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
Most likely to cause a diabetic ulcer
Neuropathy (60 to 70%)
*Duet to ischemia – 15 to 20%
*Motor neuropathy or Charcot foot – leads to collapse or dislocation of the interphalangeal or metatarsophalangeal joints, causing pressure on areas with little protection
A teenage, African American girl presents with large keloids on both ear lobes 12 months following ear piercing. What therapy should be added to surgical debulking of the lesion
Intralesional corticosteroids
The risk of small bowel obstruction in the first 10 years after left colectomy is
30%
Intra-abdominal adhesions can be decreased after laparotomy by
Frequent irrigation to keep bowel surfaces moist
A healthy 20-year-old presents to the emergency room with a large, contaminated laceration that he received during a touch football game. What solution should be used to irrigate the wound
Normal saline
*What suture should be used to close the subcutaneous layer = Absorbable braided
*Subcutaneous tissues should be closed with braided absorbable suture, with care to avoid placement of suture in fat
Most suitable suture for approximating deep fascial layers, particularly in the abdominal wall
Nonabsorbable or slowly absorbing monofilament suture
*Drains may be placed in areas at risk of forming fluid collections
An alginate dressing is best used in
An open surgical wound
*Used in:
Skin loss
Open surgical wounds with medium exudation
Full-thickness chronic wounds
What topical agent has been shown to improve healing in diabetic foot ulcers
Platelet derived growth factor BB (PDGF-BB)
First vasopressor to be administered
Norepinephrine
Preoperative dose timing for vancomycin administration is within before incision
120 minutes
qSOFA parameters
- RR >22/min (1point)
- Altered mental status (or GCS <15) (1point)
- SBP < 100mmHg (1point)
The initiating event in shock
Cellular energy deficit and hypoperfusion
Can initiate afferent impulses to the CNS which triggers the neuroendocrine response of shock
Hypothermia
*Initial inciting even usually is = Loss of circulating blood volume
*Other stimuli that can produce the neuroendocrine response include:
Pain
Hypoxemia
Hypercarbia
Acidosis
Infection
Change in temperature
Emotional arousal
Hypoglycemia
Vasoconstriction is one of the initial physiologic responses to hypovolemic shock. This is mediated by
Activation of alpha adrenergic receptors on the arterioles
Anti-diuretic hormone (ADH) is secreted in response to shock and remains elevated for approximately 1 week. Which is seen as a result of this increased level of ADH
Mesenteric vasoconstriction
*ADH acts as a potent mesenteric vasoconstrictor → shunting circulating blood away from the splanchnic organs during hypovolemia →may contribute to intestinal ischemia and predispose to intestinal mucosal barrier dysfunction in shock states
*Increase the production of ADH:
Epinephrine
Angiotensin II
Pain
Hyperglycemia
Hypoxia at the cellular level decrease ATP production (also called dysoxia). This results in
Changes in intracellular calcium signalling
Toll-like receptors play a role in the “danger signalling” pathway which modulates the immune response to injury. Stimulation of these receptors is by molecules released from
Damaged cells
Which cytokine is released immediately after major injury
TNF-alpha
*Released by:
Monocytes, macrophages, and T cells
Bacteria or endotoxin → leads to development of shock and hypoperfusion
Hemorrhage and ischemia
*Peak within 90 minutes of stimulation and return frequently to baseline levels within 4 hours
*Effects:
Peripheral vasodilation
Activate the release of other cytokines
Induce procoagulant activity
Stimulate wide array of cellular metabolic changes
*During the stress response, TNF-alpha contributes to the muscle protein breakdown and cachexia
Anti-inflammatory cytokines
IL-4, IL-10, IL-13, prostaglandin E2, TGF-β
Best describes the hemodynamic response to neurogenic shock
Increased cardiac index, unchanged venous capacitance
What percentage of the blood volume is normally in the splanchnic circulation
20%
Can be used to indirectly estimate the oxygen debt incurred during shock
