A Prospective, Multicenter Evaluation of Point-of-care Ultrasound for Small-bowel Obstruction in the Emergency Department.

OBJECTIVE: The main objective of this study was to evaluate the accuracy of emergency physician-performed point-of-care ultrasound (POCUS) for the diagnosis of small-bowel obstruction (SBO) compared to computed tomography (CT). METHODS: We performed a prospective, multicenter, observational study examining a convenience sample of adult patients with potential SBO presenting to the emergency department (ED) between July 2014 and May 2017. Each POCUS was interpreted at the bedside by the performing emergency physician and retrospectively by an expert reviewer. Test characteristics were calculated for POCUS, blinded expert interpretation, and specific POCUS parameters. RESULTS: A total of 217 subjects were included in the primary analysis with an overall SBO prevalence of 42.9%. For the diagnosis of SBO, POCUS demonstrated an overall sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of 0.88 (95% confidence interval [CI] = 0.80 to 0.94), 0.54 (95% CI = 0.45 to 0.63), 1.92 (95% CI = 1.56 to 2.35), and 0.22 (95% CI = 0.12 to 0.39), respectively. Expert review yielded a similar sensitivity (0.89 [95% CI = 0.81 to 0.95]) with a significantly higher specificity (0.82 [95% CI = 0.74 to 0.88]). The more sensitive sonographic parameters for both POC sonographers and expert reviewers were small-bowel dilation ≥ 25 mm (0.87 [95% CI = 0.79 to 0.93], 0.87 [95% CI = 0.79 to 0.93]) and abnormal peristalsis (0.82 [95% CI = 0.72 to 0.89], 0.85 [95% CI = 0.76 to 0.87]). The more specific parameters for both groups were transition point (0.82 [95% CI = 0.74 to 0.89], 0.98 [95% CI = 0.94 to 1.00]), intraperitoneal free fluid (0.82 [95% CI = 0.74 to 0.89], 0.93 [95% CI = 0.87 to 0.97]), and bowel wall edema (0.76 [95% CI = 0.67 to 0.83], 0.93 [95% CI = 0.87 to 0.97]). CONCLUSION: POCUS is moderately sensitive for SBO, although less specific, when performed by a diverse group of emergency physicians across multiple EDs. Interpretation of acquired POCUS images is significantly more accurate when performed by physicians with prior emergency ultrasound fellowship training and familiarity with the sonographic appearance of SBO.

Assessment of clinical dehydration using point of care ultrasound for pediatric patients in rural Panama.

BACKGROUND: Dehydration and its associated symptoms are among the most common chief complaints of children in rural Panama. Previous studies have shown that intravascular volume correlates to the ratio of the diameters of the inferior vena cava (IVC) to the aorta (Ao). Our study aims to determine if medical students can detect pediatric dehydration using ultrasound on patients in rural Panama. METHODS: This was a prospective, observational study conducted in the Bocas del Toro region of rural Panama. Children between the ages of 1 to 15 years presenting with diarrhea, vomiting, or parasitic infection were enrolled in the study. Ultrasound measurements of the diameters of the IVC and abdominal aorta were taken to assess for dehydration. RESULTS: A total of 59 patients were enrolled in this study. Twenty-four patients were clinically diagnosed with dehydration and 35 were classified to have normal hydration status. Of the 24 patients with dehydration, half (n=12) of these patients had an IVC/Ao ratio below the American threshold of 0.8. Of the remaining asymptomatic subjects, about half (n=18) of these subjects also had an IVC/Ao ratio below the American threshold of 0.8. CONCLUSION: Our study did not support previous literature showing that the IVC/Ao ratio is lower in children with dehydration. It is possible that the American standard for evaluating clinical dehydration is not compatible with the rural pediatric populations of Panama.

Feasibility study of minimally trained medical students using the Rural Obstetrical Ultrasound Triage Exam (ROUTE) in rural Panama.

BACKGROUND: Maternal and infant mortality rates reported in rural Panama are greater than those in urban regions. Bocas del Toro is a region of Panama inhabited by indigenous people at greater risk for pregnancy-related complications and deaths due to geographic isolation and limited access to health care. Portable ultrasound training programs have recently been implemented in low-resource settings to increase access to diagnostic imaging. The goal of this study is to determine the feasibility of teaching first-year medical students the Rural Obstetrical Ultrasound Triage Exam (ROUTE) to help identify pathology in pregnant women of the Bocas del Toro region of Panama. METHODS: Eight first-year medical students completed ROUTE training sessions. After training, the students were compared to professional sonographers to evaluate their accuracy in performing the ROUTE. Students then performed the ROUTE in mobile clinics within Bocas del Toro. They enrolled women pregnant in their 2nd or 3rd trimesters and measured biparietal diameter, head circumference, amniotic fluid index, fetal lie and placental position. Any abnormal measurement would be further analyzed by the lead physician for a potential hospital referral. RESULTS: A total of 60 women were enrolled in the study. Four women were detected as having a possible high-risk pregnancy and thus referred to a hospital for further evaluation. CONCLUSION: Based on our data, first-year medical students with additional training can use the ROUTE to identify complications in pregnancy using ultrasound in rural Panama. Additional studies are required to determine the optimal amount of training required for proficiency.

Feasibility study of first-year medical students identifying cardiac anatomy using ultrasound in rural Panama.

BACKGROUND: There are over 15 million children who have cardiac anomalies around the world, resulting in a significant morbidity and mortality. Early recognition and treatment can improve the outcomes and lengthen life-expectancy of these patients. The NIH and WHO have promoted guidelines for screening for congenital cardiac anomalies using ultrasound in rural environments. METHODS: Our study took place in Bocas Del Toro, Panama where a mobile clinic was established for community healthcare screening and ultrasonographic evaluation by medical student volunteers and volunteer clinical faculty. This was a non-blinded, investigational study utilizing a convenience sample of pediatric patients presenting for voluntary evaluation. Seven first-year medical students were recruited for the study. These students underwent a training program for advanced cardiac ultrasound instruction, termed "Pediatric Echocardiography Cardiac Screening (PECS)". RESULTS: Ten patients were enrolled in the study. Nine patients had adequate images as defined by the PECS criteria and were all classified as normal cardiac pathology by the medical students, resulting in a sensitivity and specificity of 100%. A single patient was identified by medical students as having a pathologic pulmonic stenosis. This was confirmed as correct by a blinded ultrasonographer. CONCLUSIONS: In this pilot study, the first-year medical students were able to correctly identify pediatric cardiac anatomy and pathology in rural Panama after undergoing a 12-hour ultrasound PECS training session. We believe that with this knowledge, minimally trained practitioners can be used to screen for cardiac anomalies in rural Panama using ultrasound.