Ultrasound: Soft Tissue Infection WITH DR. STOLZ
Several studies have been performed examining the benefit of ultrasound (US) in addition to history and physical exam compared to history and exam alone.
- One study had providers assess soft tissue infections/abscesses without ultrasound and make a determination of whether or not an infection required drainage. An ultrasound was then performed to see if it would change management
- Of patients determined to not require drainage, US changed the management in 40% of cases
- Of patients determined to require drainage, 50% did not actually require it. 73% of cases changed their management due to US assessment
- A study in pediatric patients assessed the utility of US for soft tissue infection
- For patients with clinically evident abscesses, US was shown to not add much additional benefit
- In patients with questionable abscess, US increased both sensitivity and specificity
- Another study in pediatric patients in 2016 compared physical exam vs. physical exam + US.
- US changed management in 1/4 of cases
- Large meta-analysis demonstrated that US was more sensitive and specific for abscess than physical exam findings alone.
General Tips for Soft Tissue Infection US:
- Compare to the other side: Luckily, in most patients, when examining soft tissue infections there is an opposite side of the body / opposite limb you can use for comparison. This can make subtle findings appear more evident.
- Muscle: In the short axis, muscle can look largely anechoic with hyper-echoic speckles. In the longitudinal axis you should be able to visualize the striations of the muscle fibers helping to distinguish it from other tissues.
- Aligment: When assessing skin infections, sometimes it's difficult to obey the convention of keeping the indicator on the probe always to the paitent's right (ex: if the infection is on the posterior body and the patient is prone). In general, keep the indicator aligned with the dot on the screen and prioritize your anatomic alignment
- Depth: Make sure to adjust the depth of your image to include normal tissue deep to the abscess in order to visualize the entire infection.
- Scan in 2 Orthogonal Planes: Helps to assess dimensions.
- Use Water to Improve Images: Distancing the area of interest from the probe can improve image quality.
- Submerging a Limb/Extremity: USE COLD WATER. Do not submerge more than 2/3 of the probe.
- Use a step-off Device: Saline bag or glove filled with gel or water.
- Early signs: Early cellulitis may show increased echogenicity compared to the other side (Will look brighter). Soft tissue/skin thickness may also appear greater compared to the other side.
- Late signs: Cobblestoning. This is hypoechoic fluid surrounding fat lobules giving the skin and sub q tissue a cobblestone appearance.
- May appear anechoic (completely black), hypo-echoic, or mixed echogenicity
- Adjust the screen to include the entire abscess. Increase depth to include some normal tissue beneath site of infection. You can also use "Dual Mode" to extend the image width if needed to capture the whole area.
- Scan in multiple axes
- Compression looking for the "Squish Sign" of heteroechoic fluid moving through abscess can help distinguish an abscess from other hypoechoic structures such as a lymph node.
- Color can help distinguish abscesses from vessels.
- Useful for procedural guidance in drainage.
- Foreign Body (up to 98% Specific, sensitivity second only to MRI)
- Check in multiple planes to help assess dimensions and better visualize the object.
- Look for shadowing to distinguish from hyper-echoic fascial planes.
- "Halo Sign," where a hypo-echoic rim of fluid or edema/pus begins to surround the object after time can help locate/distinguish the object.
- US can be used to help procedural guidance as well (can use needle to identify / cut down for removal)
- Mimics of foreign bodies include air in the tissue from wound opening which can create shadow, as well as injection of air after lidocaine administration.
- Narcotizing Fasciitis
- Early on it can appear identical to cellulitis.
- US is better than plain film for detecting subcutaneous air (Not better than CT, however).
- Mimics to look out for:
- Air from injection after IV drug use.
- Fascial fluid, particularly in the anterior tibial compartment.
- Air from open wounds.
- Peritonsilar Abscess
- Can use the endocavitary probe.
- Can use the US to measure the distance to the center of the abscess, as well as to the vessels.
- Can help you determine how to cut your needle guard prior to the procedure.
- Can use as real time procedural guidance.
