Respiratory complications 2

Question 1

partial vs complete airway obstruction

Answer 1

§ Complete
* Inability to move air through airways into the lungs

§ Partial
* Airflow occurs but with increased resistance

Question 2

examples of upper airway obstructions

Answer 2

• Foreign body aspiration at any level of airway (nasal passage, larynx, trachea)
• Masses at any level of airway
• Inflammation of larynx
• Left laryngeal hemiplegia
• Kinked or clogged endotracheal tube
• Bandage

Question 3

examples of lower airway obstructions

Answer 3

• Bronchioles (bronchitis)
• Infection
• Asthma
• Atelectasis (seen with pneumothorax)

Question 4

how to diagnose airway obstruction

Answer 4

§ Paradoxical breathing
§ Hypoxemia
§ Hypercapnia
§ Monitoring:
> Abnormal capnographic wave (absent or decreased in size, and
abnormal in shape)
> Reservoir doesn’t move
§ High peak inspiratory pressures upon manual or mechanical ventilation

Question 5

what is paradoxical breathing?

Answer 5

§ No inflation of the chest; instead, it moves inwards
§ Negative inspiratory pressures on manometer of anesthetic machine
§ Abdominal expansion instead of moving inwards
§ Increased effort and work of breathing

Question 6

what volume of air changes when we have Chronic obstructive pulmonary disease, ie. how does the way we breathe change? (most significant change)

Answer 6

-residual volume increases significantly (volume of air remaining in the lungs after maximum forceful expiration)

Question 7

what volume of air changes when we have restrictive pulmonary disease (penumothorax, atelectasis, bronchospasm, airway obstruction), ie. how does the way we breathe change? (most significant change)

Answer 7

all volumes decrease, esp inspiratory reserve and expiratory reserve volume

Question 8

issues with Brachycephalic Obstructive Airway Syndrome (BOAS)

Answer 8

• Stenotic nares, enlongated soft palate, distortion of pharyngeal soft tissue, hypoplastic trachea, oversized tongue
• Increased resistance to airflow and increased intraluminal pressure during inspiration
  > Causes everted laryngeal saccules, pharyngeal hyperplasia, tonsillar hyperplasia, laryngeal collapse

Question 9

breathing issues we see with brachycephalic breeds

Answer 9

Stertor (snoring-like), stridor (high pitch), dyspnea, exercise intolerance, gagging, regurgitation, cyanosis, hyperthermia, syncope

Question 10

when do complications associated with the breathing apparatus occur for brachycephalic breeds, and what are they?

Answer 10

§ EXTUBATION time is when complications occur
* Obstruction
* Desaturation
* Anxiety

Question 11

how to extubate brachycephalic breeds to avoid issues

Answer 11

• Delay extubation until “fully” awake and able to swallow
• Pull the tongue forward until dog can breathe with ease
• Be prepared to re-intubate
• Steroidal anti-inflammatory

Question 12

what is the result of pre-oxygenation and what do we need to do it?

Answer 12

§ Increases PaO2 from 100 to potentially 600 mmHg
§ Increases SO2 from 98% to 100%
§ Requires a high FGF (> 100 mL/kg/min) and sealed administration (mask with diaphragm)

Question 13

how long does it take to reach equilibrium with pre-oxygenation, and how long does it take for levels to fall back to normal values?

Answer 13

§ 3-5 minutes to reach equilibrium at high levels
§ If pre-oxygenation stops
* < 2-3 minutes to lower to room air values
* Assuming maximum levels were achieved with pre-oxygenation

Question 14

mortality causes in horses recovering from anesthesia

Answer 14

fractures most common by far, followed by resp, then myopathy and CNS

Question 15

why do horses experience myopathy during surgery?

Answer 15

• Due to compression and decreased perfusion of the dependent
  muscles (low Mean arterial pressure, low Cardiac output)
• Bad positioning/padding

Question 16

why do horses experience neuropathy during surgery?

Answer 16

• Due to nerve compression
• Bad positioning/padding

Question 17

When administered intravenously barbiturates cause the following in order of increasing dose resulting in death:

Answer 17

Loss of consciousness, respiratory arrest, followed by cardiac arrest

Question 18

Hypoventilation is always associated with

Answer 18

an increase in arterial carbon dioxide levels

Question 19

Side-effects of sedative doses of detomidine when given IV or IM to a horse may include:

Answer 19

An increase in upper airway resistance to breathing, transient increase in blood pressure and bradycardia

Question 20

Hypovolemic shock in a non-anesthetized patient is noted when a patient has:

Answer 20

Lost ≥ 30% of its blood volume or is 10% dehydrated

Question 21

Choose the correct answer
a. The pulse oximeter is a good monitor to detect hypoventilation
b. A capnograph is used to detect the degree of oxygenation of the patient
c. Pulse oximeters display a value for PaO2 and pulse rate
d. The oscillometric method measures systolic, diastolic and mean blood pressure
e. The Doppler reading can be used to estimate mean blood pressure

Answer 21

d. The oscillometric method measures systolic, diastolic and mean blood pressure