Exam 2 - Approach to the Dyspneic Patient Flashcards
what is tachypnea?
increased respiratory rate
what is dyspnea?
increased respiratory effort
what is orthopnea?
body position used to ease breathing - elbows abducted, extended neck, & open mouth
what is hypoxemia?
low partial pressure of oxygen in arterial blood, <80mmHg
what are signs of dyspnea?
open mouth breathing (especially in cats), vigorous chest excursions, flaring nostrils, using abs to breath, orthopnea, cyanosis
if a patient is in respiratory distress, what should be done?
urgent & emergent treatment
often empirical therapies
what is reverse sneezing?
paroxysms of abrupt inspiratory effort (snorts) that indicates obstruction/irritation of the nasopharynx
what is the general presentation of a patient experiencing reverse sneezing?
patient is standing with the neck extended, head tilted backward, lips pulled back, & nostrils flared
event may last seconds to minutes and is distressing to owners
during the distance exam of a patient in respiratory distress, what should be determined first?
the phase in which difficulty is occuring
if an animal has inspiratory dyspnea, what anatomic locations are typically involved?
upper respiratory tract & pleural space
what are the clinical signs of inspiratory dyspnea?
long inspiratory time & short shallow breaths
if an animal has expiratory dyspnea, what anatomic locations are typically involved?
lower airways
what is the difference between stertor & stridor?
stertor - snore, upper respiratory tract, above the thoracic inlet
stridor - high-pitched coo sound, narrowed larynx, almost always laryngeal disease
if an animal has both inspiratory & expiratory dyspnea, what anatomic locations are typically involved?
bronchioles, alveoli, or pulmonary interstitium
upper respiratory tract disease is often associated with a _______ inspiratory phase & will often have audible noise
prolonged
what causes stertor?
turbulent airflow - localizes lesions to the upper respiratory tract
what causes stridor?
airflow through a narrowed larynx - indicative of laryngeal disease
what is included in ‘pleural space disease’?
pleural effusion, pneumothorax, & diaphragmatic hernias
what is a restrictive breathing pattern? what is it associated with?
short, shallow breathing pattern
pleural space disease - increased inspiratory effort
what is increased expiratory effort indicative of?
small airway disease
what causes increased expiratory effort associated with small airway disease?
air is trapped in the lungs
small airway disease is most commonly due to what condition?
feline asthma - may occur with other disorders such as severe collapse of mainstem bronchi
a patient with both inspiratory & expiratory effort is common with what disease?
disease of the bronchioles, alveoli, or pulmonary interstitium
or metabolic disease
upon thoracic auscultation, decreased lung sounds indicate what disease?
pleural space disease
T/F: crackles heard upon thoracic auscultation is specific for cardiogenic pulmonary edema
false
what are ‘crackles’ in regards to thoracic auscultation?
popping sound heard on inspiration
what causes the ‘crackles’ sound?
fluid in the bronchioles or alveoli
what are the risks associated with using an oxygen hood for your patient?
risk of CO2 accumulation, risk of overheating, & requires 24-hour supervision
what causes oxygen toxicity?
100% oxygen for more than 12 hours
what is the pathogenesis of oxygen toxicity?
free radical formation - endothelial & epithelial damage occur
gentle palpation of the ventral cervical region may elicit a cough in patients with what condition?
tracheal irritation - infectious tracheobronchitis or tracheal collapse
T/F: hyperthermia may develop secondary to upper respiratory disease
true
what factors should be considered when supplying oxygen to a patient in respiratory distress?
available options, minimizing stress, & severity of hypoxemia
when is mechanical ventilation required in a patient in respiratory distress?
conventional oxygen therapy fails or patient has impending respiratory fatigue
what are the pros & cons of using flow-by oxygen for your patient?
pros - simple, available, & allows patient handling
cons - requires a person to hold the patient & tubing & only a short-term option
what are the pros & cons of using a face mask when supplying oxygen for your patient?
pros - better oxygenation than flow by, simple, available, patient handling
cons - not tolerated by some animals, short-term option, & requires a person to hold the tubing & patient
what are the pros & cons of an oxygen hood for your patient?
