Sleep apnea Flashcards
study (139 cards)
1
Q
What are signs and symptoms of Sleep Apnea
A
Sleepiness Breath-holding choking gasping observed snoring or gasping hypertension mood disorder cognitive dysfunction stroke coronary artery disease congestive failure atrial fibrillation diabetes mellitus 5 events per hour or 15 events per hour
2
Q
What is the frequency of overlap syndrome
A
1%
3
Q
What is the prevalence of sleep apnea
A
OSA with sleepiness occurs in 3-7% of adult men
OSA with sleepiness occurs in 2-5% of adult women
4
Q
Using criteria of 5/h, what is the prevalence of sleep apnea
A
24% in man and 9% in women
5
Q
What is the proportion of sleep apnea attributed to body mass
A
60%
6
Q
What is the genetic contribution to OSA
A
OSA Twice as frequent with family history
7
Q
What are the criteria for pediatric sleep apnea
A
Snoring
Labored paradoxical or obstructive breathing
Sleepiness
hyperactivity
behavioral or learning problems
Plus one obstructive apneas per hour sleep
Or
Hypoventilation 25% of total sleep time with hypercapnia greater than 50 mm associated with snoring pressure waveform flattening or paradoxical thoracoabdominal motion
8
Q
What is the prevalence of obstructive apnea in pediatric population
A
1 to 4%
9
Q
When do arousals occur in Cheyne Stokes respiration
A
At peak respirations
10
Q
Do apneas or hypopneas predominate in children.
A
Hypopneas predominate
11
Q
What are normal Gas concentrations
A
pH 7.35–7.45 pCO2 35–45 torr 4.5–6.0 kPa pO2 >79 torr >10.5 kPa CO2 23-30 mmol/L Base excess/deficit ± 3 mEq/L ± 2 mmol/L
12
Q
How does oxygen saturation affect hypopneas
A
Reduces the number of hypopneas because hypopneas require oxygen saturation in the definition
13
Q
What is normal serum bicarbonate
A
The normal range is 23 to 29 milliequivalents per liter (mEq/L) or 23 to 29 millimoles per liter (mmol/L).
14
Q
Is the PCO2 in Cheyne-Stokes respirations increased or decreased
A
Decreased
15
Q
What is normal FEV1%.
A
80%
16
Q
What FEV1% predisposes to sleep related hypoventilation
A
less than 60%
FEV1 greater than 80 percent of predicted is normal
FEV1 60 percent to 79 percent of predicted indicates mild obstruction
FEV1 40 percent to 59 percent of predicted indicates moderate obstruction
FEV1 less than 40 percent of predicted indicates severe obstruction
17
Q
What are risk factors for obstructive sleep apnea
A
Untreated hypothyroidism
upper airway narrowing macroglossia
upper airway myopathy
impairment of ventilatory control systems
18
Q
What are the guidelines for increasing CPAP pressure
A
CPAP pressure should be increased once 3 obstructive Hypopneas are observed 2 obstructive apneas or 5 respiratory effort related arousals
19
Q
What conditions lead to Infiltration of pharyngeal tissue
A
Obesity Prader Willi Cushing syndrome mucopolysaccharidosis
20
Q
During sleep what happens to V/Q imbalance
A
V/Q imbalance becomes lower in the lung basis leading to more blood traversing the lungs unoxygeninated
21
Q
What were the results of the CANPAP trial
A
CPAP reduced AHI and plasma catecholamines.
60 minute walk distance, nocturnal oxygenation,
and injection fraction improved.
No reduction in hospitalizations or mortality.
22
Q
What is idiopathic alveolar hypoventilation
A
Decreased responsiveness to CO2 and O2 levels with respiratory drive suppression
23
Q
What is sleep related hypoxemia
A
sp02 less than or equal to 88% over 5 minutes if sleep-related hypoventilation is documented in the diagnosis of hypoventilation is made.
In the event characterized by an increase of PCO2 greater than 55 mg mercury for greater than 10 minutes maybe scored as hypoventilation.
24
Q
What is late onset hypoventilation with hypothalamic dysfunction.
A
Associated with obesity
emotional disturbances
neural tumors
hypothalamic dysfunction.
25
If a home study fails when is polysomnography indicated
If there is high suspicion of sleep apnea
26
What are the complications of sleep apnea
Obstructive sleep apnea is associated with decreased SaO2 and PaO2, increased PaCO2, increased systemic and pulmonary artery pressures, decreased left and right ventricular output and increased vascular resistance because of sympathetic activity.
