Training novice in ultrasound-guided venipuncture: A randomized controlled trial comparing out-of-plane needle-guided versus free-hand ultrasound techniques on a simulator

Where do ICU trainees really look? An eye-tracking analysis of gaze patterns during central venous catheter insertion

BACKGROUND

There is limited knowledge about gaze patterns of intensive care unit (ICU) trainee doctors during the insertion of a central venous catheter (CVC). The primary objective of this study was to examine visual patterns exhibited by ICU trainee doctors during CVC insertion. Additionally, the study investigated whether differences in gaze patterns could be identified between more and less experienced trainee doctors.

METHODS

In a real-life, prospective observational study conducted at the interdisciplinary ICU at the University Hospital Zurich, Switzerland, ICU trainee doctors underwent eye-tracking during CVC insertion in a real ICU patient. Using mixed-effects model analyses, the primary outcomes were dwell time, first fixation duration, revisits, fixation count, and average fixation time on different areas of interest (AOI). Secondary outcomes were above eye-tracking outcome measures stratified according to experience level of participants.

RESULTS

Eighteen participants were included, of whom 10 were inexperienced and eight more experienced. Dwell time was highest for CVC preparation table (p = 0.02), jugular vein on ultrasound image (p < 0.001) and cervical puncture location (p < 0.001). Concerning experience, dwell time and revisits on jugular vein on ultrasound image (p = 0.02 and p = 0.04, respectively) and cervical puncture location (p = 0.004 and p = 0.01, respectively) were decreased in more experienced ICU trainees.

CONCLUSIONS

Various AOIs have distinct significance for ICU trainee doctors during CVC insertion. Experienced participants exhibited different gaze behavior, requiring less attention for preparation and handling tasks, emphasizing the importance of hand-eye coordination.

Influential factors on the echogenicity of peripheral venous catheters: Insights from an experimental phantom study

INTRODUCTION

Ultrasound-guided placement of peripheral venous catheters requires appropriate equipment. Among the devices used, peripheral venous catheters have different structure and properties. This study aimed to define the impact of these different factors on the echogenicity of peripheral venous catheters.

METHOD

An open comparative study was conducted from September 2022 to May 2023. Thirteen devices were introduced in a standardized manner along the longitudinal and transverse axes with the help of guides into a phantom at different angles. Two criteria defined the echogenicity of these devices: the surface occupied by the device in the image (composite criterion: length and diameter of the device and angle of insertion) and its brightness (average of the pixel intensity of gray). Sixty-five ultrasound images were recorded and postprocessed twice (blinded to the previous measurement) by an expert operator, for reproducibility purposes.

RESULTS

The intra-observer reproducibility of all measurements was excellent, with an intra-class coefficient of >0.90 over the entire dataset. On the longitudinal axis, echogenicity was significantly influenced by insertion angle (p = 0.009), device length (p = 0.006), and the interaction of cannula component and insertion angle (p = 0.007). On the transverse axis, no factors significantly influenced the device's echogenicity.

DISCUSSION

The echogenicity of a device is an essential component of successful ultrasound-guided peripheral venous catheter placement. Optimizing catheter intrinsic factors such as components of the cannula and length, and extrinsic factor like the insertion angle should be considered in their design and use to reduce puncture failure rates.

Effect of a thin-tipped short bevel needle for peripheral intravenous access on the compressive deformation and displacement of the vein: A preclinical study

BACKGROUND

Peripheral intravenous catheter (PIVC) insertion often fails on the first attempt. Risk factors include small vein size and dehydration, causing vein deformation and displacement due to puncture resistance of the vessel. The authors developed a short, thin-tipped bevel needle and compared its puncture performance with needles of four available PIVCs using an ex vivo model.

METHODS

The PIVC with the thin-tipped short bevel needle was compared to four available PIVCs using an ex vivo model which simulated the cephalic vein of the human forearm. The ex vivo model consisted of a porcine shoulder and porcine internal jugular vein, and was used for evaluation of the rate of vein deformation and vessel displacement during needle insertion.

RESULTS

An ex vivo model was created with a vessel diameter of 2.7-3.7 mm and a depth of 2-5 mm. The thin-tipped short bevel PIVC needle was associated with a significantly lower compressive deformation rate and venous displacement compared to the needles of the other four PIVCs.

CONCLUSION

The thin-tipped short bevel needle induced lower compressive deformation and displacement of the vein than the conventional needles. This needle has the potential to improve the first-attempt success rate of peripheral intravenous catheterization in patients with difficult venous access.

Ultrasound-Guided Percutaneous Arteriovenous Fistula Creation Simulation Training in a Lifelike Flow Model

Objectives: To assess the feasibility and training effect of simulation training for ultrasound-guided percutaneous arteriovenous fistula (pAVF) creation in a lifelike flow model. Methods: Twenty vascular trainees and specialists were shown an instructional video on creating a pAVF in a dedicated flow model and then randomized to a study or control group. The procedure was divided into five clearly defined steps. Two observers rated the performance on each step, and the time to perform the exercise was recorded. The study group participants underwent supervised hands-on training on the model before performing a second rated pAVF creation. All participants subsequently completed a feedback questionnaire. Results: After supervised simulation training, the study groups participants increased their mean performance rating from 2.2 ± 0.9 to 3.2 ± 0.7. A mean of 3.8 ± 0.8 procedure steps was accomplished independently (control group 2.1 ± 1.4; p < 0.05). The time taken to perform the procedure was 15.6 ± 3.8 min in the study group (control group 27.2 ± 7.3, p < 0.05). The participants with previous experience in ultrasound-guided vascular procedures (n = 5) achieved higher overall mean scores 3.0 ± 0.8 and accomplished more steps without assistance (2.0 ± 1.0) during the simulation training compared to their inexperienced peers (1.5 ± 0.3 and 0.8 ± 0.4, respectively). The feedback questionnaire revealed that the study group participants strongly agreed (n = 7) or agreed (n = 3) that training on the simulation model improved their skills regarding catheter handling. Conclusions: The study group participants increased their overall performance after training on the simulator. More experienced attendees performed better from the beginning, indicating the model to be lifelike and a potential skill assessment tool. Simulation training for pAVF creation using a lifelike model may be an intermediate step between acquiring ultrasound and theoretical pAVF skills and procedure guidance in theatre. However, this type of training is limited by its reliance on the simulator quality, demonstration devices and costs.