A patient undergoes split-thickness skin grafting (STSG) for a large burn wound. The STSG fails to take in one area with underlying granulation tissue appearing unhealthy. Wound swab grows >10^5 organisms/gram of tissue. The most likely reason for graft failure is:

• A Inadequate immobilization of the graft (mechanical shear)
• B Incorrect meshing ratio (1:1.5 was used instead of 1:3)
• C Use of dilute epinephrine in the donor site injection
• D Bacterial bioburden >10^5 organisms/gram preventing graft adherence and neovascularization ✓

Explanation

The critical threshold for split-thickness skin graft failure due to wound infection is bacterial count >10^5 organisms per gram of tissue; at this density, bacteria release proteases that lyse fibrin attachment (the first step in graft take within 24-48 hours) and produce metabolic competition, preventing revascularization. Beta-haemolytic Streptococcus is particularly virulent at any count. Management requires wound bed preparation with debridement, topical antimicrobials (silver sulfadiazine or Mafenide), and re-grafting only when the bioburden is controlled.

Reference: Bailey & Love's Short Practice of Surgery, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.