1 .Wound healing is a complex and dynamic process of restoring cellular structures and

tissue layers. The human adult wound healing process can be divided into 3 distinct

phases: the inflammatory phase, the proliferative phase, and the remodeling phase. Within these 3 broad phases is a

complex and coordinated series of events that includes chemotaxis, phagocytosis,

neocollagenesis, collagen degradation, and collagen remodeling. In addition,

angiogenesis, epithelization, and the production of new glycosaminoglycans

(GAGs) and proteolysis are vital to the wound healing milieu. The culmination of these

biological processes results in the replacement of normal skin structures with fibroblastic mediated scar tissue. For more information on wound healing, visit Meds

cape's Wound Management Resource Center

Introduction

♣Categories of Wound Healing ♥Category 1

2 .Primary wound healing or healing by first intention occurs within hours of repairing a full-thickness surgical

incision. This surgical insult results in the mortality of a minimal

number of cellular constituents

♥Category 23 .If the wound edges are not reapproximated

immediately, delayed primary wound healing transpires. This type of healing may be desired in the case of contaminated wounds. By the fourth

day, phagocytosis of contaminated tissues is well underway, and the processes of epithelization,

collagen deposition, and maturation are occurring. Foreign materials are walled off by macrophages

that may

♣Overview of Wound Healing4 .The amalgam of coordinated

events that constitute the process of wound healing is quite complex.

The steps in the procession of wound healing include

inflammation, the fibroblastic phase, scar maturation, and

wound contracture.2,3 Wound contracture is a process that

occurs throughout the healing process, commencing in the

fibroblastic stage.2

♣Initial phase - Hemostasis5 .Following vasoconstriction, platelets

adhere to damaged endothelium and discharge adenosine diphosphate (ADP),

promoting thrombocyte clumping, which dams the wound. The inflammatory phase is

initiated by the release of numerous cytokines by platelets. Alpha granules liberate platelet-derived growth factor (PDGF), platelet factor

IV, and transforming growth factor beta (TGF-b), while vasoactive amines such as

histamine and serotonin are released from dense bodies found in thrombocytes. PDGF is

chemotactic for fibroblasts and, along with TGF-b, is a potent modulator of fibroblastic

mitosis ,

♣Second phase - Inflammation6 .Within the first 6-8 hours, the next phase of the

healing process is underway, with polymorphonuclear leukocytes (PMNs) engorging the wound. TGF-b facilitates PMN migration from

surrounding blood vessels where they extrude themselves from these vessels. These cells

"cleanse" the wound, clearing it of debris. The PMNs attain their maximal numbers in 24-48 hours and commence their departure by hour 72. Other

chemotactic agents are released, including fibroblastic growth factor (FGF), transforming

growth factors (TGF-b and TGF-a), PDGF, and plasma-activated complements C3a and C5a

(anaphylactic toxins). They are sequestered by macrophages or interred within the scab or eschar

♣Third phase - Granulation

7.This phase consists of different subphases. These subphases do not happen in discrete

time frames but constitute an overall and ongoing process. The subphases are

"fibroplasia, matrix deposition, angiogenesis and re-epithelialization".4

In days 5-7, fibroblasts have migrated into the wound, laying down new collagen of the subtypes I and III. Early in normal wound

healing, type III collagen predominates but is later replaced by type I collagen.

♣Healing By Blood-Clot8 .Healing by blood-clot differs but little from

that just described. It occurs when, in consequence of the edges of a wound not

being brought immediately into apposition with each other, the space between them becomes filled with blood-clot, into which white blood corpuscles and plasma cells soon penetrate.By a process of development the latter are

resolved into fibrous tissue, which, as in healing by the first intention, form the

permanent bond of union between the divided parts. These two modes of union can only be

effected where the lips of the wound are undisturbed and all causes of irritation are

excluded.

♣Healing Under A Scab9 .This is nature's method of repairing

wounded parts, and in suitable circumstances the best that can be devised. It is well

illustrated when, after the surface of the skin has been broken, the blood and other exuded matters are allowed to dry upon it, and form,

as they will, a complete defensive covering or scab. In this condition all foreign substances which would irritate and inflame the wound

are excluded from it, and so long as this state continues, healing proceeds rapidly without

interruption. Anything, however, that inflames and provokes the formation of pus (matter)

beneath the scab, interferes with the process and delays reparation.

