Point-of-Care Ultrasonography for the Diagnosis of Skin and Soft Tissue Abscesses: A Systematic Review and Meta-analysis

A Man With Chest Pain After An Assault - A Case Report

This case report highlights an uncommon sequelae of chest wall trauma that should be evaluated for patients presenting with similar history and symptoms. A 60-year-old man presented to the emergency department (ED) with swelling, fever, and chest wall pain two days after an assault with blunt chest wall trauma. On exam, there was a suspected chest wall abscess, verified on computed tomography (CT) with associated displaced midsternal fracture. This patient was admitted for abscess incision and drainage. While uncommon, chest wall abscess formation is an important condition that should be considered as a differential diagnosis in any patient presenting with chest wall pain post blunt trauma. With few reported similar presentations in the literature, this case is an important addition in a likely underreported phenomenon that requires prompt evaluation and treatment.

Topics

Blunt chest trauma, chest wall abscess, sternal fracture complication.

Current challenges in acute bacterial skin infection management

PURPOSE OF REVIEW

There are aspects of skin and soft tissue infections (SSTIs) that remain unresolved, such as current numbers, classification criteria, how best to define severity and predict the outcome, what diagnostic tests to perform, what new treatment options are available, or what the duration of antibiotic treatment should be. We have reviewed the literature over the last 18 months to clarify these issues and provide our opinion.

RECENT FINDINGS

SSTIs are common and among the top 10 most frequent infections worldwide. They represent a burden on the healthcare system and have a major impact on the quality of life of patients. Regarding classification, the Infectious Diseases Society of America (IDSA) provides a practical guide that distinguishes between uncomplicated and complicated infections, acute and chronic wound infections, and necrotising and nonnecrotizing infections based on skin extension and tissue necrosis. With new microbiological and imaging diagnostic techniques, SSTIs can now be better diagnosed. New PCR techniques are available, and mass spectrometry can be applied to samples collected in liquid transport media. Moreover, new treatment methods such as photodynamic therapy, reactive oxygen, and phages are emerging. SSTI patients can be treated with shorter antibiotic courses if they receive an active drug with good tissue penetration. Antibiotic treatment in necrotizing infections can be shortened to 48 h after the last debridement.

SUMMARY

SSTIs remain a challenge regarding rapid and accurate diagnosis and clinical management.

Ultrasound-An Easy Available and Useful Point-of-Care Adjunct for Clinical Decision-Making in Hand Infections: Review of the Literature and a Case Series

ABSTRACT

Initial findings of hand infections warrant a thorough treatment strategy depending on the progress of the infection. The decision for surgical treatment can be unclear. Searching to improve the quality of diagnostics, we reviewed the literature regarding the use of point-of-care ultrasound (PCUS) in hand infections and analyzed patients undergoing decision-making with PCUS. We searched PubMed, Scopus, Cochrane Register, and Google Scholar for the use of PCUS in therapy planning in infections of the hand. In addition, we screened our patients from July 1, 2020, to November 30, 2020, to validate the potential benefit of ultrasound examination in suspected hand infections. We evaluated initial clinical examinations versus blinded sonographic assessments in the context of correct decision to proceed with surgery or conservative treatment. Two thousand forty-eight studies within the topic were identified, but only 9 studies were found eligible to be included with a total of 88 patients. The studies illustrate that ultrasound can be performed on all patients, including children and pregnant women, and can be performed in a timely manner. In our retrospective analysis of 20 patients with suspected hand infection, the clinical and ultrasound assessment led to surgery in 13 cases. Of those 13 patients, 7 revealed intraoperative pus. By retrospective assessment of solely the ultrasound images, surgery would have been indicated in 9 cases, including all 7 cases with intraoperative pus. Clinical examination and ultrasound can help in detecting infections of the hand. Ultrasound examination, however, seems to yield a lower false-positive rate than clinical examination. Ultrasound could be a valuable addition to clinical examination.

