Respiratory Emergencies Flashcards
what causes decreased respiratory rate and effort
respiratory paralysis from neurologic disease
leads to hypoventilation
clinical signs of respiratory paralysis
laterally recumbent
decreased RR
increased to decreased effort
how to diagnose hypoventilation
elevated PCO2 - requires a blood gas to diagnose
can use a venous or arterial blood sample (only if CV stable can do venous)
treating hypoventilation
O2 Supplementation
Treat Underlying Cause
+/- IPPV if respiratory centers are depressed from neuro disease
causes of respiratory distress
- upper airway disease
- lower airway disease
- pulmonary parenchymal disease
- pleural space disease
- thoracic wall disease
- abdominal enlargement
- pulmonary embolism
- look alikes
how to stabilize a respiratory disease patient
- O2 supplementation
- minimize stress
- abbreviated PE
- cage side thoracic POCUS
- empiric therapy - treat the most likely rule outs
what is the extrathoracic airway
nose
pharynx
larynx
trachea (above thoracic inlet)
large vs small breed predispositions for upper airway disease
large - laryngeal paralysis
small - tracheal collapse
when is a temporary tracheostomy indicated
- severe upper airway disease ROSTRAL to the site of the tracheostomy tube
- treatment of disease is expected to take days
- able to have sufficient patient care post-op
what is the intrathoracic airway
trachea (below thoracic inlet)
mainstem bronchi
small bronchi/bronchioles
does pleural space disease cause hypoventilation or hypoxemia
hypoxemia due to pulmonary collapse and small tidal volume
how does pulmonary collapse cause hypoxemia
lung collapse –> loss of ventilated alveoli –> loss of gas exchange units –> low to no V/Q mismatch –> hypoxemia
causes of traumatic pneumothorax
blunt trauma
penetrating chest trauma
airway or esophageal injury
causes of spontaneous pneumothorax
pulmonary blebs or bullae
migrating foreign bodies
abscesses
closed pneumothorax
intact chest wall
air is coming from the lungs, airways, or esophagus
open pneumothorax
defect in the chest wall
air is coming from outside the body
tension pneumothorax
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
hemothorax
blood in the pleural space
PCV of effusion is > or = PCV of peripheral blood
etiologies of hemothorax
- trauma
- coagulopathy
- bleeding neoplasia
what pleural space disease is best identified on ultrasound
pleural effusion
ST
what pleural space disease is best identified on radiographs
pneumothorax
how to evaluate for chest wall injury
visual observation
sound - “sucking” chest wounds
when is a chest tube indicated
- pneumothorax when intermittent thoracocentesis is no longer working
- pyothorax
- post-op thoracotomy
flail chest
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
how to manage open pneumothorax
- anesthetize and intubate
- ventilate if struggling - if using IPPV, keep the chest wound open
- analgesia
- thoracocentesis
- seal wound +/- surgical repair
what are measures of hypoxemia
PaO2 < 80 mmHg
SpO2 < 95%
what are measures of severe hypoxemia
PaO2 < 60 mmHg
SpO2 < 90%
causes of hypoxemia
- low inspired oxygen
- hypoventilation (only assess if on room air)
- venous admixture - pulmonary parenchymal disease
cardiogenic pulmonary edema
increased hydrostatic pressure from volume overload during congestive heart failure
non cardiogenic pulmonary edema
transient increase in hydrostatic pressure vs abnormal pulmonary vascular permeability
ARDS
acute respiratory distress syndrome
occurs secondary to a severe primary inflammatory disease –> increased pro inflammatory cytokines –> SIRS/MODS –> increased vascular permeability
what is the most common cause of ARDS in dogs
pneumonia
what is the most common cause of ARDS in cats
SIRS/sepsis
criteria for ARDS
- severe primary disease causing systemic inflammation
- acute onset < 72 hours
- severe hypoxemia
- diffuse alveolar infiltrates on radiographs
ARDS treatment
often euthanasia
O2, IPPV, resolve underlying cause
what is the goal PaO2 and SpO2 of O2 supplementation
PaO2: 80-120 mmHg
SpO2: 95-99%
resolution of respiratory distress
considerations for long term O2 supplementation
try to maintain oxygenation with FiO2 < 60%
indications for mechanical ventilation
- severe hypoxemia despite O2 (PaO2 < 60 mmHg)
- severe hypoventilation despite O2 (PaCO2 > 60 mmHg)
- excessive breathing effort or concern for fatigue
