A/S - Intro, depth, and monitoring
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- Anesthesia - Intro, depth, and monitoring
- Anesthesia - Intro, depth, and monitoring
- What are the short term effects of exposure to waste anesthetic gases? How do they resolve?
- neurological effects that resolve when no longer exposed to the gases
- What are some long term effects of exposure to waste anesthetic gases?
- reproductive disorders, renal and hepatic damage, bone marrow abnormalities, chronic nervous system disfunction
- How is exposure to waste gases reduced?
- scavenging devices, perform prev maint on equip, alter/improve anesthetic techniques/protocols
- What are two hazards of compresed gas cylinders?
- Fire hazard, hazard of suddenly released pressure.
- Define anesthesia
- loss of feeling or sensation
- Define local anesthesia
- acts where applied, no effect on brain
- Define general anesthesia
- complete unconsciousness
- Define analgesia
- reflief from pain
- Define opioids
- *Synthetic* morphine derivative drugs that produce sedation and pain relief
- Define opiates
- *Natural* morphine derivative drugs that produce sedation and pain relief
- Define narcotic
- opioid or opiate that induces physical dependence and addiction
- Define neuroleptanalgesia
- combination of narcotic w/ a tranquilizer
- Define preanesthesia
- any drug given w/i 1 hour prior to induction
- Define induction
- admin of fast-acting drugs (usually IV) to cause loss of consciousness
- Define maintenance
- admin of drugs to keep pt under anesthesia
- Define surgical anesthesia
- depth of anesthesia under which surgical procedures can be safely and effectively performed (enough muscle relaxation) w/o pain to the pt
- Define tranquilizaton/sedation
- a state of calmness associated w/ some CNS depression
- What are 6 general reasons for using anesthesia?
- Restraint, examination, manipulation, general surgery, seizure control, euthanasia
- What are 5 goals of anesthesia?
- relax skeletal muscles, decrease protective reflexes, induce deep sleep, produce amnesia, and provide analgesia
- When checking to see if anesthesia goals were met one checks for signs of pain - what are 5 of these signs?
- inc heart rate, inc resp rate, gross movement, vocalization, abdominal pressing
- What is balanced anesthesia? How common is this technique?
- The practice of combining a general anesthetic w/ other drugs to minimize the neg effects of the general anesthetic - it is the most common anesthesia technique
- Does balanced anesthesia increase or decrease the amount of gen anesthetic needed?
- decrease
- What are four general considerations re: the pt to receive anesthesia?
- species variations, breed variations, indiv variation, and anesthetic risk
- What is species variation?
- the same anesthetic drug may have different effects in different species
- What is breed variation?
- same drug may have different effect in different breeds
- What dogs are vy sensitive to barbituates?
- sighthounds
- Do smaller breeds need a greater or lesser amt of anesthetic per pound of body wt in comparison to larger breeds? Why?
- greater amount because they have a higher metabolic rate
- Why do you leave brachycephalic breeds inubated as long as possible during recovery?
- They have a long soft palate and are suceptible to laryngospasm
- What can cause individual variation?
- poor condition, age, reproductive status, disposition
- Define "normal" anesthetic classification of risk
- animal is normal, apparently healthy
- Define "moderate" anesthetic classification of risk
- organ abnormality which does not affect overall health
- Define "poor" anesthetic classification of risk
- organ abnormality that does affect overall health - liver/kidney failure, pancreatitis
- Define "grave" anesthetic classification of risk
- organ abnormailty that makes anesthesia life threatening
- What are the two most important vital signs to look at when assessing the pts depth of anesthesia?
- resp rate and heart rate/rhythm/pulse
- As defined by our surg text, what is the normal resp rate for a normal awake dog? Cat?
- dog 10-30 rpm, cat 25-40 rpm
- What is a normal resp rate for an anesthetized dog or cat?
- 8-20 rpm
- a resp rate of less than __rpm may indicate that the anesthesia is too deep
- less than 8 rpm
- What is tidal volume? Does anesthesia increase or decrease?