Multiorgan Point-of-Care Ultrasound Assessment in Critically Ill Adults

Traditional point-of-care ultrasound (POCUS) training highlights discrete techniques, single-organ assessment, and focused protocols. More recent developments argue for a whole-body approach, where the experienced clinician-ultrasonographer crafts a personalized POCUS protocol depending on specific clinical circumstances. This article describes this problem-based approach, focusing on common acute care scenarios while highlighting practical considerations and performance characteristics.

Validation of an Educational Tool for Skin Abscess Incision and Drainage by Delphi and Angoff Methods

BACKGROUND

Bedside incision and drainage (I&D) of skin abscesses is a common medical procedure performed in a variety of medical settings. Yet, there is a paucity of published validated educational tools to teach and assess competency for this procedure.

OBJECTIVE

To validate an educational tool to teach and assess competency for bedside I&D of skin abscesses via the Delphi consensus and Angoff standard setting methods.

DESIGN

Expert consensus on the importance of each procedural step in the educational tool was obtained using the Delphi method, consisting of four rounds of iterative revisions based on input from a panel of experts. The passing cut-off score for a proficient provider was determined using the modified dichotomous Angoff method.

PARTICIPANTS

All participants met the minimum criteria of active involvement in resident education and performance of at least 20 skin abscess I&D's within the past 5 years. Participant specialties included general surgery, emergency medicine, and internal medicine.

MAIN MEASURES

The primary outcome was consensus on procedural steps and errors, defined as an interquartile range ≤ 2 on a 9-point Likert scale. A cut-off score was determined by the average across all respondents for the anticipated number of errors that would be committed by a provider with the level of proficiency defined in the survey. Qualitative input was incorporated into the educational tool.

KEY RESULTS

At the end of four rounds of review via the Delphi process, participants achieved consensus on 93% of items on the clinical checklist and 85% of errors on the assessment checklist. Via the modified dichotomous Angoff method, the determined passing cut-off for competency was 6 out of 22 errors.

CONCLUSION

An educational and evaluation tool for bedside I&D of skin abscesses was validated via the Delphi and Angoff methods.

Diagnostic methods for the confirmation of non-purulent cellulitis: a review

Cellulitis is the most common cause for skin disease hospitalization with costs totaling over $7 billion. It can be challenging to diagnose due to clinical similarities with other inflammatory conditions and the lack of a gold-standard diagnostic test. This article reviews the different testing methods for the diagnosis of non-purulent cellulitis based on three categories (1) clinical scoring assessments, (2) in vivo imaging techniques, and (3) laboratory assessments.

Subcutaneous Extended-release Buprenorphine Depot Misdiagnosed as an Abscess Resulting in Incision and Drainage and Disruption of Opioid Use Disorder Treatment

Monthly extended-release buprenorphine subcutaneous injection (BUP-XR) is a newer treatment formulation for use in moderate to severe opioid use disorder. After injection into the subcutaneous tissue of the abdomen, the medication forms a depot to allow for slow release of buprenorphine. As such, a small yet visible and palpable nodule is normal and is expected to decrease in size over the following weeks to months. Given the newness of this medication, it is possible that not all healthcare providers are familiar with this formulation, nor will they interpret the BUP-XR depot as normal findings. Herein, we provide a case report where a patient's BUP-XR depot was misdiagnosed as an abscess, resulting in incision and drainage and disruption of life-saving opioid use disorder treatment. To prevent cases like this in the future, it is important that providers administering BUP-XR properly educate patients on what to expect during treatment with BUP-XR and when to seek care for potential abnormalities. In addition, it is critical that healthcare providers working in other treatment settings are aware of how to properly evaluate BUP-XR injection sites.

Ultrasound for the diagnosis of necrotizing fasciitis: A systematic review of the literature

BACKGROUND

Necrotizing fasciitis (NF) is a deadly disorder that can be challenging to diagnose on history and examination alone. Point-of-care ultrasound (POCUS) is widely available and has been increasingly used for diagnosing skin and soft tissue infections. We performed a systematic review to determine the accuracy of POCUS for diagnosing NF with subgroup analyses of the accuracy of specific POCUS examination components.

