Sedation & Anesthesia Flashcards
What’s the difference between tranquilization and sedation?
state of reduced consciousness without CNS depression, but with behavioral change —> patient aware of surroundings
state of reduced consciousness with CNS depression —> patient unaware of surroundings
What is shock? How is it associated with anesthesia?
failure of appropriate perfusion or oxygenation for cells of the body
means of calculated/planned/reversible reducing of perfusion, similar to shock
What is considered successful sedation/anesthesia?
optimal/improved function post-anesthesia
- not just waking up
What are the major steps to success for sedation and anesthesia?
- risk identification and drug planning
- optimizing patients pre-anesthesia
- supportive care
- monitoring
- troubleshooting
- prep for emergencies
What 3 things does ASA risk have to do with? What does it have nothing to do with?
- cardiovascular and renal systems
- airway, pulmonary, and pleural systems
- central and peripheral neurologic systems
surgery, age, breed
What is the main difference between ASA 1/2 and ASA 3/4/5?
patients in ASA 1 and 2 are considered low risk and not clinical for their problem
patients in ASA 3, 4, and 5 are considered high-risk and clinical for their problems
What are the 3 major components of a peroperative ASA assessment?
- historical medical facts
- current physical exam, BCS, temperament, pain, body type
- objective diagnostics - bloodwork, imaging, function tests
What premeds are recommended for low-risk (ASA 1 and 2) patients? What local blocks, induction agents, and maintenance are recommended?
mini dose Dex or Ace, an opioid, and an NSAID
+ local block
Ket Val or Propofol
inhalant in 100% O2
What premeds are recommended for high-risk (ASA 3 and 4) patients? What local blocks, induction agents, and maintenance are recommended?
Midaz, opioid, steroid, +/- micro dose Dex
+++++ local block
Ketofol, Alfaxan, Fent/Mid/Ket
less inhalant in 100% O2
What criteria must be optimized to ensure patients are ready for anesthesia?
- neurologic status: cranial nerve function, mentation, ambulation
- temperature: 98-103 F
- pulse rate and rhythm
- respiratory rate and rhythm: 3-40 bpm
- arterial blood pressure: MAP 70-80 mmHg; SAP 100-160 mmHg
- oxygen status: PaO2 > 80% on room air; > 95% on oxygen
- ventilation status: PaCO2 < 50%
- urine output: 1-2 mL/kg/ hr
Why should all tranquilized, sedated, and anesthetized patients be supported?
- loss of homeostasis due to drugs
- main pillar to anesthesia success
- indicator of quality care
- cheap, easy
- in the clients eyes, care is imperative
What do all anesthetized and sedated patients require?
a patent airway, either by intubation or extended head with tongue pulled forward
- objective monitoring (capnograph)
What makes up a patent airway? How is it maintained without an ET tube? With?
nose, nasopharynx, glottis, trachea
sedated or TIA = head and neck extended, tongue pulled forward, no masses or obstructions, monitored with pulse oximeter
fully anesthetized
In what 3 situations is an ET tube recommended for obtaining a patent airway?
- low pulse ox unintubated
- oronasal, facial, or otic surgery
- regurgitation possibility
Do all sedated or anesthetized animals need to be intubated? How does plane of sedation affect this?
NO
deeper plane = fully anesthetized and requires intubation
What are 3 aspects of positioning to obtain a patent airway?
- open mouth
- tongue pulled forward
- neck straightened
What are 3 reasons to provide flow by or mask oxygen to anesthetized or sedated patients?
- hypoxia is inevitable and causes vasoconstriction, shunting of blood, and differential tissue demands
- oxygen is a great carrier for anesthetic gases
- preoxygenation prevents hemoglobin depletion in low CO phases of sedation and anesthesia
In what situations is it recommended to have a tight or loose fitting oxygen mask?
TIGHT = short-nosed, non-panting patients
LOOSE = hyperthermic, brachycephalic, stressed
When is flow by oxygen recommended?
end of rebreathing or non-rebreathing circuits
What does adequate respiration require?
oxygenation and ventilation
(one does not imply the other)
What is ventilation? What happens during hypoventilation?
removal of CO2
buildup of CO2 waste, resulting in increased H+ ions (acidosis), decreased O2, and low perfusion of anesthesia
What are the normal CO2 levels in arterial/venous blood gas of non-intubated patients? ETCO2?
PaCO2 = 25-60 mmHg in cats and dogs
PvCO2 = 30-55 mmHg
tight press mask for 15 seconds = 25-60 mmHg
What are the normal CO2 levels in arterial/venous blood gas of intubated patients? ETCO2?
PaCO2 = 25-40 mmHg, mildly lowing in cats
PvCO2 = mildly lower
ETCO2 = 35-50 mmHg
What are the 4 subtle signs of hypercarbia seen in un-intubated patients?
- tachycardia
- deep plane of anesthesia despite high pulse ox readings
- dampened pulse ox curves
- normothermia to hyperthermia
What should be monitored in intubated patients to assure adequate ventilation? How should the patients plane of anesthesia be maintained?
- arterial and venous blood gases
- capnography
keep patient light enough to respond to CO2 levels —> keep Iso or Sevo minimal necessary for surgery
What is commonly provided to intubated patients to ensure there is adequate ventilation?
intermittent positive pressure ventilation (IPPV), providing an occasional sigh by deflating the breathing bag by hand