Ultrasound detection of foreign bodies and procedure guidance

Foreign Glass Bodies in Pleura and Pancreas: Systematic Review for Entry Hypotheses and Treatment Options in an Unresolved Case

BACKGROUND

Foreign bodies within the pleura and pancreas are infrequent, and the approaches to their treatment still a subject of debate. There is limited knowledge particularly regarding glass foreign bodies.

METHODS

We present a case involving large glass splinters in the pleura and pancreas, with an unknown entry point. In addition, a systematic review was conducted to explore entry hypotheses and management options.

RESULTS

In addition to our case, our review uncovered eight incidents of intrapleural glass, and another eight cases of glass in other intrathoracic areas. The fragments entered the body through impalement (81%), migrated through the diaphragm after impalement (6%), or caused transesophageal perforation (19%) following ingestion. Eight instances of glass inside the abdominal cavity were documented, with seven resulting from impalement injuries and one from transintestinal migration. There were no recorded instances of glass being discovered within the pancreas. Among the 41 nonglass intrapancreatic foreign bodies found, sewing needles (34%) and fish bones (46%) were the most common; following ingestion, they had migrated through either a transgastric or transduodenal perforation. In all these cases, how the foreign bodies were introduced was often poorly recalled by the patient. Many nonglass foreign bodies tend to become encapsulated by fibrous tissue, rendering them inert, though this is less common with glass. Glass has been reported to migrate through various tissues and cavities, sometimes with a significant delay spanning even decades. There are cases of intrapleural migration of glass causing hemothorax, pneumothorax, and heart and major blood vessels injury. For intrapleural glass fragment management, thoracoscopy proved to be effective in 5 reported cases, in addition to our patient. Most intrapancreatic nonglass foreign bodies tend to trigger pancreatitis and abscess formation, necessitating management ranging from laparoscopic procedures to subtotal pancreatectomy. There have been only four documented cases of intrapancreatic needles that remained asymptomatic with conservative management. There is no direct guidance from the existing literature regarding management of intrapancreatic glass foreign bodies. Consequently, our patient is under observation with regular follow-ups and has remained asymptomatic for the past 2 years.

CONCLUSIONS

Glass foreign bodies in the pleura are rare, and our report of an intrapancreatic glass fragment is the first of its kind. Impalement is the most likely method of introduction. As glass has significant migration and an ensuing complication potential, preventive removal of intrapleural loose glass should be considered. However, intrapancreatic glass fragment management remains uncertain.

Emergency Management Strategies and Antimicrobial Considerations for Nonmammalian Marine Vertebrate Penetrating Trauma in North America, the Caribbean, and Hawaii: A Review Article

There are numerous emergency department visits in the United States for all types of marine animal injuries each year. These injuries may result in significant morbidity or mortality if not managed appropriately. Accurate identification of the offending species, thorough wound hygiene, and judicious use of antibiotics are important for preventing infections. This review aims to describe management strategies and antimicrobial considerations for nonmammalian marine vertebrate penetrating trauma in North America, the Caribbean, and Hawaii. A literature search was performed to identify studies on this subject. This literature consisted of clinical case reports and case series. Reports extracted included those on sharks, barracuda, eels, catfish, stingrays, lionfish, stonefish, and scorpionfish. The majority of reported trauma occurred to beachgoers, fishermen, or commercial aquarium employees who routinely handle these animals. Injury patterns depended on the species but most commonly affected the lower extremities. Infections were seen from saltwater bacteria, human skin flora, or marine animal oral flora. After thorough wound irrigation and exploration, most authors recommended prophylactic antimicrobials to cover Vibrio species, in addition to other gram-negative and gram-positive species. The literature is notable for the lack of controlled studies. Some authors recommended radiographic and/or ultrasonographic imaging to identify retained foreign bodies, such as spines, sand, or teeth.

