Pearl of the Day: Legg-Calvé-Perthes Disease

Legg-Calvé-Perthes Disease Background - hip disorder that occurs between ages 2 - 13 (mostly ages 4 - 9) - avascular necrosis or osteochondrosis in femoral head - repeated episodes of ischemia leading to infarction and necrosis - reossification and remodeling occur over 2 - 4 years -> femoral head collapses -> increased risk of subluxation

Signs/Symptoms - insidious onset - may have mild pain for weeks to months - pain may be referred to anteromedial thigh or knee - muscle spasms, soft tissue contractures, proximal thigh atrophy, limb shortening - decreased hip abduction and internal rotation

Diagnosis/Work-up - initial stages (1 - 3 months): capital femoral epiphysis fails to grow -> radiographs demonstrate widening of cartilage space of affected hip - later, Caffey's sign (subchondral stress fracture line in femoral head) - new bone deposited on avascular trabeculae, calcification of necrotic marrow -> crushing of avascular trabeculae in dome of epiphysis - subluxation and extrusion of femoral head from acetabulum - initial X-rays may be negative, may require bone scan and MRI - differential dx: toxic synovitis, slipped capital femoral epiphysis, acute rheumatic fever, tuberculous arthritis, tumors

Treatment - non-weight bearing - referral to pediatric orthopedist

Resources Tintinalli's Emergency Medicine, 8th Edition

Pearl of the Day: Acute Infectious and Traveler's Diarrhea

Acute Infectious and Traveler's Diarrhea Background - causes: norovirus > non-Shiga toxin producing E. coli > C. difficile > invasive bacteria, Shiga toxin-producing E. coli, protozoa - increased probability of bacterial diarrhea with foreign travel to Asia, Africa, Latin America, Middle East - other risk factors: food contamination, rainy season while traveling, use of proton pump inhibitor, previous history of traveler's diarrhea, type of travel (e.g., adventure travel, living with native inhabitants)

Signs/Symptoms - at least three unformed stools within 24 hours in association with at least one symptom of GI disease (e.g., nausea, vomiting, fever, abdominal pain, cramps, fecal urgency) - usually 4- 5 loose stools without fever, lasting for 3 - 4 days

Work-up - stool studies indicated for severe abdominal pain, fever, or bloody stool - fecal leukocytes - stool culture (for Salmonella, Shigella, Campylobacter, E. coli O157:H7) - assay for Shiga toxin - microscopy or antigen assay for E. histolytica - exposure to untreated water, illness > 7 days -> evaluate for protozoal infections (enzyme assay for E. histolytica, Giardia intestinalis, Cryptosporidium parvum antigens)

Management - primarily supportive care - antibiotics reduce duration of illness by 24 hours, recommended for patients with ≥3 unformed stools in 8 hours - antibiotics contraindicated for bloody diarrhea due to risk of hemolytic uremic syndrome - all patients, regardless of work-up, improve on ciprofloxacin (may be given as single dose; full three-day course if presence of invasive disease) - trimethoprim/sulfamethoxazole also shortens duration, but inferior to ciprofloxacin - azithromycin for children and pregnant women, areas with fluoruinolone resistance - loperamide shortens duration of symptoms when combined with antibiotics - avoid use of antimotility agents (may prolong fever, increase risk of toxic megacolon, HUS)

Resources Tintinalli's Emergency Medicine, 8th Edition https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1539099/

Pearl of The Day: Disposition of Atrial Fibrillation

Disposition of Atrial Fibrillation For other pearls of the day regarding afib, follow the links here: Rhythm Control and Cardioversion Holiday Heart Syndrome Ottawa Aggressive Protocol

Admit - indications: hyperthyroidism, ischemia, infectious process, CHF, difficulty with rate control - ablation therapy indications: difficulty with controlling ventricular rate, LV dysfunction, rate-related cardiomyopathy, refractory symptomatic paroxysmal afib

Discharge - stable patients may be discharged with outpatient follow up if rate-controlled and absence of structural heart disease - if required medications for rate control during ED stay, prescribe same class of medications when discharged (e.g., metoprolol tartrate 50 mg PO BID or dilitiazem ER 120 mg or 180 mg PO daily) - risk of stroke is equal for paroxysmal and persistent afib, and so anticoagulation should always be considered based on CHA2DS2VASc score

CHA2DS2VASc Score - congestive heart failure - hypertension - age > 74 (2 points) - diabetes - previous TIA/CVA (2 points) - vascular diseases (e.g., CAD, MI, PVD) - age 65 - 74 - female - score 0 = low risk - score 1 = low-moderate risk (consider antiplatelet or anticoagulation) - score 2 = moderate-high risk (anticoagulation indicated) - consider bleeding risk for patients prior to starting (ATRIA Bleeding Risk Score)

Anticoagulation - oral anticoagulation preferred: apixaban, dabigatran, rivaroxaban, warfarin - patients not suitable for anticoagulation (if not due to risk of bleed) -> clopidogrel and ASA (81 mg - 325 mg) - afib + mitral stenosis -> warfarin - afib + stable CAD -> warfarin - afib > 48h -> warfarin OR heparin OR dabigatran for at least 3 weeks prior to cardioversion

Resources LITFL, Atrial Fibrillation: https://lifeinthefastlane.com/ccc/atrial-fibrillation/ Anticoagulation Dosing: http://www.acc.org/tools-and-practice-support/clinical-toolkits/atrial-fibrillation-afib/anticoagulant-dosing-table Emergency Medicine Cases: https://emergencymedicinecases.com/episode-20-atrial-fibrillation/ Ann Arbor Afib Algorithm: https://www.acep.org/_QIPS-Section-Microsite/Improving-and-Standardizing-Care-of-Patients-with-Atrial-Fibrillation-in-a-Community-Emergency-Department/#sm.0000o9mbwcinmefstkr1zrovyb3vu