intubation Flashcards
items needed for intubation
ET tubes (prepare 3 to choose from)
Laryngoscope + extra blade
Local anaesthetic spray (for cats) lidocaine
Gauze
Lubricant
Tube tie
Syringe for inflating the cuff
choosing ET tube size
length: from nose to throacic inlet (where the trachea biferedtes-splits into 2) - tie to mark, ensuring its not inserterted deeper than decided.
sizeL diameter of tube conpare with distance between nostrils-> indication of how wide the trachea is= how wide ET tube needs to be
different methods to test et tube fore correct placement
-Watch for movement of the reservoir bag as the animal breathes (means et tube in in trachea)
-Feel for air movement from the tube connector as the patient exhales (placing hand at the opeing of the tube- the thing that connects to circuit)
-Watch for fogging of the tube with condensation during exhalation
-Check the unidirectional valves on the machine (its its for a big dog and a rebreathing system is used)
-Palpate the neck- the trachea is the only naturally firm structure. If you feel 2, then your tube is in the wrong place (means tube is in the esophagus-> need to reintubate)
-An animal that can vocalise indicates that the tube is in the oesophagus (cos tube is not in trachea, animal can vocalise)
-Coughing in light planes (still a bit conscious) of anaesthesia usually indicate the tube is correctly placed
pros of intubation
Maintain access to airway (if trachea collapse-> airway is still maintained-> can still provide 02)
Able to titrate (adjust) anaesthetic depth with more precision (can control, mask less precise cos breathe in env air)
Reduces risk of aspiration (cuff-> create a seal in trachea-> no fluid entering lungs)
Overall safer GA (because reduce asp)
cons of intubation
Stimulation of vagus nerve (cranial nerve in neck region) can cause bradycardia, hypotension and heart arrhythmias
Some breeds are difficult to intubate (get someone more expereinced)
Can cause tracheal irritation or damage (cough after intubation)
Possible introduction of infection (need to ensure et tube is clean/maintained well)
Coughing 1-2 days after possible
how much gas to administer for transition and maintainace phase
Transition phase: (alr induced with iv drugs, intubated, starting on gas GA
2- 3% isoflurane and 3L/min oxygen (slightly above MAC) (higher amt to enter deeper plane of anesthesia) (more 02 to deliver more iso, 02 carrier anes)
Maintenance phase:
1.5-3% isoflurane and 1- 1.5L/min (1.5 is MAC for iso)
what are the different ways to record heart rate
- stethoscope (place on left side of chest, count beats for 15s, X4)
- oesophageal stesthoscope (placed in oesphagus, sits near the heart, picks up heart beats sound)
minimum accewptable heart rate under anesthesia
minimum acceptable HR under anes:
60bpm in dogs
100bpm in cats
HR of 60-120bpm is common under anes
(extra info: bradycardia: d<60, c<100) (tachycardia: d>160, c>180)
what are the differnt ways to obtains pulse rate
in a healthy animal, pulse rate should be the same as HR, sm use PR as H
1.feeling pulse at femoral artery (middle od medial thight) or digital pulse (behind paw in the middle, be gentle-> can acclude the artery-> cannot feel pulse well)
2.pulse oxymeter
(not tested)
what and where are the different probes placed
clip: places on ear pinna, tongue, prepuce, vulva
tail prob: placed on the base on the tail
troubleshooting pulse oxymeter
what to do if the pulse oxymeter reading is sus
- clean probe
- if using the tongue, place a wet gauze between the probe and tongue to moisten tongue
- ensure there is goof contact: check the bar level on the pulse oxymeter, low-> weak signal. if reading is accurate, bar should be full
- after making adjustments, wait 30-60s for machine to read accurately
- still sus, check manually/ tell vet
what are the different ways to record breathing rate
1.auscultate the chest
2.watch the chest rise and fall
3.watch the reservoir bag
4.multiparameter machine (ETCO2 monitoring)
what is the normal resp rate and dept
normal rate: 8-20 bpm, <8, excessive anesthetic depth
observing characteristics of breathing:
-Respirations tend to become more shallow as depth increases
-Shallow breaths= possible insufficient oxygenation
how to obtain oxygen saturation value
SPO2- indicates approx amt of oxygen in the blood
-pulse oxymeter/multiparameter machine
-mm colour (blue-low SPO2)
what is normla SPO2 level
> 95%
fyi
what does blood pressure mean and what does systolic, diastolic and mean arterial pressure measure
blood pressure meaures pressure in the circulatory system, indicates how fast and what force blood travels to tissue beds and organs