pros - no special equipment (use an e-collar), better tolerated than a mask, & doesn’t require restraint
cons - careful monitoring, CO2 accumulation, & risk of overheating
what are the pros & cons of using an oxygen cage for your patient?
pros - well tolerated, no restraint, can monitor visually, temperature & humidity control
cons - cost, availability, no access to the patient because oxygen concentration drops when the door is opened
what are the pros & cons of using a nasal cannula for supplying oxygen for your patient?
pros - minimal equipment, easy to place, well tolerated most of the time, & no ongoing restraint
cons - more invasive, less effective if panting, & requires a humidified oxygen source
what are the pros & cons of using high flow oxygen therapy for your patient?
pros - non-invasive & useful when other methods are not effective
cons - special equipment required
what are the pros & cons of using positive pressure ventilation for your patient?
pros - provides ventilation & useful when other methods fail
cons - special equipment required & need staff trained for chronic therapy
why should IV access be established in a patient in respiratory distress?
allow administration of therapeutic drugs & to induce anesthesia if intubation is required
sedatives/anxiolytics are especially helpful in patients with what disease? why?
upper respiratory tract disease patients
help reduce stress associated with respiratory difficulty
what sedatives/anxiolytics are commonly used in patients with respiratory distress?
low dose butorphanol & acepromazine
what animals are predisposed to developing hyperthermia with respiratory distress?
dogs with upper respiratory tract disease, brachycephalic breeds, & dogs with laryngeal paralysis
what are some differentials for upper airway disease?
intraluminal masses, extraluminal masses, trauma, foreign bodies, laryngeal paralysis, BOAS, & extrathoracic tracheal collapse
why is secondary edema a problem in upper airway disease?
edema of the tissues can develop secondary to the disease & further increase the resistance to airflow
what should be done if your dyspneic patient remains in distress after oxygen supplementation, sedative administration, & anti-inflammatories have been given?
emergency intubation
what is the general pathogenesis of lower airway disease?
narrowing of the lower airways causes increased resistance & effort during exhalation & may result in an expiratory push
what is the general history of an animal with suspected lower airway disease?
chronic history of coughing - especially in dogs
T/F: it is common for dogs to have an expiratory push with chronic bronchitis
false - uncommon
what are the main differentials for lower airway disease in dogs & cats?
cats - feline asthma
dogs - collapse/compression of mainstem bronchi
what may be considered for empirical treatment in cats with suspected lower airway disease?
empirical administration of a bronchodilator - injectable aminophylline or terbutaline
empirical administration of a glucocorticoids - if feline asthma is suspected
what may be considered for empirical treatment in cats with suspected feline asthma?
empirical administration of glucocorticoids
T/F: in pulmonary parenchymal disease, they are often signs of both increased inspiratory & expiratory effort & may have other systemic signs present
true
what are the general differentials for pulmonary parenchymal disease?
cardiogenic edema, non-cardiogenic pulmonary edema, pneumonia, & pulmonary hemorrhage
what drug can be given in a patient with pulmonary parenchymal disease if you suspect left-sided heart failure?
furosemide
what is commonly heard on thoracic auscultation in a patient with pulmonary parenchymal disease?
crackles in the lungs
what does PTE stand for?
pulmonary thromboembolism
what is a pulmonary thromboembolism?
life-threatening disorder where a thrombus obstructs a pulmonary vessel or vessels
what is the clinical presentation of an animal with suspected PTE?
acute, severe respiratory distress with normal pulmonary auscultation
what is PTE associated with?
diseases that cause hypercoagulability
what is the general pathogenesis of pleural space disease?
accumulation of fluid, air, or tissue reduces functional residual capacity & lung expansion
what is the clinical presentation of an animal with suspected pleural space disease?
increased inspiratory effort with shallow breaths (restrictive breathing pattern) & decreased lung/heart sounds on thoracic auscultation
typical pleural effusion results in muffled _____ lung sounds & pneumothorax causes muffled ____ lung sounds
ventral
dorsal
what are the differentials for pleural space disease?
pleural effusion, pneumothorax, & diaphragmatic hernia
if your patient has pleural effusion, what else should you evaluate for?
pericardial effusion
what location is an emergency thoracocentesis performed on the patient?
side of the thorax where fluid is suspected based on ultrasound/auscultation
7-8th intercostal space - ventrally for fluid & dorsally for air
if the fluid collected from a thoracocentesis is bloody, what should you run next?
