Respiratory tract therapeutics Flashcards
Goal of oxygen therapy is to
increase the fraction of inspired oxygen FiO2.
▪ Improves oxygen delivery, decreases the risk of organ damage due to hypoxia.
Any animal with respiratory difficulty, any animal in shock should get oxygen.
▪ Especially when PaO2 < 70 mmHg, SpO2 < 93%.
Methods of O2 administration:
▪ Face mask, flow-by, oxygen collar, oxygen cage, nasal oxygen catheter, mechanical ventilation.
NB Oxygen is no wonder drug, it can be toxic!
Describe flow-by oxygen therapy.
▪ Keep the oxygen tube as close as you can
▪ Easy, well tolerated, for short term emergencies
▪ An Oxygen flow rate of 2-3l/min gets you 25-40% FiO2.
Describe face mask oxygen therapy.
▪ Place a mask over the muzzle
▪ Easy, higher FiO2 than in flow-by (>40%).
▪ Do not place a mask that is too small and tight!
Describe oxygen collar O2 therapy.
▪ Easily made
▪One size bigger collar, wrap 75% of the opening, tape oxygen tube ventrally.
▪Not for panting dogs, risk of hyperthermia
▪ Flow rate approximately 1l/10kg/min
Describe nasal oxygen catheter O2 therapy.
▪ For long-term use in hospital setting.
▪ Catheters simple to place,
minimal equipment, well tolerated.
▪ Needs Humidified oxygen source!
▪ Flow rate maximum 1l/10kg/min
Describe oxygen cage O2 therapy.
▪ Long-term use in hospital setting, expensive.
▪ Pro is Administration of a known FiO2
Describe corticosteroids in resp. patients.
▪Reduce inflammation by inhibiting the production of inflammatory mediators and decreasing the migration of inflammatory cells to the airways.
▪Injectable, oral, inhaled steroids avail.
▪ Short-acting oral steroids preferred over long-acting steroids.
▪ Prednisolone preferred over injectable methylprednisolone acetate.
▪Dose and treatment length depend on the individual, severity of the disease, response to treatment, side effects.
Indications for use of Injectable corticosteroids. (2)
Give two drug examples, doses if you remember them.
▪ Emergency treatment for upper airway
obstruction
▪ Emergency treatment for feline asthma/bronchitis
▪ Dexamethasone 0.1-1 mg/kg iv, long-acting
▪ Hydrocortisone 5-10 mg/kg iv, rapid-acting
Indications for use of oral corticosteroids in cats vs dogs. (1+4)
Give two drug examples, doses if you remember them.
Long-term management of inflammatory airway diseases:
▪ Cats: Feline asthma/bronchitis
▪ Dogs: Chronic bronchitis,
eosinophilic bronchopneumopathy,
idiopathic pulmonary fibrosis?,
tracheal collapse
Prednisolone po is preferred over prednisone.
▪ Feline asthma: 1-2mg/kg BID for 1-2 weeks, then gradually taper down.
▪ Canine chronic bronchitis: 0,5-1mg/kg BID 1 week or until signs resolve, then gradually taper.
▪ Canine eosinophilic bronchopneumopathy: 1mg/kg BID for 2 weeks, then gradually taper down.
Indications for use of inhaled corticosteroids in cats vs dogs. (1+2)
Give two drug examples, doses if you remember them.
Long-term management of inflammatory airway diseases:
▪ Cats: Feline asthma/bronchitis
▪ Dogs: Chronic bronchitis,
eosinophilic bronchopneumopathy
▪Minimal systemic adverse effects compared to oral medications.
▪ Fluticasone or budesonide metered dose inhaler, fitting facemask and chamber!
Give two drug examples of inhaled corticosteroids commonly used in small animals.
Fluticasone & budesonide (metered dose inhalers)
Describe Aerokat® and Aerodawg®
Brand of small animal corticosteroid Inhalation chamber and facemask.
▪May take several days up to two weeks
before full effect.
▪Use oral corticosteroids to start treatment
if immediate treatment needed.
Describe Inhaled fluticasone.
▪ 50µg, 125µg or 250µg/puff concentrations available
▪Dose depends on the severity of the disease and the size of the animal.
Cats: 50-125µg/puff, 1 puff BID starting dose.
Dogs: 125µg/puff, 1 puff BID < 10kg starting dose
and
250 µg/puff, 1 puff BID > 10kg starting dose
Antibiotics and the dyspneic or respiratory patient.
▪Not all coughing animals require antibiotic treatment
▪ Viral infections common!
▪Ideally, antibiotic choice should base on bacterial culture of a respiratory sample and antibiotic sensitivity testing which is Often not possible!
▪ Know what are the most common bacteria are, make an empirical choice, consider your patient characteristics.