♣Management of surgical wound infections10 .The type of surgery (clean,

clean/contaminated, contaminated or dirty) will determine the risk level of infection and the

likely spectrum of pathogens.  Empirical therapy should be primarily directed against

Staphylococcus aureus.If wounds are not grossly infected, they may

respond to local measures such as removal of sutures.  Frequent saline bathing should be

undertaken and the wound requires a drain to allow healing.  Deep-seated infection related to

complicated abdominal surgery may require broad-spectrum antibiotics and investigation for

possible surgical intervention

♣Indications for prophylaxis

11 .Prophylaxis is particularly recommended in surgery where there is a high-risk of infection such as abdominal surgery or

where the development of infection would be very serious

eg.

Indications for prophylaxis in clean surgery where infection

would be very serious

♣Disinfection.12 .The O.C. Sanitary Section of the area occupied, is

responsible for the disinfection of billets and camps in which cases of the following diseases have occurred—:

1.Scarlet fever2.Diphtheria3.Small-pox

4.Cerebro-spinal meningitis5.Cholera

6.Relapsing fever7.Typhus

The O.C. Sanitary Section will be communicated with by the A.D.M.S. of the Division.

The O.C. Sanitary Section will generally demand a fatigue from the R.M.O. to assist him. This fatigue will be provided from the

sanitary personnel of the unit.In cases of other infections diseases, disinfection will be carried

out by the R.M.O. A spraying apparatus and fluid for use in it will generally be lent by O.C. Sanitary Section when asked for in

writing by the R.M.O.

Second Intention Healing, cause and effect

•When first intention healing does not occur, the wound

heals by “second intention.”  This is a slower healing

process. As we mentioned last week, healing occurs when

cells move in from the border of the wound, one layer at a time. These overlap until the

wound is full. As this ‘filler’ tightens and contracts, the

edges are pulled together. If this process continues without

interference ,

NON Healing Wound

•Wound infections are one of the most common

complications after surgery. This means that bacteria have started to grow in your wound.

If you develop an infection ,•smoke •have diabetes •become more painful •look red, inflamed or swollen •leak or weep liquid, pus or

blood •smell unpleasant

Healing Under A Scab

•This is nature's method of repairing wounded parts,

and in suitable circumstances the best

that can be devised. It is well illustrated when, after

the surface of the skin has been broken, the

blood and other exuded matters are allowed to dry upon it, and form, as they will, a complete defensive

covering or scab .

Complete Healing

•After the third week, the wound undergoes

constant alterations, known as remodeling,

which can last for years after the initial injury

occurred. Collagen is degraded and deposited

in an equilibrium-producing fashion,

resulting in no change in the amount of collagen

present in the wound .

Self-Inflicted and Accidental Wounds

•The occurrence of these must be immediately reported to the O.C. of the soldier's Company, Battery, etc., and a note made

on the Tally that the case is one of self-inflicted (or

suspected self-inflicted wound) by marking it distinctly with the

letters "S.I".•It must be remembered that a

self-inflicted wound may be accidental or intentional, but in either case a Court-Martial will

be required .

Clothing of Wounds

•Preparatory to dressing a wound, it is frequently found

necessary to cut the clothing in order to remove it without aggravating the injury or

causing pain to the patient.•Although this matter is one for

the judgment of the M.O. in each case, these officers will (as far as is consisistent with the welfare of their patients)

avoid unnecessary mutilation of clothing, and especially of

boots, gum, thigh.

Our Outer Layer...the Skin•The epidermis is continually

exposed to the environment and sustains most of the injury

to the skin. As a result, it is shed and regenerated on a

daily basis. Its major role is to produce the stratum corneum-a waterproof, semi-permeable

membrane on the outermost portion of the epidermis that

acts to prevent water loss from the tissues it surrounds. When

this upper layer is injured-as can occur with minor scrapes

and cuts-it simply regenerates itself without scar formation.

The same is not true for deeper injuries

End Of Healing

•healing by second intention is to use a

treatment that is beneficial to the process and does a minimum of

damage when used.  The wound will heal quicker

and the resulting scar will be smaller.  Whether

healed by first or second intention, the horse’s

recollection of how it hurt itself will have been

forgotten long before the wound is healed !

Tissue adhesive (skin glue)

•Special skin glue can be used to close small wounds that are less than 5cm (two inches) long. Although the

glue is waterproof, the area needs to be kept dry for at

least five days. The glue usually peels off in five to 10

days.•Sometimes for larger

(longer) skin cuts, glue is used together with stitches

or special self-adhesive skin-closure strips (Steri-strips) to seal the wound