METHODS

PubMed, Scopus, CINAHL, LILACS, the Cochrane databases, Google Scholar, and bibliographies of selected articles were assessed for all retrospective, prospective, and randomized control trials evaluating the accuracy of POCUS for diagnosing NF. Data were dual extracted into a predefined worksheet and quality analysis was performed with the QUADAS-2 tool. Data were summarized and an overall summary was completed.

RESULTS

We identified three papers (n = 221 patients; 33% NF) that met our inclusion criteria. The overall sensitivity ranged from 85.4%-100% while the specificity ranged from 44.7% to 98.2%. Fluid accumulation along the fascial plane was the most sensitive (85.4%; 95% CI 72.2% - 93.9%), while subcutaneous emphysema was the most specific (100%; 95% CI 92.5% - 100%).

CONCLUSIONS

POCUS has good sensitivity and specificity for the diagnosis of NF. POCUS should be considered as an adjunct to the initial clinical decision making for the diagnosis of NF.

Prevalence of misdiagnosis of cellulitis: A systematic review and meta-analysis

BACKGROUND

There is no gold standard test to accurately identify patients with cellulitis and therefore misdiagnosis is common. Using the clinical impression of a dermatology or an infectious disease specialist as a reference standard, we sought to determine the prevalence of misdiagnosis of cellulitis among nonspecialist physicians.

METHODS

A systemic search was performed using MEDLINE, Cochrane Library, and EMBASE databases for studies reporting diagnostic accuracy of cellulitis. Inclusion criteria required dermatology or infectious disease consultation for all patients diagnosed with cellulitis by generalist physicians. We used random effects modeling to estimate the prevalence of misdiagnosis using consultant diagnosis as a reference standard.

RESULTS

Eight studies contributed to the analysis. For the seven studies involving inpatients, the results were sufficiently homogeneous to justify pooling data. Of 858 inpatients initially diagnosed with cellulitis, 335 (39%, 95% confidence interval: 31-47) received an alternative diagnosis from the specialist. Heterogeneity was large (I²  = 74%) and the greatest contributor to between-study variance was the year of publication. Alternative diagnoses were mostly noninfectious (68%, 221/327), with stasis dermatitis (18%, 60/327) being the most common. An abscess was the most common alternative infectious diagnosis (10%, 32/327).

DISCUSSION

Cellulitis is commonly misdiagnosed among inpatients, leading to unnecessary hospital admissions and antibiotic overuse. Most alternative diagnoses are noninfectious. Continuing medical education among general practitioners and urgent care providers will likely reduce cellulitis misdiagnoses.

The Frequency of POCUS in the Treatment of Sepsis in the Emergency Department: A Retrospective Cohort Study

Background: Point of care ultrasound (POCUS) is ubiquitous in the modern emergency department (ED). POCUS can be helpful in the management of patients with sepsis in many ways including determining the cause of sepsis, assessing fluid status, guiding resuscitation, and performing procedures. However, the frequency and manner in which POCUS is incorporated into the care of septic patients in community emergency medicine remains unclear. Objective: To evaluate POCUS frequency and exam types used in the care of patients with sepsis in two community EDs in Southern California. Methods: We performed a retrospective analysis of 5,264 ED visits with a diagnosis of sepsis at two community emergency departments between January 2014 and December 2018. Patients 18 years or older who were diagnosed with sepsis and had either lactate ≥ 4 mmol, a documented mean arterial pressure (MAP) < 65 mmHg, or a systolic blood pressure (SBP) < 90 mmHg were included. Charts were reviewed to determine if POCUS was used during the ED evaluation. Primary outcomes were frequency of POCUS use in the cohort, change in POCUS use over the study period, and the types of exams performed. Results: POCUS was used in 21% of encounters meeting inclusion criteria and was positively correlated with ED arrival year (OR = 1.09; CI 1.04, 1.15; p=0.001). The most common POCUS exam was ultrasound-guided central line placement, with the next most common exams being cardiac, followed by inferior vena cava (IVC). Only the frequency of cardiac, IVC, lung and Focused Assessment with Sonography in Trauma (FAST) exams were found to increase significantly over the study period. Conclusions: Total POCUS use increased significantly in this cohort of septic patients over the study period due to more cardiac, IVC, lung and FAST exams being performed.

