How does a skin graft survive within the first 24 hours?
A. Capillary network neovascularization
D. Oxygen diffusion from open air
Plasmotic imbibition is how the skin graft survives for the first 24 hours; capillary inosculation occurs in the next 48 hours followed by neovascularization.
What is the most common reason for free flap failure?
Venous thrombosis is the most common reason for free flap failure; clinical signs of venous thrombosis include congested blue appearing flap, cap refill <2 seconds, eventual loss of Doppler signals, and arterial insufficiency.
What is the perfusion pressure of the capillary network of skin?
Once tissue compression exceeds perfusion pressure, tissue necrosis can occur. Generally tissues can tolerate ischemia for short periods of time as long as compression is relieved every 1 to 2 hours for 5 to 10 minutes, hence the reason debilitated patients are turned Q2 hours to prevent pressure sores.
What is the third layer of the epidermis called?
Starting from outside to in, the skin layers are stratum corneum, stratum lucidum (not always present), stratum granulosum, stratum spinosum, and stratum basalis. When measuring depth of extension for melanoma, the stratum granulosum is used as the starting point of the lesion for Breslow thickness.
What is a local anesthetic that has both anesthetic and vasoconstrictive properties?
Cocaine is the only topical anesthetic that provides both an anesthetic and vasoconstrictive effect. It is often used in nasal surgery because of the added bonus of vasoconstriction in an extremely vascular area.
Which topical antimicrobial has the adverse side effect of metabolic acidosis?
Sulfamylon is a carbonic anhydrase inhibitor that has the known side effect of metabolic acidosis. This can be especially problematic in burn patients during their initial hospital course because of lactic acidosis or respiratory acidosis from inhalation injury.
Which nerve supplies the pectoralis minor muscle?
B. Lateral pectoral nerve
D. Medial and lateral pectoral nerves
The pectoralis minor muscle is innervated by the medial pectoral nerve. Pectoralis major is innervated by both medial and lateral pectoral nerves.
Which artery supplies the latissimus dorsi muscle?
B. Intercostal muscle perforator artery branches
C. Thoracoacromial artery
The thoracodorsal artery supplies the latissimus dorsi muscle.
Which muscle flap is most affected in a patient that has undergone coronary artery bypass graft with the left internal mammary artery?
Rectus abdominis has a dual blood supply from the deep inferior epigastric artery and the superior epigastric artery (distal extension of the internal mammary). For sternal wound infections in a patient that is post CABG, the rectus muscle flap may not be of use if the ipsilateral internal mammary has been used in the CABG.
In a 100 kg man, what is the safe dose of bupivicaine that can be administered for local anesthesia?
2.5 to 3 mg/kg of bupivicaine can be administered to a patient. Bupivicaine has a tendency to cause more systemic side effects than other local anesthetics.