The learning curve of sonographic inferior vena cava evaluation by novice medical students: the Pavia experience

Point-of-Care Ultrasound Psychomotor Learning Curves: A Systematic Review of the Literature

OBJECTIVES

Use of point-of-care ultrasound (POCUS) in clinical medicine and inclusion in medical training is increasing. Some professional societies recommend that 25-50 POCUS examinations be completed for each application learned; however, the amount of practice required is not well studied. As such, a better understanding of the learning curves of POCUS psychomotor skills is needed. This systematic review characterizes the learning curves for POCUS psychomotor skill acquisition.

METHODS

With the assistance of a research librarian, the available literature through August 28, 2023, was identified. The titles and abstracts, and then the full text were reviewed by two reviewers to screen for inclusion. All studies included after full-text review then underwent data extraction and analysis.

RESULTS

The search identified 893 unique studies. Forty-five studies underwent full-text review, with 17 meeting full inclusion criteria. Substantial heterogeneity was noted in study design, duration of education, number and type of learners, and methods for statistical analysis. Clear and validated definitions for learning endpoints, such as plateau points or competency, are lacking. Learning curves and endpoints differ for different applications of POCUS.

CONCLUSION

The results are overall supportive of the recommendations to complete 25-50 examinations per application of POCUS learned. However, specific applications require more practice than others. Certain applications, such as cardiac and the Focused Assessment with Sonography in Trauma (FAST) exams, are closer to 50; while others, such as soft tissue, airway, and eye require no more than 25.

Inferior vena cava to aorta ratio in dehydrated pediatric patients: a systematic review and meta-analysis

BACKGROUND

Dehydration due to acute diarrhea is among the leading causes of mortality. However, advancements in management and technology do not help clinicians differentiate dehydration degrees. Ultrasound using the inferior vena cava to aorta (IVC/ Ao) ratio is a promising noninvasive technique to identify significant pediatric dehydration.

PUSPOSE

Therefore, this systematic review and meta-analysis aimed to examine the diagnostic parameters of the IVC/Ao ratio for predicting clinically significant dehydration in pediatric patients.

METHODS

We searched the MEDLINE, PubMed, Cochrane Library, ScienceDirect, and Google Scholar databases for studies of pediatric patients (≤18 years old) who presented with signs and symptoms of dehydration due to acute diarrhea, gastroenteritis, or vomiting. The inclusion criteria were cross-sectional, case-control, cohort, and randomized controlled trial study design and publication in any language. We then conducted a meta-analysis using the midas and metandi commands from Stata software.

RESULTS

Five studies of 461 patients were included. The combined sensitivity was 86% (95% confidence interval [CI], 79%-91%), while the specificity was 73% (95% CI, 59%-84%). The area under the curve was 0.89 (95% CI, 0.86-0.91). The positive likelihood ratio (LR+) was 3.2 (95% CI, 2.1-5.1) with a 76% posttest probability, while the negative likelihood ratio (LR-) was 0.18 (95% CI, 0.12-0.28) with a 16% posttest probability. The combined negative predictive value was 0.83 (95% CI, 0.75-0.91), while the positive predictive value was 0.75 (95% CI, 0.68-0.82).

CONCLUSION

The IVC/Ao ratio was insufficient to exclude or confirm significant dehydration in pediatric patients. More studies are needed, especially multicenter, adequately powered diagnostic research, to will help establish the usefulness of the IVC/Ao ratio.

Bedside ultrasound of the internal jugular vein to assess fluid status and right ventricular function: The POCUS-JVD study

BACKGROUND

Accurate estimation of fluid status is important in the management of heart failure patients, however, the current methods for bedside assessment can be unreliable or impractical for daily use.

METHODS

Non-ventilated patients were enrolled immediately prior to scheduled right heart catheterization (RHC). Using M-mode, IJV maximum (Dmax) and minimum (Dmin) anteroposterior diameters were measured during normal breathing, while supine. Respiratory variation in diameter (RVD) was calculated as [(Dmax - Dmin)/Dmax] in percentage. Collapsibility with sniff maneuver (COS) was assessed. Lastly, inferior vena cava (IVC) was assessed. Pulmonary artery pulsatility index (PAPi) was calculated. Data was obtained by five investigators.

