Principles of Anesthesia II Unit III Flashcards
What type of immunity does not have “memory”, but the response to the pathogen is always identical?
Innate immunity
What are the non-cellular elements of innate immunity?
Epithelial and mucous membranes
Complement system
Acute phase proteins
What are the cellular elements of innate immunity?
Neutrophils, macrophages, monocytes and natural killer cells
What cellular element has the fastest response?
Neutrophils
What cellular element has a slower but more sustained response?
Macrophages
What is the complement system?
A large number of distinct plasma proteins that react with one another to opsonize pathogens and induce a series of inflammatory responses that help to fight infection
What augments phagocytes and antibodies?
The complement system
Where are the proteins for the complement system produced?
Most in the liver
What activates the complement system?
C1 or C3
What is the most numerous type of WBC?
Neutrophils
What cell releases cytokines and phagocytizes pathogens?
Neutrophils
Why do neutrophils break down quickly in the presence of infection?
An infection likely creates an acidic environment which neutrophils are sensitive to so they break down quickly
this breakdown of neutrophils is also what creates pus
What is the largest blood cell?
Monocytes
What type of monocytes are found in the: epidermis, liver, lung and CNS?
Epidermis = Langerhans
Liver = Kupffer
Lung = Alveolar cells
CNS = Microglia
Where would you expect to find Langerhans cells?
The skin (epidermis specifically)
Where would you expect to find Kupffer cells?
Liver
Monocytes/macrophages produce what 2 substances in response to infection?
Cytokines and NO
What is the least common blood granulocyte?
Basophils
Where would you expect to find mast cells?
In connective tissue close to blood vessels
Basophils and mast cells have high affinity receptors for what substance?
IgE
Basophils and mast cells release what in a hypersensitivity reaction?
Histamine, leukotrienes, cytokines, prostaglandins
Where would you expect to find the highest concentration of eosinophils?
In the GI tract (they protect against parasites and degrade mast cell inflammation)
What type of immunity has a “memory” to specific antigen response?
Adaptive immunity
only present in vertebrates
Adaptive immunity is derived from what cell?
Hematopoietic stem cells
Adaptive immunity primarily uses what cells to respond to pathogens?
T-cells, B-cells and NK cells
What role do T and B cells perform in adaptive immunity?
B cell = make antibodies
T cell = make interferon/interleukin and has a role in chronic inflammation and responding to infection as well as activating IgE
What cell activates IgE?
T-cells
A vaccine is what category of immunity?
Active
What is an example of passive immunity?
Getting antibodies from another - such as from maternal breast milk (this only lasts for a few weeks/months)
IvIG and IV immunoglobin are examples of what kind of immunity when used in a hospital setting?
Passive immunity
Neutropenia is what category of immune response?
Inadequate
Asthma is an example of what category of immune response?
Excessive/exaggerated
Autoimmune disorders are an example of what category of immune response?
Misdirection
What drugs commonly cause a hypersensitivity reaction?
NSAIDs, ABX and PPIs
What is a type I allergic response?
Immediate hypersensitivity, think asthma or response to a bee sting
Anaphylaxis, asthma, angioedema, conjunctivitis, dermatitis are all examples of what type of allergic response?
Type I
What interventions can be performed to reduce the effects of histamine in a type I allergic response?
First step is stop/remove trigger, then:
Prevent histamine effects:
Antihistamines
Cromolyn sodium
Bronchodilators
COX pathway inhibitors
Diagnostic tests
Small doses of allergen to desensitize (slightly controversial, must be done with an immunologist present)
Hemolytic anemia, myasthenia gravis, transfusion reactions are examples of what type of allergic response?
Type II
Treatment of a type II allergic response?
Anti-inflammatories and immunosuppressives
Systemic lupus erythematosus (SLE), and rheumatoid arthritis are examples of what type of allergic response?
Type III
Failure of the immune system to eliminate antibody-antigen complex causes is the classic presentation of what type of allergic response?
Type III
This also causes complexes to be deposited in the joints, kidneys, skin and eyes
What type of allergic response is mediated by IgG and IgM?
Type III
What type of allergic response does not involve antibodies?
Type IV
Contact dermatitis, tuberculosis, Stevens-Johnson syndrome (allergy response to NSAIDs) are examples of what type of allergic response?
Type IV
What types of allergic reactions are treated with Anti-inflammatories and immunosuppressives?
Type II and IV
What is biphasic anaphylaxis?
When a secondary anaphylactic episode occurs after the primary episode
Risk factors for a secondary anaphylactic episode?
Severe initial response and the initial response required multiple doses of epinephrine
Risk factors for perioperative anaphylaxis?
Asthma
Longer duration of anesthesia
Females (Not in teen years)
Multiple past surgeries
Presence of other allergic conditions
What are 3 tests that can be used to diagnose whether or not you have an anaphylaxis response to a certain irritant?
Plasma tryptase concentration, plasma histamine concentration and skin testing (wheal/flare response)
What lab test verifies mast cell activation/release?
Plasma tryptase concentration
If an anaphylactic response is resistant to epi, what are the other drugs you can give?
Give vasopressin, methylene blue
to inhibit NO production
What does epinephrine do in an anaphylactic response that makes it the DOC?
Decreases degranulation of mast cells and basophils which ↓ effect of degranulation causing less vasodilation
Alpha1: supports BP
Beta 1: inotropic and chronotropic effects
Beta 2: bronchodilation
What are 3 common examples of specific immune reactions?
Transfusion reactions, transplant rejection and Graves disease (d/t antibodies activating the TSH receptors too much)
Hereditary angioedema has a deficiency/dysfunction of what part of the immune system response?