- volume of air inspired w/ ea breath - anesthesia decreases tidal volume
- What is a normal pulse in an awake dog? Cat?
-
Dog: 70-140 bpm
Cat: 110-220 bpm - A pulse of less than __bpm in a dog may indicate bradycardia or that the pt is too deep. In cat?
-
<70 bpm in a dog
<100 bpm in a cat - Where are two spots to take a pulse from in an anesthetized pt?
- femoral artery, lingual artery
- What are 5 monitoring methods for pulse/heart rate in an anesthetized patient?
- palpate, esophageal stethoscope, ECG, pulse ox, blood pressure monitor
- Other than HR and RR, what are two other vitals that can be used to assess depth of anesthesia?
- CRT and MM
- What is a normal CRT?
- < 2 seconds
- What are some abnormal MM colors and what are they associated with?
-
blue/purple - cyanosis (dec O2)
brick red: endotoxic shock
pale white/grey: poor perfusion(shock) - What is a palpebral reflex? How is it tested?
- Blinking - tested by touching the corner of the eye
- What is a pinnal reflex? How is it tested?
- ear/pinnae movement - lightly touch hair in ear canal or blow in canal
- What is a pedal reflex? How is it tested?
- movement of foot in response to sensation/pain - pich toes or between toes
- What is a corneal reflex? How is it tested?
- eye - touching cornea w/ sterile object and seeing if the pt blinks and withdraws eye into orbital fossa
- How is jaw tone used to assess anesthetic depth?
- pull down on mandible, want no resistance
- What are two other patient responses that can be used to assess depth of anesthesia?
- eye position, pupillary light response (PLR)
- When is stage one anesthesia seen?
- From start of anesthetic administration to loss of consciousness
- If resp are reg, pupils are resp to light, eyes are central, and all reflexes are present, what stage of anesthesia is pt in?
- Stage 1
- What is stage 2 of anesthesia also called?
- Excitatory stage
- If resp is irreg w/ poss breath holding or hyperventalation, pupils are dilated, eyes are central w/ poss nystagmus, reflexes are present & poss exaggerated, tachycardia, chewing/yawning/vocalization, & vomitting &/or diarrhea are present - w
- Stage 2/excitatory stage
- What is another name for stage 3 plane 1 anesthesia?
- Restraint anesthesia
- At what stage is a pt in if the following are present: regular resp w/ inc rate & depth, resp pupils, eye central moving toward VD, laryngeal reflex gone, losing palpebral, other reflexes present, HR regular & strong
- Stage 3, plane 1
- What is another name for Stage 3, plane 2 anesthesia?
- surgical plane
- What stage? RR reg rhythm & rate, dec tidal vol, pupils slightly dilated, eyes ventral-medial, reflexes - laryngeal, palpebral, & jaw tone gone, pedal diminished or absent, mild dec in blood pressure and HR
- Stage 3, plane 2
- What is another name for stage 3, plane 3?
- Orthopedic plane
- What stage? Resp slow & shallow, pupils moderately dilated, PLR dimished, eyes central or moving central, reflexes all diminished or absent, dec cardiac output, weak pulse, delayed CRT
- Stage 3, plane 3
- What is another name for stage 3, plane 4 anesthesia?
- TOO DEEP!
- What stage? resp - irreg, jerky, shallow, pupils dilated & fixed, eyes central, reflexes absent, pale MM, prolonged CRT, weak pulse, muscles flaccid
- Stage 3, plane 4 - too deep
- What is another name for Stage 4 anesthesia?
- Terminal stage
- What stage? resp arrest, cardiac arrest
- Stage 4
- At what stage may breath holding or hyperventiliation be seen?
- Stage 2/Excitatory stage
- At what stage may nystagmus &/or exaggerated reflexes be seen?
- Stage 2/excitatory stage
- At what stage may chewing, yawning, &/or vocalization be seen?