Ultrasound in primary care: Consensus recommendations on its applications and training. Results of a 3-round Delphi study

BACKGROUND

The introduction of portable and pocket ultrasound scanners has potentiated the use of ultrasound in primary care, whose many applications have been studied, analyzed and collected in the literature. However, its use is heterogeneous in Europe and there is a lack of guidelines on the necessary training and skills.

OBJECTIVES

To identify the fundamental applications and indications of ultrasound for family physicians, the necessary knowledge and skills, and the definition of a framework of academic and pragmatic training for the development of these competencies.

METHODS

A modified 3-round Delphi study was carried out in Catalonia, with the participation of 65 family physicians experts in ultrasound. The study was carried out over six months (from September 2020 to February 2021). The indications of ultrasound for family physicians were agreed (the > = 75th percentile was considered) and prioritised, as was the necessary training plan.

RESULTS

The ultrasound applications in primary care were classified into seven main categories. For each application, the main indications (according to reason for consultation) in primary care were specified. A progressive training plan was developed, characterised by five levels of competence: A (principles of ultrasound and management of ultrasound scanners); B (basic normal ultrasound anatomy); C (advanced normal ultrasound anatomy); D (pathologic ultrasound, description of pathological images and diagnostic orientation); E (practical skills under conditions of routine clinical practice).

CONCLUSION

Training family physicians in ultrasound may consider seven main applications and indications. The proposed training plan establishes five different levels of competencies until skill in real clinical practice is achieved.

Current international and national guidelines for managing skin and soft tissue infections

PURPOSE OF REVIEW

Skin and soft tissue infections account for a significant percentage of both community and nosocomial infections. Several nosological entities are included in this concept. However, there is a very scarce body of doctrine for their treatment based on randomised trials. Therefore, we considered it necessary to review current treatment guidelines to bring new recommendations and improvements to our colleagues. In this review of recent literature, we identified updated guidelines in this area by searching the databases PubMed, evidence-based medicine online, York University reviewers group, Cochrane, MBE-Trip and Sumsearch using the terms: soft tissue infection, therapy, guideline.

RECENT FINDINGS

Developments focus on using new antimicrobials and on the prescription of shorter antibiotic treatment courses.

SUMMARY

With the development of new drugs and the current evidence of their use, there is a need to refine the appropriate drug's decision-making. Drugs with a long half-life, which allows weekly administration, can reduce hospital admission and length of stay with fewer healthcare resources. Shorter courses of antibiotics are recommended. The role of stewardship programmes will continue to expand. The surgical indication and its value are evident in many patients. Therefore, management should rely on a collaborative group with experience in this disease.

Applications of Ultrasound in the Postoperative Period: A Review

Background Recent advances in ultrasound technology have further increased its potential for routine use by plastic and reconstructive surgeons.

Methods An extensive literature review was performed to determine the most common applications of ultrasound in the postoperative care of plastic and reconstructive surgery patients.

Results In contrast with other available imaging modalities, ultrasound is cost-effective, rapid to obtain, eliminates the need for ionizing radiation or intravenous contrast, and has virtually no contraindications. In addition to its diagnostic capabilities, ultrasound can also be used to facilitate treatment of common postoperative concerns conveniently at the bedside or in an office setting.

Conclusion This article presents a review of the current applications of ultrasound imaging in the postoperative care of plastic and reconstructive surgery patients, including free flap monitoring following microsurgery, diagnosis and treatment of hematoma and seroma, including those associated with BIA-ALCL, and breast implant surveillance.

