Abscess
Conditions
Keywords
Bedside emergency ultrasound, Abscess, Cellulitis, Soft tissue infection, Methicillin resistant staphylococcus aureus (MRSA)
Brief summary
The purpose of this study is to determine if soft tissue infections in pediatric patients can be more accurately diagnosed (i.e. the presence of a drainable abscess) with the addition of bedside ultrasound to the clinical examination compared to the clinical examination alone.
Detailed description
Skin and soft tissue infections, particularly abscesses caused by community-acquired methicillin resistant Staphylococcus aureus (CA-MRSA) are a growing public health problem. The treatment of a skin abscess usually requires incision and drainage or needle aspiration. In addition to providing definitive therapy, appropriate drainage can allow for organism identification and antibiotic susceptibility testing should antibiotics be utilized. A skin cellulitis, which is treated with systemic antibiotics and supportive care alone, may be hard to distinguish from an abscess, as both have similar clinical features. Therefore, as the presence or absence of purulent material may be difficult to determine, children may undergo an unnecessary drainage procedure. If drainage is avoided, the patient may require a subsequent ED visit if the diagnosis is missed on initial examination. This can lead to worsened clinical outcome, an extra financial burden for the family, and added emotional distress for the patient. Bedside emergency ultrasound (EUS), which has been used since the mid-1980s is being used in adults to detect fluid collections such as soft tissue abscesses. Studies in adult patients have shown that EUS adds useful information to the history and physical examination and may even alter physicians' clinical impressions and management of patients. Currently, it is not known whether children represent a different population for EUS than adults and how EUS would perform in the pediatric outpatient setting. With improved diagnosis of soft tissue infections, better epidemiologic data about organism prevalence, improved and more prompt treatment, and more appropriate use of antibiotic therapy can be done. To date, no study exists evaluating its utility specifically for the evaluation of soft tissue infections in pediatric patients. The goal of this study is to evaluate the test characteristics of EUS in pediatric patients presenting with evidence of soft tissue infection.
Interventions
DEVICEBedside emergency ultrasound
Ultrasound will be performed on the lesion in question.
Sponsors
Children's Hospital of Philadelphia
Study design
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Age
2 Months to 18 Years
Healthy volunteers
Yes
Inclusion criteria
* Evidence of at least one of the following: skin elevation, induration, tenderness, fluctuance, or history of purulent drainage from the lesion
Exclusion criteria
* Suspected paronychia or felon * Lesion involving the face, perirectal, or vaginal area * Surgical wound infection * Underlying immunodeficiency * Non-soft tissue infectious mass (e.g. lymphadenitis) * Suspected non-infectious mass (e.g. hernia, lymph node)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Sensitivity and Specificity of Bedside Emergency Ultrasound When Added to the Clinical Examination Compared With Clinical Examination Alone. | 18 mos | The sensitivity and specificity of clinical examination with the addition of bedside emergency ultrasound will be compared against that of clinical examination alone.The number of lesions determined to actually have a drainable fluid collection will serve as the denominator in the calculation of sensitivity, and the number of lesions correctly identified as having a drainable fluid collection by clinical exam plus ultrasound and clinical exam alone, respectively, will serve as the numerator.The number of lesions determined to not have a drainable fluid collection will serve as the denominator in the calculation of specificity, and the number of lesions correctly identified as not having a drainable fluid collection by clinical exam plus ultrasound and clinical exam alone, respectively, will serve as the numerator. Significance will be defined as a 95% confidence interval surrounding the differences between the two groups for sensitivity and specificity that does not include 0. |
Countries
United States
Participant flow
Recruitment details
Patients were recruited over a 22 month period
Participants by arm
| Arm | Count |
|---|---|
| Ultrasound One group of patients will undergo emergency bedside ultrasound in addition to the clinical examination. | 420 |
| Total | 420 |
Baseline characteristics
| Characteristic | Ultrasound |
|---|---|
| Age, Categorical <=18 years | 420 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 0 Participants |
| Age Continuous | 7.8 years STANDARD_DEVIATION 6 |
| Region of Enrollment United States | 420 participants |
| Sex: Female, Male Female | 218 Participants |
| Sex: Female, Male Male | 202 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | — / — |
| other Total, other adverse events | 0 / 420 |
| serious Total, serious adverse events | 0 / 420 |
Outcome results
Primary
Sensitivity and Specificity of Bedside Emergency Ultrasound When Added to the Clinical Examination Compared With Clinical Examination Alone.
The sensitivity and specificity of clinical examination with the addition of bedside emergency ultrasound will be compared against that of clinical examination alone.The number of lesions determined to actually have a drainable fluid collection will serve as the denominator in the calculation of sensitivity, and the number of lesions correctly identified as having a drainable fluid collection by clinical exam plus ultrasound and clinical exam alone, respectively, will serve as the numerator.The number of lesions determined to not have a drainable fluid collection will serve as the denominator in the calculation of specificity, and the number of lesions correctly identified as not having a drainable fluid collection by clinical exam plus ultrasound and clinical exam alone, respectively, will serve as the numerator. Significance will be defined as a 95% confidence interval surrounding the differences between the two groups for sensitivity and specificity that does not include 0.
Time frame: 18 mos
Population: Assuming a baseline sensitivity of clinical exam alone similar to that previously published (86%), type 1 error rate 0.05, and intraclass correlation coefficient of 0.5 for lesions within patients, we estimated a sample size of 393 lesions would provide 80% power to detect at least a 9% difference in the sensitivity of CE+EUS compared to CE alone.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Clinical Exam Alone | Sensitivity and Specificity of Bedside Emergency Ultrasound When Added to the Clinical Examination Compared With Clinical Examination Alone. | Specificity | 84.2 Ratio as a percentage |
| Clinical Exam Alone | Sensitivity and Specificity of Bedside Emergency Ultrasound When Added to the Clinical Examination Compared With Clinical Examination Alone. | Sensitivity | 94.7 Ratio as a percentage |
| Clinical Exam+ Ultrasound | Sensitivity and Specificity of Bedside Emergency Ultrasound When Added to the Clinical Examination Compared With Clinical Examination Alone. | Specificity | 81.4 Ratio as a percentage |
| Clinical Exam+ Ultrasound | Sensitivity and Specificity of Bedside Emergency Ultrasound When Added to the Clinical Examination Compared With Clinical Examination Alone. | Sensitivity | 93.1 Ratio as a percentage |
Comparison: See sample size calculations already entered. Null hypothesis is that there is no difference in the sensitivity or specificity of clinical exam alone compared with clinical exam+ultrasound.95% CI: [-3.4, 0]Mixed effects logistic regression
Comparison: as previously described for sensitivity95% CI: [-9.7, 4.1]