- Stage 2/Excitatory stage
- At what stage may vomiting or defecation be seen?
- Stage 2/excitatory stage
- At what stage may eyes in a ventral-medial position be seen?
- Stage 3, plane 2/surgical plane
- At what stage is the laryngeal reflex gone, the palpebral diminishing, and other present?
- Stage 3, plane 1/restraint anesthesia
- At what stage are the laryngeal & palpebral reflexes gone, jaw tone gone, and the pedal diminished or absent?
- Stage 3, plane 2/surgical plane
- At what stage is a mild decrease in HR and blood pressure seen?
- Stage 3, plane 2/surgical plane
- At what stage is a decreased tidal volume seen w/ regular resp rhythm & rate?
- Stage 3, plane 2/surgical plane
- At what stage are resp slow & shallow?
- Stage 3, plane 3/orthopedic plne
- At what stage are all reflexes diminished or absent?
- Stage 3, plane 3/orthopedic plane
- At what stage is there dec cardic output, weak pulse and delayed CRT?
- Stage 3,plane 3/orthopedic plane
- At what stage are the pupils moderately dilated and the PLR diminished?
- Stage 3, plane 3/orthopedic plane
- At what stage are resp irregular, jerky, &/or shallow?
- Plane 4 - too deep
- At what stage are the pupils dilated & fixed which indicates brain hypoxia?
- Plane 4 - too deep
- At what stage are all reflexes absent?
- Plane 4 - too deep
- At what stage is there pale mm, prolonged CRT, and a weak pulse?
- Plane 4 - too deep
- At what stage are muscles flaccid?
- Plane 4 - too deep
- What should the tech do if signs of plane 4 present?
- Inform vet and lighten anesthesia by turning vaporizer off or down and ventilating at 8-12 rpm
- When does cardiac arrest occur?
- 60-90 seconds after resp arrest
- What does tech do to start emergency procedures?
- turn off vaporizer, flush system 3x w/ pure O2, begin CPR, epinephrine
- What does an analeptic agent do? Example of?
- stimulates CNS and respiration - Doxapram
- What kind of drug is Doxapram?
- analeptic agent
- What is an indication for Doxapram?
- respiratory arrest
- What does a catecholamine drug do? Example of?
- stimulates sympathetic nervous system - epinephrine
- What is an indication for epinephrine?
- cardiac arrest
- What is a counterindication for epinephrine?
- when heart is still beating - can cause tachycardia & fatal arrhythmia
- What are two commom emergency drugs? What are they ea used for?
- Doxapram for rep arrest, epinephrine for cardiac arrest
- What are two manual methods for monitoring the anesthetized patient?
- visual & palpation
- What are 5 mechanical methods for monitoring the anesthetized patient?
- esophageal stethoscpe, ECG, Pulse Ox, Doppler blood pressure monitor, Capnography (CO2 monitor)
- What are some respiratory signs of anesthetic overdose?
- <8 rpm, irregular or exaggerated resps, decreased tidal volume
- What are some cardiac signs of anesthetic overdose?
- bradycardia, prolonged CRT, cyantotic MM, weak pulse
- Hypothermia may be a sign of what?
- anesthetic overdose
- What are some pupilary signs of anesthetic overdose?
- decreased PLR, dilated pupils
- What are some reflex signs of anesthetic overdose?
- greatly diminished or absent
- Recovery from anesthesia requires elimination of the anesthetic drug(s) from the ___
- brain
- What are three ways that gases are eliminated from the brain?
- exhalation, redistribution, and liver metabolism
- The ___ the anesthetic period, the longer the recovery time.
- longer
- What route of anesthetic admin has the greatest recovery time? The shortest?
- IM>IV>Inhalation
- What are some signs of anesthetic recovery?
- resp rate & depth increase, eyes rotate to next shallow stage, reflexes return in reverse order lost, shivering, tongue movement, chewing, movement, lifting of head, attempts to stand
- It is very important to watch for ___ during anesthetic recovery
- seizures