Page 40 - Orthopedic Casting Manual

4.1 Cardinal Signs of Inflammation

✓ Rubor LRedness)
✓ Physiology: Redness, or rubor, occurs due to vasodilation, which is the widening of blood vessels in the
affected are a. This process incre ases blood flow and is mediated by chemic al signals such as histamine,
prostaglandins, and bradykinin LSer han & Levy, 2018M. These mediators are rele ased by immune cells like
mast cells and macrophages in response to injur y or infection.
✓ Clinic al Signif ic ance: Incre ased blood flow delivers immune cells, oxygen, and nutr ients necessar y for
tissue rep air. The redness is a visible indic ator of incre ased vascular activit y and c an help clinicians
identify the foc al point of inflammation.
✓ Calor LHe atM
✓ Physiology: He at in the inflamed are a resul ts from the same incre ased blood flow c aused by vasodilation.
The temperature r ise is loc alized to the affected tissue and resul ts from the deliver y of war m ar ter ial blood.
✓ Protective Role: Elevated temperature cre ates an unfavorable environment for p athogens like b acter ia and
viruses. Additionally, it accelerates the metabolic rate of immune and rep air cells, enhancing the he aling
process LChovatiya & Medzhitov, 2014M.
✓ Clinic al Signif ic ance: The war mth is a p alp able sign that complements visual redness, offer ing insight into
the intensit y of the inflammator y response.
✓ Tumor LSwelling)
✓ Physiology: Swelling, or tumor, occurs due to incre ased vascular per me abilit y, allowing plasma, immune

cells, and proteins to le ak into the ex tracellular sp ace. This fluid accumulation is dr iven by inflammator y
mediators such as vascular endothelial growth factor LVEGF) and histamine LAbb as et al., 2021M.
✓ Protective Role: Swelling ser ves to dilute toxins produced by p athogens and provides a medium for
immune cells to travel to the injur y site.
✓ Clinic al Consideration: Swelling c an compress adjacent structures, le ading to discomfor t or imp aired
function. However, it is a cr itic al p ar t of the inflammator y response, facilitating he aling.
✓ Dolor LPainM
✓ Physiology: Pain ar ises from the sensitization of nociceptors (p ain receptors) by inflammator y mediators,
such as prostaglandins, bradykinin, and substance P. Additionally, the physic al pressure from swelling c an
activate these receptors LCoul thard et al., 2020M.
✓ Pur pose: Pain acts as a protective signal, discouraging movement or fur ther use of the injured are a. This
rest promotes tissue rep air and minimizes the r isk of additional damage.
✓ Clinic al Perspective: Understanding the biochemic al p athways le ading to p ain has guided the
development of anti-inflammator y and analgesic tre atments, such as NSAIDs, which inhibit prostaglandin
synthesis.
✓ Functio Laesa LLoss of Function)
✓ Def inition: Loss of function, or functio laesa, occurs when inflammation disrupts the nor mal activit y of the
affected tissue.
✓ Mechanisms: This symptom is often a combination of the other signs. Pain and swelling restr ict
movement, while the structural integr it y of the tissue may be temporar ily compromised.
✓ Pur pose: Al though inconvenient, loss of function encourages rest, preventing fur ther injur y and allowing

the he aling process to proceed unhindered LSer han et al., 2020M.
✓ Clinic al Implic ation: Loss of function must be evaluated in the contex t of the p atient's condition. Persistent
dysfunction may indic ate chronic inflammation or under lying damage that requires inter vention.
Conclusion The c ardinal signs of inflammation — redness, he at, swelling, p ain, and loss of function — are vital
diagnostic tools for he al thc are professionals. Recognizing these signs and understanding their under l ying
mechanisms allow clinicians to assess the severit y and c auses of inflammation accuratel y. By addressing the
root c ause of inflammation and suppor ting the bod yʼs he aling processes, he al thc are providers c an optimize
p atient outcomes.