Base deficit and lactate levels
*Mild (-3 to -5 mmol/L)
*Moderate (-6 to -9 mmol/L)
* Severe (less than -10 mmol/L)
The probability of death for a patient with a base deficit of -6 is approximately
25%
A 70-kg man with a laceration to the brachial artery loses a total of 800 mL of blood. What is the class of haemorrhage would this represent
Class II haemorrhage
*CLASSIFICATION OF HEMORRHAGE
A patient arrives in the ER following a motor vehicle accident with multiple injuries. Hypotension in this patient is define as SBP
Less than 110
In a patient with ongoing haemorrhage, the risk of death increase 1%
In every 3 minutes in the ER
A 24-year-old arrives at the emergency department (ED) with multiple stab wounds to the abdomen, severe blunt trauma to the head (GCS 10), and a SBP of 80 mmHg. An appropriate goal for resuscitation in the ED would be a SBP of
80 to 90 mmHg
An INR of 1.5 on arrival to the intensive care unit (ICU) is associated with what probability of death
20%
Shock following severe carbon monoxide poisoning is most commonly
Vasodilatory shock
Insulin drips should be used to maintain serum glucose in nondiabetic, critically ill patients at levels between
80 and 110 mg/dL
An unconscious patient with a systolic BP of 80 and a HR of 80 most likely has
Cardiogenic shock
A 72-year-old woman suffered an acute MI and, 12 hours later, is in cardiogenic shock. Best treatment for this patient
Immediate PTCA with stenting, if feasible
*Percutaneous Transluminal Coronary Angiography
*For patients with multiple vessel disease or left main coronary artery disease = Coronary artery bypass grafting
A patient unresponsive to catecholamines after an acute myocardial infarction is placed on amrinone. What is the common side effect of amrinone
Thrombocytopenia
Critical component of the initial response to bacterial contamination of the peritoneal cavity
Macrophage upregulation
Severe sepsis is differentiated from sepsis by
Acute organ failure such as renal insufficiency
*Presence of new-onset organ failure
* Most common cause of death in noncoronary critical units
What antifungal agent is associated with decreased cardiac contractility
Itraconazole
*Liposomal amphotericin B = Renal toxicity
*Voriconazole = Visual disturbances
Antibiotic of choice in a penicillin allergic patient undergoing a cholecystectomy for acute cholecystitis is
Fluoroquinolone + Metronidazole or Clindamycin
*Ampicillin-sulbactam, ticarcillin-clavulanate, piperacillin-tazobactam
Appropriate duration of antibiotic therapy for most patients with bacterial peritonitis from perforated appendicitis is
3-5 days
*12 to 24 hours – for penetrating GI trauma in the absence of extensive contamination
*3 to 5 days – for perforated or gangrenous appendicitis
*5 to 7 days for treatment of peritoneal soilage due to a perforated viscus with moderate degrees of contamination
*7 to 14 days – to adjunctively treat extensive peritoneal soilage (e.g., feculent peritonitis) or that occurring in the immunosuppressed host
Best estimates the risk of surgical site infection (SSI) in a patient undergoing an elective low anterior colon resection
10 – 25%
Components of PIRO staging for sepsis
- (P) – Predisposing conditions/ pre-existing medical conditions
- (I) – Insult (infection) / the nature and extend of the infection
- (R) – Response / the nature and magnitude of the host response
- (O) – Organ dysfunction / the degree of concomitant organ dysfunction
Has been shown to decrease the rate of pancreatic abscess in patients with necrotizing pancreatitis
Enteral nutrition
Most suggestive of a necrotizing soft tissue infection and would mandate immediate surgical exploration
A small amount of grayish, cloudy fluid from a wound
*Any of these findings mandates immediate surgical intervention:
A small break or sinus from which graying turbid semipurulent material (“dishwater pus”) can be expressed
Presence of skin changes – bronze hue or brawny induration, blebs, or crepitus
The appropriate duration of antibiotic therapy for nosocomial urinary tract infection is
3-5 days
The typical CXR finding in anthrax is
Widened mediastinum and pleural effusions