R1 Clinical diagnostics: Pediatric KUB (Kidney, Ureter, Bladder) WITH DR. SKrobut
Definition: KUB is an abdominal radiograph initially designed to evaluate the kidneys, ureter, and bladder. It has since become the standard 1-2 view when evaluating the abdomen, and although often not an ideal test compared to CT, is still a common test ordered in the ED and has focal indications.
- American College of Radiology has 16 indications for ordering a KUB
- General rules of thumb:
- Order the test if there will likely be a finding for a suspected disease process.
- Avoid if it will not change management.
- Avoid ordering a KUB in reproductive age females.
- Try to start with 1 view, and only order subsequent views as needed.
- Radiation Exposure
- Radiation exposure in a KUB is not negligible at 1.2-1.5 mSv.
- This is equivalent to 75 chest x-rays.
- Increased cancer risk may occur between 10 and 100 mSv, which is roughly equivalent to 8-10 abdominal plain films.
- GASES: Examine the lower lung fields. Also look at the bowel gas pattern (presence/absence of gas, air fluid levels). Also look for gas in the solid organs and sub-q tissues.
- MASSES: Look at solid organs, assess their outline.
- STONES: Assess the gallbladder for stones, assess for kidney stones, and look for aortic calcifications (may represent mass, vessel, etc),
- BONES: Look for evidence of non-accidental trauma, as well as for masses or tumors.
- LEADS: Check for presence of monitoring leads that may be confused for other findings.
- LINES: Assess number of lines as well as line placement.
- Volvulus / Malrotation: This is a twisting of the midgut/intestine due to a problem during development, which essentially leads to obstruction. Some of the more common findings on KUB are listed below. KUB is neither sensitive nor specific for malrotation.
- Double Bubble Sign can be seen on XR, which is 2 loops of small bowel
- Air Fluid Lines: This is 30-70% sensitive and roughly 50% specific. The more air fluid levels, the more likely there is an obstruction.
- Air Pneumotosis: Usually only seen in severe disease.
- Intussusception: Telescoping bowel that folds in on itself. Sensitivity is only 74-90% on plain film for ileocecal intussusception. Signs you might see in intussusception:
- Target sign
- Crescent sign
- Meniscus sign
- Air in the cecum is 100% sensitive
- Constipation: Abdominal plain film is actually only 60-80% sensitive for constipation, and the amount of stool on plain film does not correlate with the level of clinical constipation. Diagnosing constipation on plain film can also lead to misdiagnosis and premature closure. Studies have shown that of children diagnosed with constipation on plain film, 10% return within 7 days and 20/3600 were significantly misdiagnosed subsequently needing surgery or admission.
- Necrotizing Enterocolitis (NEC): Usually presents within the 1st week of life in premature births, however, 10% are born full term. Abdominal plain film or KUB is the study of choice for screening for NEC.
- Mosaic pattern: Seen in early NEC. This is essentially where areas of bowel appear more or less bright than other regions.
- Localized dilation of bowel loops
- Pneumatosis: Seen in 75% of cases, it is 100% specific but only 44% sensitive.
- Rigler Sign: Double bowel wall.
- Visualization of the falciform ligament.
- Continuous diaphragm sign.
Quick Hit Pathology
- Inguinal Hernia: May see bowel gas in the scrotum.
- Gall Stones: Only 15% sensitive in adults, 50% in children as children are more likely to have hemolytic or be on TPN.
- Renal Stones: 90% of stones visualized. Can sometimes be ordered to check for change in position.
- Tumor: Calcificaions may be evident. May see mass effect.
- Inflammatory Bowel Disease: May see "Thumb Printing" caused by bowel wall edema.
- Toxic Megacolon: X-Ray may be good initial screening tool for toxic megacolon given speed and ease.
- KUB / Abdominal plain film is a commonly ordered test, however it involves a decent amount of radiation exposure. It is only the test of choice in very specific pathology, so it's important to have a systematic ordering approach to minimize radiation exposure.
- Do NOT order KUB for constipation, as stool burden does not correlate to clinical level of constipation and can lead to premature closure.
