Transcript Pneumomediastinum, Pneumothorax and SQ Emphysema

Veterinary Specialists of South Florida
Presents
SQ Emphysema,
Pneumomediastinum, and
Pneumothorax
Veterinary Specialists of South
Florida
Karina Tam, DVM
Romeo - History
► 18
year-old MN DSH
► Indoor/outdoor cat
► 5 days history of wheezing and skin wounds
after a suspected cat fight
► rDVM: treated with convenia and cleaned
wounds
► Lethargic, hyporexic
Romeo - Physical exam
► Puncture
wounds on both side of the chest
► Crackling sensation on palpation around
cervical and thoracic regions
► Increased respiratory effort and rate
► Stridor and wheezes
► Crackles on thoracic auscultation
Diagnostics – Thoracic radiographs
► SQ
emphysema
 Gas pockets in the SQ
tissues around cervical,
axillary and thoracic
regions
Diagnostics – Thoracic radiographs
► Pneumediastinum
 Air outlined the vessels
in the mediastinum
Diagnostics – Thoracic radiographs
►
Mild pneumothorax
 Dorsal displacement of the
cardiac silhouette from
sternum
 Retracted right caudal lung
lobe
 Air in pleural space
SQ Emphysema
► Airway
trauma
 From pharynx to trachea to terminal bronchioles
► Bite
► Air
wounds, foreign body, iatrogenic (ET tube placement,
surgery)
can be trapped
 Unidirectional valve action
► Treatment:
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Cage rest and wait for the absorption of the air
Needle suction
Penrose drain
Surgical repair of the trachea
Usually resolved in 1-6 weeks
Pneumomediastinum
► Etiologies
 injury of the esophagus, trachea, pharynx or lung
► Most cases are
► Progressive
mild and self-limiting
 Medisastinal tissue ruptures and allows air to get into
surrounding spaces
 pneumopericardium, pneumothorax,
pneumoretroperitoneum, SQ emphysema
► Underlying cause contributing to clinical signs
► Some worse cases – rarely, increase mediastinal
pressure, decrease venous return
Pneumothorax
► Pleural
space
 Maintain a negative intrathoracic pressure
 When this pressure is disrupted
► Affect the expansion and relaxation
► Lung atelectasis  hypoxia
► Ventilation
of the lung
perfusion mismatch  decrease arterial pressure of
oxygen
► Decreased venous return and cardiac output  shock
► Diagnostics
 Auscultation – dull lung sounds in caudal dorsal chest
 Thoracic radiographs
 CT for underlying disease
Pneumothorax
► Traumatic
► Spontaneous
► Iatrogenic
Pneumothorax
► Traumatic
 Open pneumothorax
► Air
accesses through thoracic wall injury
 Closed pneumothorax
► Air
goes from lung parenchyma to lacerated visceral or parietal
pleurae
► E.g. from rib fractures, barotraumas, tensile and shearing forces
in HBC
 Tension pneumothorax
► Lesion
is a one-way valve
► Causes progressive air accumulation
► Increased intrapleural pressure
► Caudal displacement of diaphragm on radiographs
► Rapid deterioration
Pneumothorax
►
Spontaneous
 Closed pneumothorax
 Pulmonary abscess, neoplasia, FB migration, ruptured bullae,
pneumonia, asthma, parasites (such as lung worms or heart
worms)
►
Iatrogenic
Thoracocentesis
FNA
Needle biopsy
Thoracostomy tube
Barotrauma or mechanical ventilation (excessive positive pressure
ventilation) from anesthesia
 Jugular venipucture in cats
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Pneumothorax
► Treatment
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Oxygen
Closure of thoracic wall defect if present
Thoracocentesis
Thoracostomy tube
► When
repeated thoracocentesis is needed or negative pressure
cannot be achieved by thracocentesis
► Aspirate air every 4 hours until 3 negative pressures, or
► Continuous suction with a pleural drainage system
 Thoracotomy (prefer median sternotomy) and positive
pressure ventilation
 Treat underlying disease
Romeo
► Conservative
treatment
 Cage rest
 Pain meds
► Owner’s
update
 Breathing fine on the next few days
Romeo
► On
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the 4th day… he came back
Open mouth breathing
Rapid shallow breathing
Inspiratory wheezes
Muddy mucous membrane
TXR – same as 4 days ago
► After
physical exam
 Respiratory arrest!
 Intubated and got 100% oxygen  responded well
► Bronchoscopy
Romeo
 Approximately 6cm caudal to larynx
 Narrowing of trachea
 Tracheal laceration
► Ischemic
injury of the trachea  obstruction of air flow 
respiratory distress
Romeo
► Surgical
repair of the tracheal laceration
 Laceration – 2/3 of the tracheal circumference
►Damaged
mucosa was debrided
►Tracheal rings were approximated using a simple
interrupted pattern
 Right and left parathyroid glands were
traumatized
 Confirmed patent tracheal lumen with a ridgid
bronchoscope
Romeo
► The
next day
 TXR – nearly complete
resolution of SQ
emphysema,
pneumomediastinum and
pneumothorax
 Moved from the oxygen
cage to room air
 Sent home
Follow up
►3
days after discharge
 Romeo was doing well
 Eating and drinking, active
 No difficulty breathing
► Recheck
today for suture removal
References
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Kirk & Bistner. 2006. Respiratory Emergency. Veterinary Procedures and Emergency
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Nelson & Couto. 2009. Diagnostic Tests for the Pleural Cavity and Mediastinum. Small
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http://www.veterinarypracticenews.com/web-exclusives/how-to-avoid-trachealtears.aspx. Accessed on July 24th, 2011.
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