Cardiorespiratory Emergencies Flashcards
What are some possible causes of tachypnoea/dyspnoea?
Physiological - stress, pain, excitement, exercise
Hypoxaemia, hypercapnia
Resp. disease
Cardiac disease
Describe upper airway dyspnoea.
Nasal passages, pharynx, larynx, trachea
Inspiratory dyspnoea
Stertor (snoring) common with brachycephalics
Stridor (harsh, high-pitched) common with laryngeal paralysis
Abnormal sound easily heard without touching patient
What are some causes of upper airway dyspnoea?
Laryngeal paralysis
Brachycephalic syndrome
Neoplasia
Polyps
FBs
Inflammation
Tracheal collapse
How can we treat upper airway dyspnoea?
If obstructed - anaesthesia and intubation
Decompensation can be rapid
Describe lower airway dyspnoea.
Bronchi, bronchioli
Quick short inspiration, prolonged expiration
Harsh lung sounds on auscultation (wheezes, crackles) - bronchoconstriction, secretions blocking airways
What are some lower airway causes of dyspnoea?
Asthma
Bronchitis
Smoke inhalation
Bronchopneumonia
Chronic obstructive pulmonary disease
Describe lung parenchymal dyspnoea.
Inspiratory and expiratory components
Accordion-like resp. movements
Subtle, hard to recognise
Difficult inspiration and expiration
What are some lung parenchymal causes of dyspnoea?
Pulmonary oedema (cardiac e.g. CHF or non-cardiac e.g. electrocution/strangulation)
Pneumonia
Haemorrhage (RTA, rat poisoning etc.)
Contusion
Neoplasia
Thromboembolism
Parasites
Describe pleural space dyspnoea.
Restrictive pattern of breathing
Increased rate but reduced depth because lungs cannot expand
On auscultation: muffled heart and lung sounds ventrally, normal lung sounds dorsally
What are some pleural space causes of dyspnoea?
Pneumothorax
Pleural effusion
Masses
Diaphragmatic hernia
What are some causes of pleural effusions?
Haemorrhage
Infection (pyothorax)
Neoplasia
Heart failure
Chylothorax
How should we carry out the initial clinical exam of respiratory patients?
Oxygen supplementation
Physical exam
Upper resp. tract? - stridor/stertor
Resp. rate and effort
MMs
HR, arrhythmias, heart murmurs
Peripheral pulses
What are some methods of supplementing oxygen?
Flow-by
Mask
Nasal prongs
Oxygen catheter
Collar
Oxygen cage
Intubation/ventilation
How can we begin to diagnose and stabilise pleural effusion/pneumothorax?
Physical exam, thoracic radiographs/ultrasound (more common due to positioning allowing patient to breathe comfortably)
Thoracocentesis - sedate, collect samples for cytology/culture/biochem
What should we be monitoring in respiratory patients?
Physical exam (HR, RR and effort, MMs, peripheral pulses)
Arterial blood gas (PaO2 ideally 80-120mmHg)
Pulse oximetry (ideally >90%)
Describe the difference between left- and right-sided CHF.
Left-sided = pulmonary veins, fluid collects in lung tissue then alveoli
Right-sided = systemic veins (cranial and caudal vena cava), effusions outside organs e.g. ascites/pleural/pericardial effusion
What are the common causes of CHF in dogs?
Left-sided - myxomatous mitral valve disease, dilated cardiomyopathy
Right-sided - pericardial effusion
Congenital heart disease in young dogs
What are the common causes of CHF in cats?
Biventricular failure - hypertrophic cardiomyopathy
What can cause reduced cardiac output (forward failure)?
DCM, end-stage heart disease
What are the clinical signs of left-sided CHF?
Heart murmur?
Tachypnoea/dyspnoea
Tachycardia
Pale MMs, prolonged CRT
Arrhythmias?
Weak peripheral pulses, pulse deficits?
How do we approach left-sided CHF patients?
