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
Tx OSA
- weight loss
- sleep positioning
- avoid resp suppressants (ETOH/narcotics)
- CPAP** (MAIN, doesnt work for Central sleep apnea)
- BiPaP (if central sleep apnea)
- oral dental appliances
- surgery (uvulopalatophasryngoplasty)
What is the difference between CPAP and BIPAP?
CPAP:
- continuous positive airway pressure
- standard tx for OSA
BIPAP:
- non-invasive positive pressure ventilation
- for use when taking a deep breath is difficult
- lower pressure for exhalation and higher pressure for inhalation.
- can have “back up rate”
- used for mixed (central and obstructive) sleep apnea and also for impending respiratory failure
Central Sleep apnea
- how does this differ from OSA
- common in what pt
-no ventilatory effor seen during episodes of apnea because brain forgets to tell body to breathe.
Common in premature infants, post stroke, TBI, and CHF.
Conditions that may be associated with central sleep apna
- CHF
- hypothyroid dz
- kidney failure
- neurologic dz (parkinsons, alzheimers, als)
- damage to the brainstem caused by encephalitis, stroke, injury, etc.
