Clinician-performed abdominal sonography

Optimal bowel diameter thresholds for diagnosing small bowel obstruction and surgical intervention with point-of-care ultrasound

OBJECTIVES

A bowel diameter threshold of ≥2.5 cm, originally derived from the research using computed tomography, is frequently used for diagnosing small bowel obstruction (SBO) with point-of-care ultrasound (POCUS). We sought to determine the optimal bowel diameter threshold for diagnosing SBO using POCUS and its accuracy in predicting surgical intervention.

METHODS

We conducted a secondary analysis using individual patient-level data from a previous systematic review on POCUS for SBO diagnosis across five academic EDs. Patient data were collected, including imaging results, surgical findings, and final diagnosis. The measured diameter of the small bowel using POCUS was recorded. ROC area under the receiver operating characteristic curves (AUC) were constructed to determine the optimal threshold for bowel diameter in predicting SBO diagnosis and surgical intervention. Subgroup analyses were performed based on sex and age.

RESULTS

A total of 403 patients had individual patient-level data available, with 367 patients included in the final analysis. The most accurate bowel diameter overall for predicting SBO was 2.75 cm (AUC = 0.76, 95% CI 0.71-0.81). A bowel diameter of ≤1.7 cm had 100% sensitivity with no miss rate, while a bowel diameter of ≥4 cm had 90.7% specificity in confirming SBO. Patients under 65 had an optimal threshold of 2.75 cm versus 2.95 cm in patients over 65. Females had an optimal threshold of 2.75 cm, while males had a value of 2.95 cm. There was no significant correlation between bowel diameter thresholds and surgical intervention.

CONCLUSION

A bowel diameter threshold of 2.75 cm on POCUS is more discriminative diagnostic accuracy for diagnosing SBO. Patients' age and sex may impact diagnostic accuracy, suggesting that tailored approaches may be needed.

Impact of emergency physician performed ultrasound in the evaluation of adult patients with acute abdominal pain: a prospective randomized bicentric trial

BACKGROUND

Abdominal pain is common in patients visiting the emergency department (ED). The aim of this study was to assess the diagnostic contribution of point-of-care ultrasound (POCUS) in patients presenting to the ED with acute abdominal pain.

METHODS

We designed an interventional randomized, controlled, open label, parallel-group, trial in two French EDs. We included adult patients presenting to the ED with acute abdominal pain. Exclusion criteria were a documented end-of-life, an immediate need of life-support therapy and pregnant or breast-feeding women. Patients were randomized in the experimental group (i.e., workup including POCUS) or control group (usual care). The primary objective of the study was to assess the added value of POCUS on diagnostic pathway in the ED, according to the diagnostic established a posteriori by an adjudication committee. The primary endpoint was the proportion of exact preliminary diagnosis between the 2 groups. The preliminary diagnosis made after clinical examination and biological results with POCUS (intervention arm) or without POCUS (usual care) was considered exact if it was similar to the adjudication committee diagnosis.

RESULTS

Between June 2021 11th and June 2022 23th, 256 patients were randomized, but five were not included in the primary analysis, leaving 125 patients in the POCUS group and 126 patients in the usual care group (130 women and 121 men, median [Q1-Q3] age: 42 [30;57]). There was no difference for exact diagnosis between the two groups (POCUS 70/125, 56% versus control 78/126 (62%), RD 1.23 [95% CI 0.74-2.04]). There was no difference in the accuracy for the diagnosis of non-specific abdominal pain nor number of biological or radiological exams. Diagnostic delays and length of stay in the ED were also similar.

CONCLUSIONS

In this trial, systematic POCUS did not improve the rate of diagnostic accuracy in unselected patients presenting to the ED with acute abdominal pain. However, as it was a safe procedure, further research should focus on patients with suspected etiologies where POCUS is particularly useful.

TRIAL REGISTRATION

 This trial was registered on ClinicalTrials.gov on 2022/07/20 ( https://clinicaltrials.gov/study/NCT04912206?id=NCT04912206&rank=1 ) (NCT04912206).

