Obstructive Sleep Apnea Flashcards
obstructive sleep apnea: definition + repetitive collapse of _________?
Definition:
- Recurrent episodes of partial or complete airway obstruction during sleep
- Caused by repetitive collapse of PHARYNX
- Results in recurrent awakenings/arousal = ↓ Quality of sleep
epidemiology of sleep apnea
Commonly:
- Sleep apnea does not pose any symptoms even with >5 events per hour
sleep apnea: risk factors
-Obesity**
-Older age
-ETOH or sedative drugs
-Nasal obstruction
-Smoking
-Craniofacial and upper airway soft tissue abnormalities
—–
sleep apnea: FAT old guy that loves smoking and drinking; who has messed up nose that snores lots
hypopnea vs apnea
HYPOPNEA- REDUCTION in airflow
-10s event with breathing BUT
- ventilation during sleep is REDUCED
-respiratory effort: at least 50% from baseline
APNEA: complete CESSATION of airflow
-10s event with cessation of airflow
-Obstructive apnea: no airflow but with continued respiratory EFFORT
-Central apnea: no airflow and no respiratory effort
pathophysiology of sleep apnea.irway occlusion is limited to ________.
pathophysiology: Narrowing of upper airway during sleep!!!
- Airway occlusion is LIMITED TO INSPIRATION**
OSAHS pts have smaller upper airway size due to:
-fat deposition
- facial bone structures
-Genetics
Sleep apnea comorbidities
Strong association with and potential cause of many medical conditions:
- Hypertension
- Pulmonary HTN/cor pulmonare
- cardiovascular disease
- Stroke
- Diabetes
- Depression
- Sleepiness-related accidents
Lots of cormorbid ds and can result in pul hypertension or cor pulmoare
Sleep apnea needs to be identified and treated
sleep apnea symptoms
-Sleepiness and daytime somnolence: MC*
-Poor concentration*
-snoring*
-Bed partners report: snoring, apneas, restless sleep, or irritability*
-Fatigue
-Unrefreshing sleep
-Nocturnal choking
-Nocturia: pee at night
-Depression and decreased libido
signs of sleep apnea
-Macroglossia, enlarged tonsils, nasal obstruction
-HTN common
-“crowded” upper airway
-Obesity
-Large NECK circumference ( >17 inch [males]; >16 inch [females])*
-Craniofacial abnormalities: retrognathia
cardinal symptoms of sleep apnea apnea
epworth sleepiness scale
Used to define whether someone is abnormally sleepy
A ESS Score > 12 is suggestive of Sleep Apnea
Sleep apnea: labs
-Secondary polycythemia: from hypoxia
-Some may have hypercapnea, lowP02
-Proteinuria
-Hypothyroidism
Sleep apnea: ekg
-Nocturnal cardiac arrhythmia
-Sinus bradycardia, sinus arrest or AV block
-SVT, A fib and VT may occur once airflow is re-established
dx of sleep apnea
Golden Standard = Polysomnography (AKA Sleep Study)
-There is night-to-night variability so first night negative test does NOT r/o sleep apnea
Apnea Hypopnea Index:
- 15 events/hr: asymptomatic
- 5 events/hr: symptomatic or with comorbidities
definitive dx: apnea hypopnea index (AHI) criteria
Apnea Hypopnea Index diagnosis criteria:
- 15 events /hr of sleep: asymptomatic
- 5 events/hr: symptomatic
SYMPTOMS (one or more)
-Excessive daytime sleepiness
-Choking or gasping from sleep
-Recurrent awakenings from sleep
-Feeling unrefreshed after sleep
-Daytime fatigue
-Poor concentration
severity of sleep apnea: AHI index
Mild:
- 5-14 events per hour of sleep
Moderate:
- 15-30 events per hour of sleep
Severe:
- >30 events per hour of sleep
just know vaguely
tx of sleep apnea
- Weight loss **
- AVOID EtOH & Hypnotics **
- CPAP: Continuous Positive Airway Pressure
- Oral Appliances: Recommended for more severe cases
- Surgical Procedures: Indicated if only there is some surgical intervention (enlarged tonsils, etc)
- Hypoglossal nerve stimulation (INSPIRE)
new sleep apnea tx- inspire
-Implantable upper airway stimulation device functions like a pacemaker
-sends regular electrical impulses to the hypoglossal nerve to maintain upper airway patency
Components:
- programmable neuro-stimulator placed in chest
- pressure sensing lead: detects patient’s breathing
- stimulator lead: stimulates hypoglossal nerve
obesity hypoventilation syndrome
Definition:
- presence of awake alveolar hypoventilation (PaCO2 ≥45 mmHg)
-pt is OBESE (BMI ≥30 kg/m2),
-Hypoventilation cannot be attributed to other conditions
obesity hypoventilation syndrome: clinical features of cns, respiratory, cardiovascular
CNS:
- decreased CENTRAL respiratory drive
Respiratory:
- restrictive chest physiology
- pulmonary HTN
- hypoxemia/hypercapnia
-severe airway obstruction
- obstructive sleep apnea
Cardiovascular:
- CAD
- CHF
obesity hypoventilation syndrome: dx
DX:
- Chronic respiratory acidosis (PaCO2 ≥45 mmHg) with compensatory metabolic alkalosis
-must exclude other diseases that can cause or contribute to chronic alveolar hypoventilation or hypercapnia.
