CVR Week 10

Low‑pitched, snoring/snuffling sound. Originates from the nasopharynx or oropharynx. Caused by turbulent airflow through partially obstructed soft tissues e.g. soft palate, pharyngeal tissues.

Stertor

High-pitched, harsh sound produced by turbulent airflow through a narrowed upper airway, most commonly at the level of the larynx or proximal trachea.

Stridor

Discontinuous popping primarily on inspiration from sudden opening of collapsed or fluid filled small airways/alveoli. Commonly associated with pulmonary edema, pneumonia, pulmonary fibrosis, atelectasis.

Crackles (rales)

Continuous musical, high pitched primary on expiration from airflow through narrowed bronchi/bronchioles causing airway wall oscillation. Associated with feline asthma, chronic bronchitis, lower airway obstruction.

Wheezes

Continuous low pitched rumbling/snoring often expiratory but sometimes biphasic from airflow through large airways containing mucus or secretions in the trachea and bronchi. Associated with bronchitis, tracheobronchial secretions.

Rhonchi

Grating, creaking, leathery sound which is biphasic from inflamed pleural surfaces rubbing together. Associated with pleuritis and pleural inflammation.

Pleural friction rub

Markedly reduced or absent breath sounds from air or fluid separating lungs from the thoracic wall. Associated with pneumothorax, pleural effusion, and diaphragmatic hernia.

Absent or diminished lung sounds

How does a bronchiole lung pattern appear

Bronchial wall is infiltrated by cells or fluid→ thickening of those structures results in enhanced radiographic visualization of the bronchial tree.

Thickened, end-on bronchi appear as rings, or “do-nuts” Thickened bronchi seen longitudinally appear as parallel radiopaque lines, sometimes referred to as “railroad tracks.”

Which structure is usually effected if you have abnormal respiratory patterns on inspiration

Upper airway

Which structure is usually effected if you have abnormal respiratory patterns on expiration

Lower airway

What is the FRITA acronym for pulse evaulation

Frequency

Rhythm

Intensity

Tension

Amplitude

What are some structural problems with brachycephalics

Stenotic nares

Hypertrophic nasal turbinates

Hypoplastic trachea

Elongated soft palate

Hyperplasic tonsils

Macroglossia (of the tongue root)

Everted laryngeal saccules

Dental problems

Ocular problems

How does an elongated soft palate lead to breathing issues in brachycephalics

It will overlay the tip of the epiglottis and form a seal

Which grade(s) are considered clinically BOAS-affected and require management or treatment

Grade II or III

What leads to laryngeal saccule eversion in brachycephalics

Increased inspiratory effort causes increased negative pressure in the airway

What are some anesthetic considerations for brachycephalics

Respiratory system- dyspnea, upper resp airway obstruction → hypoxia

Difficulty intubating (small trachea)

Cardio- increased vagal tone → bradycardia

Ophthalmologic- exophthalmos → corneal ulcer

Gastrointestinal- hiatal hernia → GI reflux (aspiration pneumonia risk)

What sedatives and what opioids are used for brachycephalics

Sedation- lower dose alpha 2 agonist or ACE

Analgesia- methadone better than morphine (vomiting)

Consider anticholinergics if blood pressure affected

What are some sx options for dogs with BOAS

Temporary tracheostomy

Rhinoplasty (alaplasty or alapexy)

Laser assisted turbinectomy

Staphylectomy (to shorten the soft palate)

Folded flap palatoplasty

Where should the soft palate be resected to in a staphylectomy

To the tip of the epiglottis (to avoid secondary rhinitis)

Why must you used caution when removing the laryngeal saccules in brachycephalics

Webbing scar tissue

How do you perform a folded flap palatoplasty

Remove the buccal mucosa and decreased the thickness of the muscle then suture the end of the mucosa over to the other edge (folding it over)

What are the 2 opposing forces in the thorax

Muscle tension of diaphragm and chest wall and elastic recoil of the lungs

How does pneumothorax lead to lung collapse

Negative pleural pressure is lost and the 2 opposing forces do not oppose each other anymore causing lung collapse

What are type of pneumothorax

Spontaneous (bulla air pocket breaks)

Traumatic

Tension (creates one way valve for air to flow in the pleural space)

What does NOSE stand for

N- noisy breathing

O- oxygen

S- sedation (ACE and butorphanol)

E- endotracheal tubes

What is needed to stabilize the patient

Oxygen first

Fluids if in shock

Pain meds

Thoracocentesis

Sedation

DO NOT STRESS THEM OUT

Why does giving O2 increase the partial pressure of O2 in the blood

It has a higher conc of O2 than room air

How does giving O2 help in a pneumothorax

It decreases the pp of other gases in the blood which is good because they will diffuse down the gradient out of the chest back into lungs and out

When is giving O2 contraindicated

Fire

What is the interaction of giving O2 with paraquat poisoning

Its an herbicide which is uniformly fatal and releases ROS in the lungs so if you give them O2 is kills them faster (you want to euthanize)

