Bedside ultrasound: a useful tool for the on-call urologist?

Integrating Basic and Clinical Sciences Using Point-of-Care Renal Ultrasound for Preclerkship Education

INTRODUCTION

Point-of-care ultrasound (POCUS) is a valuable asset in bedside clinical care. Undergraduate medical education is increasingly using POCUS as an adjunct tool for teaching anatomy, pathophysiology, and physical exam in an integrated manner. Many medical schools teach content in an organ systems-based format in the preclerkship years. POCUS teaching can be very effectively tailored to specific organ systems. Though pilot curricula for generalized ultrasound education exist, few teach organ systems-based content using POCUS. To address this gap, we designed and implemented an integrated POCUS module to supplement anatomy, pathophysiology, and physical exam teaching in the renal course.

METHODS

The module consisted of (1) a 30-minute didactic lecture introducing students to renal ultrasound technique and image interpretation and (2) a practical hands-on skills session. Pre- and postmodule surveys assessed the efficacy and impact of the curriculum.

RESULTS

A total of 31 first-year medical students completed the POCUS renal curriculum. A majority reported that the module positively affected their understanding of renal pathophysiology and the physical exam. They also reported increased confidence in using POCUS to detect renal pathology and make clinical decisions.

DISCUSSION

It was feasible to implement a POCUS curriculum to supplement integrated teaching of renal system concepts in the first year of medical school, and students found POCUS teaching valuable. POCUS provides educators with another tool to integrate basic and clinical sciences with hands-on relevant clinical skills practice in early medical school years.

Prognostic significance of maternal urinary carbohydrate antigen 19-9 for antenatal diagnosis of posterior urethral valve associated with fetal hydronephrosis

PURPOSE

To evaluate the predictive role of maternal urinary CA 19-9 as a non-invasive marker for diagnosing antenatal posterior urethral valve (PUV).

METHODS

A total of 40 women in the third pregnancy trimester were enrolled. Case group (group A) consisted of 20 women with a diagnosis of antenatal PUV. Twenty women with similar gestational age, fetal sex, normal US, and no history of congenital anomalies were chosen as a control group (group B). Maternal urine samples were collected and urinary CA 19-9 was measured in both groups. The correlations between maternal urinary CA 19-9 and APD (measured during pregnancy and the initial evaluation of the newborn) were assessed. CA 19-9 level in first urine of neonates was also evaluated.

RESULTS

The mean ± SD of maternal urine CA 19-9 was higher in PUV group compared to the control group (131.6 ± 23.8 vs. 13 ± 2.7 U/mL). In addition, there was a significant correlation between maternal urinary CA 19-9 and the APD measured at the third trimester (p < 0.001) and the initial evaluation of fetus after birth according to SFU grading system (p < 0.001). However, no significant difference was found between gestational age and urinary CA 19-9 level (p = 0.34). There was also a significant correlation between the CA 19-9 level in first urine of neonates and CA 19-9 level of maternal urine (p < 0.001).

CONCLUSIONS

This is the first time that maternal urinary CA 19-9 has been applied as a noninvasive and practical diagnostic marker in antenatal PUV.

Hospital Medicine Point of Care Ultrasound Credentialing: An Example Protocol

Though the use of point-of-care ultrasound (POCUS) has increased over the last decade, formal hospital credentialing for POCUS may still be a challenge for hospitalists. This document details the Hospital Medicine Department Ultrasound Credentialing Policy from Regions Hospital, which is part of the HealthPartners organization in Saint Paul, Minnesota. National organizations from internal medicine and hospital medicine (HM) have not published recommended guidelines for POCUS credentialing. Revised guidelines for POCUS have been published by the American College of Emergency Physicians, though these are not likely intended to guide hospitalists when working with credentialing committees and medical boards. This document describes the scope of ultrasound in HM and our training, credentialing, and quality assurance program. This report is intended to be used as a guide for hospitalists as they work with their own credentialing committees and will require modification for each institution. However, the overall process described here should assist in the establishment of POCUS at various institutions.

A urologic stethoscope? Urologist performed sonography using a pocket-size ultrasound device in the point-of-care setting

PURPOSE

Ultrasound is commonly used in urology. Technical advances with reduced size and cost led to diffusion of small ultrasound devices to many clinical settings. Even so, most ultrasound studies are performed by non-urologists. We aimed to evaluate the utility of a pocket-size ultrasound device (Vscan™ GE Healthcare) and the quality of urologist performed study.

METHODS

Three consecutive studies were performed: (1) a urologist using the pocket ultrasound, (2) a sonographist using the pocket ultrasound, and (3) a sonographist using a standard ultrasound device. Thirty-six patients were evaluated with a basic urologic ultrasound study. An excepted deviation between studies was preset for numeric parameters and t test performed. Ordinal parameters were analyzed using Cohen's kappa coefficient.

RESULTS

Kidney length, renal pelvis length, renal cyst diameter, post-void residual and prostate volume (transabdominal) differences were found to be insignificant when comparing a urologist pocket ultrasound study to a sonographist standard ultrasound study (P = 0.15; P = 0.21; P = 0.81; P = 0.32; P = 0.07, respectively). Hydronpehrosis evaluation (none, mild, moderate and severe) and the presence of ureteral jet signs conferred a high inter-observer agreement when comparing the above studies using the Cohen's kappa coefficient (K = 0.63; K = 0.62, respectively).

CONCLUSIONS

Urologist performed pocket ultrasound study is valid in evaluating the upper and lower urinary tract and is practical in many clinical scenarios. The urologic stethoscope is now becoming a reality within reach.