CPC: Infant with vomiting / Pyloric Stenosis WITH DRS. KISER AND VENTURA
Approach to Child with Vomiting with Dr. Kiser
History: The differential for vomiting in an infant is fairly broad. The history can help to narrow the differential significantly. It can also help you to determining whether the child is SICK vs. NOT SICK. Important elements to cover include:
- Timing of Emesis
- Presence of Pain
- Presence of Hunger/Appetite
- Stooling History
- Weight Loss
- Decreased Urinary Output
- Birth Order
- Reflux: One of the most common causes of vomiting. Also termed "Effortless Regurgitation" or "Happy Spitting." Can occasionally seem forceful.
- Milk or protein intolerance: Often presents with colitis, as well as watery or blood tinged stools. This can also occur in breast fed infants.
- Adrenal crisis / metabolic disorders: Often present with vomiting and dehydration. They may also have decreased appetite.
- Liver Disease (Biliary Atresia, Gilbert's, etc): May present with vomiting, poor weight gain, jaundice, pale color stools.
- Infection: Can be anywhere (UTI, URI, Meningitis, etc). Typically presents with fever but may not.
- Increased ICP: Will often present with altered mental status.
- Congenital or acquired hydrocephalus.
- Non accidental trauma
- Tox/Ingestion: Usually in ambulatory age ranges.
- Obstructive Causes:
- Malrotation: Usually presents less than 1 year old with acute bilious emesis. Also usually presents with pain out of proportion of exam, and intolerance of solid food.
- Hirschsprung's: Usually presents in first few days of life, but mild disease may present later in life.
- Congenital Atresia
- Pyloric Stenosis: Predominantly in males, and frequently affects the first born. Usually presents between 3 and 5 weeks with painless and usually non bilious vomiting. They also usually present with strong appetite.
Pyloric Stenosis with Dr. Ventura
- First born
- Male sex
- C-Section delivery
- Young maternal age
- Bottle feeding
- Formula > Breast milk
- Maternal smoking
- Maternal or infant use of macrolides
Differential: (See Dr. Kiser's List Above)
- Usually presents in infants between 3-5 weeks old
- Symptoms include:
- Non bloody/non bilious vomiting as the obstruction is above the common bile duct.
- Patients often maintain their appetite despite vomiting.
- Weight loss and dehydration are also common on presentation.
- Exam findings:
- "Palpable Olive": Usually in the right upper quadrant, it may not be as common a finding as classically taught. The prevalence of this exam finding is actually decreasing over time. This may be because the diagnosis is made with ultrasound/imaging earlier on in the disease course.
- Laboratory studies will often show signs of a metabolic alkalosis due to the excessive vomiting. This can actually be significant enough to cause compensatory hypo-ventilation.
- Low potassium is common due to renal excretion of K+ to preserve H+
- Low chloride also present from gastric HCl loss.
- Signs of dehydration are also common.
- Surgical Pyloromyotomy: Performed in most cases, especially in the developed world.
- Atropine: Can be used as more conservative management in high risk operative patients. Often it as given initially in IV form, and then transitioned to oral going home. This actually has an 87% rate of symptoms improvement, however it often results in a longer hospital stay.
R4 Simulation: Resource Limited Medicine/Global Medicine WITH DRS. GOEL, LUDMER, and MILLER
Setting: Dual patient encounter. Cases take place in a low resource environment. Oxygen therapy is available, and one ventilator for the hospital. Laboratory studies available include CBC, BMP, LFTs, Urine dipstick, Rapid Malarial Testing, TB PCR. Imaging available includes bedside ultrasound and X-Ray. However, X-Ray is not immediately available in the acute care area of the hospital.
History: Elderly man with no known past medical history brought in by family. Family states that for the past 6 weeks or so he has been getting progressively more short of breath, as well as having a lot of cough. They normally wouldn't have come to the hospital, except over the last couple of days he also seems to be more confused/altered, and having significantly worsening difficulty with breathing.
ROS: + for fevers, weight loss, cough, SOB, hemoptysis, and pleuritic chest pain
PMHx / PSHx: Known history of HTN
Exam: Vitals: T 38 C, HR 118, RR 35, BP 110/76, O2 Saturation 76%
General: Patient is thin, ill appearing.
