Term
| List inhalant anesth in order of solubility coefficients (highest to lowest). |
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Definition
| Methoxy>>Haloth>Iso>Sevo>Des>NO |
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Term
| What does solubility mean in terms of inhalant anesthetics? |
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Definition
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Term
| Define MAC (Minimum Alveolar Concentration) |
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Definition
The alveolar concentration of an inhalant anesthetic required to prevent purposeful movement in 50% of a given patient population when exposed to a noxious stimulus.
The lower the MAC the more potent the anesthetic. MAC is additive. |
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Term
| Rank MAC values in various spp. |
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Definition
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Term
| List factors that increase MAC. |
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Definition
-hyperthermia
-hypernatremia
-increased levels of excitatory NTs (cocaine, amphetamines, etc.) |
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Term
| List factors that decrease MAC. |
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Definition
-increase age
-hypothermia
-hypnatremia
-severe hypotension
-severe hypercarbia
-severe hypoxemia
-metabolic acidosis
-other anesthetics
-preg |
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Term
| Factors that don't affect MAC. |
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Definition
-duration of anesthesia
-gender
-alkalosis
-hypertension
-anemia
-change in most electrolytes |
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Term
| Uptake and Distribution of Inhalant Anesth |
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Definition
| Pdelivered->P circuit-> P inspired ->P alveolar->Parterial->P brain-> P venous-->P alveolar |
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Term
| _______________(not concentration) of anesthesia in brain produces anesthesia. |
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Definition
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Term
| Brain partial pressure_______________quickly with alveolar partial pressure. |
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Definition
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Term
| Brain partial pressure always moves ____________ alveolar partial pressure. |
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Definition
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Term
| The alveoli are like a bucket that are being filled, but have a leak (uptake). How would you increase delivery? Decrease the leak? |
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Definition
-Increase: increase inhaled PP, increase alveolar ventilation
-Decrease: decrease solubility, decrease CO, decrease alveolar-venous PP difference |
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Term
| Factors influencing delivery of inhalant anesthetics. |
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Definition
-vol% being delivered by vaporizer (as turn up-> increases)
-higher total fresh gas flow
-total volume of breathing circuit (larger-> slower rate of rise)
-other minor factors: concentration effect, second gas effect (for NO)
-alveolar ventilation-major factor in rise of alveolar concentration (=rate of flow in to alveoli); greater alveolar ventilation-> more rapidly inh anesth flow in and out of alveoli-> more rapidly partial pressure approaches partial pressure of the inspired gasp
- |
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Term
| Factors influencing uptake of inhalant anesthetics. |
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Definition
-solubility!
-CO
-alveolar-venous pressure differer |
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Term
| Elimination of inhalant anesthetics |
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Definition
-reverse of uptake (with some differences): can use a relatively high inspired concentration of inhalant anesthetic during induction to increase rate of rise of alveolar concentration ("overpressure"). We cannot lower the inspired concentration of inhalant anesthetic lower than 0% during recovery
-can speed the rate at which inhalant washed out of breathing circuit by increasing flow of O2 to the circuit at the end of the procedure
-duration of anesthetic procedure will affect rate of recovery (longer-> more inhalant absorbed by peripheral tissues) |
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Term
| Inhalant A is highly soluble in blood and inhalant B is not. This means that: |
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Definition
| -Inhalant A will cause a faster induction |
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Term
Which of the following is incorrect:
1. MAC is a measure of potency
2. MAC is a measure of speed of induction
3. MAC is additive among multiple inhalants |
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Definition
| 2 is incorrect (MAC is not a measure of speed of induction) |
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Term
| Properties of inhalants for Halothane, Iso, Sevo,Des and NO list: MAC, Blood-Gas Partition Coefficient, and Maximum Concentration |