Why is O2 good for surgical wounds

It decreases infection risk

What 2 conditions can be diagnosed on PE

Hemothorax and pneumothorax (you won’t hear lung sounds)

What should you do prior to radiographs if the animal is critical and has a restrictive respiratory pattern

Thoracocentesis (therapeutic, diagnostic and prognostic)

How do you perform a thoracocentesis

7-9 intercostal space cranial to the rib with the bevel angled flat to lungs (so you don’t stab the lungs) with a 3 way stopcock and quantitate the amount

If repeated thoracocentesis are required what should you do

Place a chest tube

What is the best lung function test

Arterial blood gas

What is your QATS (quick assessment tests) or STAT database of initial diagnostics

PCV/TS/BG/Lactate/Azo-stick/blood smear

BP

TPR

ABG/VBG

ECG

± throacocentesis

What are diagnostic tests you should do after initial stabilization

CBC/Chem/UA

Monitor (BP, urine output, pulses)

Imagining (POCUS, rads, ± contrast studies)

What can arterial blood gas tell you

Acid base status and A-a gradient (to assess V/Q mismatch)

What does flail chest cause

Paradoxical chest wall motion (ribs move in during inspiration and out during expiration)

Open pneumothorax

How do you treat flail chest

Oxygen

Local blocks + systemic pain control

Keep animal on effect side down on table and place bandage on opening

Sx to fix after stabilization

What sign should you see on POCUS on the pleural wall

Glide sign (motion of the visceral and parietal pleural rubbing past each other)

What is most likely the cause of a loss of glide sign on POCUS

Pneumothorax

What pulmonary injury should be assumed in all dogs with thoracic trauma

Pulmonary contusions (can see increased lung sounds, coughing or hemophysis)

How can you iatrogenically cause pneumomediastinum in cats

If you extubate without deflating the cuff you can rip the trachea an cause a hole in the mediastinum

Which arrhythmias can you expect with traumatic myocarditis and myocardial contusions

VPCs, V tach, AIVR

How can blunt trauma lead to hemopericardial effusion

It causes rupture of the atria and bleeding in the pericardium

What can cause a diaphragmatic hernia

Blunt thoracic trauma or penetrating trauma causes rapid compression of abdomen with force directed cranially

How do diaphragmatic hernias present

Can present years later

Decreased ventral/diffuse lung sounds

Borborygmi on thoracic auscultation

± pleural effusion

What is CT good to evaluate for

Bullae and blebs

<3mm masses

What can restrictive respiratory pattern cause

Decrease compliance of lungs

Atelectasis

V/Q mismatchArterial hypoxia

Myocardial dysfunction

Lactic acidosis

Hypercarbic acidosis

Hypoxic pulmonary vasoconstriction

Pulmonary hypertension

R heart compromise and failure

What are the different types of pneumothorax

Open or closed

Traumatic, spontaneous, iatrogenic

What can be seen with closed pneumothorax

On impact the chest is compressed with closed glottis causing a tension pneumothorax

Pneumomediastinum, pericardial effusion, rib fractures

Which animals is spontaneous pneumothorax usually seen in

Deep chested large breeds and Huskies

What causes tension pnuemothorax

There is a one way valve that will close when the lung collapses throwing off the pressure of the thorax leading to tension → this will progress to death rapidly

What can cause spontaneous pneumothorax

Cavitary lesions (blebs, bullae, poneumatoceles, cysts, abscess, granuloma)

Foreign body

Pneumonia

Chronic granulomatous infection

Neoplasia

Asthma/idiopathic bronchitis

What is the difference in a bleb and bullae

Bleb- air accumulation in visceral pleural

Bullae- result of destruction, dilation, convergence of alveoli secondary to obstruction of small airways

What can cause iatrogenic pneumothorax

FNA, intubation, ventilation, chest taps/tubes, chronic effusion

What type of effusion looks like red wine with cottage cheese

Pyothorax

What type of effusion looks like a pink milkshake

Chylothorax

How can neoplastic effusions look

Black

What can lead to hemothorax

Disruption of vessels (pulmonary, thoracic, mediastinal)

Diaphragmatic hernia

What is important to consider when tapping a chest of a dog with hemothorax

Leave some blood to clot and fix it up

Herniation of abdominal esophagus, stomach, or gastroesophageal junction through the esophageal hiatus.

Hiatal hernia

Congenital defect between the pleural and peritoneal cavities.

Pleuroperitoneal hernia

Fibrous attachments between herniated organs and thoracic structures, common in chronic cases

Adhesions

Surgical repair of the diaphragmatic defect.

Herniorrhaphy

Surgical incision into the abdominal cavity, commonly used for repair

Celiotomy

Surgical approach through the chest, used in select cases.

Thoracotomy

Return of herniated organs to the abdominal cavity.

Reduction

Potential complication following rapid lung reinflation.

Postoperative re-expansion pulmonary edema

Which injury in thoracic trauma causes progressively worsening dyspnea is considered life-threatening and often requires immediate intervention?