My patient has abdominal and flank pain: Identifying renal causes

Acute flank and abdominal pain are common presenting complaints in the emergency department. With increasing access to point-of-care ultrasound (PoCUS), emergency physicians have an added tool to help identify renal problems as a cause of a patient's pain. PoCUS for hydronephrosis has a sensitivity of 72-83.3% and a varying specificity, similar to radiology-performed ultrasonography. In addition to assessment for hydronephrosis, PoCUS can help emergency physicians to exclude other serious causes of flank and abdominal pain such as the presence of an abdominal aortic aneurysm, or free fluid in the intraperitoneal space, which could represent hemorrhage. Use of PoCUS for the assessment of flank pain has resulted in more rapid diagnosis, decreased use of computed tomography, and shorter emergency department length of stay.

Content and face validation of a curriculum for ultrasonic propulsion of calculi in a human renal model

PURPOSE

Ultrasonic propulsion to reposition urinary tract calculi requires knowledge about ultrasound image capture, device manipulation, and interpretation. The purpose of this study was to validate a cognitive and technical skills curriculum to teach urologists ultrasonic propulsion to reposition kidney stones in tissue phantoms.

MATERIALS AND METHODS

Ten board-certified urologists recruited from a single institution underwent a didactic session on renal ultrasound imaging. Subjects completed technical skills modules in tissue phantoms, including kidney imaging, pushing a stone through a translucent maze, and repositioning a lower pole calyceal stone. Objective cognitive and technical performance metrics were recorded. Subjects completed a questionnaire to ascertain face and content validity on a five-point Likert scale.

RESULTS

Eight urologists (80%) had never attended a previous ultrasound course, and nine (90%) performed renal ultrasounds less frequently than every 6 months. Mean cognitive skills scores improved from 55% to 91% (p<0.0001) on pre- and post-didactic tests. In the kidney phantom, 10 subjects (100%) repositioned the lower pole calyceal stone to at least the lower pole infundibulum, while 9 (90%) successfully repositioned the stone to the renal pelvis. A mean±SD (15.7±13.3) pushes were required to complete the task over an average of 4.6±2.2 minutes. Urologists rated the curriculum's effectiveness and realism as a training tool at a mean score of 4.6/5.0 and 4.1/5.0, respectively.

CONCLUSIONS

The curriculum for ultrasonic propulsion is effective and useful for training urologists with limited ultrasound proficiency in stone repositioning technique. Further studies in animate and human models will be required to assess predictive validity.

Focused renal sonography performed and interpreted by internal medicine residents

OBJECTIVES

Intensivist-performed focused sonography, including renal sonography, is becoming accepted practice. Whether internal medicine residents can be trained to accurately rule out renal obstruction and identify sonographic findings of chronic kidney disease is unknown. The purpose of this study was to test the ability of residents to evaluate for this specific constellation of findings.

METHODS

Internal medicine residents were trained in a 5-hour module on focused renal sonography evaluating renal length, echogenicity, hydronephrosis, and cysts on a convenience sample of medical ward, intermediate care, and medical intensive care unit patients. All patients underwent comprehensive sonography within 24 hours. The primary outcome was represented by the Fleiss κ statistic, which indicated the degree of interobserver agreement between residents and radiologists. Sensitivity, specificity, and positive and negative predictive values were calculated using the comprehensive radiologist-read examination as the reference.

RESULTS

Seventeen internal medicine residents imaged 125 kidneys on 66 patients. The average number of studies performed was 7.3 (SD, 6.6). Residents demonstrated excellent agreement with radiologists for hydronephrosis (κ = 0.73; P < .001; SE, 0.15; sensitivity, 94%; specificity, 93%), moderate agreement for echogenic kidneys (κ = 0.43; P < .001; SE, 0.13; sensitivity, 40%; specificity, 98%), and substantial agreement for renal cysts (κ = 0.61; P < .001; SE, 0.12; sensitivity, 60%; specificity, 96%). Residents showed sensitivity of 100% and specificity of 88% for identification of atrophic kidneys, defined as length less than 8 cm.

CONCLUSIONS

After a 5-hour training course, medical residents accurately identified hydronephrosis and key sonographic findings of chronic kidney disease in a cohort of medical patients. Screening for hydronephrosis and renal atrophy can be performed by medical residents after adequate training.

Is the Pocket Ultrasound the “Phonendoscope” of the Urologist?

The objective was to evaluate the utility of the “pocket ultrasound” in making clinical decisions in urologic emergencies. From May to September 2011, 105 patients were assessed for urologic emergencies: acute flank pain, macroscopic hematuria, urinary retention, and lower urinary tract symptoms. All patients underwent an ultrasonographic examination whereby the pocket ultrasound was used to evaluate the kidneys and bladder, followed by another appropriate diagnostic test to verify the suggested diagnosis. Urinary retention was diagnosed in 10 patients. Of 48 subjects with hematuria, 34 had an immediate diagnosis: there were 18 cases of a bladder tumor, 13 cases of urolithiasis, and 2 cases of renal cell carcinoma; one ureteral stent was detected. Of 30 patients referred with lower urinary tract symptoms, 14 showed a high post micturition residual and 2 were seen to have bladder diverticula. Of 17 patients with acute flank pain, 1 had a kidney abscess, 5 had hydronephrosis, and 11 had urolithiasis. Ultrasonography provided a conclusive diagnosis in 67.6% of cases. Point-of-care pocket ultrasound allows a rapid diagnosis for treatment or triage of patients for appropriate referral to other diagnostic methods.