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Definition
1. MAC: Hal (0.8), Iso (1.3), Sevo (2.3), Des (8.0), NO (200)
2. Blood-Gas Partition Coefficient: Halo (2.3), Iso (1.4), Sevo (0.6), Des (0.4), NO (0.5)
3. Maximum concentratino: Halo (32.0), Iso (31.3), Sevo (20.7), Des (88.0), and NO (66)-safely |
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Term
| What else should we consider in choosing and inhalant? |
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Definition
-effect on organ systems
-ease of clinical use
-cost |
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Term
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Definition
-most commonly used inhalant
-color code: purple
-no preservative needed |
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Term
| Isoflurane: systemic effects |
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Definition
1. Resp: dose-dependent depression
2. CV: dose-related hypotension, primarily vasodilation
3. GI: hepatic metabolism (0.2 %)
4. Renal: none
5. Muscular: excellent relaxation
6. Uterus/Fetus: crosses placenta, rapidly exhaled
7. Other: no analgesia |
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Term
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Definition
1. MAC 1.3%
2. Vaporizer settings: induction (3-5%), early anesthesia (2-3%), maintenance (1-2.5%)
3. Other considerations: depth changes slowest among modern inhalants |
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Term
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Definition
-very popular
-color code: yellow
-no preservative needed |
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Term
| Sevoflurane-Systemic effects |
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Definition
1. Resp: dose-dependent depression
2. CV: Dose related hypotension
3. GI: hepatic metabolism (5%)
4. Renal: Compound A
5. Muscular: excellent relaxation
6. Uterus/fetus: crosses placenta, rapidly exhaled
7. Other: no analgesia |
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Term
| Sevoflurane: clinical use |
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Definition
1. MAC: 2.3 %
2. Vaporizer settings: induction (5-7%), early anesthesia (2-5%), maintenance (1.5-4%)
3. Other considerations: depth changes quickly |
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Term
| Desflurane-general information |
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Definition
1. LEAST soluble inhalant available
2. Color code: blue
3. requires a special vaporizer: heated, pressurized, electronic controls
4. Airway constriction?? |
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Term
| Desflurane: systemic effects. |
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Definition
1. Resp: dose-dependent depression
2. CV: dose-related hypotension; vasodilation+myocardial depression
3. GI: NOT METABOLIZED!
4. Muscular: excellent relaxation
5. Uterus/fetus: crosses placenta/rapidly exhaled
6. Other: No analgesia |
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Term
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Definition
1. MAC: 8%
2. Vaporizer settings: induction (15-18%), early anesthesia (12-15%), maintenance (8-12%)
3. Other considerations: depth changes VERY quickly |
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Term
| Nitrous Oxide general information. |
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Definition
-gas at room temp, and atmospheric pressure
-can be compressed to liquid (N20 tanks)
-flowmeters (vs vaporizer) |
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Term
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Definition
| NONE-except is a mild analgesic |
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Term
| Nitrous oxide: clinical use |
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Definition
1. MAC: 200%
2. Flowmeter settings: must be used in combination with another anesthetic agent, prevent hypoxic gas mixture (<75% N2O), usually 2:1 ratio with oxygen
3. Other considerations: diffuses into closed gas spaces! Contraindicated in patients with pneumothorax, GDV, etc.; diffusion hypoxia at termination of anesthesia |
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Term
| Halothane: general information |
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Definition
-no longer in US
-color code: red
-requires a preservative (thymol)
-smells sweet |
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Term
| Halothane: systemic effects |
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Definition
1. Resp: depression, especially in ruminants
2. CV: dose related hypotension, vasodilation + myocardial depression, sensitizes heart to catecholamines
3. GI: hepatic metabolism (20%), hepatotoxic metabolites
4. Renal: none
5. Muscular: moderate relaxation
6. Uterus/fetus: decreases uterine tone
7. Other: malignant hyperthermia (most potent trigger) |
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Term
|
Definition
1. MAC: 0.8%
2. Vaporizer settings: induction (3-5%, early anesthesia (2-5%), maintenance (0.5-2%) |
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Term
|
Definition
1. Iso: $28/250 ml; $0.11/ml
2. Sevo: $128/250 ml; $0.48/ml
3. Desf: $183/240 ml; $0.55/ml
**Estimate mL LIQUID per hour= 3*FGF (L/min)*volume% |
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Term
| Name the phases of wound healing: |
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Definition
