Signs of respiratory disease Flashcards
List signs of respiratory disease - 7
Coughing and bronchoconstriction Sneezing Tachypnoea and hyperpnoea Respiratory distress (dyspnoea) Nasal discharge, epistaxis and haemoptysis Cyanosis Abnormal respiratory noise (stridor)
Define bronchoconstriction
constant component of cough but separate reflex. slower onset and longer lasting may increase efficiency of coughing
What 2 main drugs can target coughing?
Demulcents - to soothe irritant receptors
Opioid-R agonists - butorphanol, codeine
What is the neural basis of coughing?
Irritant receptors through tracheobronchial tree. Afferent input carried in vagus. Cental cough centre in brainstem. Efferent motor side: vagus, phrenic, intercostal, lumbar, trigeminal, facial hyoglossal and accessory nerves/
List stimuli for coughing - 7
bronchoconsctriction excessive mucous inhaled particles cold or hot air intramural/extramural pressure epithelial sloughng enhanced epithelial permeability
Typical cough - upper airway problem
harsh, loud, non-productive
Typical cough - lower airway problem
soft, muted, productive
Typical cough - painful conditions
more muted cough
What else indicates a productive cough?
swallowing after coughing
Where does sneezing originate?
MM of nasal cavity
What is sneezing a sign of?
Nasal disorders (usually) or can be secondary to more distal disorders
Define tachypnoea
increased RR
Define hyperpnoea
increased RR and depth
Normal RR horse
8-15
Normal RR cow, sheep, pigs
10-30
Normal RR goats
25-35
Normal RR - foal and calf
20-40
Normal RR dog
10-30
Normal RR - cat
24-42
Normal RR - rabbit
30-60
Physiological causes - tachypnoea and hyperpnoea - 4
pain, exertion, heat, anxiety
Pathological causes - tachypnoea and hyperpnoea
high CO2 low pH low O2 compensation (metabolic acidosis) excessive environmental heat damaged/diseased CNS (resp centres) pain/restriction in breathing
Define dyspnoea
subjective feeling (therefore should be humans only) of respiratory distress
Define respiratory distress
laboured breathing, abnormal rate, rhythm and character, nostril flaring, exaggerated intercostal/abdominal effort, abducted elbows, stridor, anxious expression, inactivity.
SOME SPECIES (not horse) - extended head and neck, mouth breathing
Broad causes - inspiratory distress
Extrathoracic non-fixed airway obstruction
Restrictive diseases
What is an Extrathoracic non-fixed airway obstruction?
as negative pressures of inspiration suck them into airway (upper airway obstructions including laryngeal hemiplegia, soft palate disorders)
Give an example of a restrictive disease
pleural effusion - limits lung expansion
What is expiratory distress caused by? Example?
intra-thoracic airway obstruction - such as bronchoconstriction caused by RAO, farmer’s disease (cattle), tracheal collapse (dogs and horses)
What are heaves lines?
in cases of chronic expiratory distress, body wall muscles hypertrophy and this becomes visible as heaves lines.
What is combined inspiratory and expiratory distress caused by?
an extra-thoracic fixed obstruction (intraluminal mass, FB)
Define orthopnoea
difficulty breathing whilst recumbent - pleural fluid accumulation, neonates (pliable ribs), diagphragmatic hernia, CHF
How is nasal discharge characterised?
Serous, mucoid, purulent, sanguinous Combination Ingested food/fluid Scant-profuse Continuous-intermittent Unilateral-bilateral
Where does unilateral nasal discharge tend to originate?
structures rostral to the caudal end of the nasal septum, although low volume discharges from lower in the RespT can be unilateral too.
Where does bilateral nasal discharge tend to originate? 2
Caudal structures OR bilaterally affected rostral structures
What does a foul odour of discharge indicate?
anaerobic infections, necrotising conditions, or connection to oral cavity - tooth root infections
What may food/fluid indicate?
dysphagia or communication between oral and nasal cavities
Define epistaxis
presence of blood in the external nares. Commonest cause in horses = tram
Define haemoptysis
presence of blood in the sputum (i.e. coughed up blood).
Causes - epistaxis and haemoptysis
Trauma
Coagulopathies
Erosive/invasive conditions
EIPH - equines
Look for accompanying signs - stridor (SOL), discharge (purulent or malodorous) and lung disease (cough or auscultate).
Define cyanosis
blue discolouration - skin, conjunctivae, MM - i.e. reflection of RespT problem in the CVS
How low does PaO2 have to fall for cyanosis?
<50mmHg
When is cyanosis present?
Only if [Hb] is normal or near normal. Not with anaemia.
Define polycythaemia
higher than normal [Hb]
Whenare polycythaemic patients cyanotic?
at higher PaO2
When can peripheral cyanosis occur?
poor peripheral perfusion (shock, HF).
Define pulmonary cyansis
= hypoxaemia. (V/Q mismatch, alveolar hyperventilation, shunting, diffusion impairment)
When does cardiac cyanosis occur?
shunting
What is acquired cyanosis?
usually reducing chemical - e.g. acetaminophen, nitrates, red mapleleaf-methaemoglobin
Define stridor. What should be determined?
abnormal, intense respiratory sound heard without a stethoscope. Determine if inspiratory OR expiratory.
What is linked gait and respiration in horses?
expiration when leading forelimb contacts the ground(bt at trot, breathing and stride rate are independent)
Causes - stridor. Examples?
Fixed or dynamic obstructions (laryngeal paralysis, stenotic/paralysed nares, nasal masses, soft palate elongation)