Tension pneumothorax

A dog presents after a car accident with labored breathing, paradoxical chest wall movement, and multiple rib fractures. What is the most likely diagnosis?

Flail chest

Where are the alar folds in the horse?

Bulbous thickening of the ventral nasal concha that projects into the nasal vestibule that lies within the false nostril. They form the ventral and medial boundaries of the false nostril, dividing the nostril into two compartments — the true nostril (ventral) and the false nostril (dorsal). They are supported by the medial ala of the alar cartilage, which creates the structural base from which the alar fold extends and play a role in airflow dynamics during breathing and exercise.  

Where are the ethmoid turbinates located in the horse?

Located in the caudal (rear) portion of the nasal cavity, forming part of the ethmoidal labyrinth of the ethmoid bone, close to the cribriform plate. They project from the dorsal and lateral walls of the ethmoid and extend forward into the nasal cavity. They contribute to the olfactory region, with their surfaces covered by olfactory and respiratory mucosa.

They are why it is important to place a nasograstric tube through the ventral meatus – otherwise you will hit the ethmoids and cause a nosebleed.

What is the relationship of the epiglottis to the soft palate in the horse?

In horses, the epiglottis normally sits above the soft palate, with the soft palate cupping tightly around its base. This creates a mechanical lock, dividing the pharynx into separate respiratory and digestive pathways. During swallowing the soft palate briefly elevates and the epiglottis flips up to protect the airway (rima glottis), allowing food to pass into the esophagus. The structures then promptly return to their locked resting position.

What the relationship of the epiglottis to the soft palate mean for the horse regarding its breathing?

Because of the unique anatomical relationship between the epiglottis and the soft palate, the horse becomes an obligate nasal breather, meaning it can only breathe through its nose.

Because of this locked arrangement, the only airway pathway available is:

nostrils → nasal cavity → over epiglottis → trachea → lungs.

This arrangement is why horses cannot pant or switch to oral breathing even during intense exertion.

The fixed nasal-only breathing route provides a long, straight pathway for airflow, which helps maximize oxygen delivery during galloping. This is one reason horses can sustain high-speed exercise.

Describe the locations of tonsillar (lymphoid) tissue in the horse and explain how this distribution differs from that of species with discrete tonsils such as humans.

Horses do not possess a single, discrete tonsil like humans. Instead, they have diffuse aggregates of lymphoid tissue throughout the pharynx. Tonsillar tissue in the horse forms part of a lymphoid ring and is found in several areas, including the pharyngeal tonsil in the nasopharynx, diffuse palatine tonsils in the oropharyngeal walls, tonsillar tissue on the ventral soft palate, tubal tonsils around the opening of the auditory tube, and lingual tonsils at the root of the tongue. This tissue is very active in young horses developing their naïve immune system and can lead to a condition called lymphoid hyperplasia.

What percentage of thoracic trauma result in pulmonary contusions

55%

What percentage of thoracic trauma result in pneumothorax

47.1%

If dogs HBC have forelimb trauma they are likely to have what

Chest trauma (38.9%)

If a dog is HBC on the rear end what is likely

Bladder/urethra rupture

What is a pneumothorax

An emergent condition caused by air leaking into the pleural space thereby restricting lung expansion and eventually causing lung collapse

What diagnostic test is helpful for pneumothorax

Rads

Why can the heart appear floating on a chest X ray in pneumothorax

Loss of support from the adjacent collapsed lung (causes the heart to rotate downward increasing the distance of the apex from the sternum)

What is the name of a normal lung sound

Vesicular murmur is the normal lung sound auscultated

What are useful instruments for thoracic surgery

Rib spreaders (must place lap sponges between them and tissue to keep moist)

What tool is used to evacuate what is free in the thoracic cavity

Thoracostomy tube

What causes a spontaneous pneumothorax

Rupture of bullae or bleb

How can a tension pneumothorax cause changes to the ECG

Accumulated air compresses the lungs and shifts the mediastinum and therefore the heart

What is the main difference between a closed pneumothorax and a tension pneumothorax

A tension pneumothorax involves progressive pressure buildup that compresses mediastinal structures unlike a closed pneumothorax

What is the difference between blebs and bullae

Bleb- <1cm and on edge of lung

Bullae- >1cm and centered in lung

What is another term for tension pneumothorax

Hypertensive pneumothorax

What is the treatment for a mild pneumothorax

Cage rest and observation

What is the treatment for a moderate pneumothorax

Thoracocentesis initially to get the negative pressure back

What is the treatment for a severe pneumothorax

Tube thoracostomy and exploratory thoracotomy

What can cause an open pneumothorax

Penetration or rupture of chest wall: bite wound, stab wound, gunshot wound, impalement, inadequate closure

Should you remove the impaled object

NO: keeping the object in place may aid ventilation by maintaining negative pressure within the chest (removing could lead to respiratory collapse)

What should you do if you suture up a big incision on the chest

Place a drain

What is a special catheter that can be helpful for thoracocentesis

Turkel catheter