RESULTS

Total 176 patients were enrolled. Mean BMI was 30.5 kg/m2, LVEF 14-69% (range), 38% with LVEF ≤35%. The POCUS of IJV could be performed in all patients in <5 min. Increasing RAP demonstrated progressive increase in IJV and IVC diameters. For high filling pressure (RAP ≥10 mmHg), an IJV Dmax ≥1.2 cm or IJV-RVD < 30% had specificity >70%. Combining the POCUS of IJV to physical examination improved the combined specificity to 97% for RAP ≥10 mmHg. Conversely, a finding of IJV-COS was 88% specific for normal RAP (<10 mmHg). An IJV-RVD <15% is suggested as a cutoff for RAP ≥15 mmHg. The performance of IJV POCUS was comparable to IVC. For RV function assessment, IJV-RVD < 30% had 76% sensitivity and 73% specificity for PAPi <3, while IJV-COS was 80% specific for PAPi ≥3.

CONCLUSION

POCUS of IJV is an easy to perform, specific and reliable method for volume status estimation in daily practice. An IJV-RVD < 30% is suggested for estimation of RAP ≥10 mmHg and PAPi <3.

Learning curves for point-of-care ultrasound image acquisition for novice learners in a longitudinal curriculum

BACKGROUND

A learning curve is graphical representation of the relationship between effort, such as repetitive practice or time spent, and the resultant learning based on specific outcomes. Group learning curves provide information for designing educational interventions or assessments. Little is known regarding the learning curves for Point-of-Care Ultrasound (POCUS) psychomotor skill acquisition of novice learners. As POCUS inclusion in education increases, a more thorough understanding of this topic is needed to allow educators to make informed decisions regarding curriculum design. The purpose of this research study is to: (A) define the psychomotor skill acquisition learning curves of novice Physician Assistant students, and (B) analyze the learning curves for the individual image quality components of depth, gain and tomographic axis.

RESULTS

A total of 2695 examinations were completed and reviewed. On group-level learning curves, plateau points were noted to be similar for abdominal, lung, and renal systems around 17 examinations. Bladder scores were consistently good across all exam components from the start of the curriculum. For cardiac exams, students improved even after 25 exams. Learning curves for tomographic axis (angle of intersection of the ultrasound with the structure of interest) were longer than those for depth and gain. Learning curves for axis were longer than those for depth and gain.

CONCLUSION

Bladder POCUS skills can be rapidly acquired and have the shortest learning curve. Abdominal aorta, kidney, and lung POCUS have similar learning curves, while cardiac POCUS has the longest learning curve. Analysis of learning curves for depth, axis, and gain demonstrates that axis has the longest learner curve of the three components of image quality. This finding has previously not been reported and provides a more nuanced understanding of psychomotor skill learning for novices. Learners might benefit from educators paying particular attention to optimizing the unique tomographic axis for each organ system.

A Hybrid Musculoskeletal Ultrasound Curriculum for Physical Medicine and Rehabilitation Residents-a Multi-center Pilot Program

Purpose of Review

The increased use of musculoskeletal ultrasound (MSKUS) in clinical practice warrants achieving competency earlier in physiatrists' careers. Physical Medicine and Rehabilitation (PM&R) residency programs have started incorporating formal MSKUS training in their curricula; however, significant heterogeneity remains in MSKUS education.

Recent Findings

Numerous barriers contribute to the lack of consensus for MSKUS training during residency, but the COVID-19 pandemic severely disrupted in-person learning. As an adjunct or alternative to in-person learning, teleguided technology is being utilized.

Summary

This curriculum demonstrates the role of a hybrid MSKUS training with interinstitutional collaboration. Twenty PM&R learners, from two institutions, were divided into a fundamental or advanced track. Virtual didactic sessions alternated weekly with hands-on ultrasonographic scanning sessions. Following a 12-month longitudinal curriculum, an end-of-year practical examination was used for competency assessment, in addition to a survey assessing resident perceptions and feedback. To our knowledge, this is the first collaborative and hybrid MSKUS curriculum for PM&R learners that can be easily reproduced at most training institutions and circumvent some of the barriers amplified by the COVID-19 pandemic.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40141-023-00380-z.

Learning rate of students detecting and annotating pediatric wrist fractures in supervised artificial intelligence dataset preparations

The use of artificial intelligence (AI) in image analysis is an intensively debated topic in the radiology community these days. AI computer vision algorithms typically rely on large-scale image databases, annotated by specialists. Developing and maintaining them is time-consuming, thus, the involvement of non-experts into the workflow of annotation should be considered. We assessed the learning rate of inexperienced evaluators regarding correct labeling of pediatric wrist fractures on digital radiographs. Students with and without a medical background labeled wrist fractures with bounding boxes in 7,000 radiographs over ten days. Pediatric radiologists regularly discussed their mistakes. We found F1 scores-as a measure for detection rate-to increase substantially under specialist feedback (mean 0.61±0.19 at day 1 to 0.97±0.02 at day 10, p<0.001), but not the Intersection over Union as a parameter for labeling precision (mean 0.27±0.29 at day 1 to 0.53±0.25 at day 10, p<0.001). The times needed to correct the students decreased significantly (mean 22.7±6.3 seconds per image at day 1 to 8.9±1.2 seconds at day 10, p<0.001) and were substantially lower as annotated by the radiologists alone. In conclusion our data showed, that the involvement of undergraduated students into annotation of pediatric wrist radiographs enables a substantial time saving for specialists, therefore, it should be considered.