(low bp-> body causes more blood to flow to brain, heart, liver, kidney, gut instead of limbs-> thats why we measure BP at the limbs)
systole: higher blood pressure in venticles, whne ventricle contracts
diastole: lowest BP in ventricles, when ventircle relaxes
mean arterial pressure: approx avg between systole and diastole
what is the normal blood pressure values in cats and dogs
systolic arteriall pressure:
D90-140mm Hg
cat: 80-140mm Hg
diastole:
D: 50-80mm Hg
c: 55-75 mm Hg
MAP: C&D: 60-100mm Hg
<60: hypotension, >100 hypertension
what are the different ways to measure BP
indirect blood pressure measurements:
1. oscillometry: measures pulse that is picked up under and inflatable cuff placed over an artery, on arm: limb around the heart level to minimise false reading
-imp to choose right size cuff to minimise errors
- dopper flow: relies on the absence/presence of a pulse heard over the doppler (like an ultrasound, can hear the beats) : cuff id placed over artery and inflated, cuff is slowly released and first audible sound on the doppler correlates to the systolic blood pressure- read on the sphygmomanometer)
fyi
what is normla body temp under anes
37.5-38.3
different ways to measure temperature
rectal thermometer
eosophageal thermometer (placed inside eosophagus measuring core temperature)
what are the contributing factor that cause decrease in temperature under anes
Contributing factors:
-The thermoregulation centre in the brain is affected by anaesthesia
-Routinely shave, skin washed with antiseptic and alcohol solution (makes patient coller)
-During surgery, body cavity may be opened exposing the viscera to air at room temperature
-Vasodilation caused by anaesthetic drugs
normal mm and crt
mm: pink, crt < 2
extra
abnormal mm and crt and what it means
blue, >3 poor perfusion of blood, low 02, hypotension (bradycardia, arrthymias), blood loss
sol: IVFT, suplemental oxygen, decrease anes dept by lower iso level only
what are the reflexes we focus on and what do they indicate
-eye position ( light: central, adaquate anes: ventral-medial, deep: central)
-palpebral reflex (relfex to protect eye, adaquate anes, no blink)
-jaw tone (adaquate anes: feels slacked with no resis-> can intubate)
-withrawal reflex: pinching firmly between toes, conscious animal will pull back (ensures they dont feel pain during surgery)
What are some situations during a surgical procedure where usual anaesthetic levels may need to be altered?
bradycardia, hypothermia, low RR: need to lower iso lvl
tachy, hypertehnsion, twitching, returning of reflexes, cutting procedure, stretching, suturing/closing
what happens when anesthetic is too light
patient in in anethetic stage III plan I or even sateg II
tachycardia (inc HR)
tachyponea (inc RR)
hypertension (inc BP)
positive palpebral and withrawal reflexs, some return on jaw tone
what to do if patient is too lightly anesthetisied
- look at patient,recheck monitoring machines , take vital signs
- increase iso 3% and O2 to 3l/min , wait for 60-90s for it to take effect (avoid common mistake of turining iso up to 5 without changing O2 flow)
- injcetable anethethics can be used to increase aneththic depth rapidly (eg. alfax, propofol-usually the induction agent used)
- analgesia (painful stimualtion could be the reason they are waking up, some animals may require more)
- after making changes, wait a min, cnages in anesthetic dept takes times
additional things to consider:
-check ET tube is in the trachea and not the osophagus
-anesthethic tubing is connected correctly to the machine
-pop off valuve is opened (goes in scavenger and not back to patient)
-there is no leakage of gas from the machine
-oxygen supply has been turned on (no O2, no iso)
what are some of the vitals signs if anethetic is too deep
anethethic stage III plane 3
HR: 75bpm (normal 60-120)
BR: 6bpm (normal 8-20)
blood pressure: 90/60 (mean is 60-100)
what to do if patient is too deeply anethetised
1.check patient, check monitoring device, manual check of vitals
2. turn down iso to 0.5%-1% (o2 remain at 1.5-2l/min)
3. flush anethetic system (disconnect patient, cover end of tube, pop of valve open, flush with oxygen, reconnect)
4. no improvement to HR,BR,BP, remains low-> drug may be needed (eg atropine for bradycardia)
5. increase IVFT rate (to increase BP)
max: 10ml/kg/hr (usual is 5 during surgery) given in 15mins with reassesments after each bolus. once resolved, dose should go back to usual anethetic rates (5ml)
6. still not resloved, may need to stop the procedure
