Postoperative care - Wound healing and Management

Question 1

Wound:

Answer 1

“a disruption of the normal structure and function of the skin and underlying soft tissue.”
● May arise through traumatic injury (including surgery) or from the breakdown of previously intact skin
● Are generally classified as acute or chronic

Question 2

Acute Wounds

Answer 2

• Often acute wounds have an easily
  identifiable mechanism of injury, often due
  to trauma or surgery
• Normally heal in a linear process through
  the stages of wound healing.
• Have a predictable time frame (Around a 6-12 week duration)

Question 3

Chronic Wounds

Answer 3

• Chronic wounds can develop from acute
  traumatic or surgical skin injury or result from
  breakdown of previously intact skin.
• Wound healing has failed.
• Does not progress linearly through the stages
  of healing, chronic wounds are often stuck in
  the inflammation stage.
• No specific orderly sequence

Question 4

Primary wound closure

Answer 4

reapproximation of the edges, then closed

Question 5

Secondary wound closure

Answer 5

Left open, heal through granulation development, reepithelialization, scarring is an issue
○ “Healing by secondary intention”
○ Infected tissue and burns; or lack of tissue

Question 6

Delayed primary closure

Answer 6

left open for short time (in a controlled, moist
environment), then closed primarily

Question 7

Which wounds typically are closed by secondary intention?

Answer 7

Infected tissue and burns; or lack of tissue

Question 8

Which wounds typically are closed by delayed primary closure?

Answer 8

Contaminated wounds, perhaps crush or blast injuries, or avulsion injuries, with attempt to avoid infection

Question 9

Which wound closure technique is preferred?

Answer 9

Primary wound closure is preferable because of faster healing, less scarring,
improved hemostasis, and better
aesthetic and functional results.

Question 10

Stages of wound healing:

Answer 10

Hemostasis/Coagulation
Inflammation
Migratory/Proliferation
Maturation/Remodeling

Question 11

Coagulation/Inflammation (Days 0-4 to 6)

Answer 11

● Begins immediately after an acute injury
● The clot provides hemostasis/coagulation and also provides a matrix for cell migration, formation of extracellular matrix, and a
reservoir for cytokines and growth factors
● Coagulation products (i.e. fibrin, fibrinopeptides, thrombin split
products, complement components) are produced immediately after
injury to attract inflammatory cells
● Platelets are the primary component here; directs clotting via intrinsic and extrinsic pathways

Question 12

Interleukins and other inflammatory components (histamine,
serotonin, and bradykinin) cause vessels to _____

Answer 12

constrict for hemostasis, then dilate, so that blood plasma and leukocytes can
migrate into the injured area.

Question 13

● Macrophages (stimulated by fibrin) release ____, it builds up. Its level is
tightly regulated by tissue oxygen levels

Answer 13

lactate

Question 14

Lactate function

Answer 14

Signals acute wound healing → stimulates angiogenesis
and collagen deposition

Question 15

Oxygen function in coagulation/inflammation

Answer 15

Tissue O2 falls due to metabolic demand of the inflammatory cells, causing oxidative stress and moderate hypoxia which is an important signal for tissue repair and angiogenesis

Question 16

Fibroblasts function

Answer 16

● Fibroblasts organize and begin to contribute to healing
○ Circulating stem cells contribute fibroblasts (connective tissue) to
the healing wound but the exact process is unknown

Question 17

Fibroplasia

Answer 17

(replication of fibroblasts)- foundation of wound
It is stimulated throughout the wound healing process by many mechanisms including
various growth factors released by platelets, also by the continual release of peptide
growth factors from macrophages

Question 18

Proliferation (Days 4 to 6-14)

Answer 18

• Fibroplasia (replication of fibroblasts)- foundation of wound
• Matrix Synthesis- fibroblasts secrete collagen and proteoglycans
• Angiogenesis- required for wound healing.
• Epithelialization- several growth factors regulate epithelial cell replication.

Question 19

Matrix Synthesis

Answer 19

• fibroblasts secrete collagen and proteoglycans of the connective tissue matrix that holds the wound edges together and embeds cells of the healing wound matrix.
• These extracellular molecules polymerize, form a scaffold, and become the physical basis
  of wound strength.

Question 20

Angiogenesis

Answer 20

• required for wound healing. New capillaries sprout from preexisting venules and grow toward the injury in response to chemoattractants released by platelets and macrophages.