Bacterial pneumonia typically presents with the following:
▪ Animal systemically ill, respiratory distress, elevated CRP (dogs), +/- fever,
+/- leukocytosis, left shift, neutrophilia, leukopenia
▪ Alveolar pattern in thoracic radiographs (typical in dogs)
Bacterial tracheobronchitis typically presents with…
▪ Persistent cough, more common in young dogs, otherwise bright and alert
Pyothorax is a
▪ Bacterial infection of pleural cavity with free, highly cellular, bad-smelling fluid in pleural cavity (Intracellular bacteria).
Common pathogens and Antibiotic choice for dogs with bacterial pneumonia.
▪ Pasteurella, Klebsiella, E. coli, Streptococcus, Staphylococcus,
Bordetella bronchiseptica
Mild disease: Doxycycline po / trimetoprim sulfonamide po / amoxicillin-clavulanate po
Severe disease: Ampicillin + enrofloxacin iv / amoxicillin-clavulanate iv
Antibiotic choice for Bacterial tracheobronchitis (Bordetella bronchiseptica!) in dogs. (3)
▪ Doxycycline po / trimetoprim sulfonamide po / amoxicillin-clavulanate po
Cats with Respiratory infections caused by Mycoplasma, Pasteurella, Bordetella, Streptococcus spp., Stapyhylococcus spp., Escherischia coli.
Whats your antibiotic choice?
Mild disease: Doxycycline po / amoxicillin-clavulanate +/- fluoroquinolone po
Severe disease: Ampicillin + enrofloxacin iv
Dogs with Pyothorax. What pathogens may be at play?
Whats your AB choice?
Broad spectrum, both aerobe and anaerobe coverage
▪ Pasteurella spp. Actinomyces spp., E. coli, Nocardia spp. Streptococcus spp., Staphylococcus spp., Corynebacterium, Bacteroides, Fusobacterium
Choose Ampicillin or clindamycin + enrofloxacin iv.
Cats with Pyothorax. What pathogens? Whats your AB choice?
Broad spectrum, both aerobe and anaerobe coverage.
▪ Pasteurella spp. Clostridium spp., Fusobacterium spp, Bacteroides spp., Actinomyces spp., Peptostreptococcus spp., Mycoplasma spp. …
Choose Ampicillin or amoxicillin-clavulanate.
When are bronchodilators needed?
Emergency treatment for asthmatic attack in cats.
+ Long term management of Cats with asthma/bronchitis which continue to have symptoms despite corticosteroid treatment.
May be tried in dogs with airway disease. but NB! In dogs, Reversible smooth muscle contraction leading to bronchoconstriction is not a feature in dogs with airway disease.
Name 2 groups of bronchodilators.
Methylxanthines and ß-2 agonists.
Name and Describe a methylxanthine + dosages.
Theophylline po
▪ Relatively weak bronchodilator, not for emergency use
Additional benefits:
▪ Increases diaphragmatic strength, reduces respiratory effort, stimulates mucociliary clearance (dogs).
Dosages:
▪ Extended release 10mg/kg BID dogs, 100mg/cat SID or eod (?)
Low therapeutic index
Consider drug interactions!
▪ NB Reduce dosage or discontinue when on enrofloxacin
Name and Describe a beta-2 agonist bronchodilator + dosages.
Parenteral terbutaline
▪ Fast and short-acting
▪ Emergency treatment for asthmatic attack in cats 0.01mg/kg iv, im, sc, can be repeated once after 30 min if no effect
Name 2 inhaled options for corticosteroids.
ß-2 agonists:
▪Salbutamol inhalation (also called albuterol) or Combined salmeterol/fluticasone –inhalation
Describe Salbutamol inhalation (also called albuterol).
▪ Fast-acting
▪ Proinflammatory in cats! Only use for rescue!
▪ Cats: One 100 µg puff when asthmatic attack, can be repeated in 30 min
▪Dogs: 1-2 puffs of 100 µg BID-TID
Describe Combined salmeterol/fluticasone –inhalation
▪ Longer acting
▪ Cats: E.g. 25µg/125µg 1 puff BID
▪Dogs: as in cats if < 10 kg, 2 puffs BID if > 10 kg
Describe Cough suppressants in small animals.
Palliative treatment when cough is disturbing sleep or exhausting the dog
▪ Centrally acting antitussives inhibit cough reflex
▪ Do not use if cough is productive
▪Maropitant suppresses cough in dogs
- detromethorphan
- butorphanol
- hydrocodone
Describe mucolytics in small animals.
Makes secretions more watery and easier
to cough/sneeze out.
▪ Saline drops to nostrils in rhinitis
▪ Saline nebulization with a nebulizer
▪ Nebulizer turns liquid into mist
▪ N-acetylcysteine?
Sedation of respiratory patients.
▪Light sedation useful in dyspneic patients:
stress increases oxygen demand!
▪ Consider short-acting drugs with minimal respiratory effect
Butorphanol
▪ Light sedative and cough suppressant
▪ Dogs: 0.1-0.4mg/kg iv, 0.25-0.5mg/kg sc, im
▪ Cats: 0.10-0.25mg/kg iv, 0.2-0.4 mg/kg im
Acepromazine may be used in dogs if otherwise healthy.
Do not use medetomidine or dexmedetomidine!
