Disorders of Ventilation Flashcards
How common is Primary alveolar hypoventilation (Odine’s Curse)?
Describe the pathology.
When during the day is it worse?
What is the etiology? 2
Rare
Inadequate alveolar ventilation
–normal neurologic function, airways, lungs, chest wall and ventilatory muscles.
Hypoventilation is worse during sleep
Etiology is congenital or severe trauma/insult to the brainstem
Patient profile of Primary alveolar hypoventilation (Odine’s Curse):
- weight?
- gender?
- age?
- Present with what symptoms?3
- What will we see on physical exam? 4
- Usually non-obese
- Males in their 3rd of 4th decade
- Present with
- lethargy,
- headache and
- somnolence - Physical exam
- No dyspnea
- Cyanosis
- Evidence of Pulm HTN
What labs should we get for hypoventilation? 4
Imagaing? 3
Tests? 3
Labs:
- chem,
- TSH,
- CBC,
- ABG
Imaging:
- CXR (rule out lung disease)
- Brain imaging CT/MRI (rule out stroke, tumor)
- Echo (right heart changes from chronic hypoxemia)
Tests:
- PFTs
- Can include negative inspiratory pressure to rule out neuromuscular disease
- Muscle stimulation tests/nerve conduction velocity to rule out neuromuscular disease
- What disease process results secondary to hypoxemia?
2. GIve an example of a disease where this would occur?
- pulmonary hypertension
(shunts blood to an area where it can pick oxygen up) - Sleep apnea pts for example
Treatment of primary alveolar hypoventilation
4
- Supplemental oxygen
- Positive pressure ventilation
- Respiratory stimulants
- -Medroxyprogesterone
- -Acetazolamide
- -Theophylline - Diaphragm pacing with phrenic nerve stimulation
What is Pickwickian Syndrome?
Blunted ventilatory drive and increased mechanical load imposed upon the chest by obesity
In Pickwickian Syndrome, why would the pt voluntarily hyperventilate?
What is the pt also likely to have?
Voluntary hyperventilation returns the Pco2 and Po2 toward normal values
Most likely also have obstructive sleep apnea
Treatment for Pickwickian Syndrome?
4
- Weight loss
- NPPV (noninvasive positive pressure ventilation) is helpful (Bipap (those who cant support their tidal volume, CPAP)
- Tracheostomy
- Respiratory stimulants (not the primary treatment)
- -Theophylline
- -Acetazolmide
Describe the process of hyperventilation?
Causes?
10
Increase in alveolar ventilation that leads to decreased CO2
- Brainstem injury
- Pregnancy
- Hypoxemia
- Lung diseases (that cause hypoxia)
- Sepsis
- Liver failure
- Fever
- Pain
- Anxiety
- Hyperthyroidism
Signs and Symtpoms of Acute hyperventilation?
8
- Rapid respiratory rate
- Paresthesias
- Carpopedal spasm
- Tetany
- Anxiety
- Arrhythmias
- Cerebral vasoconstriction and cerebral ischemia
- Seizures
Treatment of hyperventilation?
3
Treat underlying cause
- Pursed lip breathing (have them do this to slow it down) or
- Rebreathing expired gas from a paper bag
- Anxiolytic drugs (antiaxiety)
Describe the symptoms of chronic hyperventilation?
5
Nonspecific symptoms that can be reproduced by voluntary hyperventilation
- Fatigue
- Dyspnea
- Anxiety
- Palpitations
- Dizziness
What is OSA caused by?
What happens becuase of this?3
recurrent collapse of the pharyngeal airway during sleep
- Cessation of airflow
- Disturbances in gas exchange
- Poor sleep quality (reduced REM sleep)
Sleep apnea risk factors
12
- Obesity
- Advancing age
- Smoking
- Craniofacial or upper airway soft tissue abnormalities
- Nasal congestion
- Pregnancy
- End stage renal disease
- CHF
- Chronic lung disease
- Family history
- Menopause
- Hypothyroidism
Patient factors associated with a high likelihood of sleep apnea
3
- Neck circumference:
- Narrowing of the lateral airway walls,
- Enlarged (ie, “kissing”) tonsils (3+ to 4+)