Measuring Cannulation Skills for Hemodialysis: Objective Versus Subjective Assessment

Abstract

Lack of cannulation skill during hemodialysis treatments results in poor clinical outcomes due to infiltration and other cannulation-related trauma. Unfortunately, training of patient care technicians and nurses, specifically on the “technical” aspects of cannulation, has traditionally not received much attention. Simulators have been successfully deployed in many medical specialties for assessment and training of clinical skills. However, simulators have not been as widely used in nursing, especially in the context of training clinical personnel in the dialysis unit. We designed a state-of-the-art simulator for quantifying skill for hemodialysis cannulation. In this study, 52 nurses and patient care technicians with varying levels of clinical experience performed 16 cannulations on the simulator with different fistula properties. We formulated a composite metric for objectively measuring overall success of cannulation and compared this metric with subjective assessment by experts. In addition, we examined if years of clinical experience correlated with objective and subjective scores for cannulation skill. Results indicated that, while subjective and objective metrics generally correlated with each other, the objective metric was more precise and better suited for quantifying cannulation skill. Further, the simulator-based objective metric provides several advantages over subjective ratings, including providing fine-grained assessment of skill, consistency in measurement unaffected by subjective biases, and basing assessment on a more complete evaluation of performance. Years of clinical experience, however, demonstrated little correlation with either method of skill assessment. The methods presented for cannulation skill assessment in this study, if widely applied, could result in improved cannulation skill among our PCTs and nurses, which could positively impact patient outcomes in a tangible way.

Simulator-Based Metrics for Quantifying Vascular Palpation Skill for Cannulation

“…This study examines subject data collected from a novel hemodialysis (HD) cannulation simulator [34], which has been previously demonstrated for successful quantification of cannulation skill [35]. The simulator itself is comprised of four fistulas located radially around the simulator bed with motors in each fistula vibrating at an intensity and pattern to simulate "thrill" at the point of anastomosis, where the fistula was created.…”

“…Finally, subjects completed a post-experimental questionnaire, scoring the simulator's realism and usefulness for training. Peer-recognized experts observed participants as they performed the trials and rated each subject on a global rating scale (GRS) on a scale of 1-7 in five categories [35]. Only two of the categories could be argued to be relevant to palpation (palpation skill and overall), while the other categories focus on needle insertion.…”

“…As described in our earlier work, we used stb, the indicator of whether or not stable flashback was achieved upon cannulation as our outcome metric in this study. stb = 1 when "there is at least 2 s of flashback without any interruption until the end of a trial" [35]. All other trials had stb = 0.…”

“…Building on our previous work [33], this study aims to (1) identify metrics which objectively differentiate between high performer (HP), mid performer (MP), and low performer (LP) behavior during cannulation towards quantitatively understanding vascular palpation skill and (2) to relate these metrics to objective cannulation outcome measures that were previously described [34], [35]. To our knowledge, for the first time, we use both force and motion sensor data to understand vascular palpation skill specifically.…”

Needle Angle Matters: An Investigation of the Effect of Needle Angle on Hemodialysis Cannulation Skill

“…11 In line with this, our team has developed a "smart" cannulation simulator with the ability to comprehensively quantify cannulation skill. [12][13][14][15][16][17] In this work-and to the best of our knowledge, for the first time-we present a simulator-based, quantitative study examining the relationship between needle angles, cannulation outcomes, and cannulation skill from a cohort of nurses and PCTs. Toward this, we introduce three kinds of novel angle metrics on the basis of needle insertion angle profiles during cannulation to quantify cannulation performance.…”