Evaluation of an Object Detection Algorithm for Shrapnel and Development of a Triage Tool to Determine Injury Severity

Emergency medicine in austere environments rely on ultrasound imaging as an essential diagnostic tool. Without extensive training, identifying abnormalities such as shrapnel embedded in tissue, is challenging. Medical professionals with appropriate expertise are limited in resource-constrained environments. Incorporating artificial intelligence models to aid the interpretation can reduce the skill gap, enabling identification of shrapnel, and its proximity to important anatomical features for improved medical treatment. Here, we apply a deep learning object detection framework, YOLOv3, for shrapnel detection in various sizes and locations with respect to a neurovascular bundle. Ultrasound images were collected in a tissue phantom containing shrapnel, vein, artery, and nerve features. The YOLOv3 framework, classifies the object types and identifies the location. In the testing dataset, the model was successful at identifying each object class, with a mean Intersection over Union and average precision of 0.73 and 0.94, respectively. Furthermore, a triage tool was developed to quantify shrapnel distance from neurovascular features that could notify the end user when a proximity threshold is surpassed, and, thus, may warrant evacuation or surgical intervention. Overall, object detection models such as this will be vital to compensate for lack of expertise in ultrasound interpretation, increasing its availability for emergency and military medicine.

Ultrasonography of subcutaneous foreign bodies: differences depending on their nature, complications, and potential diagnostic errors

Patients with penetrating wounds with suspected foreign bodies retained in the wound are often seen in emergency departments. Imaging studies are necessary to rule out the presence of retained foreign bodies. Plain-film X-rays, however, are only useful when the foreign bodies contain radiopaque material (metal, glass, stone, and some plastics). In cases with strong diagnostic suspicion and negative plain films, other imaging tests are necessary. Ultrasonography has proven useful in the identification and location of both radiopaque and radiotransparent foreign bodies. Ultrasonography enables excellent assessment of adjacent anatomical structures (muscles, tendons, ligaments, and neurovascular structures) and of associated lesions. The different materials found in foreign bodies have characteristic ultrasonographic patterns that are useful for diagnosis. Finally, it is important to be familiar with the diagnostic pitfalls to avoid false positives.

Ultrasound Evaluation of Soft-Tissue Foreign Bodies by US Army Medics

Objective:

The study's primary objective was to determine army medics' accuracy performing bedside ultrasound (US) to detect radiolucent foreign bodies (FBs) in a soft-tissue hand model. Secondary objectives included the assessment of US stand-off pad effects on soft-tissue FB detection rates and assess established FB detectable lower limit size of 2 mm.

Methods:

Prospective, single blinded, observational study of US-naïve Army medics' abilities utilizing bedside US to detect wooden FBs in a chicken thigh model with or without an US stand-off pad. After a 2 h training period, medics' abilities to detect 1–3 mm FB utilizing a SonoSite^® M-Turbo US and 13–6 MHz linear probe were assessed.

Results:

After a 2 h training period, 28 medics had a sensitivity and specificity of 73% and 78% detecting 1–3 mm FBs utilizing standard US equipment. The medics' sensitivity and specificity were both 78% in detecting radiolucent FBs 2 mm and larger without a stand-off pad. The sensitivity and specificity decreased to 48%, 62%, and 67% when utilizing a stand-off pad to detect 1, 2, and 3 mm soft-tissue FBs. Sub 2 mm detection rates decreased from 82% for 2 mm FB to 64% for 1 mm FBs without utilizing a stand-off pad.

Conclusion:

Army medics with minimal US experience successfully identified FBs embedded in hand models with accuracies similar to radiologists and emergency medicine physicians. However, radiolucent FB detection sensitivity and specificity decreased in US-naïve Army medics utilizing stand-off pads. In addition, this study reconfirmed the lower limit of FB detection rates at 2 mm. These results support Army medics' utilization of US to evaluate for superficial radiolucent FBs of the hand.

