2016.09.034. Epub 2016 Nov 23. PMID: 27889072.

8. Foor J, Moureau N. The role of hemodilution ratio in correlation to blood flow velocity and the impact of venous valves in retrograde blood reflux. Presented at the Association for Vascular Access Scientific Meeting. October 2019. Las Vegas, NV.

9. Spencer TR, Mahoney KJ. Reducing catheter-related thrombosis using a risk reduction tool centered on catheter to vessel ratio. J Thomb Thombolysis. 2017;44(4):427-432.

American Hospital Association. Fast Facts on US Hospitals. Page updated March 2020. Available at https://www.aha.org/statistics/fast-facts-us-hospitals. Accessed Oct. 25, 2020.

Carr PJ, Rippey JCR. Upper extremity deep vein thrombosis: a complication of an indwelling peripherally inserted central venous catheter. Clin Case Rep. 2015;3(3):170–174.

Constantino TG, et al. Ultrasonography-guided peripheral intravenous access versus traditional approaches in patients with difficult intravenous access. Ann Emerg Med. 2005;46(5):456-461.

Gagne P, Sharma K. Relationship of common vascular anatomy to cannulated catheters. J Vasc Med. 2017;2017:5157914.

Gonzalez Lopez JL, et al. Indwell times, complications and costs of open vs closed safety peripheral intravenous catheters: a randomized study. J Hosp Infect. 2014;86(2):117-126.

Helm R. Accepted but Unacceptable: Peripheral IV Catheter Failure. J Infus Nurs. 2015;38(3):189-203.

Lurie F, et al, Mechanism of venous valve changes and their role in circulation: a new concept. J Vasc Surg. 2003;38(5):955-61.

Marsh N, et al. Observational study of peripheral intravenous catheter outcomes in adult hospitalized patients: a multivariable analysis of peripheral intravenous catheter failure. J Hosp Med. 2018;13(2):83-89.

Moureau NL. Is the pH of Vancomycin an indication for central venous access? J Vasc Access. 2014;15(4):249-250.

Murayama R, et al. The relationship between the tip position of an indwelling venous catheter and the subcutaneous edema. Biosci Trends. 2015;9(6):414–419.

Nifong TP, McDevitt TJ. The effect of catheter to vein ratio on blood flow rates in a simulated model of peripherally inserted central venous catheters. Chest. 2011;140(1):48-53

Paauw J, et al. The incidence of PICC line-associated thrombosis with and without the use of prophylactic anticoagulants. J Parenter Enteral Nutr. 2008;32(4):443–447.

Patel SA, Alebich MM, Feldman LS. Routine replacement of peripheral intravenous catheters. J Hosp Med. 2017;12(1):42-45.

Piper R, et al. The mechanistic causes of peripheral intravenous catheter failure based on a parametric computational study. Sci Rep. 2018;8(1):3441.

Rickard CM, Marsh NM. Inpatient Notes: The Other Catheter, The Mighty Peripheral IV. Ann Intern Med. 2017;167(10):HO2-HO3.

Rippey JC, et al. Predicting and preventing peripheral intravenous cannula insertion failure in the emergency department: clinician ‘gestalt’ wins again. Emerg Med Australas. 2016;28(6):658-665.

Sharp R, et al. Measurement of vein diameter for peripherally inserted central catheter (PICC) insertion. J Infus Nurs. 2015;38(5):351-357.

Steere L, Ficara C, Davis M, Moureau N. Reaching One Peripheral Intravenous Catheter (PIVC) Per Patient Visit with LEAN multimodal strategy: The PIV5Rights™ Bundle. JAVA. 2019;24(3):31-43.

Tanabe H, et al. Using ultrasonography for vessel diameter assessment to prevent infiltration. J Infus Nurs. 2016;39(2):105-111.

Roethlisberger D, Mahler HC, Altenburger U, Pappenberger A. If Euhydric and Isotonic Do Not Work, What Are Acceptable pH and Osmolality for Parenteral Drug Dosage Forms? J Pharm Sci. 2017 Feb;106(2):446-456. doi: 10.1016/j.xphs.2016.09.034. Epub 2016 Nov 23. PMID: 27889072.