Week 1 - monitoring the anaesthetised patient/ dosages

Question 1

Why is continuous monitoring critical for an anesthetized animal?

Answer 1

An anesthetized animal must never be left unattended. Monitoring is a continual process throughout the anesthetic event, from pre-medication to recovery, with vital signs recorded every 5 minutes.

Question 2

What parameters must be continuously assessed during anesthesia?

Answer 2

Respiratory rate, depth and character, oxygen saturation (SpO2), heart rate and rhythm, pulse strength, mucous membrane color, capillary refill time, arterial blood pressure, body temperature, anesthetic depth, and equipment function.

Question 3

What are the key components of respiratory monitoring?

Answer 3

Airway patency, respiratory rate, depth, character, and oxygen saturation (SpO2)

Question 4

What cardiovascular parameters are monitored during anesthesia?

Answer 4

Heart rate and rhythm, pulse strength and rate, mucous membrane color, capillary refill time (CRT), and arterial blood pressure.

Question 5

How is body temperature monitored and managed during anesthesia?

Answer 5

Body temperature is monitored frequently, and warming devices are used to prevent hypothermia. Overheating and burns must also be avoided.

Question 6

What indicators are used to assess anesthetic depth?

Answer 6

Reflexes, muscle tone, eye position, pupillary reflex activity, and heart and respiratory rates.

Question 7

How do you ensure airway patency during anesthesia?

Answer 7

Check the endotracheal tube for kinking, slippage, or deep placement, and listen for moisture accumulation. Extend the neck during recovery to prevent airway obstruction.

Question 8

What are normal respiratory characteristics for an anesthetized patient?

Answer 8

A rate of 10–20 breaths/minute, smooth chest movements, and nearly inaudible respiratory sounds.

Question 9

What does a low respiratory rate (<8–10 bpm) indicate?

Answer 9

It indicates a potential problem, requiring immediate notification of a veterinarian or technician and possibly manual ventilation.

Question 10

What could hyperventilation during anesthesia signify?

Answer 10

Elevated CO2 levels in the blood, metabolic acidosis, or response to surgical stimuli.

Question 11

Why might an animal under ketamine anesthesia show irregular respiratory patterns?

Answer 11

Ketamine can cause apneustic breathing, characterized by prolonged pauses after inspiration.

Question 12

What is the normal oxygen saturation (SpO2) range, and why is it important?

Answer 12

Normal SpO2 is 95–100%. It ensures adequate oxygen delivery to the blood and tissues.

Question 13

What should be done if a pulse oximeter reading falls below 90%?

Answer 13

Investigate and address respiratory or cardiovascular issues immediately to prevent hypoxia.

Question 14

What is the normal heart rate for anesthetized dogs and cats?

Answer 14

Dogs: 80–120 bpm; Cats: 100–180 bpm.

Question 15

How is mucous membrane color used to assess patient status?

Answer 15

Pink mucous membranes with a CRT < 2 seconds indicate good perfusion. Pale or cyanotic membranes suggest serious issues.

Question 16

What is the minimum acceptable arterial blood pressure during anesthesia?

Answer 16

Arterial Blood Pressure
Normal BP: 120/80 mm Hg (80-120 mmHg systolic, 60-100 mmHg diastolic).
Normal Mean Arterial Pressure between 70-90 mmHg

The minimum acceptable BP is 80/40. If the mean arterial blood pressure (MAP) is below 60 mmHg, organ and tissue perfusion is inadequate.

Question 17

What complications can arise from hypotension during anesthesia?

Answer 17

Inadequate tissue perfusion, organ failure, and prolonged recovery.

Question 18

What is the greatest risk for body heat loss during anesthesia?

Answer 18

The first 20 minutes of anesthesia pose the highest risk of hypothermia.

Question 19

What are the five classic stages of anesthesia?

Answer 19

Stage I: Induction
Stage II: Excitatory phase
Stage III: Surgical anesthesia (Planes 1–3)
Stage IV: Overdose
Stage V: Death

Question 20

What reflexes are used to monitor anesthetic depth? (5)

Answer 20

Palpebral (blink), swallowing, pedal, corneal, and laryngeal reflexes.