Flexible Microwave Biosensor for Skin Abnormality Detection Based on Spoof Surface Plasmon Polaritons

Point-of-care testing plays an important role in the detection of skin abnormalities. The detection of skin abnormalities requires sufficient depth and no harm. A flexible microwave biosensor based on spoof surface plasmon polaritons was designed to meet the requirements of skin abnormalities. The designed biosensor, which works at 11.3 GHz, is small and can be flexibly attached to the skin surface of any part of the human body for measurement. The health status of the skin can be evaluated by the resonant frequency and the magnitude of the reflection coefficient of the sensor. The sensor was tested on pork skin. The experiment results showed that the sensor can detect skin abnormalities such as skin burn, skin tumor, and others. Compared with other sensors, the sensor has sufficient penetration depth because of the strong penetration of microwave electromagnetic waves. It is the first flexible microwave biosensor used for skin, which involves point-of-care testing, and continuous monitoring of skin.

Diagnosis and Management of Cellulitis and Abscess in the Emergency Department Setting: An Evidence-Based Review

BACKGROUND

Cellulitis and abscess are a common reason for presentation to the emergency department, although there are several nuances to the care of these patients.

OBJECTIVE

The purpose of this narrative review article was to provide a summary of the background, pathophysiology, diagnosis, and management of cellulitis and abscesses with a focus on emergency clinicians.

DISCUSSION

The most common bacteria causing cellulitis are Staphylococcus aureus, Streptococcus pyogenes, and other β-hemolytic streptococci, and methicillin-resistant S. aureus is most common in abscesses. The history and physical examination are helpful in differentiating cellulitis and abscess in many cases, and point-of-care ultrasound can be a useful tool in unclear cases. Treatment for cellulitis typically involves a penicillin or cephalosporin, and treatment of abscesses is incision and drainage. Loop drainage is preferred over the traditional incision and drainage technique, and adjunctive antibiotics can be considered. Most patients can be managed as outpatient.

CONCLUSIONS

It is essential for emergency physicians to be aware of the current evidence regarding the diagnosis and management of patients with cellulitis and abscess.

Procedural Applications of Point-of-Care Ultrasound in Pediatric Emergency Medicine

Point-of-care ultrasound can improve efficacy and safety of pediatric procedures performed in the emergency department. This article reviews ultrasound guidance for the following pediatric emergency medicine procedures: soft tissue (abscess incision and drainage, foreign body identification and removal, and peritonsillar abscess drainage), musculoskeletal and neurologic (hip arthrocentesis, peripheral nerve blocks, and lumbar puncture), vascular access (peripheral intravenous access and central line placement), and critical care (endotracheal tube placement, pericardiocentesis, thoracentesis, and paracentesis). By incorporating ultrasound, emergency physicians caring for pediatric patients have the potential to enhance their procedural scope, confidence, safety, and success.

Pediatric Subcutaneous Abscess: Still a Clinical Exam-Based Diagnosis and Treatment

Subcutaneous abscesses occur frequently in the pediatric population, yet there is great variability in the approach to diagnosis and management, partly due to opposing recommendations in the current literature and the lack of a standardized protocol for diagnosis and management among pediatric medical centers. This has led to inconsistencies by the providers, as well as the hospital clinical pathways, with regards to the appropriate management of subcutaneous abscesses. We hypothesize that the current variability in diagnostic work-up and management contributes to the wide use of unnecessary imaging and therapeutics without altering the overall outcomes. We performed a retrospective chart review that compared 200 encounters for patients < 18 years of age with a diagnosis of subcutaneous abscess at a single large tertiary pediatric institution. Our results showed that only 13.6% of wound cultures obtained led to a change in the antibiotic regimen and that blood cultures were positive in only 2.1% of cases. There was no difference in the incision and drainage performed based on ultrasound findings in the presence of fluctuance on physical exam. Patients presenting with fever were more likely to be admitted to the hospital for further care than those without fever. Our results showed no difference in outcome after incision and drainage for abscesses packed with gauze versus those left to drain via a vessel loop drain. There was no difference in recurrence in patients discharged with oral antibiotics versus without oral antibiotic treatment. Our data indicate that many of the diagnostic studies used for the management of a subcutaneous abscess have little to no effect on the outcome. Subcutaneous abscesses are a common pediatric complaint, and this study could help healthcare providers utilize more effective and efficient management strategies for skin and soft tissue infections.

