W4P2 Flashcards
Trick for epidermis layers?
Come Let’s Get Sun Burned
Which skin layer has the hair follicles and the nerve?
Reticular layer of the dermis
Burn effects on other organs
Lungs: leads to broncho constriction
Cardio: edematous, a lot of water loss. so keep hydrated
The Parkland Formula*
- what type of fluid is given?
Formula: 4 cc/kg/%TBSA
- this does NOT include first degree burns
- first half is given in the first 8 h
- second half is given in the next 16 h
Most commonly used method for estimating total amount of fluid to be administered in the first 24 h post burn.
Fluid given: Ringer’s lactate
- NOT NS (due to risk of hypercholeremia acidiosis)
- ** formula only provides an estimate of fluid req
- clinically: monitor urine output by means of Foley catheter and titrate fluids to achieve a urine output of 30 cc/h in adults and 1 cc/kg/h in children.
Degrees of burns, best to worse
first degree: superficial
third degree: not good, deep, serious
Based on the Parkland Formula at what percentage can you give oral fluids only?
Burns <20% TBSA in adults and <10-15% TBSA in children can be treated with oral fluids only.
Burn Size Assessment
Quantifying the degree of injury is an important initial step in the treatment of burns as it affects decisions regarding resuscitation, transfer, and surgical debridement.
- average overestimate of 75% by referring physicians
Should be performed with a standardized Lund-Browder diagram for 2nd and 3rd degree burns
The simpler rule of nines is helpful for rapid assessment but is less accurate
The patients palm, including the fingers, is often used to estimate 1% TBSA (variable accuracy)
What is a 1st degree burn
like a sun burn
it DOES not go into the dermis
painful, the nerves aren’t cut off, they still sensate skin
if you DON’T have blisters then you know its epidermal or hypodermal
(blisters= indicate it is in the dermal level. scars only form if the dermis is involved)
2nd degree burns
two types:
a. superficial: you can see the blistering that occurs. this is above the reticular layer. so they are SENSATE, the nerves are intact. good capillary refill. they will heal without surgery
b. deep burn: change in colour- more red. less feeling of pain… not a good sign, infiltrated reticular layer. must watch closely, might need surgery so it doesn’t progress and scar.
burns evolve over time
Third degree burn
full thickness, charred appearance
these NEED surgery
Burn Center Referral Criteria
Early transfer to a burn center should be arranged following the secondary survey if the patient’s injuries meet the burn center referral criteria set forth by the American Burn Association
Following criteria means you REFER:
- 3rd degree burns: refer
- 2nd degree burn over 10% BSA, if the patient is <10 or >50 yrs old
- 2nd or 3rd burn over 20% in other groups
- burns to genitalia, face, hands, feet, any functional parts– refer*
- Electrical burn
- Inhalation burn
- Circumferential burns
The oral Mucosal Immune System
This is a part of the MALT: Mucosal associated lymphoid tissue
At three different sites:
- The oral mucosa
- Salivary glands
- Gingival Crevice
Oral Mucosa
- Mechanical barrier formed by the squamous epithelium and lamina propria
- Intraepithelial DC/langerhans cells sample the environment
- Ab, especially IgA are secreted
- Pro-inflammatory cytokines can be secreted by epithelial cells as well as immune cells in the oral mucosa
- the DC and T cells will decide whether to release a regulatory/tolerant/non responsive out put or to activate immune system
Salivary glands and Saliva
Saliva acts as a mechanical flush
Contains IgA, Lactoferrin, lysozyme, complement, leukocytes among other antimicrobial elements
IgA function inpart to inhibit attachment of bacteria and viruses to the oral epithelium
Gingival Crevice
- Neutrophils continuously traffic from gingival capillaries into the sulcus
- Leukocytes accumulate in response to plaque
- Neutrophils in the gingiva are activated by local cytokine production and co-receptors and are able to phagocytose and kill microorganisms
- Neutropenia results in gingivitis and loss of peridontal attachment (if chronic)
Oral Health and Disease
- recall hyper IgE case
poor oral health is associated with disorder of the innate immune system.
hyper IgE syndrome caused by mutations in an important messenger protein, STAT 3 result in peridontal disease as well as failure to exfoliate the primary teeth.
Apthous ulcers are associated with autoimmune syndromes such as Behcet’s disease, although the complete mechanisms are to be elucidated
What are some DDx for 30 year old female presents with multiple dental caries, despite a good routine of oral hygiene and previous low rate of caries formation
GERD,
eating disorder w vomitting
micronutrient deficiency: diets
GI tract defense mechanisms
- Mucosal barrier with tight junctions, cilia*, IgA and commensal organisms are first line of defense
- Recognition of potential pathogens is mediated by innate receptors, such as TLR’s and NOD molecules
- Mutations in NOD receptors are associated with the development of the autoimmune inflammatory bowel disease, Crohn’s disease
we need most of the response to be PRIMARILY immunoREGULATORY*
Peyer’s patches
- Principal sites of mucosal responses are the Peyer’s patches found in SI, the appendix, and in lymphoid follicles of the large intestine
- These contain specialized epithelial cells, M cells, which interact directly with molecules and particles of the gut lumen
Function of the M cells
found in Peyer’s patches
M cells are interspersed between enterocytes and in close contact with subepithelial lymphocytes and DCs
They take up antigens from the gut lumen by endocytosis
Ag are released beneath M cellsa nd taken up by APCs (DC/T cells)
what are gut homing effector T cells
Gut derived lymphocytes will enter the mucosal and lymphatic circulation will be also “home” to mucosal sites
Gut homing effector T cells bind to MADCAM1 on epithelium
Gut epithelial cells express chemoknines specific for gut-homing T cells
What cells protect the gut?