Work up:
-assess for common complications
-ex: pulmonary hypertension + cardiovascular disorders
obesity hypoventilation syndrome: tx
Tx: CPAP therapy
- improves gas exchange, lung volumes, and sleep-disordered breathing
- reduces mortality
Crap im obese
acute respiratory distress syndrome (ARDS)
Definition:
-Acute hypoxemic respiratory failure WITHOUT HF
- acute event caused by systemic or pulmonary insult (infection, trauma, sepsis)
-will have NORMAL pulmonary capillary wedge pressure (≤ 18 mm Hg) -> normal heart; no HF
-Bilateral, widespread pulmonary infiltrates on x-ray (“WHITE OUT”)
ARDS PaO2/FIO2 ratio
-pt will have PaO2/FIO2 ratio <300: Arterial oxygen over concentration of oxygen being inhaled
so for ex, if PT has Pa02 of 60 while receiving 80% o2= 60/.8= 75.
severity of ARDS
Based on PaO2/FIO2 ratio :
-Mild: 200-300 mm Hg
-Moderate: 100-200 mm Hg
-Severe: less than 100 mm Hg
PaO2/FIO2 ratio: tells you degree of hypoxemia
PaO2 = arterial O2
FIO2 = fraction of inspired oxygen (expressed as decimal)
common risk factors for ARDS
-Sepsis (1/3 of pts)**
-Severe multiple trauma **
-large Aspiration of gastric contents **
-Shock
-Infection
-Lung contusion
-Nonthoracic trauma
-Toxic inhalation
-Near-drowning
-Multiple blood transfusions
-Drugs
all of these are the “systemic or pulmonary insults”
ARDS pathophysiology
1) insult causes release of pro-inflammatory cytokines -> promotes tissue destruction + inflammation
Lung Inflammation causes:
- ↑ Vascular Permeability = Interstitial & Alveolar Edema + Bilateral Diffuse Infiltrates
- ↓ Alveolar Surfactants = Alveolar Collapse + Hypoxemia
ARDS symptoms and signs
RAPID onset of really bad dyspnea:
-FROTHY RED OR PINK SPUTUM**
-Diffuse crackles everywhere
-Marked hypoxemia refractory to tx with supplemental oxygen ***
- Many pts demonstrate multiple organ failure
——-
-Labored breathing
-Tachypnea
-accessory inspiratory muscles
ADRS: what must you r/o?
HEART FAILURE
- diffuse crackles
-multiple organ failure
- dyspnea
-cadiogenic pulmonary edema
ARDS Chest radiography
Findings: “white out”
- May be normal at first
-BILATERAL infiltrates usually peripheral
- Air BRONCHOGRAMS * (80%) -> alveolar inflitrates
Normal:
-Heart size normal
- spares costophrenic angles: no pleural effusions
ARDS tx
-Treatment of underlying precipitating or secondary conditions (ex: sepsis)
-Tracheal intubation
-PEEP: Positive End Expiratory Pressure = Keeps alveoli open
-Supplemental O2
- Fluid Management
basically: give PEEP and O2 but not too much for O2 toxicity and give fluids but not too much to cause HF
ARDS: O2 + PEEP
PEEP: Positive End Expiratory Pressure = Keeps alveoli open
- Ideally keep PEEP ↓ and Supplemental O2 ↓ as possible
PEEP goal:
- PaO2 > 55 mmHg or SaO2 > 88%
O2 goal:
- Recommended FIO2 < 60% with <40% the safest
- avoid oxygen toxicity
Fraction of inspired oxygen (FIO2): percentage of O2 in the gas mixture that is inhaled
Oxygen saturation (SaO2): proportion of Hb that are saturation
ARDS: fluid management
- want to maintain pulmonary capillary wedge pressure at the LOWEST level compatible with adequate cardiac output
- don’t want to fluid overload (HF)
ARDS prognosis
-30-40% Mortality Rate
-90% Mortality with Sepsis
-Median Survival Time ~ 2 weeks
- If pts survive: will have SIGNIFICANT respiratory impairments
pulmonary aspiration syndromes definition and causes
Definition: Aspiration of material
Causes: Impaired deglutition
- Secondary to Altered Consciousness
- Secondary to Esophageal Dysfunction
Different types of aspirations
-Aspiration of Inert Material
-Aspiration of Toxic Material
-“Café Coronary”
-Retention of Aspirated FB
-Chronic Aspiration of Gastric Contents
-Acute Aspiration of Gastric contents