Emergency physician-performed bedside ultrasound of pyomyositis

Point-of-care ultrasound (POCUS) is an indispensable tool for emergency physicians in the rapid bedside diagnosis of skin and soft tissue infections. The utility of POCUS for the differentiation of cellulitis and subcutaneous abscess is well established; however, there is a paucity of studies highlighting POCUS as a first-line imaging approach for pyomyositis, an uncommon skeletal muscle infection and/or intramuscular abscess formation requiring emergent diagnosis. This report describes a case in which emergency physician-performed POCUS led to the early detection and timely management of pyomyositis in the emergency department.

Comparison of the Loop Technique With Incision and Drainage for Skin and Soft Tissue Abscesses: A Systematic Review and Meta-analysis

BACKGROUND

Cutaneous abscesses are common presentations to the emergency department. While the primary treatment for most abscesses is conventional incision and drainage (CID), this is painful and can lead to multiple return visits. The loop drainage technique (LDT) has been proposed as an alternate, less-invasive approach to abscess management. The primary outcome of this study was to compare LDT with CID for skin and soft tissue abscesses.

METHODS

PubMed, Scopus, CINAHL, LILACS, Google Scholar, the Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, and bibliographies of selected articles were assessed for all retrospective, prospective observational, and randomized controlled trials comparing treatment failures between LDT and CID among patients with skin and soft tissue abscesses. Data were dual extracted into a predefined worksheet and quality analysis was performed using the Cochrane Risk of Bias tool or the Newcastle-Ottawa scale. Data were summarized and presented as odds ratios (ORs) with 95% confidence intervals (CIs). Subgroup analyses were performed for adult and pediatric patients.

RESULTS

A total of 1,374 studies were identified with eight studies (n = 910 patients) selected for inclusion. Overall, CID failed in 69 of 487 patients (14.17%), while LDT failed in 35 of 423 patients (8.27%). There was an OR of 2.02 (95% CI = 1.29 to 3.18) in favor of higher failures in the CID group. This finding remained consistent with only randomized controlled trials (OR = 1.75, 95% CI = 1.07 to 2.86), but no difference was identified in the adult or pediatric subgroups.

CONCLUSION

The LDT was associated with reduced treatment failures when compared with CID. Future studies should further assess the impact on pain, cosmetic outcomes, and health care costs.

Abscess Management: An Evidence-Based Review for Emergency Medicine Clinicians

BACKGROUND

Abscesses are commonly evaluated and managed in the emergency department. Recent research has evaluated the use of ultrasonography, packing, incision and drainage (I&D), and antibiotics. There are evidence-based nuances to the management of specific types of abscesses, such as Bartholin, breast, dental, hidradenitis suppurativa, peritonsillar, and pilonidal abscesses.

OBJECTIVE

This review provides emergency medicine clinicians with a summary of the current literature regarding abscess management in the emergency department.

DISCUSSION

Ultrasound is valuable in diagnosing abscesses that are not clinically evident and in guiding I&D procedures. Although I&D is traditionally followed by packing, this practice may be unnecessary for small abscesses. Antibiotics, needle aspiration, and loop drainage are suitable alternatives to I&D of abscesses with certain characteristics. Oral antibiotics can improve outcomes after I&D, although this improvement must be weighed against potential risks. Many strategies are useful in managing Bartholin abscesses, with the Word catheter proving consistently effective. Needle aspiration is the recommended first-line therapy for small breast abscesses. Dental abscesses are often diagnosed with clinical examination alone, but ultrasound may be a useful adjunct. Acute abscess formation caused by hidradenitis suppurativa should be managed surgically by excision when possible, because I&D has a high rate of abscess recurrence. Peritonsillar abscesses can be diagnosed with either intraoral or transcervical ultrasound if clinical examination is inconclusive. Needle aspiration and I&D are both suitable for the management of peritonsillar abscesses. Pilonidal abscesses have traditionally been managed with I&D, but needle aspiration with antibiotics may be a suitable alternative.

CONCLUSIONS

This review evaluates the recent literature surrounding abscess management for emergency medicine clinicians.