Decreased inferior vena cava diameter as an early marker in postpartum hemorrhage

OBJECTIVES

To examine the association between inferior vena cava (IVC) diameter and postpartum blood loss and assess whether IVC diameter is a useful marker in the evaluation of intravascular volume status in women with postpartum hemorrhage (PPH).

METHODS

This was a prospective case-control study conducted in a university medical teaching center in Afula, Israel, between November 2018 and March 2020. The study cohort consisted of women with a singleton pregnancy who delivered vaginally at term. The PPH group included women diagnosed with PPH based on visually estimated blood loss of 1000 mL or more at the time of enrolment. Hemodynamically unstable women or women with major bleeding at the time of diagnosis were not included. The control group consisted of women with an uneventful fourth stage of labor. IVC diameter was measured using transabdominal ultrasonography during inspiration (IVCi diameter) and expiration (IVCe diameter), and the collapsibility index was calculated ((IVCe - IVCi)/IVCe × 100). The primary outcome was the percentage difference in IVC diameter and collapsibility index between the PPH group and controls. The performance of the IVC collapsibility index in the prediction of the need for blood transfusion in women with PPH was assessed. In order to demonstrate a difference of 20% with a power of 80% and alpha of 0.05, 108 women, at a ratio of 1:2 in the study and control groups, respectively, were needed.

RESULTS

Overall, 36 and 72 women were included in the final analysis in the PPH and control groups, respectively. IVCi and IVCe diameters were significantly smaller in the PPH group (0.93 ± 0.30 cm and 1.26 ± 0.32 cm, respectively) than in controls (1.42 ± 0.31 cm and 1.75 ± 0.28 cm, respectively) (P = 0.001 for both). The percentage reductions in IVCi and IVCe diameters in the PPH group compared with controls were 35.0% and 28.0%, respectively. IVC collapsibility index was increased significantly, by 42.9% (26.04 ± 8.67% vs 18.15 ± 5.07%; P = 0.001) in the PPH group compared with controls. IVC collapsibility index was a significant predictor of the need for blood transfusion and correctly predicted 81% of cases. Logistic regression analysis demonstrated that IVC collapsibility index was also a significant predictor of a drop in hemoglobin level of ≥ 2 g/dL (P = 0.001).

CONCLUSIONS

IVC diameter changes in response to postpartum blood loss. Measurement of IVC diameter using transabdominal ultrasonography is an objective and useful non-invasive method for the early evaluation of intravascular volume status in women with PPH and for the prediction of cases that might require blood transfusion. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Influence of age and scanning system on the learning curve of experienced and novel intraoral scanner operators: A multi-centric clinical trial

OBJECTIVES

To evaluate the effect of age and intra-oral scanner (IOS) on the learning curve of inexperienced operators.

METHODS

Thirty-four operators pertaining to 1 of 3 groups: (G1) students ≤ 25 years (y), (G2) dentists ≥ 40y, and (G3) a control group of experienced IOS operators (no age limitation), were included. All participants performed baseline and final quadrant scans on a volunteer subject, before and after a training program of 3 sessions, with two different IOS: TRIOS 3 (S1) and True Definition (S2). Baseline and final scanning times were registered in seconds. A Pearson correlation was applied to evaluate the correlation between age and scanning time. An ANOVA of repeated measures test was applied to evaluate inter-group (G1, G2, G3) and inter-system performance. Significance level was set at a = 0.05.

RESULTS

Age and scanning time for inexperienced operators showed a weak positive correlation for final scanning time (r = 0.29, p < 0.05). When comparing groups and filtering by IOS, S1 failed to show differences between groups (p > 0.05). With S2, the control group demonstrated a better performance than G2 (p < 0.05), while G1 only demonstrated a better performance than G2 at final scanning time (p = 0.005). Overall, the type of IOS had a significant impact on the scanning time (p < 0.001).

CONCLUSION

Results from this study indicate that age and type of IOS have an impact on the performance and learning curve of inexperienced IOS operators.

