oh my gangrene!

HPI:

The patient is a middle-aged male with PMH of diabetes and hyperlipidemia who presented to the emergency department with right second toe pain. Two months prior, the patient dropped a heavy object on his toe causing the nail to fall off. Since that time, he has had persistent pain in that digit. Seven days prior admission, the patient reports that his second right digit turned black with associated right foot swelling and erythema. Patient denied any systemic symptoms.  

PE: 
Right second toe is black and entirely discolored with obvious necrosis. Minimal peeling at the plantar surface, 2+ DP and PT pulses bilaterally. Decreased sensation over the 2nd right toe. Patient is able to flex and extend all digits without difficulty. Mild erythema over the dorsum of the foot. 

Imaging:

Right foot xray: 
Peripheral calcified vasculopathy concerning for ischemic change. Negative for tissue pneumatosis. Negative for stress fracture. Mild degenerative arthrosis of the talonavicular joint.

CTA Pelvis with unilateral runoff:
Diffuse scattered atherosclerotic and intimal thickening changes within the patient's right lower extremity. Runoff from the superficial femoral artery to the level the popliteal artery. There is severe diffuse atherosclerotic change of the posterior tibial artery extending to the plantar aspect of the foot and also to the vessels supplying the digits.

Management:

Patient received IV antibiotics in the ED given the erythema over the plantar surface of the foot. Patient admitted to orthopedic service and underwent amputation of 2nd digit.

 Discussion:
-Gangrene is the progressive death of tissue secondary to lack of blood supply
-Two most common types are dry and wet
-Dry gangrene is secondary to lack of blood supply. Wet occurs when tissue becomes infected with bacteria.
-Patients are increased risk because of conditions such as diabetes, trauma, smoking, obesity, excessive alcohol use and IV drug use
-Symptoms include pain, shedding of skin, foul smell and skin color changes. Systemic symptoms include fever, chills, confusion, nausea, vomiting, diarrhea, and hypotension
-Diagnosis includes basic laboratory work-up, xray of the affected area, CTA as needed
-Treatment includes IV antibiotics to treat any overlying infection, supportive care including fluids and pain control, surgical debridement, revascularization if possible, hyperbaric oxygen and amputation if all else fails

 Key Points:
-Initiate antibiotics early if infection is suspected
-If ischemia is detected early, revascularization with vascular surgery consultation is recommended
-Dry gangrene is a result of chronic ischemia
-Once gangrene has developed, affected tissue is typically not salvageable and orthopedics or vascular surgery should be consulted by amputation
-Gas gangrene is caused by exotoxin producing bacteria and should always be on an emergency physicians differential – ALWAYS consider this on the differential