Respiratory Emergencies

Question 1

what causes decreased respiratory rate and effort

Answer 1

respiratory paralysis from neurologic disease

leads to hypoventilation

Question 2

clinical signs of respiratory paralysis

Answer 2

laterally recumbent
decreased RR
increased to decreased effort

Question 3

how to diagnose hypoventilation

Answer 3

elevated PCO2 - requires a blood gas to diagnose

can use a venous or arterial blood sample (only if CV stable can do venous)

Question 4

treating hypoventilation

Answer 4

O2 Supplementation
Treat Underlying Cause

+/- IPPV if respiratory centers are depressed from neuro disease

Question 5

causes of respiratory distress

Answer 5

1. upper airway disease
2. lower airway disease
3. pulmonary parenchymal disease
4. pleural space disease
5. thoracic wall disease
6. abdominal enlargement
7. pulmonary embolism
8. look alikes

Question 6

how to stabilize a respiratory disease patient

Answer 6

1. O2 supplementation
2. minimize stress
3. abbreviated PE
4. cage side thoracic POCUS
5. empiric therapy - treat the most likely rule outs

Question 7

what is the extrathoracic airway

Answer 7

nose
pharynx
larynx
trachea (above thoracic inlet)

Question 8

large vs small breed predispositions for upper airway disease

Answer 8

large - laryngeal paralysis
small - tracheal collapse

Question 9

when is a temporary tracheostomy indicated

Answer 9

1. severe upper airway disease ROSTRAL to the site of the tracheostomy tube
2. treatment of disease is expected to take days
3. able to have sufficient patient care post-op

Question 10

what is the intrathoracic airway

Answer 10

trachea (below thoracic inlet)
mainstem bronchi
small bronchi/bronchioles

Question 11

does pleural space disease cause hypoventilation or hypoxemia

Answer 11

hypoxemia due to pulmonary collapse and small tidal volume

Question 12

how does pulmonary collapse cause hypoxemia

Answer 12

lung collapse –> loss of ventilated alveoli –> loss of gas exchange units –> low to no V/Q mismatch –> hypoxemia

Question 13

causes of traumatic pneumothorax

Answer 13

blunt trauma
penetrating chest trauma
airway or esophageal injury

Question 14

causes of spontaneous pneumothorax

Answer 14

pulmonary blebs or bullae
migrating foreign bodies
abscesses

Question 15

closed pneumothorax

Answer 15

intact chest wall
air is coming from the lungs, airways, or esophagus

Question 16

open pneumothorax

Answer 16

defect in the chest wall

air is coming from outside the body

Question 17

tension pneumothorax

Answer 17

severe pneumothorax in which the pleural pressure continues to increase as air is forced into the pleural space but cannot escape

causes a “one way valve” effect

Question 18

hemothorax

Answer 18

blood in the pleural space

PCV of effusion is > or = PCV of peripheral blood

Question 19

etiologies of hemothorax

Answer 19

1. trauma
2. coagulopathy
3. bleeding neoplasia

Question 20

what pleural space disease is best identified on ultrasound

Answer 20

pleural effusion
ST

Question 21

what pleural space disease is best identified on radiographs

Answer 21

pneumothorax

Question 22

how to evaluate for chest wall injury

Answer 22

visual observation
sound - “sucking” chest wounds

Question 23

when is a chest tube indicated

Answer 23

1. pneumothorax when intermittent thoracocentesis is no longer working
2. pyothorax
3. post-op thoracotomy

Question 24

flail chest

Answer 24

rib fractures consisting of penumo and hemothorax > or = 2 adjoining ribs

free floating section of chest wall (no rigid attachment to the rest)

paradoxical movement - moves in on inspiration and out on expiration

Question 25

how to manage open pneumothorax

Answer 25

1. anesthetize and intubate
2. ventilate if struggling - if using IPPV, keep the chest wound open
3. analgesia
4. thoracocentesis
5. seal wound +/- surgical repair

Question 26

what are measures of hypoxemia

Answer 26

PaO2 < 80 mmHg
SpO2 < 95%

Question 27

what are measures of severe hypoxemia

Answer 27

PaO2 < 60 mmHg
SpO2 < 90%

Question 28

causes of hypoxemia

Answer 28

1. low inspired oxygen
2. hypoventilation (only assess if on room air)
3. venous admixture - pulmonary parenchymal disease

Question 29

cardiogenic pulmonary edema

Answer 29

increased hydrostatic pressure from volume overload during congestive heart failure

Question 30

non cardiogenic pulmonary edema

Answer 30

transient increase in hydrostatic pressure vs abnormal pulmonary vascular permeability

Question 31

ARDS

Answer 31

acute respiratory distress syndrome

occurs secondary to a severe primary inflammatory disease –> increased pro inflammatory cytokines –> SIRS/MODS –> increased vascular permeability

Question 32

what is the most common cause of ARDS in dogs

Answer 32

pneumonia

Question 33

what is the most common cause of ARDS in cats

Answer 33

SIRS/sepsis

Question 34

criteria for ARDS

Answer 34

1. severe primary disease causing systemic inflammation
2. acute onset < 72 hours
3. severe hypoxemia
4. diffuse alveolar infiltrates on radiographs

Question 35

ARDS treatment

Answer 35

often euthanasia

O2, IPPV, resolve underlying cause

Question 36

what is the goal PaO2 and SpO2 of O2 supplementation

Answer 36

PaO2: 80-120 mmHg
SpO2: 95-99%

resolution of respiratory distress

Question 37

considerations for long term O2 supplementation

Answer 37

try to maintain oxygenation with FiO2 < 60%

Question 38

indications for mechanical ventilation

Answer 38

1. severe hypoxemia despite O2 (PaO2 < 60 mmHg)
2. severe hypoventilation despite O2 (PaCO2 > 60 mmHg)
3. excessive breathing effort or concern for fatigue