1. Inflammatory phase
2. Debridement phase
3. Repair phase
4. Maturation |
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Term
| How is hemostasis initiated? |
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Definition
-precedes inflammation
-vasoconstriction is an immediate response (lasts 5-10 min), followed by vasodilation
-increased vascular permeability induced by release of various substances allows intravascular fluid to escape
-aggregation and activation of platelets and the coag cascade achieves hemostasis by formation of fibrin-based plugs |
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Term
| What are the major characteristics of the Inflammatory phase of wound healing? |
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Definition
-increased vascular permeability
-chemotaxis of cells from circulation into wounded area
-local release of cytokines and growth factors
-activation of migrating cells |
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Term
| Which cells are first drawn to the area of the wound? |
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Definition
| -neutrophils (then monocytes) |
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Term
| What is the origin of these cells (that are first drawn to the wound)? |
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Definition
-neutrophils are first to appear followed by monocytes (which become macrophages once they leave the circulatory system)
-circulatory system |
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Term
| What substances stimulate the attraction of cells to a wounded area? |
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Definition
| -PDGF is chemotactic for these cells (platelet-derived growth factor) |
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Term
| What role do these first cells play in healing of wounded tissue? |
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Definition
-monocytes become macrophages
-neutrophils remove debris via phagocytosis during debridement and release proteolytic enzymes and free radicals
-macrophages secrete proteolytic enzymes and can phagocytize material by coalescing do form multi-nucleated giant cells (during debridement phase) |
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Term
| What are the major cells of the debridement phase of wound healing? What cells are responsible for this main function? What is their origin? |
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Definition
-macrophages
-neutrophils
-degenerated neutrophils debride dead tissue and certain amount of viable tissue
-fibrin (from coagulated blood plugs lymphatic vessels) keeping inflammatory products localized to wound
-neutrophils are NOT essential to debridement (are beneficial)
-macrophages are essential to proceed beyond debridement phase (macrophages release factors that recruit mesenchymal cells from surrounding tissue and vascular compartment, stimulate vascular ingrowth into wound, and modulate cell activity in repair phase |
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Term
| What is the main feature of the proliferative phase of wound healing?What cells are responsible for this main function? |
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Definition
-subdivided: matrix formation, angiogenesis and epithelialization
-fibroblasts migrate to wound site from surrounding tissue (growth factors and cytokines responsible fro proliferation are derived mainly from platelets and activated macrophages)
-fibroblasts-by day 4 predominate cell |
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Term
| What is "wound matrix"? What is it's composition? |
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Definition
-scaffold for wound repair
-initially is fibrin and fibrinonectin, then GAG/proteoglycans and other proteins synthesized. Ultimately collagens become predominant scar protein (cross-link and maturation) |
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Term
| What is the process(es) by which wound contraction occurs? |
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Definition
-active process in which an open wound defect is "healed" or "closed" by the inward centripetal movement of the normal bordering skin
-independent from epithelialization
-myofibroblasts/fibroblasts responsible for inward migration (dogs 5th and 9th day) |
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Term
| What is the composition of granulation tissue? |
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Definition
| perfused, fibrous connective tissue that replaces a fibrin clot |
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Term
| What is the process of wound epithelialization? What is the origin of the cells in the epithelialization process? |
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Definition
-process in which epithelium grows over a wound
-myofibroblasts |
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Term
| What are the major systemic and local factors affecting wound healing? |
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Definition
-age: young heal faster
-metabolic and nutritional factors: bad: prolonged hypoproteinemia, low plasma protein (indirectly associated), Vit A/C deficiencies
-blood supply and oxygen: maintain local blood supply
-radiation and chemotherapy
-infection |
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