PCV of the fluid & patient’s peripheral blood
what are some potential complications of thoracocentesis?
hemorrhage, infection, pneumothorax, lung puncture, & cardiac puncture
what are your main differentials for thoracic wall disease?
trauma (flail chest) or neuromuscular disease
what is the typically clinical presentation of an animal with thoracic wall disease?
lack of chest wall movement or a paradoxical breathing pattern
why don’t animals with thoracic wall disease respond to oxygen supplementation?
their primary problem is ventilation - consider mechanical ventilation
when running diagnostics on a dyspneic patient, what should be considered?
may not be appropriate until after the patient is stabilized
should be selected & performed in a step-wise order to obtain a diagnosis without jeopardizing patient stability
what are the pros of using SpO2 for monitoring?
non-invasive option that provides a crude estimate of PaO2
instrument also measures a pulse so it can be matched to patient’s peripheral pulse
what is a normal SpO2? what is an abnormal SpO2?
normal - >97%, correlates with a PaO2 of 80-100mmHg
abnormal - 90-95%, correlates with a PaO2 60-80mmHg
what does it mean if there is a discrepancy between the pulse oximeter & your patient’s peripheral pulse?
discrepancy - pulse ox reading is invalid
what can affect results of the pulse ox?
probe positioning, patient movement (respiration/shivering), weak or irregular pulses, vasoconstriction, & anemia
what is the gold standard for assessing patient oxygenation?
arterial blood gas
why is arterial blood gas measurements the gold standard for patient oxygenation?
allows evaluation of acid-base & actual patient oxygenation
what does it mean if you have an arterial blood gas reading of PaO2 <80 mmHg? what if it’s PaO2 <60 mmHg?
PaO2 <80 - hypoxemia
PaO2 <60 - severe hypoxemia
in response to a metabolic acidosis, how does the respiratory system compensate?
hyperventilation to decrease PaCO2
in response to a metabolic alkalosis, how does the respiratory system compensate?
hypoventilation to increase PaCO2
what are the pros & cons of using thoracic radiographs for the dyspneic patient?
pros - readily available & allows for assessment of airways & cardiopulmonary structures
cons - stress of positioning can result in respiratory decompensation & respiratory/cardiac arrest
what are the pros & cons of using ultrasound for the dyspneic patient?
pros - TFAST scan to look for pleural effusion/pericardial effusion/pneumothorax, VETBLUE to look for b-lines (lung rockets) that indicate fluid/cells in the interstitium or alveoli
cons - none listed
how can ultrasound be used to evaluate the heart in the dyspneic patient?
measure left atrial-to-aortic-root ratio
normal - 1:1
abnormal - >1.5, suggests CHF in cats
what is a proBNP?
measures the n-terminal fragment of the proBNP which is released during myocardial stretch
what is proBNP used for?
help differentiate cardiac from non-cardiac causes of respiratory distress in cats
what other conditions may have a release of proBNP?
pulmonary hypertension, arrhythmias, renal disease, & systemic hypertension due to myocardial stretch
what parasite tests may be used in a dyspneic patient?
heartworm snap tests to look for antigens in dogs & antibodies in cats
lung worm antigen snap tests for cats
if available, why may a thromboelastography or viscoelastic coagulation monitor be useful in a dyspneic patient?
help support the diagnosis of pulmonary thromboembolism
what oxygen supplementation provides up to 100% inspired oxygen with continuous positive airway pressure without intubation?
high flow oxygen therapy
how is a nasal oxygen cannula placed?
topical anesthetic applied to nostril
measure distance of nostril to medial canthus
apply water soluble lube to cannula
insert to the pre-marked distance
secure with suture or glue
put an e-collar on the patient
