Managing Anesthetic Complications

Question 1

True or False: accidents are inevitable

Answer 1

True

Question 2

True or False: risk can be managed

Answer 2

True

Question 3

True or False: anesthetic risk is independent of procedural risk

Answer 3

False

Question 4

What is increased perioperative risk associated with?

Answer 4

Smaller patients

Question 5

Are mortality rates in cats better or worse than for dogs?

Answer 5

Worse. Dogs have an overall mortality rate of 0.17% and cats have a mortality rate of 0.24%

Question 6

True or False: Compared to dogs or humans, Rabbits and Horses have lower anesthetic risk for elective procedures.

Answer 6

False. Horses have a 2% overall anesthetic risk rate and rabbits have a 1.39%

Question 7

When do more than half of all dog and cat deaths occur?

Answer 7

During recovery

Question 8

True or False: Technical solutions and strict procedural guidelines have eliminated accidents.

Answer 8

False, it has decreased, but not eliminated

Question 9

What are the two types of errors committed in medicine?

Answer 9

Errors of ignorance: mistakes we make because we don’t know enough
Errors of ineptitude: mistakes we make because we don’t make proper use of what we do know

Question 10

What are the two key elements which make a system vulnerable to accidents?

Answer 10

Complex interactions: Complexity can be due to uncertainty to proliferation or it can be intrinsic
Tight coupling: Where what happens in one part directly and quickly affects another

Question 11

True or False: Systems exhibiting complex interactions and tight coupling are less likely to have accidents than systems exhibiting linear interactions and loose coupling.

Answer 11

False

Question 12

What are three proven methods to prevent or reduce accidents?

Answer 12

Teamwork
Checklists
Team discussion before the procedure produces “activation phenomenon”

Question 13

What is practical drift? Give an example.

Answer 13

Practical drift is the slow, steady uncoupling of local practice from best practice
This occurs when individuals try to meet operational requirements by making small adjustments in recommended procedures

Question 14

What should be done if an elective OHE has a subnormal temperature prior to induction?

Answer 14

Stop and determine what is going on

Question 15

True or False: “Bad” drugs/acute drug reactions are a major cause for anesthetic accidents.

Answer 15

False, it is rare for them to be the reason

Question 16

Which anesthetic agent is MOST associated with intraoperative hypotension?

Answer 16

Inhaled anesthetics

Question 17

What is the intravascular residence time for isotonic crystalloid solutions like Plasmalyte M or lactate Ringer’s solution?

Answer 17

30 minutes

Question 18

What is the intravascular residence time for isotonic colloid solutions like Vetastarch or Hetastarch?

Answer 18

24 hours

Question 19

True or False: Giving > 10 ml/kg/hr of isotonic crystalloid fluids during anesthesia will increase urine production

Answer 19

False, it does not change urine production

Question 20

What should you do when a patient with previously normal blood volume undergoes cardiac arrest during anesthesia?

Answer 20

Administer a vasopressor

Question 21

When does hypoventilation occur?

Answer 21

When PaCO2 > 45 mmHg

Question 22

When does hypoxemia occur?

Answer 22

SpO2 < 85-90%

PaO2 < 60-80 mmHg

Question 23

When does hypothermia occur?

Answer 23

< 32 deg. C

Question 24

When does hypotension occur?

Answer 24

MAP < 60 mmHg

Question 25

Does giving O2 to a hypoventilating animal resolve the hypoventilation?

Answer 25

No

Question 26

What are clinical signs associated with respiratory difficulty?

Answer 26

Apnea or dyspnea Increased respiratory rate, depth, or effort Stridor or sonorous breathing Cyanosis Wheezes and crackles Deformities of head, neck, thorax Abnormal positioning of head, neck, forelimbs

Question 27

What is extra-pulmonary respiratory inadequacy?

Answer 27

Conditions that inhibit air movement into and out of the lungs

Question 28

What is pulmonary respiratory inadequacy?

Answer 28

Conditions that inhibit gas exchange within the lung

Question 29

What are common causes of extra-pulmonary respiratory inadequacy?

Answer 29

Drug-induced hypoventilation Upper airway obstruction Pleural cavity disease Iatrogenic

Question 30

What are common causes of pulmonary respiratory inadequacy?

Answer 30

Parenchymal pulmonary disease | Iatrogenic

Question 31

What are causes of isoflurane-induced hypoventilation?

Answer 31

Increase PaCO2 | Iatrogenic, extrapulmonary

Question 32

What is the treatment for isoflurane-induced hypoventilation?

Answer 32

Improve ventilation

Question 33

What are causes of propofol-induced hypoventilation?

Answer 33

Increase PaCO2 | Iatrogenic, extrapulmonary

Question 34

What is the treatment for propofol-induced hypoventilation?

Answer 34

Improve ventilation

Question 35

What is the cause of laryngeal paralysis?

Answer 35

Extrapulmonary

Question 36

What is the treatment for laryngeal paralysis?

Answer 36

Bypass obstruction to secure open airway, provide O2 as needed

Question 37

What is the cause of pneumonia?

Answer 37

Decreased PaO2 LowV/Q ratio Pulmonary

Question 38

What is the treatment for pneumonia?

Answer 38

Increased FIO2

Question 39

Describe physiologic stunts

Answer 39

Dynamic Low V/Q units Given 100% O2, PaO2 tends to increase

Question 40

Describe anatomic shunts

Answer 40

Static Venous admixture Given 100% O2, PaO2 tends to stay the same

Question 41

What is accidental hypothermia common with?

Answer 41

Vet anesthesia

Question 42

What is accidental hyperthermia due to?

Answer 42

Mainly environment

Question 43

How do animals normally stay warm?

Answer 43

Hypothalamus (central thermoregulatory center) Shivering thermogenesis/voluntary muscle movement/cutaneous vasomotion Oronasal countercurrent air/blood heat exchanger present in many species

Question 44

What is heat loss during anesthesia due to from most common to least?

Answer 44

Radiation (40%) Convection (30%) Evaporation (20%) Respiration (10%)

Question 45

How does hypothermia affect CO? Hyperthermia?

Answer 45

Decrease | Increase

Question 46

How does hypothermia affect impulse condition? Hyperthermia?

Answer 46

Decrease | Increase

Question 47

How does hypothermia affect contractility? Hyperthermia?

Answer 47

+/- or decrease | Increase

Question 48

How does hypothermia affect HR? Hyperthermia?

Answer 48

Decrease | Increase

Question 49

How does hypothermia affect PVR? Hyperthermia?

Answer 49

+/- or increase | Decrease

Question 50

How does hypothermia affect O2 consumption? Hyperthermia?

Answer 50

Decrease | Increase

Question 51

How does hypothermia affect renal/hepatic function? Hyperthermia?

Answer 51

Decrease | Increase

Question 52

How does hypothermia affect coagulation? Hyperthermia?

Answer 52

Decrease | Increase

Question 53

How does hypothermia affect cerebral protection? Hyperthermia?

Answer 53

Increase | Decrease

Question 54

What happens to MAC for each degree C under 37C?

Answer 54

Decreases 5%

Question 55

Does the anesthetic requirement for febrile patients increase or decrease?

Answer 55

Increase

Question 56

How can high IV fluid rate lead to worsened outcomes?

Answer 56

``` Increase lung water; decrease pulmonary function Increase body weight Coagulation defects Reduced gut motility Reduced tissue oxygenation Increased infection rate Decreased PCV, TP, body temperature ```

Question 57

How do you treat hypotension?

Answer 57

Decrease anesthetic depth Give IV crystalloid bolus Give colloid If patient is normovolemic, use a vasopressor