foal resp diseases Flashcards
Neonatal Respiratory Disease of importance to us
▪ NERDS
▪ Congenital abnormalities
▪ EqALI & EqARDS
▪ Aspiration
▪ Trauma
▪ Bacterial pneumonia
▪ Viral pneumonia
Foal Respiratory Diseases of importance to us
▪ Streptococcus equi subspecies zooepidemicus
▪ Rhodococcus equi
when is a foal considered premature? what can cause this?
- resp dysfunction issues?
▪ Generally <320 days
▪ +/- in utero stress
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Respiratory dysfunction:
▪ Surfactant deficiency > would normally develop in week before birth
▪ Decreased respiratory drive
▪ Weak muscles of respiration
▪ Highly compliant chest wall
▪ Poor lung compliance
Neonatal Equine Respiratory Distress Syndrome
- what is the cause?
- diagnosis?
▪ Non-infectious
▪ Etiology- Surfactant deficiency
- super-premature foals are the major at risk population
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Diagnosis
▪ Hypoxemia- PaO2 <60mm Hg
▪ Progressive hypercapnia
▪ 1 or more risk factors
> <290 days of gestation, or <88% of dam’s previous gestation
> Induction of parturition
> Caesarian section
NERDS DIAGNOSTIC CRITERIA
Abnormal respiration
▪ Persistent tachypnea
▪ Paradoxical respiratory pattern
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Thoracic radiographs
▪ “Ground glass” pattern
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▪ No congenital cardiac disease
▪ Response to O2 > Minimal or absent
NERDS
PATHOPHYSIOLOGY?
progression of disease?
Normal physiology
▪ Surfactant production
> Begins ~ day 290(88%) gestation
> Type II alveolar cells
▪ Roles
> Prevent atelectasis at end of expiration
> Increase pulmonary compliance
▪ Surfactant and lung maturation are not complete at birth
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Abnormal physiology
▪ Surfactant deficiency
> Progressive atelectasis
> Decreased pulmonary compliance
> Ventilation/ perfusion mismatching
> Increased work of breathing
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Progression of disease
▪ Progressive hypoxia and hypercapnia
▪ Respiratory failure
NERDS- TREATMENT
▪ O2 supplementation
▪ Corticosteroids > enhance maturation of lungs
▪ Inhaled bronchodilators
▪ Intravenous fluid therapy
▪ Nutritional support
▪ Systemic antimicrobials
▪ Last line of treatment > Mechanical ventilation
Upper airway congenital abnormalities, and clinical presentation
Examples
▪ Wry nose
▪ Choanal atresia
▪ Cleft palate
▪ Nasopharyngeal cyst
▪ Sub/aryepiglottic cyst
▪ Guttural pouch tympany
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Clinical presentation
▪ Respiratory distress
▪ Dysphagia
common risk factors for acute lung injury in foals <1 week of age
▪ Pneumonia
▪ Sepsis
▪ Meconium or milk aspiration
▪ Thoracic trauma
signs of acute lung injury / acute resp distress syndrome in foal <1 week of age
▪ Acute onset respiratory distress
▪ Presence of known risk factor
▪ Absence of cardiogenic pulmonary edema
▪ Evidence of insufficient gas exchange
▪ Presence of diffuse pulmonary inflammation
acute lung injury vs acute respiratory distress syndrome
- it is a spectrum, depending on PaO2
- acute lung injury is the less severe condition, NARDS is more severe
ACUTE LUNG INJURY & ACUTE RESPIRATORY DISTRESS SYNDROME
- treatment, prognosis
▪ Treat underlying etiology
▪ Oxygen supplementation
> Intranasal
> CPAP
> Mechanical ventilation
▪ Systemic anti-inflammatories
> Corticosteroids early and aggressively
> Taper before discontinuing
▪ Prognosis
> Poor- guarded
neonatal bacterial pneumonia
- pathogenesis
- risk factors
- etiology
Pathogenesis
▪ Hematogenous spread
▪ In utero infection
▪ Meconium or milk aspiration
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Risk factors for sepsis
▪ Prematurity or dysmaturity
▪ Failure of passive transfer
▪ Maternal illness
▪ Poor environmental conditions
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Etiology
▪ Same as septicemia
> E. coli most common
neonatal bacterial pneumonia
- diagnosis and treatment
Diagnosis
▪ Physical examination
▪ Presence of a risk factor
▪ Thoracic ultrasonography
▪ Thoracic radiography
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Treatment
▪ O2 supplementation
▪ Antimicrobials
▪ Supportive care
▪ Treatment of co-morbidities
meconium aspiration syndrome
- risk factors
- pathogenesis
Risk factors
▪ Fetal stress/ hypoxia
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▪ Premature passage of meconium
▪ Pulmonary dysfunction
> Mechanical obstruction
> Surfactant inactivation/ displacement
> Chemical pneumonitis
> Persistent pulmonary hypertension