disorders of ventilation and sleep apnea Flashcards
1
Q
What is primary alveolar hypoventilation? (Odine’s curse)
A
- rare
- inadequate alveolar ventilation: normal neuro function, airways, lungs, chest wall and ventilatory muscles
- hypoventilation is worse during sleep
- etiology is congenital or severe trauma/insult to the brainstem
2
Q
Pt profile of primary alveolar hypoventilation?
A
- usually non-obese
- males in 30s or 40s
- present with lethargy, HA and somnolence
PE:
no dyspnea, cyanosis, and evidence of pulmonary HTN (shunting of blood)
3
Q
dx workup of hypoventilation?
A
- labs (chem, TSH, CBC, ABG)
- CXR (rule out lung disease)
- brain imaging CT/MRI (rule out stroke, tumor)
- echo: right heart changes from chronic hypoxemia
- PFTs: can include negative inspiratory pressure to rule out neuromuscular disease
- muscle stim. tests/nerve conduction velocity to rule out neuromuscular disease
4
Q
Tx of primary alveolar hypoventilation?
A
- supp oxygen
- positive pressure ventilation
- respiratory stimulants (not that effective): medroxyprogesterone, acetazolamide, theophylline
- diaphragm pacing with phrenic nerve stimulation
5
Q
What is Pickwickian syndrome?
A
- blunted ventilatory drive and increased mechanical load imposed upon the chest by obesity
- voluntary hyperventilation returns the PCO2 and PO2 toward normal values
- most likely also have obstructive sleep apnea
6
Q
Tx of pickwickian syndrome?
A
- wt loss
- NPPV (noninvasive positive pressure ventilation) - Bipap or CPAP
- tracheostomy
- respiratory stimulants (not primary tx) - theophylline or acetazolmide (works in babies but otherwise not effective)
7
Q
What is hyperventilation and what are the causes?
A
- increase in alveolar ventilation that leads to decreased CO2
- causes:
brainstem injury (comp. mechanism overshooting)
pregnancy
hypoxemia
lung diseases (that cause hypoxia)
sepsis
liver failure
fever
pain
anxiety
hyperthyroidism
8
Q
Signs and sxs of acute hyperventilation?
A
- rapid RR
- paresthesias
- carpopedal spasm
- tetany
- anxiety
- arrhythmias
- cerebral vasoconstriction and cerebral ischemia
- seizures
9
Q
Tx of acute hyperventilation?
A
- tx underlying cause
- pursed lip breathing or
- rebreathing expired gas from paper bag
- anxiolytic drugs
10
Q
Sxs of chronic hyperventilation?
A
- nonspecific sxs that can be reproduced by voluntary hyperventilation: fatigue dyspnea anxiety palpitations dizziness
11
Q
What is the most common sleep related breathing disorder?
A
- sleep apnea
- 20-30% males
- 10-15% females
- more common in young (less than 35) African americans compared to caucasians of the same age, independent of body weight
- prevalence in Asia similar to US despite lower rates of obesity (genetic and ethnic component)
- people with certain chin and jaw structure more at risk for sleep apnea, down syndrome (larger tongues) - anything that obstructs the airway - tonsils, tongue, soft palate (lose muscle tone while asleep - blocked airway)
12
Q
What occurs in sleep apnea to cause obstruction of the airway?
A
- caused by recurrent collapse of pharyngeal airway during sleep
- cessation of airflow
- disturbances in gas exchange, and poor sleep quality (reduced REM sleep)
13
Q
What are RFs for sleep apnea?
A
- obesity
- advancing age
- smoking
- craniofacial or upper airway soft tissue abnormalities
- nasal congestion
- pregnancy
- end stage renal disease
- CHF
- chronic lung disease
- family hx
- menopause
- hypothyroidism
14
Q
Pt factors that are associated with high likelihood of sleep apnea?
A
- neck circumference greater than 43 cm (17 inch) in men and 37 cm (15 inches) in women
- narrowing of lateral airway walls, which is an independent predictor in men but not women
- enlarged kissing tonsils (3+ to 4+)
15
Q
WHat are the signs and sxs that are suspicious for sleep apnea?
A
- HTN: difficult to control
- excessive daytime somnolence
- morning sluggishness
- AM HAs
- daytime fatigue
- cognitive impairment
- impotence
- obesity
- loud snoring
- witnessed apneas
- nocturnal restlessness
- personality changes
- poor judgement
- depression
- memory impairment
- falling asleep while driving or in waiting room
