Carolinas Core Concepts Core Concepts in EM; a repository for Carolinas lecture summaries.


Finding the Appendix

James Cao, MD

  • Negative ultrasound doesn’t rule out disease
  • Non-visualized appendix without inflammation is reassuring on CT
  • Equivocal CT does not rule out disease
  • Consider MRI in pregnant patients after ultrasound

Ligamentous Injuries of the Knee

Katherine Mahoney, MD

  • When injury to the knee causes immediate joint dysfunction, the injury will almost always be to the ACL or PCL.
  • Lateral collateral ligament injury will take up to 24 hours to swell and cause dysfunction.
  • In PCL injuries and knee dislocations, careful assess for neurovascular injury.
  • Unhappy triad: ACL, MCL, Medial Meniscus
    • Evaluate for associated injuries in the presence of any of the three injuries.

Hyperkalemia, Marine Envenomations, and SBO

  • In addition to the 1st line treatments of calcium, insulin-d10, bicarbonate and dialysis, effective treatment of hyperkalemia involves β2-agonists; 20mg albuterol nebulized over 10 minutes or terbutaline 0.5mg IV quickly drives potassium intracellularly.
  • Proper treatment of most marine envenomations, catfish being the most common, is hot water soaks for 30-90 minutes with good wound care and a quinolone or augmentin for 5 days.
  • CT abd/pelvis is only 92% sensitive for small bowel obstruction.  Keep an open mind if you have strong clinical suspicion.
    • Allon M. Hyperkalemia in end-stage renal disease: mechanisms and management. J Am Soc Nephrol. 1995;6(4):1134.
    • Allon M, Copkney C. Albuterol and insulin for treatment of hyperkalemia in hemodialysis patients. Kidney Int. 1990;38(5):869.
    • Carrette TJ, Cullen M, et al. 2002. Temperature effects on box jellyfish venom, a possible treatment for envenomated patients? Med J Aust. 177: 654.
    • Glenister KM, Corke CF. Infarcted intestine: a diagnostic void. Journal of Surgery 2004. 74:260

C-Spine Imaging in the ED

  • In low-risk groups with an adequate c-spine XRay, the negative predictive value is 99.9%.   However, C-spine XRay sensitivity for all comers is only 36-64% and average time-to-dispo is 1.9 hours vs 1 hour on average for CT.
  • CT c-spine disadvantages:  Cancer risk 1:200 in 15 y/o, 1:2,000 in 30 y/o, 1:5,000 in 70 y/o.  Cost is also higher, although when inadequate CSXR and "missed fracture" costs are added in they may be comparable.
  • In the alert patient with a negative CT c-spine but persistent bony tenderness there are three options: continue collar upon discharge, MRI for ligamentous injury, or flex-extension films.