Ventilation Disorders Flashcards
What is Odines Curse?
- etiology
- when is this worse?
-primary alveolar hypoventilation (inadequate alveolar ventilation)
- etiology:
- congenital or severe trauma/insult to the brainstem
- central nervous system failure
-hypoventilation is worse during sleep
Patient Profile of Primary alveolar hypoventilation
- usually non-obese
- males in 3rd or 4th decade of life
- lethargy, HA, adn somnolence
Physical exam findings of pt with Primary alveolar hypoventilation
- no dyspnea
- cyanosis
- evidence of pulm HTN (develops 2ndry to chronic hypoxemia)
Primary Alveolar Hypoventilation Work up to find causes of hypoventilation
- labs (Chem, TSH, CBC, ABG)
- CXR
- Brain CT/MRI (R/O stroke/tumor)
- Echo (right heart changes from chronic hypoxemia)
- PFTs (can include negative inspiratory pressure to rule out neuromuscular disease
- Muscle stimulation tests/nerve conduction velocity to R/O neuromuscular dx
Tx primary alveolar hypoventilation
- supplemental O2
- positive pressure ventilation (tracheostomy at night or positive pressure mask)
- respiratory stimulants (not very effective but may be worth a try)
- -medroxyprogesterone
- acetazolamide
- theophylline
-diaphragm pacing w/ phrenic nerve stimulation
Pickwickian Syndrome
-what is this?
-blunted ventilatory drive and increased mechanical load imposed upon the chest by obesity.
Tx of Pickwickian syndrome
- weight loss
- Noninvasive positive pressure ventilation (BIPAP & CPAP)
- Tracheostomy
- respiratory stimulants (theophylline, acetazolmide; these are best used in babies because they are not well developed)
Hyperventilation Syndromes
- what is it?
- causes
What is this?
-increase in alveolar ventilation that leads to decreased CO2
Causes
- brainstem injury
- pregnancy
- hypoxemia
- lung dz
- sepsis
- liver failure
- fever
- pain
- anxiety
- hyperthyroidism
Signs and sx of acute hyperventilation
- Rapid respiratory rate
- paresthesias
- carpopedal spasm
- tetany
- anxiety
- arrhythmias
- cerebral vasoconstriction and cerebral ischemia
- seziures
Tx of Acute Hyperventilation
- treat underlying cause
- rebreathing expired gas from a paper bag
- pursed lip breathing
- anxiolytic drugs
Chronic Hyperventilation
-signs and sx
- fatigue
- dyspnea
- anxiety
- palpitations
- dizziness
Obstructive sleep apnea (OSA)
-who is this most common in?
-most common in young (less than 35) African american males
what type of pt is genetically more likely to develop sleep apnea?
- pts with down syndrome because they have a fat tongue.
- people with weird structured chin and jaws
- remember, if a child snores there is most likely obstruction going on.
Obstructive sleep apnea is caused from?
-recurrent collapse of the pharyngeal airway during sleep;
Pathophysiology of OSA
- cessation of airflow
- disturbances in gas exchange, hypoxia, increased catecholamie release, increased BP and HR, poor sleep quality
Risk factors OSA
- obesity
- advancing age
- smoking
- craniofacial or upper airway soft tissue abnormalities
- nasal congestion
- pregnancy
- end stage renal dz
- CHF
- chronic lung dz
- fmaily hx
- menopause
- hypothyroidism
Patient factors associated with a high likelihood of sleep apnea
- neck circumference greater than 43cm men and 37cm in women
- narrowing of lateral airway walls
- enlarged tonsils (3+ 4+)
Signs and Sx that are suspicious for sleep apnea
- HTN
- excessive daytime solmnolence
- morning sluggishness
- AM HA
- daytime fatigue
- impotence*
- Obesity*
- Loud snoring
- poor judgement
- memory impairment
- falling asleep while driving
Complications of OSA
- MVA
- High users of medical resources (Insulin resistance, DM)
- CVD (HTN, Pulm HTN, CAD, CHF, CVA)
- Increased risk of perioperative complications
- -2-3x increased risk of all cause mortality
Dx of OSA
- Lab tests, TSH, RBC (looking for polycythemia)
- polysomnography (sleep study)
- Home testing
- home overnight oximetry (cannot dx with this but if their overnight oximetry is good they probably dont have OSA
Define
- apnea
- hypopna
- Apnea-hypopnea index
- respiratory disturbance index
Apnea: breathing cessation for at least 10 sec with decrease in O2 sat.
Hypopnea: decreased airflow iwth drop in O2 sat of at least 4%
APnea-hypopnea: the number of combined events per hour
RDI: number of apneas, hypopneas, and respiratory effort related arousals per hour of sleep
What is all tested in a polysomnography (sleep study)
- EEG (tells us what stage of sleep they are in)
- Electro-oculography (Checks muscle tension and movement of the eye, rapid eye movement in REM)
- EMG (place on face muscle, describes muscle tone)
- EKG
- Pulse oximetry
- respiratory effort
- airflow
*respiratory effort with cessation of airflow in nose and mouth = sleep apnea.
apnea with no respiratory effor and no obstrutcion = central sleep apean from CNS
*respiratory effort with cessation of airflow in nose and mouth =_____.
apnea with no respiratory effort and no obstrutcion =____.
sleep apnea
central sleep apnea
Respiratory Disturbance Index
- mild sleep apnea
- moderate sleep apnea
- sever sleep apnea
- mild: 5-14/hr
- moderate: 15-29/hr
-severe: greater than 30/hr
(you have stopped breathing and woke up to a later sleep stage 30x/hr