Multi-center analysis of point-of-care ultrasound for small bowel obstruction: A systematic review and individual patient-level meta-analysis

OBJECTIVE

The study aimed to assess the diagnostic accuracy of point-of-care ultrasound (POCUS) in identifying small bowel obstruction (SBO) and to investigate the impact of clinician experience level and body mass index (BMI) on POCUS performance for diagnosing SBO in the Emergency Department.

METHODS

We systematically searched PubMed and Cochrane databases from January 2011-2022. We performed a meta-analysis using individual patient-level data from prospective diagnostic accuracy studies from which we obtained data from the corresponding authors. Overall test characteristics and subgroup analysis across clinician experience levels and a range of BMI were calculated. The primary outcome was SBO as the final diagnosis during hospitalization.

RESULTS

We included Individual patient data from 433 patients from 5 prospective studies. Overall, 33% of patients had a final diagnosis of SBO. POCUS had 83.0% (95%CI 71.7%-90.4%) sensitivity and 93.0% (95%CI 55.3%-99.3%) specificity; LR+ was 11.9 (95%CI 1.2-114.9) and LR- was 0.2 (95%CI 0.1-0.3). Residents had exhibited a sensitivity of 73.0% (95%CI 56.6%-84.9%) and specificity of 88.2% (95%CI 58.8%-97.5%), whereas attendings had demonstrated a sensitivity of 87.7% (95%CI 71.1%-95.4%) and specificity of 91.4% (95%CI 57.4%-98.8%). Among those patients with BMI<30 kg/m², POCUS showed a sensitivity of 88.6% (95%CI 79.5%-94.7%) and a specificity of 84.0% (95%CI 75.3%-90.6%), while patients with BMI ≥ 30 kg/m² exhibited a sensitivity of 72.0% (95%CI 50.6%-87.9%) and specificity of 89.5% (95%CI 75.2%-97.1%).

CONCLUSIONS

POCUS correctly identified those patients with SBO with high sensitivity and specificity. Diagnostic accuracy was slightly reduced when performed by resident physicians and among patients with a BMI ≥ 30 kg/m².

REGISTRATION

PROSPERO registration number: CRD42022303598.

Impact of emergency physician-performed ultrasound for the evaluation of patients with acute abdominal pain, prospective randomized dual Centre study: study protocol for a diagnostic trial

Background

Abdominal pain is frequent in patients consulting in emergency departments. The aim of this study is to determine the diagnosis efficacy of point-of-care ultrasound (POCUS) in patients consulting in the ED for acute abdominal pain by comparing the rate of exact diagnostic between the two arms (with or without POCUS), according to the index diagnostic established by an adjudication committee.

Methods

It is a randomized, controlled, open and interventional study in two emergency departments. The included patients will be adults admitted for acute abdominal pain. Exclusion criteria will be a documented end-of-life, an immediate need of life-support therapy and pregnant or breast-feeding women. Patients will be randomized in intervention (POCUS) or control groups. POCUS will only be performed by trained physicians and will be added to the diagnosis procedure in the intervention group. In the control group, the diagnosis will be established after clinical examination and reception of biological analysis results. In the interventional group, the diagnosis will be established after a clinical exam, biological analysis reception and POCUS. An adjudication committee will review all data from case report forms and will determine the index diagnosis which will be used for the analysis.

The primary endpoint will be the comparison of the rate of exact diagnostic between the two arms according to the adjudication committee diagnostic. Secondary endpoints will be the comparison between the two groups for diagnostic delay, duration of ED stay, diagnostic performances for non-specific abdominal pain and hospitalization rate. The primary endpoint will be compared between the two groups using a mixed model taking into account the recruiting centre. Delays will be compared by a mixed linear generalized model. Diagnostic performances will be estimated with their 95% confidence intervals. For a correct diagnostic rate of 57% in the control group and 74% in the intervention group with a 0.05 alpha risk and a 80% power, 244 patients will be required.

Discussion

POCUS diagnostic abilities have been mainly demonstrated in monocentric studies but the level of evidence of its diagnostic efficacy remains controversial in particular in Europe. The aim of this study is to address this question with a rigorous methodology.