Question 21

How is jaw tone evaluated during anesthesia?

Answer 21

By opening the jaws to assess passive resistance. Extreme laxity indicates excessive anesthetic depth.

Question 22

What is the significance of eye position during anesthesia?

Answer 22

Eye position and pupil size vary with anesthetic depth and can indicate status in conjunction with other parameters.

Question 23

What does an increase in heart rate during surgery indicate?

Answer 23

It may signal inadequate anesthetic depth or response to surgical stimulation.

Question 24

How can anesthetic machines contribute to complications?

Answer 24

Equipment malfunction or human error can cause issues; regular checks are essential.

Question 25

How does the vaporizer setting affect anesthetic depth?

Answer 25

Higher settings are used during induction, while lower settings maintain stable anesthesia.

In general, a relatively high anesthetic dose (2.5-3%) will be required for the first
several minutes after induction. When a stable anesthetic plane has been reached,
the vaporizer setting is lowered and adjusted to maintain an appropriate depth.

Question 26

Why should the isoflurane vaporizer not exceed 3%?

Answer 26

Higher settings may increase complications; adjustments in oxygen flow rate are safer.

Question 27

What is the purpose of the pop-off valve?

Answer 27

It prevents excessive pressure build-up in the anesthetic circuit, protecting the lungs.

If allowed to occur (as when the valve is left in the closed position), this pressure can reach the animals lungs, causing the alveoli to distend and eventually rupture.

Question 28

How is the oxygen flow rate adjusted during anesthesia?

Answer 28

Typically set at 0.5–2 L/min, it is adjusted to maintain appropriate reservoir bag volume.

Question 29

What precautions should be taken with heating devices during anesthesia?

Answer 29

Always use barriers like towels to prevent burns. Heating pads should be set to low, and supplemental heat should be discontinued when body temperature normalizes.

supplemental heat should be discontinued when the patient’s temperature is 37,80°C.

Question 30

What are signs of insufficient anesthetic depth during surgery?

Answer 30

Increased heart rate, respiratory rate, voluntary movements, tear production, salivation, or sweating (on footpads).

Question 31

How do anesthetic drugs influence muscle relaxation?

Answer 31

Anesthetic depth and specific drugs reduce muscle tone, with extreme laxity suggesting excessive depth.

Question 32

What complications can arise from leaving the pop-off valve closed?

Answer 32

It can cause alveoli to overdistend and rupture due to high pressure in the lungs.

Question 33

How often should the vaporizer’s isoflurane level be checked?

Answer 33

Check before, during, and after the procedure, ensuring the reservoir is filled above the halfway mark.

Question 34

How can an esophageal stethoscope assist in respiratory monitoring?

Answer 34

It allows for continuous assessment of respiratory sounds, rate, and depth during anesthesia.

Question 35

What is the importance of ‘bagging’ a patient during anesthesia?

Answer 35

Manual ventilation every 5 minutes prevents atelectasis by inflating collapsed alveoli.

Question 36

What role does the capillary refill time (CRT) play in monitoring?

Answer 36

CRT reflects tissue perfusion, with a prolonged CRT (>2 seconds) indicating possible hypotension or poor circulation.

Question 37

Why is hypothermia a concern in anesthetized small animals?

Answer 37

Small animals lose body heat quickly, leading to prolonged recovery and complications. Warming devices are crucial.

Question 38

How does surgical stimulation affect anesthetic depth indicators?

Answer 38

Minor changes in heart rate or respiratory rate are normal, but significant changes may indicate insufficient depth.

Question 39

How is arterial blood pressure monitored during anesthesia?

Answer 39

Using Doppler ultrasound probes or oscillometric devices, though the latter may be less effective in small or hypotensive animals.

Question 40

Why is the MAP (Mean Arterial Pressure) critical during anesthesia?

Answer 40

MAP below 60 mmHg indicates inadequate organ and tissue perfusion, requiring immediate intervention.

Question 41

What should the anesthetist prioritize during an anesthetic procedure?

Answer 41

Continuous monitoring of all parameters (respiratory, cardiovascular, body temperature, depth, and equipment) and adjusting to ensure patient safety.