What is the correct statement regarding the inflammatory phase of wound healing in a 41-year-old lady with a deep laceration on postoperative day 2?

Inflammatory Phase of Wound Healing

The complement component C5a and platelet factor attract neutrophils to the wound is the correct statement regarding the inflammatory phase of wound healing.

Understanding the Inflammatory Phase

The inflammatory phase is a critical component of wound healing that follows immediately after hemostasis. In the case of the 41-year-old lady with a complex hand laceration repair showing a large clot with mild surrounding erythema on postoperative day 2, we are observing the classic signs of the active inflammatory phase.

Timeline and Duration

• The inflammatory phase begins immediately after injury and typically lasts 4-6 days
• It does NOT last only 24 hours as suggested in option C 1
• By postoperative day 2, the patient is still firmly in this phase

Key Cellular Components and Mediators

Neutrophil Recruitment

• Neutrophils are attracted to the wound site by several chemotactic factors:
  • Complement component C5a (anaphylatoxin) 1
  • Platelet factors released during degranulation 1
  • These two factors work together to initiate neutrophil chemotaxis to the wound site

Role of Platelets

• Following blood clot formation, degranulating platelets release:
  • Platelet-derived growth factor (PDGF)
  • Transforming growth factor beta (TGF-β)
  • Vascular endothelial growth factor (VEGF) 1
• These factors promote cell chemotaxis and increase vascular permeability

Are Neutrophils Essential for Normal Healing?

Contrary to option B, neutrophils are NOT essential for normal wound healing:

• While neutrophils are typically the first inflammatory cells to arrive at the wound site
• They primarily function to prevent infection by phagocytosing bacteria and debris
• Studies have shown that wounds can heal normally in neutropenic conditions or when neutrophil infiltration is inhibited 2
• Macrophages, not neutrophils, are the "main actors" of the wound healing phases 1

Progression of the Inflammatory Response

1. Initial Response (0-24 hours):

   • Platelet aggregation and clot formation
   • Release of inflammatory mediators
   • Initial neutrophil infiltration

2. Established Inflammatory Phase (24-72 hours):

   • Peak neutrophil activity
   • Increasing macrophage infiltration
   • Release of pro-inflammatory cytokines (IL-1, IL-6, TNF-α) 1

3. Late Inflammatory Phase (72-120 hours):

   • Transition to proliferative phase begins
   • Macrophages become predominant
   • Anti-inflammatory mediators increase

Clinical Implications

For the patient with a deep laceration repair showing a clot with mild erythema on day 2:

• These findings represent normal wound healing in the inflammatory phase
• The erythema is expected due to increased vascular permeability and local inflammation
• The clot formation is part of the normal hemostatic process

Potential Complications to Monitor

• Excessive inflammation may indicate infection
• Insufficient inflammatory response may lead to poor healing
• Prolonged inflammation can lead to chronic wounds 3

Conclusion

The inflammatory phase of wound healing is a complex, orchestrated process involving multiple cell types and mediators. The correct statement is that complement component C5a and platelet factors attract neutrophils to the wound site, which is a key event in the early inflammatory phase but not essential for normal healing. This phase typically lasts several days, not just 24 hours.