Trial registration

ClinicalTrials.gov NCT04912206. Registered on June 3, 2021.

Is Ocular Sonography a Reliable Method for the Assessment of Elevated Intracranial Pressure in Children?

Point-of-care ultrasound has been widely used by clinicians at the bedside in recent years. Various types of point-of-care ultrasound practices are employed, especially in pediatric emergency rooms and intensive care units. Pediatric intensive care specialists perform point-of-care ultrasound virtually as a part of physical examination since it provides just-in-time vital clinical information, which could assist in acute management strategies in critically ill patients. Measurement of optic nerve sheath diameter using point-of-care ultrasound is a noninvasive and radiation-free technique to determine raised intracranial pressure. Ophthalmic artery and central retinal artery Doppler indices can be used as transcranial Doppler to assess raised intracranial pressure. The aim of this review was to provide detailed information on ultrasonographic measurements of optic nerve sheath diameter and central retinal artery Doppler indices as techniques of interest for predicting increased intracranial pressure in pediatric patients in view of the literature.

Ultrasonographic inferior vena cava collapsibility and distensibility indices for detecting the volume status of critically ill pediatric patients

Especially in recent years, the use of point-of-care ultrasound by non-radiologist clinicians has become widespread. Point-of-care ultrasound provides rapid responses to the problems of critically ill patients at the bedside. This technique has many important advantages, including being non-invasive, cheap, repeatable, painless, and radiation-free. Numerous studies have revealed the most important clinical benefits of point-of-care ultrasound use by pediatric intensive care providers. The inferior vena cava is a vessel that is highly sensitive to fluid changes. The inferior vena cava diameter can be measured by a point-of-care ultrasound, and represents a critical parameter in assessing the patient’s fluid status. The inferior vena cava collapsibility index (in spontaneously breathing patients) and the inferior vena cava distensibility index (in mechanically ventilated patients) are calculated by determined formulas by using maximum and minimum diameters of the inferior vena cava. The indices are important guides for pediatric intensive care providers for managing their patients’ fluid treatment. Although some authors claim it is not a reliable method, the technique is coming to fore in intensive care units day by day, and has an increasing trend among pediatric intensive care specialists. Here, we aim to give detailed information on the ultrasonographic inferior vena cava diameter measurement methods, and calculations of the inferior vena cava collapsibility index and inferior vena cava distensibility index, and emphasize the importance of a noninvasive, bedside, and objective method of detecting the volume status of critically ill patients for pediatric intensive care specialists according to the published literature.

Diagnostic Accuracy of Ultrasound in the Diagnosis of Small Bowel Obstruction

INTRODUCTION

Small bowel obstruction (SBO) is a common presentation to the Emergency Department (ED). This study aimed to analyze the accuracy of ultrasound (US) in diagnosing and staging SBO.

OBJECTIVES

The main object of this study was to analyze the accuracy of ultrasound in diagnosing and staging SBO compared to CT.

METHODS

Retrospectively, stable patients with an ultrasonographic diagnosis of SBO who underwent abdominal CT immediately after US and before receiving naso-intestinal decompression, were included. US criteria for the diagnosis of SBO were related to morphological and functional findings. US diagnosis of obstruction was made if fluid-filled dilated small bowel loops were detected, peristalsis was abnormal and parietal abnormalities were present. Morphologic and functional sonographic findings were assigned to three categories: simple SBO, compensated SBO and decompensated SBO. US findings were compared with the results of CT examinations: Morphologic CT findings (divided into loop, vascular, mesenteric and peritoneal signs) allowed the classification of SBO in simple, decompensated and complicated.

RESULTS

US diagnostic accuracy rates in relation to CT results were calculated: ultrasound compared to CT imaging, had a sensitivity of 92.31% (95% CI, 74.87% to 99.05%) and a specificity of 94.12% (95% CI, 71.31% to 99.85%) in the diagnosis of SBO.

CONCLUSIONS

This study, similarly to the existing literature, suggests that ultrasound is highly accurate in the diagnosis of SBO, and that the most valuable sonographic signs are the presence of dilated bowel loops ad abnormal peristalsis.