C1 (complement 1) esterase inhibitor deficiency/dysfunction = excessive production of bradykinin (which is usually limited by C1)
Why is angioedema a medical emergency?
They are not responsive to anti-histamines, so they lose their airway FAST
What drug class can cause acquired angioedema?
ACE inhibitors
Acquired angioedema r/t ACE inhibitors mimics the s/sx of hereditary angioedema except for what symptoms?
Urticaria (hives) and itching
Angioedema treatment?
Airway maintenance
FFP
C1 inhibitor concentrate
Epinephrine
Antihistamines, glucocorticoids
What tests can be used to diagnose HIV/AIDS?
ELISA: 4-8 weeks after infection
Viral load
CD4/helper T lymphocytes <200,000
HAART agent sensitivity
What CV issues are common with immune system disease?
Abnormal EKG
LV dilation
Pulmonary hypertension
MI
Pericardial effusions (25%)
What neurological issues are common with immune system disease?
Dementia
Increased ICP
Autonomic nervous dysfunction
Peripheral neuropathy (35%)
Why is the rule of thumb to “start your dose low and work up” commonly used with immune system dysfunction?
It is very common for cytochrome P-450 to be inhibited in immune system disease, so drugs stick around longer
What population does scleroderma most commonly affect?
Women in their 20s - 40s
Why is scleroderma a red flag for anesthesia?
Aspiration risk: they have hypo-motility of the GI tract and their LES tone is decreased
What are the general anesthesia implications/concerns for scleroderma?
Organ system dysfunction
Arterial catheter concerns (Continue preop calcium channel blockers)
Contracted intravascular volume
Aspiration risk
Limited neck mobility/Pulmonary compliance
What anesthetic agent suppresses NK cells, induce apoptosis of T-cells, impairs phagocytes and has an unclear impact on tumor cells?
Inhalation agents
What anesthetic agent decreases migration of neutrophils?
Versed
What anesthetic agents depress NK cell activity?
Ketamine and opioids
What anesthetic agent decreases cytokines and promotes NK cells?
Propofol
What opioids in particular are notorious for suppressing NK cells?
Morphine and fentanyl
Why are NSAIDs helpful with anesthesia and the immunesystem?
They inhibit prostaglandin synthesis
What are the drawbacks of the BMI measurement?
It can’t differentiate between overweight and overfat, and doesn’t take into account waist circumference, waist-hip ratio or age
Per Cornholio, waist circumference is a more reliable measure of the severity of obesity in terms of weight gain
What obese body type is more associated with increased O2 consumption and CV disease?
Android (central obesity or upper body truncal)
What obese body type is more peripheral obesity, less metabolically active and not associated with CV disease?
Gynecoid (more accumulation in the hips, butt and thighs)
What are 3 CV system changes that occur as a result of obesity?
Total blood volume increased (On a volume-to-weight ratio is lower 50ml/kg and most is distributed to adipose tissue)
Cardiac output ↑ by20-30ml/kg of excess body fat d/t LV dilation and ↑ stroke volume
Cardiac dysrhythmias d/t fatty infiltrates of conduction system, CAD,
Low QRS voltage, LVH, left axis
What change on an 12-lead is very common in obesity?
Left axis deviation
How is the clotting cascade affected by obesity?
Increased levels of fibrinogen, factor VII, VII and von Willebrand = hypercoagulability. There is also endothelial dysfunction d/t levels of factor VIII and von Willebrand.
combine this with immobility r/t obesity = perfect storm to create clots
What gastric changes make obese patients an aspiration risk with anesthesia?
Gastric volume and acidity both increase along with delayed gastric emptying. Intra-gastric pressure increases which causes relaxation of the LES and hiatal hernia formation
What volume and pH of the stomach are risk factors for aspiration pneumonitis?
Volume greater than 25 ml and pH less than 2.5
What renal changes are common to obesity?
Increased GFR and RBF, increased renal tubular reabsorption which impairs natriuresis and activates the RAAS
Which is more common in obese patients: hyper or hypo thyroidism?
Hypothyroidism d/t thyroid hormone resistance
T/F: the SNS activity level is increased in obesity
True: so you’ll have insulin resistance, enhanced pressor activity and sodium retention
What are the abnormalities r/t DM that are progressive in nature that constitute metabolic syndrome (you must have at least 3 of the starred ones to have metabolic syndrome)?
*Abdominal obesity
*Decreases levels of HDL
*Hypertriglyceridemia
Hyperinsulinemia
*Glucose intolerance
*Hypertension
Proinflammatory state
Prothrombotic state
What are some risk factors for metabolic syndrome?
Increased age, male and hispanic or south asian ethnicity
What drug classes may cause metabolic syndrome?
Chronic corticosteroids, antidepressants, antipsychotics, protease inhibitors
What can resolve metabolic syndrome 98% of the time?
Weight loss (either via diet/exercise or bariatric surgery, it doesn’t matter if it’s one or the other, the important part is losing the weight)
What is the basic difference between OSA and hypopnea?
OSA = actual apnea
Hypopnea = decreased airflow
How many apnea/hypopnea events constitute mild/moderate/severe disease states?
Mild: 5-15/hr
Moderate: 15-30/hr
Severe: > 30/hr
Treatment for both OSA/hypopnea is CPAP and weight loss to reduce the risk of what conditions?
Systemic/Pulmonary hypertension
LVH
Cardiac dysrhythmias
Cognitive impairment
Obesity hypoventilation syndrome can result in what over time?
Pulm HTN and Cor pulmonale
How is obesity hypoventilation diagnosed?
BMI greater than 30 along with awake hypercapnia
What medical therapy worked as an appetite suppressant, but only approved for 3 months at a time d/t CV system concerns?
Phentermine (CV issues were because this drug was a sympathomimetic)