CLINICAL SIGNIFICANCE

Gaining knowledge on how different aspects, such as age, experience or IOS system, influence the learning curve to IOSs is relevant due to the financial and strategical impact associated with the acquisition of an IOS.

The Focused Assessment with Sonography in Cancer (FASC) Examination

Malignant effusions occur frequently in patients with cancer and are important to diagnose and treat. In this report, we describe a novel point-of-care ultrasound (POCUS) protocol to rapidly identify pleural effusion, pericardial effusion, and ascites: The Focused Assessment with Sonography in Cancer (FASC). This protocol utilizes six standard sonographic positions to identify the presence of fluid in common anatomic spaces. The FASC examination is intended for widespread use by oncologists and other clinicians who treat patients with cancer.

Gel Rounds: Integrating Bedside Ultrasound Training for Third-Year Medical Students Into the Internal Medicine Clerkship

Despite formal ultrasound training becoming prevalent in preclinical medical student education, significant barriers remain to the continuation of this training during clinical years. We sought to develop a program for third-year medical students to continue ultrasound training after an already robust preclinical ultrasound curriculum and evaluate their scanning confidence after participation. We developed a program to facilitate bedside ultrasound scanning of patients being cared for by third-year students. Students identified appropriate patients to be scanned, obtained consent for scanning, and determined which scans were most appropriate given the patient's clinical problems. Trained facilitators met with students at the bedside in 1-hour sessions called Gel Rounds to observe and direct the students' scans of their patients. Fifty-one students were surveyed after completing Gel Rounds. Students were significantly more likely to feel comfortable with independently acquiring and interpreting images after Gel Rounds than before completing the activity. Approximately 67% of students felt that ultrasound had utility in assisting bedside clinical reasoning, and this proportion did not change significantly after completing Gel Rounds. Gel Rounds was a positive continuation of the ultrasound curriculum into the third-year clerkship environment. A minority of students reported prior ultrasound exposure in their third year, reflecting difficulty with developing a longitudinal curriculum. The activity helped students to independently acquire and interpret images in patients. Because Gel Rounds can be performed at the discretion of students and faculty, it fits naturally in a variety of existing longitudinal curricula.

Lung-ultrasound objective structured assessment of technical skills (LUS-OSAUS): utility in the assessment of lung-ultrasound trained medical undergraduates

Purpose

Recently, some attempts have been made to integrate lung ultrasound (LUS) teaching into medical curricula. However, current education studies of LUS are extremely heterogeneous due to the lack of evidence-based guidelines on LUS education. In particular, the assessment of competencies is poorly standardized and mostly relies on non-validated scales. A new validated tool, the objective structured assessment of lung ultrasound skills (LUS-OSAUS), has the potential to overcome these limitations. Therefore, we adopted the LUS-OSAUS tool to assess the competencies of a group of LUS-trained undergraduates. Existing no prior practical applications of the LUS-OSAUS, our aim was to investigate the practical utility of this tool and its applicability in the evaluation of US-trained medical students.

Methods

Eight undergraduates (two males, six females) were enrolled on a voluntary basis to receive a theoretical and practical training in LUS. Once completed their training, each student performed an LUS examination on a different patient hospitalized for respiratory symptoms. The same eight patients were also scanned by a senior resident in emergency medicine for a comparison with students’ results. Students and the senior resident were tested by an examiner using the LUS-OSAUS tool. We compared the scores obtained by operators in all areas of competence of the LUS-OSAUS, the total scores, and the time needed to complete the sonographic task.

Results

Median students’ score in the single items of the scale was significantly lower than the ones obtained by the senior resident (4.0 [3.3–5.0] vs. 5.0 [5.0–5.0]; p < 0.0001). Students scored significantly lower than the senior resident in each item, except for B-line identification, choice of the correct transducer, and suggested focused questions. Median total score was also lower for students compared to the senior resident (70.5 [61.0–74.8] vs. 84.0 [83.5–84.3] (p = 0.0116). Median time required to complete the examination was significantly higher for students (14.1 [12.8–16.1] vs. 4.7 [3.9–5.2] min, p = 0.0117).

Conclusions

The LUS-OSAUS tool allowed for a standardized and comprehensive assessment of student’s competencies in lung ultrasound, and helped to discriminate their level of expertise from that of a more experienced operator. The scale also specifically tests the theoretical knowledge of trainees, thus making redundant the use of questionnaires designed for this purpose.

Electronic supplementary material

The online version of this article (10.1007/s40477-020-00454-x) contains supplementary material, which is available to authorized users.