Anesthesia complications

Question 1

Normal arterial blood pressure is approximately

Answer 1

120/80 mmHg

Question 2

normal mean arterial pressure is between

Answer 2

70-90 mmHg

Question 3

The minimum acceptable mean arterial pressure for anesthetized small animals is

Answer 3

65 mmHg

Question 4

name the 3 main anesthetics that cause hypotension:

Answer 4

vapors
propofol
acepromazine

Most anaesthetic drugs produce cardiovascular depression, which tends to decrease blood pressure.

Question 5

the most common cause for low blood pressure in surgical patients is

Answer 5

Isoflurane (can induce profound hypotension)

Question 6

Acepromazine and propofol both cause

Answer 6

vasodilation and thus hypotension

Question 7

3 drugs of choice for the treatment of hypotension:

Answer 7

dopamine
dobutamine
noradrenaline
(glycopyrronium bromide)

Question 8

Acepromazine, inhalants, and induction agents such as propofol and alfaxalone decrease temperature because
of

Answer 8

vasodilation and/or as a result of slowing metabolism.

Question 9

what temp is defined as hypothermia?

Answer 9

anything lower than 38’C

Question 10

passive rewarming is not useful if

Answer 10

the animal is already cold

(if its cold on the inside, it cant heat itself up. you need an active warming source)

Question 11

Arrhythmias broad causes (2)

Answer 11

cardiogenic and non-cardiogenic

The majority are non-cardiogenic causes (pain, blood loss, hypoxemia, hypercapnia, hypothermia, electrolyte imbalance etc.)

Question 12

Arrhythmias are divided into what groups based on rhythm

Answer 12

Bradyarrhythmias
¡ Sinus bradycardia
¡ Blocks (Sinoatrial block, Atrioventricular block)

Tachyarrhythmias
¡ Sinus tachycardia

Ventricular arrhythmias
¡ Extrasystoles

Question 13

Bradycardia in large dogs

Answer 13

<50 bpm

Question 14

Bradycardia in small dogs

Answer 14

<70 bpm

Question 15

Bradycardia in cats

Answer 15

<100 bpm

Question 16

Bradycardias are generally a result of: (4)

Answer 16

• administration of vagotonic drugs (α-2 adrenergic agonists, opioids)
• stimulation of vagally mediated reflexes (trigeminocardiac reflex, intubation)
• hyperkalemia
• consequences of anesthesia, including excessive depth, hypothermia, and hypoxia

Question 17

what is the trigeminocardiac reflex

Answer 17

The trigemino-cardiac reflex (TCR) is defined as the sudden onset of parasympathetic dysrhythmia, sympathetic hypotension, apnea or gastric hypermotility during stimulation of any of the sensory branches of the trigeminal nerve in the maxilla.

can occur during root canals (tooth nerve removal) and in eye enucleations

Question 18

Answer 18

sinus arrhythmia

Question 19

Answer 19

sinus bradycardia

Question 20

When the cause of bradycardia is increased
vagal tone, what should be administered

Answer 20

an anticholinergic (atropine)

Question 21

Tachycardia and tachyarrhythmias in cats, HR?

Answer 21

HR >200 bpm in cats

Question 22

Tachycardia and tachyarrhythmias in dogs, HR?

Answer 22

HR >160 bpm in dogs

Question 23

A very large T wave can indicate what electrolyte imbalance?

Answer 23

hyperkalemia

Question 24

3 most common Anesthetic-related causes of sinus tachycardia are:

Answer 24

¡ drugs (ketamine, anticholinergics)
¡ inadequate depth of anesthesia
¡ pain

Question 25

Answer 25

sinus tachycardia

Question 26

Answer 26

Premature ventricular contraction (extrasystoles):

Recurrent extrasystoles can be dangerous and need to be treated.
- treatment is Lidocaine iv

Question 27

Answer 27

ventricular fibrillation

Question 28

Anesthetics that cause a dose dependent drop in respiratory rate and depth

Answer 28

Opioids, propofol, alfaxalone, and inhalants can result in a dose dependent drop in respiratory rate and depth.

(Acepromazine and benzodiazepines cause minimal respiratory depression.)

Question 29

Patient related mechanical causes of hypoventilation (3)

Answer 29

impaired respiratory muscle effort (rib fractures, pleural space disease, obesity)

upper airway obstruction common with
brachycephalic airway syndrome and tracheal collapse

Question 30

True respiratory arrest may result from (3)

Answer 30

¡ anaesthetic overdose
¡ lack of oxygen flow
¡ preexisting disease

In this case, other vital signs are often abnormal and SpO2 values rapidly fall below 90%.