My patient is injured: identifying foreign bodies with ultrasound

Patients commonly present to the emergency department with a suspected retained foreign body, following penetrating injury. While plain radiography is often the first line in identifying radio-opaque foreign bodies, radiolucent foreign bodies such as wood and plastic can easily be missed. Furthermore, real-time visualization of such a foreign body can assist in its removal. This article evaluates the use of point-of-care ultrasound by emergency physicians in the identification and removal of soft-tissue foreign bodies along with describing the appropriate technique and highlighting the potential pitfalls. An illustrated case example is presented that highlights the benefits of point-of-care ultrasound foreign body detection and guided removal.

Accuracy of trans-abdominal ultrasound in a simulated massive acute overdose

INTRODUCTION

Toxic ingestions are a common cause of morbidity and mortality in the United States. In 2013, there were nearly 2 million reported ingestions and nearly 1000 deaths from poisonings. There is no well-validated imaging study for confirming the presence of pills in the stomach of an overdose patient. There are case reports of ultrasound used for confirmation of pills in the stomach, and we are aware of one prospective trial to evaluate sonography for this application.

OBJECTIVE

To determine the sensitivity and specificity of transabdominal ultrasound for visualization of ingested pills.

METHODS

Randomized, blinded, placebo-controlled study. Twenty Subjects were randomized to one of two groups. The experimental group ingested 50 enteric-coated placebo capsules with 1 liter of fluid. The control group ingested only 1 liter of fluid. At time 0, 60, and 90 minutes after ingestion, expert sonographers performed transabdominal ultrasound in an attempt to visualize pills in the stomach.

RESULTS

At time 0, 60, and 90 minutes post-ingestion, ultrasound had a sensitivity of 62.5% (41.1%, 81.9%), 20.8% (4.6%, 37.1%), and 25% (7.7%, 42.3%) respectively. The specificity at time 0, 60, and 90 minutes post-ingestion were 58.3% (21.9%, 61.4%), 79.1% (62.9%, 95.5%), and 70.8% (52.6%, 89.0%) respectively.

CONCLUSION

There is poor sensitivity and specificity for ultrasound detection of pills in the stomach at time 0; these values fell substantially at 60 and 90 minutes post-ingestion. In this pilot study, we did not find ultrasound to be a useful screening tool for detecting pills in the stomach.

Impact of decontamination therapy on ultrasound visualization of ingested pills

Introduction

Acute toxic ingestion is a common cause of morbidity and mortality. Emergency physicians (EP) caring for overdose (OD) patients are often required to make critical decisions with incomplete information. Point of care ultrasound (POCUS) may have a role in assisting EPs manage OD patients. We evaluated the impact of different liquid adjuncts used for gastric decontamination on examiners’ ability to identify the presence of tablets using POCUS, and assessed examiners’ ability to quantify the numbers of tablets in a simulated massive OD.

Methods

This prospective, blinded, pilot study was performed at an academic emergency department. Study participants were volunteer resident and staff EPs trained in POCUS. Five nontransparent, sealed bags were prepared with the following contents: 1 liter (L) of water, 1 L of water with 50 regular aspirin (ASA) tablets, 1 L of water with 50 enteric-coated aspirin tablets (ECA), 1 L of polyethylene glycol (PEG) with 50 ECA, and 1 L of activated charcoal (AC) with 50 ECA. After performing POCUS on each of the bags using a 10-5 MHz linear array transducer, participants completed a standardized questionnaire composed of the following questions: (1) Were pills present? YES/NO; (2) If tablets were identified, estimate the number (1–10, 11–25, >25). We used a single test on proportions using the binomial distribution to determine if the number of EPs who identified tablets differed from 50% chance. For those tablets identified in the different solutions, another test on proportions was used to determine whether the type of solution made a difference. Since 3 options were available, we used a probability of 33.3%.