History-taking
Physical exam
Stabilise BEFORE performing diagnostics - very fragile and may decompensate
How can we stabilise left-sided CHF patients?
Minimise stress - consider sedation e.g. butorphanol
O2 supplementation
Furosemide IV - diuretic for pulmonary oedema
Pimobendan PO/IV - improves myocardial contractility / stroke volume / cardiac output
What diagnostic tests can we run for left-sided CHF?
Echocardiography - diagnosis, severity
Thoracic radiography - pulmonary oedema
Electrocardiography - arrhythmias
Blood pressure measurement - hypotension
Blood tests - electrolytes, renal parameters
What should we monitor when stabilising left-sided CHF patients?
RR and effort - aim for <40brpm
BP - concern if systolic <80mmHg
HR and pulse quality
ECG if arrhythmias detected
Radiographs if no improvement
How do we manage left-sided CHF patients once they are stabilised?
Life-long medications
Feed ASAP - cardiac cachexia (lose bodyweight/muscle mass)
Revisit for blood tests/echocardiography etc.
What are some causes of right-sided CHF?
Pulmonic stenosis
Tricuspid dysplasia
Pericardial effusion
How can we diagnose right-sided CHF?
History, physical exam
Echocardiography - diagnosis, neoplasia
Thoracic radiography - heart size
Electrocardiography - arrhythmias
CT - neoplasia
Describe pericardial effusion.
Increased fluid in pericardium
Right atrium collapses due to increased external pressure (tamponade)
Filling of right side of heart impaired (leads to impaired filling of left side) - decreased cardiac output
How can we stabilise patients with pericardial effusion?
Pericardiocentesis
IV fluid administration - increase venous return
How do we carry out pericardiocentesis?
Mild sedation
Left lateral recumbency
Prepare area 3rd-8th intercostal space
Echo to guide needle
Send samples in EDTA for cytology
How do we treat pericardial effusion post-stabilisation?
Hospitalise for 12-24hrs
Monitor for improvement of parameters e.g. HR, pulse strength, demeanour, arrhythmias
Unpredictable recurrence - owners know what to look out for in future!
What clinical signs can cats in heart failure present with?
Murmur (can be stress-related or not present)
Gallop sound (more specific for heart disease but may be not present)
Tachypnoea, dyspnoea, open-mouth breathing
Tachy/bradycardia
Weak peripheral pulses
Hypothermia
How do cats with ATE present?
Sudden-onset hindlimb paresis/paralysis
Often hard gastrocnemius (essentially rigor mortis in legs)
Five Ps - Pain, Pallor/cyanosis (purple) of pads and nail beds, Paresis/paralysis, Pulselessness, Poikilothermy (cold leg)
How can we stabilise cats with cardiac emergencies?
Avoid stress!
O2 supplementation
Furosemide IV/IM - pulmonary oedema
Drain pleural effusion
Gentle warming
Analgesia!
How can we diagnose feline cardiac emergencies?
Echocardiography - diagnosis, severity
Thoracic radiography - pulmonary oedema
Electrocardiography - arrhythmias
BP measurement - hypotension
Bloods - electrolytes, renal parameters
How can we treat cats post-stabilisation of a cardiac emergency?
Lifelong treatment
Offer food
Thromboembolism - warm soft bedding, physiotherapy
Home ASAP - minimise stress, monitor appetite
Revisit for blood tests
Guarded prognosis, can die suddenly
What are the normal HRs for dogs and cats?
Dogs = 60-160bpm
Cats = 160-220bpm
How can patients with arrhythmias present?
Syncope/collapse
Weakness/exercise intolerance
Signs of CHF
Abnormal heart rhythm - irregular, too fast/slow
Weak peripheral pulses, pulse deficits
Describe 3rd degree AV block.
Bradyarrhythmia, HR 40bpm
P and QRS not associated
Describe ventricular tachycardia.
HR 300bpm
Some normal complexes present
Some wide and bizarre complexes