- Specialized T cells (the homing ones) can preferentially kill infection cells
- Intraepithelial lymphocytes play roles in minimizing gut inflammation and facilitating repair
- IgA neutralized toxin and prevents adherence of viruses and bacteria to epithelial cells
- Most gut immune responses result in tolerance
What gets activated when your gut cells get infected?
Infection signals synthesis of a series of stress induced proteins
infected cell expresses two atypical class I molecules MIC-A and MIC-B
T cells bearing the NK receptor bind to MIC-A and MIC-B
The infected epithelial cell is killed by induction of apoptosis and replaced by adjacent healthy cells
How does IgA defend the gut?
Polymeric IgA is transported into the gut lumen through epithelial cells at the base of the crypts
Polymeric IgA binds to the mucus layer overlying the gut epithelium
IgA in the gut neutralizes pathogens and their toxins
so prevents the toxin from even entering the cell
Role of Commensal Flora/ the microbiome
it is important/protective
- Antibiotic use affects commensal flora and can result super-infection by opportunistic organisms such as Clostridium difficile and Candida spp.
- Some bacteria penetrate the gut epithelial layer by entering through M cells and dendritic cells.
Probiotics
- purpose
- function
are marketed to help replace/augment intestinal flora
does it help…
they are not the same as the bacteria in your gut or something. so it doesn’t REALLY help.
studies have shown the probiotic use during antibiotics results in disturbance of the normal flora, delayed reconstitution of patients own flora pattern and increased inflammatory changes in the gut wall
IPEX
failure to produce regulatory T cells,
presents as early onset colitis
- covered in a different lecture…
Helicobacter infection results in:
In response to Hb, gastrin secreted by G cells stimulates excess acid production, which destroys gut tissue = ulceration
In some cases, chronic inflammation develops leading to atrophy of the stomach wall and occasionally malignant outgrowths
inflammatory bowel disease: how are immune cells involved in its pathogenesis
IBD results from pathogenic T cells in the lamina propria
The disease can be treated by transfer of CD4 CD25 T reg cells which home to mesenteric lymph nodes and the colon
CD4 CD25 Treg cells proliferate and inhibit the pathogenic effector T cells
After inflammation resolves, CD4,CD25, Treg cells remain in clusters with dendritic cell and pathogenic effector
Choosing wisely is about…
A campaign to help clinicians and patients engage in conversation about unnecessary tests, treatment and procedures
What are the three principles of the choosing wisely campaign
- Shared decision-making
- Harm Reduction
- Resource stewardship
Define Unnecessary care
Is clinical activity - treatments or diagnostic interventions - “that have been shown by the evidence not to provide meaningful benefits”
Define Low Value care
Is a healthcare practice providing minimal benefit to recipients
EBM recommendation 1
Don’t suggest ordering the most invasive test or treatment before considering other less invasive options
EBM recommendation 2
Don’t suggest a test, treatment or procedure that will not change the patient’s clinical course
EBM Recommendation 3
Don’t miss the opportunity to initiate conversation with patients about whether a test, treatment or procedure is necessary
EBM Recommendation 4
Don’t hesitate to ask for clarification on tests, treatments, or procedures that you believe are unnecessary
Recommendation 5
Don’t suggest ordering tests or performing procedures for the sole purpose of gaining personal clinical experience
Recommendation 6
Don’t suggest ordering tests or treatments pre-emptively for the sole purpose of anticipating what your supervisor would want
What is overdiagnosis
When people without symptoms are diagnosed and then treated for a disease that won’t ever cause them any symptoms and …
when people whose symptoms or life experiences are given a diagnostic label which brings them more harm than good
How does overdiagnosis happen?
- When asymptomatic people are screened
- when diagnostic test is too broad
- When definitions of disease are broadened (think of DSM, lowering of thresholds)
Popularity Paradox of screening
some people get screened, cancer is detected, and they get a good outcome. this encourages more people to get screened- even if they are not part of the population that meets the risk factors
What are the Four Questions to ask your health care provider
- Do I really need this test, treatment, procedure
- What are the downsides
- Are there simpler, safer options
- What happens if I do nothing
Vasculitis
Autoimmune process that is directly attacking the blood vessels. This is blood vessel inflammation
It can lead to:
- Stenosis (due to clots and inflammation)
- Occlusion
- Aneurysm formation
Aneurysm: an abnormal bulge or ballooning in the wall of a blood vessel
How do you classify Vasculitis
Primary: occuring by itself, with etiology yet to be identified
Secondary: Occuring in association with another disease (SLE, RA, infection, cancer, toxic substances etc.)
Rheumatoid Arthritis
Rheumatoid arthritis, or RA, is an autoimmune and inflammatory disease that mainly attacks the joints, usually many joints at once
(synovial joints specifically?)