Evaluation of Trainee Competency with Point-of-Care Ultrasonography (POCUS): a Conceptual Framework and Review of Existing Assessments

Point-of-care ultrasonography (POCUS) has the potential to transform healthcare delivery through its diagnostic expediency. Trainee competency with POCUS is now mandated for emergency medicine through the Accreditation Council for Graduate Medical Education (ACGME), and its use is expanding into other medical specialties, including internal medicine. However, a key question remains: how does one define "competency" with this emerging technology? As our trainees become more acquainted with POCUS, it is vital to develop validated methodology for defining and measuring competency amongst inexperienced users. As a framework, the assessment of competency should include evaluations that assess the acquisition and application of POCUS-related knowledge, demonstration of technical skill (e.g., proper probe selection, positioning, and image optimization), and effective integration into routine clinical practice. These assessments can be performed across a variety of settings, including web-based applications, simulators, standardized patients, and real clinical encounters. Several validated assessments regarding POCUS competency have recently been developed, including the Rapid Assessment of Competency in Echocardiography (RACE) or the Assessment of Competency in Thoracic Sonography (ACTS). However, these assessments focus mainly on technical skill and do not expand upon other areas of this framework, which represents a growing need. In this review, we explore the different methodologies for evaluating competency with POCUS as well as discuss current progress in the field of measuring trainee knowledge and technical skill.

The Role of Technology in the Bedside Encounter

Technology has the potential to both distract and reconnect providers with their patients. The widespread adoption of electronic medical records in recent years pulls physicians away from time at the bedside. However, when used in conjunction with patients, technology has the potential to bring patients and physicians together. The increasing use of point-of-care ultrasound by physicians is changing the bedside encounter by allowing for real-time diagnosis with the treating physician. It is a powerful example of the way technology can be a force for refocusing on the bedside encounter.

The Accuracy of Point-of-Care Ultrasound in Detecting Small Bowel Obstruction in Emergency Department

Radiological imaging plays an essential role in the evaluation of a patient with suspected small bowel obstruction (SBO). In a few studies, point-of-care ultrasound (POCUS) has been utilized as a primary imaging modality in patients with suspected SBO. POCUS has been shown to be an accurate tool in the diagnosis of SBO with multiple research studies noting a consistent high sensitivity with a range of 94–100% and specificity of 81–100%. Specific sonographic findings that increase the likelihood of SBO include dilatation of small bowel loops > 25 mm, altered intestinal peristalsis, increased thickness of the bowel wall, and intraperitoneal fluid accumulation. Studies also reported that emergency physicians could apply this technique with limited and short-term ultrasound training. In this article, we aim to review the sensitivity and specificity of ultrasound examinations performed by emergency physicians in patients with suspected SBO.

[Point-of-care ultrasound in Spanish paediatric intensive care units]

INTRODUCTION

Point-of-care (bedside) ultrasound is being increasingly used by paediatricians who treat critically ill children. The aim of this study is to describe its availability, use, and specific training in Paediatric Intensive Care Units in Spain.

MATERIAL AND METHODS

A descriptive, cross-sectional, multicentre study was performed using an online survey.

RESULTS

Of a total of 51 PICUs identified in our country, 64.7% responded to the survey. Just over half (53.1%) have their own ultrasound machine, 25% share it, with other units with the usual location in the PICU, and 21.9% share it, but it is usually located outside the PICU. Ultrasound machine availability was not related to size, care complexity, or number PICU admissions. The ultrasound was used daily in 35% of the units, and was associated with location of the machine in the PICU (P=.026), the existence of a transplant program (P=.009), availability of ECMO (P=.006), and number of admissions (P=.015). 45.5% of PICUs has less than 50% of the medical staff specifically trained in bedside ultrasound, and 18.2% have all their medical staff trained. The presence of more than 50% of medical staff trained was associated with a higher rate of daily use (P=.033), and with specific use to evaluate cardiac function (P=.033), intravascular volume estimation (P=.004), or the presence of intra-abdominal collections (P=.021).

CONCLUSIONS

Bedside ultrasound is frequently available in Spanish PICUs. Specific training is still variable, but it should serve to enhance its implementation.