aspiration of inert material
Inert Material: non-hazardous = No serious sequelae
- Aspiration of particular matter or large volumes of fluid
- May present with asphyxia if amount aspirated is MASSIVE
–
ex: waterboarding
aspiration of toxic material - what does it cause, sx, tx
May cause hydrocarbon pneumonitis**: aspiration of ingested petroleum distillates:
-Gasoline, kerosene, furniture polish
- occurs in suicide attempt or child accidentally ingesting toxic material
-Lung injury: mainly from vomiting and aspiration
Symptoms:
- vomiting, coughing
- respiratory distress
- cyanosis
- fever
Tx: supportive care
“toxicpeople go low and hide in the middle, they are initially normal and then get worse at night”
aspiration of toxic material - chest xray + tx
CXR: initially be normal -> significantly progress over the next 12 hours.
Patchy airspace consolidation particularly in:
- LOWER lobes
- medial basal segments
Tx: supportive
“toxic ppl:
- go low and hide in the medial base
- initially normal and can get worse at night (12 h)”
lipoid pneumonia
Chronic syndrome due to REPEATED aspiration of oily materials
- Mineral oil, cod liver oil, and oily nose drops
-Can cause pneumonia and fibrosis
- MC: Elderly patients with impaired swallowing
-Cough is present
Dx: lipid laden alveolar macrophages
- sputum sample or bronchial washings with + lipid-laden alveolar macrophages
“Lipoid = Oily Fat People”
- can cause Fibrosis and Pneumonia
- chronic ingestion of oily substances
- Oily: Old ppl with impaired swallowing -> cough a lot
Cafe coronary + risk factors
Definition: ACUTE obstruction of the upper airway by FOOD
Associated with:
-Difficulty swallowing
-Old age
-Dental problems that impair chewing
-Use of alcohol and sedative drugs
Tx: Heimlich procedure
Retention of Aspirated Foreign Body: what does it cause
May be acute, chronic, or asymptomatic: these are what it can cause:
“foreign Body -> Being HAPA is a foreign body”
- Bronchiectasis
- Hyperinflation
- Abscess (lung)
- Pneumonia (recurrent)
- Atelectasis”
-recurrent pneumonia
-Bronchiectasis
-Lung abscess
-Atelectasis
-Postobstructive hyperinflation
Retention of Aspirated Foreign Body imaging
CXR:
- usually suggests the site of the foreign body
Golden Standard = Bronchoscopy
- Establishes Dx & Removal of FB
“foreign BOdy = BrONchoscopy -> BB”
chronic aspiration of gastric contents
Result from primary disorder of larynx or esophagus:
-Untreated asthma
-esophageal stricture
-achalasia
-scleroderma
-chronic reflux
it can cause:
- Bronchial asthma
- pulmonary fibrosis
- bronchiectasis
chronic aspiration of gastric contents: dx and tx
Dx: “swallowing disorders”
- EGD
- barium swallow
Tx:
- EGD Dilate
- PPI
- H2 Blocker
- Metoclopramide: increase gastric emptying
acute aspiration of gastric contents def+ what can it cause?
Catastrophic event!! -> response depends on how much was aspirated
-more acidic + more quantity = WORSE chemical pneumonitis
-Aspiration of pure gastric acid (pH < 2.5) -> ARDS
What can it cause: “HEbP = HELP!!”
-Hemorrhage: bleeding in lungs
-Extensive desquamation of the bronchial epithelium
-Bronchiolitis
-Pulmonary edema
acute aspiration of gastric contents: chest xray
-Patchy alveolar infiltrates in dependent lung zones
-Appear within few hours and progresses
- If particular food matter = Obstruction may be observed
acute aspiration of gastric contents: treatment
ABCs:
-Maintain the airway
-Supplemental oxygen
- mechanical ventilation if ARDS
Supportive:
-Fluids for hypotension
-Treatment of superinfection -> prevent secondary infection
“ACUTE= ABCs
- airway: maintain airway
- Breathing: ventilate if respiratory failure (ARDS); O2
- Circulation: fluids for hypotension + treat superinfections”