Question 21

Epithelialization

Answer 21

• several growth factors regulate epithelial cell
  replication.
• During wound healing, maximal cell proliferation occurs in the epithelium a few cells away from the wound end. New cells migrate over the cells at the edge and into the unhealed area and anchor to the first non epithelialized matrix area encountered.
• Process repeats until wound is closed.

Question 22

Most effective when surface
wounds are kept moist (even short periods of drying impair this process)

Answer 22

Epithelialization-

Question 23

Maturation/Remodeling (Day 8 to two years)

Answer 23

● The very early provisional extracellular matrix is replaced with a more mature
one by forming larger, better organized, stronger, and more durable collagen
fibers.
● Fibroblasts and leukocytes secrete collagenases that cause lysis which is part
of reorganizing the new matrix.
● Healing is successful when a net excess of matrix is deposited despite
concomitant lysis.

Question 24

Common causes of delayed healing- local vs systemic

Answer 24

● Tissue hypoxia
● Inflammation
● Malnutrition
● Proliferative scarring
● Infection
● Smoking
● Aging
● Immobilization
● Diabetes
● Vascular diseases
● Immunosuppressive therapy

Question 25

Tissue hypoxia

Answer 25

● Oxygen is required for successful inflammation, bactericidal activity, angiogenesis, epithelialization, and matrix (collagen) deposition. ● Human healing is profoundly influenced by local blood supply, vasoconstriction, and all other factors that govern perfusion and blood oxygenation. ● Hypoxia → higher wound infection rates, collagen deposition impairment

Question 26

_____ causes microvascular ischemic changes.

Answer 26

Diabetes

Question 27

Failure to heal is common in patients taking these medications:

Answer 27

○ Corticosteroids/anti inflammatories ○ Immunosuppressants ○ Chemotherapeutic agents that inhibit inflammatory cells.

Question 28

_____ is a main fuel for wound repair

Answer 28

Glucose

Question 29

How Malnutrition impairs healing?

Answer 29

○ Associated with prolonged inflammation and disruption of matrix deposition, cellular proliferation, and angiogenesis ○ Monitor overall nutrition status → albumin and prealbumin

Question 30

Proliferative Scarring

Answer 30

● An excessive tissue response characterized by local fibroblast proliferation and overproduction of collagen ● Unable to find a balance of collagen deposition or lysis ● It is unknown why some wounds continue in the dysregulated repair process ○ So no good treatment options exist

Question 31

Hypertrophic scars:

Answer 31

generally raised, self-limited (not outside wound borders), are related to residual inflammation, and may regress after a year or so

Question 32

Keloid scars:

Answer 32

extend beyond the borders of the wound and are most common in pigmented skin; don’t regress Treatment: intralesional corticosteroids, excision, radiation, laser, anti-mitotic meds

Question 33

Steps to prevent scarring

Answer 33

● Keeping the wound moist in early phase healing ● Avoid stretching the area ● Limit sun exposure by covering or > 50 spf sunblock

Question 34

Local Impediments of Wound Healing

Answer 34

● Infection ● Foreign bodies (e.g. sutures) ● Smoking ● Radiation ● Trauma ● Cancer ● Arterial/venous insufficiency ● Hypothermia

Question 35

Systemic Impediments of Wound Healing

Answer 35

● Nutritional deficiencies (e.g. malnutrition = worst case) ● Aging ● Diabetes ● Liver disease ● Alcoholism ● Medications (rheumatoid drugs, chemo, etc) ● Inherited disorders (connective tissue disorders such as Ehler Danlos syndrome)

Question 36

Infection of a wound

Answer 36

● Bacteria- inhibit the inflammatory phase and prevent epithelialization ● Results in cellular death and necrotic tissue which increases local inflammation and new cell growth ● New tissue growth cannot occur in the presence of necrotic tissue

Question 37

Surgical site infection

Answer 37

an infection related to an operative procedure that occurs at or near the surgical incision within 30 days of the procedure or within 90 days if implants are placed

Question 38

*An important risk factor of surgical site infections

Answer 38

The degree of contamination of a surgical wound at the time of operation. (Clean, clean-contaminated, contaminated, dirty/infected)

Question 39

Acute vs Chronic Wounds

Answer 39

Acute wounds: ● Normal timing and linear progression of healing ● Expect to heal with steady improvement ○ 6-12 weeks Chronic wounds: ● Complex, multifactorial process that slows or halts healing in any phase ● Duration of healing? Unknown (if at all) ● Less than ~15% reduction weekly or ~50% of the surface area over a 1 month period