Results

Thirty-seven EPs completed the study. All (37/37) EP’s correctly identified the absence of tablets in the bag containing only water, and the presence of ECA in the bags containing water and PEG. For Part 2 of the study, most participants - 25/37 (67.5%) using water, 23/37 (62.1%) using PEG, and all 37 (100%) using AC - underestimated the number of ECA pills in solution by at least 50%.

Conclusion

There may be a potential role for POCUS in the evaluation of patients suspected of acute, massive ingested OD. EPs accurately identified the presence of ECA in water and PEG, but underestimated the number of tablets in all tested solutions.

Retained Stingray Barb and the Importance of Imaging

Stingray envenomation is a common occurrence. X-ray evaluation of stingray wounds is an unnecessarily misunderstood diagnostic concept. We present the case of a patient stung by a stingray with a prolonged and complicated course and permanent disability due to a retained barb. The patient had undergone multiple medical evaluations before an X-ray was obtained.

Comparison of Metallic Foreign-Body Removal between Dynamic Ultrasound and Static Radiography in a Pigs' Feet Model

Introduction

We compared the immediate cosmetic outcome of metallic foreign-body removal by emergency medicine (EM) residents with ultrasound guidance and conventional radiography.

Methods

This single-blinded, randomized, crossover study evaluated the ability of EM residents to remove metallic pins embedded in pigs' feet. Before the experiment, we embedded 1.5-cm metallic pins into numbered pigs' feet. We randomly assigned 14 EM residents to use either ultrasound or radiography to help remove the foreign body. Residents had minimal ultrasound experience. After a brief lecture, we provided residents with a scalpel, laceration kit, a bedside portable ultrasound machine, nipple markers, paper clips, a dedicated radiograph technician, and radiograph machine 20 feet away. After removal, 3 board-certified emergency physicians, who were blinded to the study group, evaluated the soft-tissue model by using a standardized form. They recorded incision length and cosmetic appearance on the Visual Analog Scale.

Results

In total, 28 foreign bodies were removed. No significant difference in the time of removal (P = 0.12), cosmetic appearance (P = 0.96), or incision length (P = 0.76) was found.

Conclusion

This study showed no difference between bedside ultrasound and radiography in assisting EM residents with metallic foreign-body removal from soft tissue. No significant difference was found in removal time or cosmetic outcome when comparing ultrasound with radiography.

ULTRASOUND FOR THE DETECTION OF VEGETATIVE FOREIGN BODY IN HAND — A CASE REPORT

Foreign bodies in soft tissues are commonly encountered in daily orthopaedic practice. While most of the metals and glass foreign bodies can be detected by plain radiograph, organic substances such as wood and vegetative materials are radiolucent. Unfortunately, these radiolucent foreign bodies are usually more prone to cause an inflammatory reaction and infection. The detection can be even more difficult in cases of multiple foreign bodies and in penetrating injuries with small innocuous skin wounds. Ultrasonography is a sensitive and reliable investigation for detection of foreign bodies in soft tissue. We present a case of penetration injury to thumb with residual radiolucent foreign bodies and demonstrate the proper role of ultrasonography in the management of foreign bodies in soft tissues.

Ultrasound guided removal of an airgun pellet from a patient's right cheek

This case report describes the use of real-time intraoperative ultrasonography to guide the removal of an airgun pellet embedded in the right cheek of a 20-year-old man. This patient had previously undergone two unsuccessful surgical attempts to have this pellet removed via blind exploration. Through the use of ultrasonography, the pellet's positional relationship throughout the procedure was accurately defined with respect to important soft and hard anatomical structures, as well as to the surgical instruments used, enabling its very efficient removal. This technique is safe, easy, cost effective and accurate, and thus minimizes post-operative morbidity and the risk of surgical complications.

Glass foreign body in soft tissue: possibility of high morbidity due to delayed migration

BACKGROUND

Soft tissue foreign bodies (FBs) are a common occurrence in emergency departments (EDs). Some FBs cause complications, whereas others are asymptomatic and remain undetected for months or years.

