Respiratory complications 2 Flashcards
partial vs complete airway obstruction
§ Complete
* Inability to move air through airways into the lungs
§ Partial
* Airflow occurs but with increased resistance
examples of upper airway obstructions
- 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
examples of lower airway obstructions
- Bronchioles (bronchitis)
- Infection
- Asthma
- Atelectasis (seen with pneumothorax)
how to diagnose airway obstruction
§ 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
what is paradoxical breathing?
§ 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
what volume of air changes when we have Chronic obstructive pulmonary disease, ie. how does the way we breathe change? (most significant change)
-residual volume increases significantly (volume of air remaining in the lungs after maximum forceful expiration)
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)
all volumes decrease, esp inspiratory reserve and expiratory reserve volume
issues with Brachycephalic Obstructive Airway Syndrome (BOAS)
- 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
breathing issues we see with brachycephalic breeds
Stertor (snoring-like), stridor (high pitch), dyspnea, exercise intolerance, gagging, regurgitation, cyanosis, hyperthermia, syncope
when do complications associated with the breathing apparatus occur for brachycephalic breeds, and what are they?
§ EXTUBATION time is when complications occur
* Obstruction
* Desaturation
* Anxiety
how to extubate brachycephalic breeds to avoid issues
- 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
what is the result of pre-oxygenation and what do we need to do it?
§ 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)
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?
§ 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
mortality causes in horses recovering from anesthesia
fractures most common by far, followed by resp, then myopathy and CNS
why do horses experience myopathy during surgery?
- Due to compression and decreased perfusion of the dependent
muscles (low Mean arterial pressure, low Cardiac output) - Bad positioning/padding
why do horses experience neuropathy during surgery?
- Due to nerve compression
- Bad positioning/padding
When administered intravenously barbiturates cause the following in order of increasing dose resulting in death:
Loss of consciousness, respiratory arrest, followed by cardiac arrest
Hypoventilation is always associated with
an increase in arterial carbon dioxide levels
Side-effects of sedative doses of detomidine when given IV or IM to a horse may include:
An increase in upper airway resistance to breathing, transient increase in blood pressure and bradycardia
Hypovolemic shock in a non-anesthetized patient is noted when a patient has:
Lost ≥ 30% of its blood volume or is 10% dehydrated
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
d. The oscillometric method measures systolic, diastolic and mean blood pressure