HEENT: Sunken temples. PERRLA. TMs clear. Throat non-erythematous.
Neck: No Masses, mild lymphadenopathy
Chest: Patient has course breath on the left. Diminished sounds on the right. No wheezing, crackles, rhochi, rales.
Abdomen: Scaphoid. Non tender, non-distended. No masses appreciable.
Skin: No rashes. No jaundice.
Neuro: Patient is AO X1 to self. Moves all extremities equally. Strength and sensation symmetric and intact.
- BMP: 125/3.4/90/18/30/2.9
- CBC: WBC 14, Hb 8, Hct 24, Plt 84
- LFT: ALT 250, AST 400, Alk Phos 250, Bili 1.8, Albumin 2.2
- Urine Dipstick: Yellow, SG 1.205, Protein 1+, Nitrite (-), Leuk esterase Positive
EKG and CXR:
- Infectious Etiology: Given fever, cough, SOB, effusion
- TB a consideration given setting, as well as insidious course and hemoptysis
- Other bacterial pneumonia vs. empyema
- Viral infections: Dengue, yellow fever, etc (Severe shock stage can cause edema)
- Malignancy: Patient with prolonged course, worsening shortness of breath, weight loss, cough, sputum production. Appears cachectic on exam.
- Cardiac Etiologies: Heart failure possible, however no peripheral edema, heart size normal, EKG without strain.
- Infectious Etiology: Given fever, cough, SOB, effusion
- Ultrasound can be a viable option to assess pulmonary findings and characterize pleural effusions. For more information, see Dr. Stolz's post on Pulmonary Ultrasound here.
- Thoracentesis can help to determine etiology of pleural effusion. It can also be therapeutic in a hypoxic or hypotensive patient. See how to perform a thoracentesis here.
- Management: Patient was antibiosed with broad spectrum antibiotics with consideration for TB. Thoracentesis was performed and placed on non-rebreather without improvement in oxygenation. Group then had goals of care discussion taking into account: Resources at hospital, resources of family, prognosis of the differential above given patient's presentation.
History: 3 Day old child born premature is brought in by family members. Mother is not doing well postpartum and is not present. Family brings the baby in because it is not feeding well and appears lethargic. Mother gave birth at home. She received no prenatal care. Family states that the baby initially seemed vigorous at birth, but became more lethargic and less responsive over the last couple of days. He is now eating and drinking less, and appears to have difficulty breathing.
ROS: + Lethargy, hypotonia, fever, slow breathing. - Seizures or shaking.
Exam: Vitals: T 35 C, HR 44, RR 12, BP unobtainable, O2 75%
General: Patient is lethargic and minimally responsive
HEENT: Fontanelle sunken, sclera clear, PERRLA but sluggish
PULM: Course breath sounds bilaterally. Labored. Almost appears to be agonal breathing.
CARD: Bradycardia. Poor cap refill.
ABD: Umbilical stump present.
NEURO: Poor tone. Poor suck. Moves all extremities equally but only to painful stimulus.
- BMP: 145/5.6/105/20/5/0.4
- CBC: 20/11/33/120
- LFT: ALT 50/AST 100/Alk Phos 200/ Bili 1.8/3
- Urine Dipstick: Clear
- Fingerstick Glucose 44
EKG: Sinus bradycardia
CXR on right
- INFECTION, INFECTION, INFECTION: Patient developed symptoms shortly after birth. In a resource limited setting, or in instances where mom received no prenatal care or screening, it is important to consider beyond bacterial sources. TORCH and other viral infections such as HIV should also be on the differential. Empiric anti-viral treatment may also be warranted in addition to antibiotics.
- Asphyxia/Hypoxic injury: This is a common cause of hypotonia around time of birth.
- TBI or Non accidental Truama
- Metabolic Disorders: Patient's glucose was 44 likely secondary to poor feeding. Patient's HR improved with Glucose administration, but remained lethargic. Other inborn errors of metabolism can also result in this presentation.
