A very important statement in Avoiding Common Surgical Errors (ACSE)book.
Abscess: Marked swelling and redness is apparent just above antecubital fossa. This is caused by an abscess, the result of bacteria innoculated under the skin during injection drug abuse.We call The surgical resident to evaluate red, tender, fluctuant masses all over the body and often incises and drains an abscess under local anaesthesia. These masses are often numbed with ethyl chloride spray and acupressure (lignocaine doesn't work well in an acid environment and pus has a low pH) before a cruciate incision is made, the contents are evacuated, samples taken for culture & sensetivity and the wound is packed with a Betadine wick.
In the book, Dr. Schneider reminds readers, however, that if the mass is in the antecubital fossa, groin or neck we should consider mycotic aneurysm in our differential.
A mycotic aneursym is a localised dilatation of an artery at least 150% of its normal diameter due to destruction of the vessel wall by bacterial infection। Usually this is due to penetrating injury, most commonly in IVDUs(intravenous drug users). Dr. Fiser (ABSITE Review book) says that the organism responsible is most commonly Staph. or Strep., and that empiric broad spectrum antibiotic cover (e.g. Flucloxacillin 500mg tds iv + benzyl-penicillin 1.2g qds iv) should be started.
Dr. Schneider says that mistakenly unroofing a mycotic aneurysm can cause life-threatening haemorrhage and so if you are suspicious, I&D(Incision and drainage)under local in the ER is verboten without first:
1. assessing the lesion clinically (for a pulse and bruit) and if necessary
2. imaging it with Doppler ultrasound or CT angiography.
If the vessel isn't radiologically involved then go for it, otherwise dissection and repair will need to take place in the OR. Operative repair includes ligation of the vessel if there is sufficient collateral supply, and vein graft if there isn't.