Ch 5 book notes Flashcards
What is the delicate balance that must be maintained during any anesthetic event?
- there must be sufficient CNS depression
- analgesia
- muscle relaxation
-immobility for the procedure to be performed
cardiopulmonary function must not be dangerously compromised
Monitoring is necessary for two reasons?
1 - it is necessary to keep the patient safe (vital signs)
2 - necessary to regulate anesthetic depth (too light? too deep?)
What can happen if vital signs are not monitored (remain within acceptable limits)?
- permanent brain damage
- death
How does the anesthetist check for depth of anesthesia?
monitor reflexes, and other indicators
What happens if anesthetist doesn’t monitor dept of anesthesia?
patient will feel pain, premature arousal - if depth is too light
overdose or slow recovery if too deep
The anesthetist when monitoring must observe various parameters which are?
1 - vital signs
2 - reflexes
3 - other indicators of anesthetic depth
Vital signs refers to variables that indicate the response of the animal’s homeostatic mechanisms to anesthesia including?
heart rate, heart rhythm, respiratory rate and depth, mucous membrane color, capillary refill time, pulse strength, blood pressure and temperature
Reflexes refers to ?
an involuntary response to a stimulus
Reflexes used in veterinary anesthesia include?
palpebral, corneal, pedal, swallowing and laryngeal reflexes as well as the pupillary light reflex
Other indicators of anesthetic depth are?
spontaneous movement, eye position, pupil size, muscle tone, nystagmus, salivary and lacrimal secretions, and response to surgical stimulation
What is not useful for determining cardiopulmonary function or homeostasis?
reflexes and other indicators
Anesthetic monitoring is based on what principle?
in the average patient each monitoring parameter is expected to show a predictable response at any given anesthetic depth
In lieu of continuous monitoring of all patients, The ACVA (American College of Veterinary Anesthesiologists) recommends that class P1 and P2 patients should be monitored at least?
once every 5 min.
In lieu of continuous monitoring of all patients, The ACVA (American College of Veterinary Anesthesiologists) recommends that class P3 and P4 and P5 patients should be monitored at least?
- should be monitored continuously they have been anesthetized for more than 45 min.
- recording intervals
What reflexes should be present is patient’s anesthesia level is too light?
swallowing and pedal reflexes
Muscle tone, HR and RR are expected to be ___ during light anesthesia and to gradually___ as anesthesia depth increases.
high, decrease
What are some signs that are indicative of pain perception?
increase RR, increased BP, or voluntary movement
What are the stages of anesthesia?
loss of consciousness marks the border between stages 1 and II
loss of spontaneous muscle movement marks the border between II and III
loss of all reflexes, widely dilated pupils, flaccid muscle tone, and cardiopulmonary collapse mark stage IV
What expected responses occurs in stage 1 (period of voluntary movement) when monitoring parameters of anesthesia?
behavior - disorientation , struggling, fear
respiration - increased rate, dogs may pant
cardiovascular function - HR increased
What expected responses occurs in stage 2 (period of involuntary movement - excitement stage) when monitoring parameters of anesthesia?
behavior - excitement: reflex struggling, vocalization, paddling, chewing
respiration - irregular, may hod breath or hyperventilate
cardiovascular function - HR often increased
What expected responses occurs in stage 3 (period of surgical anesthesia) (plane 1, light anesthesia) when monitoring parameters of anesthesia?
behavior - unconscious
respiration - regular; rate - high normal
cardiovascular function - pulse strong; heart rate high normal
(Inadequate to perform surgery)
What expected responses occurs in stage 3 ((period of surgical anesthesia)) (plane 2, medium (surgical) anesthesia) when monitoring parameters of anesthesia?
respiration - regular (may be shallow); rate - moderate
cardiovascular function - HR moderate
(suitable for most surgical procedures)
What expected responses occurs in stage 3 (period of surgical anesthesia) (plane 3, deep anesthesia) when monitoring parameters of anesthesia?
respiration - shallow; rate - low or below normal
cardiovascular function - HR low normal; capillary refill time (CRT) increased; pulse less strong
(excessively deep)
What expected responses occurs in stage 3 (stage of anesthetic overdose) (plane 4) when monitoring parameters of anesthesia?
respiration - jerky
cardiovascular function - HR below normal; prolonged CRT; pale mucous membranes
(anesthetic overdose - your patient is in real trouble)
What expected responses occurs in stage 4 when monitoring parameters of anesthesia?
behavior - moribund - (at the point of death)
respiration - apnea
cardiovascular function - cardiovascular collapse
The word Monitor comes from the latin word Monere, what does this word mean?
to warn
The main purpose for monitoring?
warn you the anesthetist of changes in anesthetic depth
warn you the anesthetist of changes in patient condition in enough time to permit appropriate intervention
Vital signs are?
- indicators of how well your patient is maintaining
- basic circulatory function
- basic respiratory function - during anesthesia
- not reliable indicators of anesthetic depth
What reflexes are involuntary responses to stimuli?
eye blink
kick, and pulling back
ACVA recommendations - assessment of ?
-circulation,oxygenation,ventilation, and body temperature
-monitoring patients under and recovery form neuromuscular blockage
- record keeping
- monitoring during the recovery period
recommendations regarding personnel
- monitoring sedated patients
What is optimum depth?
the objectives of surgical anesthesia are that the patient does not move, is not aware, does not feel pain, has not memory of the procedure afterward, and does not have dangerous depression of the cardiovascular and respiratory systems.
Interpretation of how factors may alter expected responses of anesthetic depth can come from?
drugs, disease, and individual response variations
Determining whether or not the patient is safe is accomplished by assessing vital signs, what are they?
physical means - touch, hearing, vision
use of instrumentation and machines - ECG, BP monitor, capnograph, Doppler, pulse oximeter
What is a capnograph?
measures CO₂ levels
What is a doppler?
measures pulse rate , & systolic BP when used in conjunction with a sphygomamanometer
What is a pulse oximeter?
estimates the % oxygen saturation of hemoglobin and the pulse rate
The vital signs Physical, instrumentation/machines can be grouped according to whether they reflect?
circulation, oxygenation, ventilation
What is circulation?
HR and heart rhythm, pulse strength, CRT, mucous membrane color, and BP
What is oxygenation?
mucous membrane color, hemoglobin saturation, measurement of inspired oxygen, measurement of arterial blood oxygen
What is ventilation?
RR, and respiratory depth, breath sounds, end-expired CO₂ levels, arterial carbon dioxide and blood pH
ACVA recommendations?
continuous awareness of HR and rhythm during anethesia, along with gross assessment of peripheral perfusion (pulse quality, [mucous membrane] color and CRT) are mandatory. Arterial BP and ECG should also be monitored.
Heart rate can be physically assessed by?
palpation, stethoscope, esophageal stethoscope, electrocardiography (amplifies the heart sounds), electrocardiography, a BP monitor (Doppler, Oscillometric
What is an Oscillometric?
measurement devices use an electronic pressure sensor with a numerical readout of blood pressure
HR and rhythm can be assessed with?
esophageal stethoscope, electrocardiography
What is the most common causes of Bradycardia with anesthesia?
by excessive anesthetic depth or adverse effects of drugs
What are the most common causes of tachycardia?
inadequate anesthetic depth, pain during light surgical anesthesia, hypotension, blood loss, shock, hypoxemia,and hypercapnia