Question 40

Venous Stasis Ulcers

Answer 40

○ Usually lower extremities ○ Due to venous hypertension ○ Reflects stasis of perivascular leakage of plasma into tissue which stimulates chronic inflammation ○ Contact dermatitis is common ○ Tx: elevation, compression, phlebectomies, if needed. And treat the underlying venous reflux

Question 41

Arterial/Ischemic Wounds

Answer 41

○ Due to poor perfusion; are painful ○ Treatment: ■ Needs vascular reconstruction ■ Wound care (possibly hyperbaric oxygen)

Question 42

Diabetic Foot Wounds

Answer 42

○ Major contributing factors include: ■ Neuropathy ■ Foot deformity ■ Ischemia ○ Once ulceration occurs, chances of healing are poor ○ Most diabetic wounds are infected ○ Tx: achieve good BS control and eradicate infection

Question 43

Major contributing factors of Diabetic Foot Wounds

Answer 43

■ Neuropathy ■ Foot deformity ■ Ischemia

Question 44

Decubitus (pressure) ulcers, also known as “pressure injuries”

Answer 44

A localized area of tissue necrosis that develops when soft tissue is compressed between a bony prominence and an external surface ■ Multifactorial, most result from prolonged pressure or shear force injury ■ “Most” are preventable with proper patient turning/hygiene ■ Symptom of the underlying problem

Question 45

Wounds kept moist _____ faster

Answer 45

re-epithelialize

Question 46

Types of wound dressings:

Answer 46

● Transparent films- Tegaderm ● Hydrocolloids- Duoderm ● Foams ● Gels ● Alginates ● Relatively new collagen products ● Petroleum based gauze- Xeroform

Question 47

Wound Debridement types:

Answer 47

● Irrigation ● Surgical ● Enzymatic ● Biologic

Question 48

Irrigation derbidement

Answer 48

Important to decrease the bacterial load and remove loose material. Should be part of routine management.

Question 49

Surgical debridement

Answer 49

uses a scalpel or other sharp instrument to remove devitalized tissue and debris

Question 50

Enzymatic debridement

Answer 50

apply exogenous enzymatic agents (eg, collagenase) to the wound

Question 51

Biologic debridement

Answer 51

- uses the larvae of the Australian sheep blow fly or green bottle fly. Also maggot therapy → used to treat pressure ulcers, chronic venous ulceration, diabetic ulcers, etc. ○ Excreted enzymes liquefy necrotic tissue which is then ingested

Question 52

Which wound debridement type uses maggot therapy?

Answer 52

Biologic debridement

Question 53

Wound Packing

Answer 53

● Wounds with large soft-tissue defects may have an area of dead space between the surface of intact healthy skin and the wound base. May be considered tunneled or undermined. Measure!! ● Gauze is often moistened and placed in the wound and covered with dry gauze

Question 54

Topical Therapy for wounds (antiseptics and antimicrobial agents)

Answer 54

● Iodine-based - an antimicrobial that reduces bacterial load within the wound and stimulates healing by providing a moist wound environment ● Silver-based - silver is toxic to bacteria. Dressings have not demonstrated significant benefits. ● Honey - has broad-spectrum antimicrobial activity due to its high osmolarity and high concentration of hydrogen peroxide

Question 55

Suture types

Answer 55

■ Silk- long track record, good choice, loses its strength over time ■ Synthetic non absorbable- retain strength, does not handle as well as silk- requires multiple knots ■ Synthetic absorbable- strong, incite minimal inflammation; useful in GI, GU, gyn operations that are contaminated ■ Other options- catgut (bovine), stainless steel wire

Question 56

alternative to suturing; minimizes errors in technique

Answer 56

Staples

Question 57

____ are More prone to scarring

Answer 57

Staples

Question 58

Surgical glue use

Answer 58

typically used on smaller incisions with minimal depth; often less painful

Question 59

Implantable materials

Answer 59

○ Soft tissues prostheses (e.g. hernia repair) - mesh ■ Has reduced recurrence rates ■ Related to a tension free closure ○ Skin grafting

Question 60

Negative Pressure Wound Therapy (NPWT)

Answer 60

○ Stabilizes distractive forces of an open wound (helps wound contract) ○ Promotes granulation tissue formation ○ Reduces edema and improves wound perfusion ○ Removes exudate ○ Provides clean, moist environment

Question 61

Management of chronic wounds - TIME

Answer 61

● Tissue (debridement if necessary) ● Infection/Inflammation ● Moisture ● Edge- undermine wound edges ○ Periwound skin (about 4 cm around the wound) ■ Protect the good skin