CASE REPORT

A 32-year-old man presented to the ED with complaints of back pain in the area of a subcutaneous lump that had migrated toward the midline, nearly 25 cm from its former location, over the previous 2 weeks. Twelve years previously, after falling onto a glass door that shattered, he had gone to a local ED and had his wound sutured, but no X-ray studies were taken. Within a few months, he noticed a lump near his scapula, but he did not relate it to the fall and it did not bother him much. Physical examination revealed a normal neurological examination and a palpable mass in the right paraspinal area at the level of the tenth thoracic vertebra. An X-ray study showed a 34-mm-long sharp density in the vicinity of the spinal canal near T10. Efforts lasting almost 2 h to identify and remove the foreign body were unsuccessful. The following day, a 4 × 6 × 34 mm sharp glass fragment was removed in the operating room under fluoroscopy.

CONCLUSIONS

Retained soft-tissue foreign bodies may migrate very late and can cause high morbidity or mortality. It is important to be diligent in the search for foreign bodies, using ultrasound, computed tomography scan, or magnetic resonance imaging in cases in which initial plain radiographs are negative.

Bedside ultrasound for the detection of soft tissue foreign bodies: a cadaveric study

The objective of this study was to evaluate the sensitivity and specificity of bedside ultrasound, as performed by emergency physicians with typical equipment, in detecting small, soft tissue foreign bodies, using a cadaveric model. This was a prospective study, using 6 unembalmed human cadavers and 6 ultrasound-credentialed, emergency medicine residency-trained physicians as sonographers. Incisions were made in 150 total sites of the extremities and each site was randomly assigned one of five groups: wood, metal, plastic, glass, or no foreign body. All foreign bodies were 2.5 mm3 in total volume or less, no longer than 5 mm in any dimension, and inserted to a depth of up to 3 cm. Ultrasound was performed with a SonoSite TITAN (SonoSite, Inc., Bothell, WA) ultrasound system using a L38/10-5 broadband linear array transducer. Sonographers were blinded to the number, type, and location of foreign bodies. A total of 900 ultrasound examinations were recorded. Overall sensitivity of ultrasound for foreign body detection was 52.6% (95% confidence interval [CI] 48.9%-56.2%), and overall specificity was 47.2% (95% CI 39.9%-54.5%). Positive predictive value was 79.9% (95% CI 76.3%-83.5%), and negative predictive value was 20.0% (95% CI 16.2%-23.7%). Sensitivity for individual sonographers ranged from 40.8% to 72.3% (average 52.6% +/- 13.3%), and specificity ranged from 30% to 66.7% (average 47.2% +/- 15.1%). Inter-observer reliability was poor. In our model, bedside ultrasound performed by emergency physicians was neither sensitive nor specific for the presence of small soft tissue foreign bodies.

A randomized controlled trial of ultrasound-assisted lumbar puncture

OBJECTIVE

Evidence showing the systematic utility of ultrasound imaging during lumbar puncture (LP) in the emergency department is lacking. Our hypothesis was that ultrasound-assisted LP would increase the success rate and ease of performing LP with a greater benefit in obese patients.

METHODS

This was an Institutional Review Board-approved, randomized, prospective, double-blind study conducted at the emergency department of a teaching institution. Patients undergoing LP from January to December 2004 were eligible for enrollment. Patients were randomized to undergo LP using palpation landmarks (PLs) or ultrasound landmarks (ULs). Data collected included age, body mass index, number of attempts, ease of performance and patient comfort on a 10-cm Visual Analog Scale, procedure time, success, and traumatic LP. Statistical analysis of data included relative risk (RR), the Mann-Whitney U test, and the Student t test.