Approach and Management:
- Airway: Provider's recognized the patient was hypoxic. This can lead to bradycardia, and most causes of pediatric arrest are due to hypoxia. Patient improved with bagging. The hospital only has 1 ventilator, however. After discussion with the team regarding which patient needed intubating, the child was intubated. Discussion was had about splitting the tubing on the ventilator, however, the tidal volumes in each patient are drastically different.
- Breathing: Discussion was had regarding the patient's prematurity and possible hypoplastic lungs vs. aspiration. Broad spectrum antibiotics ordered. Steroids were also discussed. Unfortunately, post partum delivery of steroids has been shown to cause a high rate of cerebral palsy and neurologic disorders, and risks are thought to outweigh the benefit.
- Circulation: Patient had chest compression performed initially, but HR improved with oxygenation and fluids. Child did not have easy vascular access. Options include IO, central line, or umbilical line.
- Umbilical Line: Can be performed up to 6-7 days post partum. Dedicated lines exist, however, in resource limited setting can improvise with other catheters (Should be between 3-5 french). Place tourniquet on umbilical stump. Cut down to fresh cord. Use hemostat to identify singular umbilical vein as opposed to thick walled umbilical arteries (X2). Loosen tourniquet just enough to pass catheter, then refasten. Cap off line with blue cap or other to prevent air getting into central circulation.
- Other: Pateint's glucose was 44. Repleted with D10 (Avoiding D50 due to risk of sclerosing veins). Calculated using the rule of 50. A = Concentration of dextrose fluid (ex. D10, D25, D50). B = cc/Kg Dose the child should receive. A x B should always = 50. Example: Dose of D10 should be 5 cc/kg. In our 3kg child, dose should be 15cc of D10.
- Consider Etiologies: Infection seemed most likely. Given broad spectrum abx as well as fluid bolus.
ORAL BOARDS CASE:
A 17 y/o female presents to the ED with abdominal pain. The patient’s vital signs are notable for a fever to 101.7 as well as mild tachycardia. She reports that she has had abdominal pain for the past several weeks, which became acutely worse today. She reports nightly fevers, decreased appetite, weight loss and nausea. She has also had non-bloody diarrhea. On exam, her abdomen is diffusely tender with organomegaly and voluntary guarding. She is also found to have an erythematous, non-blanching, popular rash on the trunk and abdomen. She reports that she recently emigrated to the US from Somalia.
Laboratory evaluation reveals that she has elevated LFTs, thrombocytopenia, anemia and a mild white count of 15. Given concern for typhoid, the patient is given antibiotics and is admitted to the hospital to watch for complications of typhoid, including perforation.
Management of the patient with suspected typhoid centers around good oral and hand hygiene, early antibiotics (focused on the susceptibility patterns of your area) and monitoring for complications of the disease. More information on typhoid here!
QUICK HIT GLOBAL HEALTH PATHOLOGY:
- Leprosy is an acid-fast bacilli with a high affinity for peripheral nerves, leaving a hypopigmented rash with decreased sensation; it’s treated with dapsone and rifampin
- Syphilis is caused by direct contact with spirochetes, and can present in primary, secondary and tertiary stages. Penicilin G remains the mainstay of patients.
- Entamoeba histolytica is transmitted via fecal-oral route; abscesses are treated with metronidazole and/or drainage, depending on the size
- Cysticercosis is caused by swallowing eggs found in the feces of a person with a certain tapeworm. It is a common cause of adult-onset seizures, and is treated with albendazole or praziquantel.
- Schistosomiasis affects 200 million people worldwide and can affect multiple organ systems; treatment is praziquantel
- Cutaneous leshmaniasis is transmitted by sand flies, and the best treatment for this is unknown, although many treatment options exist
- Tetanus can be seen from an unhealed umbilical stump. Case fatality approaches 70%, although deaths worldwide are decreasing secondary to education and vaccinations.
- African River Blindness is transmitted from the black fly, causes blindness, skin nodules and skin hypopigmentation, and is a common co-infection with loa loa. Treatment is ivermectin +/- doxycycline.
- Cutaneous anthrax is a spore-forming bacillus, and is endemic to countries such as Turkey from infected animals; treatment is with doxy or cipro.