ABS2 Flashcards
First cells to infiltrate the wound
PMNs
*Peaks at 24-48 hours post-injury
Cells that bridges transition from inflammation to proliferative phase
Lymphocytes (T cells)
Cells that peaks at 48 – 96 hours post-injury
Macrophages
Open cardiac massage is considered as what operative wound class
Class III
Final step in establishing tissue integrity
Epithelialization
The peak of fibroblasts in a healing wound occurs
6 days after injury
Macrophages are present in the wound starting on the 4th day after injury until the wound is completely healed. The primary function of the macrophages in wound healing is
Activation of cell proliferation, matrix synthesis, and angiogenesis
*Activation and recruitment of other cells via mediators such as cytokines and growth factors, as well as directly by cell-cell interaction and intercellular adhesion molecules
*Modulation of the wound environment = T lymphocytes in the wound
There are 18 types of collagen in the human body. Which two are the most important in wound healing
Type I and III
*Type I – the major component of extracellular matrix in skin
*Type III – normally present in the skin, becomes more prominent and important during the repair process
The tensile strength of a completely healed wound approaches the strength of uninjured tissue
NEVER
*The mechanical strength of the scar never achieves that of the uninjured tissue
*Scar remodelling – continues for 6 to 12 months postinjury
How long does re-epithelialization (i.e., complete repair of the external barrier) take in a well-approximated surgical wound
2 days (48 hours)
What protein is defective in patients with Marfan’s syndrome
Fibrillin
What protein is defective in patients with osteogenesis imperfecta (OI)
Collagen type I
What component of wound healing is impaired in a child with acrodermatitis enteropathica (AE)
Formation of granulation tissue
Most well-known element in wound healing
Zinc
Important cytokine mediator of wound healing
TGF β – primarily by mediating angiogenesis
The most common mode of inheritance of Ehlers-Danlos Syndrome is
Autosomal dominant
Layer of the intestine has the greatest tensile strength (i.e., ability to hold sutures)
Submucosa
Leaks from a bowel anastomosis most commonly occur 5 to 7 days after surgery. The reason is
Increased collagenolysis
*Lysis of collagen is carried out by collagenase derived from neutrophils, macrophages, and intraluminal bacteria
*During the first 3 to 5 days collagen breakdown far exceeds collagen synthesis
*Collagenase activity – not as significant role in cutaneous wounds
Ehlers-Danlos Syndrome (EDS) must be considered in every child with recurrent hernias and coagulopathy, especially when accompanied by
Platelet abnormalities and low coagulation factor levels
*Elevated PT/PTT
A patient with epidermolysis bullosa (EB) requires placement of a feeding gastrostomy due to esophageal erosions. What kind of dressing should be placed after surgery
Nonadhesive pad with circumferential bulky dressing
*To avoid blistering
Which phase of healing is most affected by exogenous corticosteroids
Initial phase of cell migration and angiogenesis
*Major effect of steroids – to inhibit the INFLAMMATORY PHASE of wound healing (angiogenesis, neutrophil and macrophage migration, and fibroblast proliferation) and release of lysosomal enzymes
*Steroid used after the first 3 to 4 days postinjury do not affect wound healing
*Effect on collagen synthesis – steroid also inhibit epithelialization and contraction and contribute to increased rates of wound infection, regardless of the time of administration
What vitamin should be given to promote wound healing in patients receiving steroids
Vitamin A
*Collagen synthesis of steroid-treated wounds can be stimulated by vitamin A
How long does protein calorie malnutrition need to be present in patients in order to affect wound healing
Days
A homeless, malnourished 48-year-old patient is admitted to the ICU after a severe blunt injury. A reasonable daily dose of vitamin C for this patient would be
≥ 1 g or as high as 2 g daily
*In severely injured or extensively burned patients = As high as 2 g daily
*Recommended dietary allowance = 60 mg daily
In severely injured patient, supplemental doses of VITAMIN A have been recommended ranging from
25,000 to 100,000 IU per day
The ideal time to administer prophylactic antibiotics to a patient undergoing a colon resection is
1 hour before surgery
A 28-year-old patient with chronic granulomatous disease is scheduled for cystoscopy under general anesthesia. What test should be obtained pre-operatively
Pulmonary function test
*Patients with CGD are predisposed to obstructive and restrictive lung disease
*Sutures should be removed as late as possible because wounds heal slowly
*Abscess drains should be left in place for a prolonged period until the infection in completely resolved
* Wound complications, mainly infection, are common
What should be performed in a patient with a suspected Marjolin ulcer
Biopsy
Considered the most effective therapy for venous stasis ulcers
Compression therapy
*Most commonly used method – the rigid, zinc oxide-impregnated, nonelastic bandage