RESULTS

A total of 46 patients were enrolled, 22 randomized to PLs and 24 to ULs. There were no differences between the groups in mean age or body mass index. Six of 22 attempts failed with PLs versus 1 of 24 with ULs (RR, 1.32; 95% confidence interval, 1.01-1.72). In 12 obese patients, 4 of 7 PL attempts failed versus 0 of 5 UL attempts (RR, 2.33; 95% confidence interval, 0.99-5.49). The ease of the procedure was better with ULs versus PLs. There were no statistical differences in the number of attempts, traumatic LPs, patient comfort, or procedure length.

CONCLUSIONS

The use of ultrasound for LP significantly reduced the number of failures in all patients and improved the ease of the procedure in obese patients.

Imaging Modalities in Wounds and Superficial Skin Infections

Open wounds and lacerations are the most commonly encountered problems in emergency medicine. Detection and removal of a foreign body is essential to avoid the many complications of a retained foreign body, which may include infection, inflammation, allergic reaction, and disability. Currently, there are several imaging modalities that the emergency medicine provider may use to aid in foreign body detection and wound management. Techniques and appropriate use of these imaging modalities for foreign bodies and soft tissue infections are discussed in this article.

Intraoperative imaging techniques: A guide to retrieval of foreign bodies

Foreign bodies are frequently introduced into the tissues of the head and neck by various mechanisms, and oral and maxillofacial surgeons are often called upon to retrieve these embedded objects. Retrieval may be quite challenging depending on many factors such as the size of the object, the location, and the surrounding anatomical structures. Preoperative imaging is very important in deciding upon the surgical approach. Computerized tomography is considered the gold standard for detection of foreign bodies because of the ability to localize an object in multiple planes and the creation of a 3-dimensional image. Difficulty arises when looking for a small object in an area with multiple important anatomical structures, such as the infratemporal fossa or the neck. Surgery can become tedious secondary to the risk of postoperative morbidity with injury to various anatomical structures. Foreign bodies in the head and neck are often difficult to manage even when a plan has been formulated from static preoperative images. Intraoperative feedback or guidance, especially when navigating through troublesome locations, can be extremely useful. In this paper, we report 2 cases and discuss the various modalities used for intraoperative imaging as a guide for surgical retrieval of foreign bodies.

Procedural applications of ultrasound

Many invasive procedures are now safer and more efficient with the use of ultrasound guidance. As emergency physicians continue to develop skills in sonography, new applications of this technology will continue to impact the practice of emergency medicine.

Value of power Doppler imaging and the hypoechoic halo in the sonographic detection of foreign bodies: correlation with histopathologic findings

OBJECTIVE

To present the power Doppler findings and evaluate the hypoechoic rim in increasing the conspicuity of foreign bodies detected on sonography and to correlate the sonographic and histopathologic findings.

METHODS

Between 1998 and 2001, all sonographic examinations for evaluation of possible foreign bodies were reviewed retrospectively. Patients who had surgical exploration and pathologic evaluation were included in the study. Gray scale and power Doppler examinations were performed with high-frequency linear array transducers. Histologic evaluation was then correlated with the sonographic findings.

RESULTS

Twenty-five patients were referred for evaluation of possible foreign bodies. Twelve patients underwent surgery and had pathologic correlation. Sonography had sensitivity of 92% for the overall detection of foreign bodies. There were 2 false-positive findings in which discrete foreign bodies were not seen at gross inspection, but inflammation and scar tissue were present at histologic examination. Pathologic findings were thought to represent chronic foreign body reactions. Hypervascularity immediately surrounding the foreign bodies was shown on power Doppler imaging in all cases, correlating with granulation tissue and neovascularity on pathologic examinations. The hypoechoic halo was shown in all but 2 cases and correlated with fibrinous exudate, granulation tissue, and collagenous capsule formation.

CONCLUSIONS

Sonography is an effective and sensitive tool for the detection of soft tissue foreign bodies. The use of power Doppler imaging may aid in detection of possible foreign bodies by increasing the conspicuity of both the hypoechoic halo and the foreign body itself.