27
What is the definition of a hypopnea
30% drop in airflow from baseline lasting > 10 seconds and: Associated with > 3% oxygen desaturation or arousal
28
What is the Respiratory Event Index (REI)
respiratory events per hour of monitoring time on Home Sleep Apnea Testing (HSAT)
29
What is the Current Prevalence of OSA
AHI > 5/hr (30-70) Women 13 -17
AHI > 15/hr Men 9-13 women 4-6
30
What is the main finding of the Sleep Heart health study (SHHS)
There is a greater risk of CVD as RDI increases
31
What is the finding of the Wisconsin Cohort study
AHI over 15 had 3x the odds of being diagnosed with hypertension than those with an AHI of zero.
32
What did Sleep Heart health study (SHHS) find regarding
| hypertension
an AHI of 30 or more had 1.5 greater odds of being diagnosed with hypertension
33
What did SHHS show regarding stroke and apnea
Sleep apnea seen in 50%–80% of acute stroke and TIA patients.
Sleep apnea improves in the sub acute phase, primarily central and Cheyne-stokes pattern, not OSA
Those with an AHI over 20 had a much higher likelihood of stroke
34
What did SHHS show regarding Apnea and Arrhythmias
Most common is bradycardia cardiac slowing increases in proportion to the severity of hypoxemia
OSA increases the risk of developing A-fib.
an association of nocturnal cardiac death with worsening sleep apnea.
35
What is the relationship of OSA to Diabetes
up to 83% of patients with type 2 diabetes have unrecognized OSA
Insulin sensitivity improves after CPAP therapy
The greatest CPAP response on glucose metabolism is in the diabetic patient with a lower BMI
36
What is the relationship of OSA to GERD
54-76% of OSA patients have Gastroesophageal Reflux Disease (GERD)
37
What are physical exam findings in OSA
```
Neck circumference >17” men, >16” women
Upper airway crowding
Lateral wall narrowing
High arched palate
Large tongue, high based
Large uvula and tonsils
High Modified Mallampati score
```
38
What is STOP-BANG
Score of ≥ 3 has >90% sensitivity to detect moderate to severe OSA
High positive predictive value (85%)
39
What are the effects of CPAP in heart failure
CPAP reduces vascular and myocardial sympathetic activity
CPAP improves diastolic dysfunction
Treatment of OSA is associated with reduced readmission rate, health cost and mortality
40
What are Oral device predictors
```
Lower initial AHI
Lower age
Lower BMI
Supine-dependent OSA
Certain cephalometric variables such as shorter soft palate or decreased distance between the mandibular plane and the hyoid bone
Low nasal resistance
```
41
What is the outcome for UPPP?
overall reduction in AHI of 33% (95 CI 23-42%).
Post-operative residual AHI remained elevated, averaging 29.8 events per hour
42
What is non hypercapnic central sleep apnea
Brief arousals accompanied by hyperventilation that decreases PaCO2 levels below apnea threshold causing central apneas
There is an increased ventilatory response to hypercapnia
43
What causes Episodes of hyperventilation followed by low paCO2
Idiopathic central sleep apnea post arousal central sleep apnea congestive heart failure high altitudes CPAP pressure titration
44
When does an increase IPAP and EPAP occur
IPAP Should be increased if 3 obstructive hypopneas or 5 respiratory effort related arousals
IPAP and EPAP should be increased simultaneously if 2 obstructive apneas occur
45
What are the signs and symptoms of obesity hypoventilation syndrome
BMI greater than 30
waking hyper capnea greater than 45
Hypoxemia PaO2 less than 70
46
What is teatment emergent central sleep apnea
Obstructive sleep apnea with AHI or RDI greater than 5
On CPAP pressure that relieves obstructive events there is central apnea hypopneas index of greater than 5
50% of all events or central
Central sleep apnea is not explained by another disorder (Reduce CPAP by 1% and observed reemergence of obstructive events)
47
What is Complex sleep apnea syndrome
Emergence of central apneic events during positive airway pressure titration for treatment of obstructive apnea
48
Define Adult hypoventilation
PaCO2 greater than 55 mmHg lasting 10 minutes or longer
Increase in PaCO2 for 10 mmHg or more above baseline and reaching a level greater than 50 mmHg and lasting 10 minutes
49
Define Child hypoventilation
PaCO2 greater than 50 mmHg for 25% of sleep or more
50
Can Hypoxemia cause right heart failure in patients with obstructive sleep apnea
Yes
51
What is Cheyne Stokes Criteria
3 central apneas or hypopneas consecutively separated by crescendo decrescendo breathing pattern of at least 40 seconds
5 central apneas or hypopneas accompanied by crescendo decrescendo pattern four hours sleep
At least 2 hours of monitoring
52
What are pediatric sleep apnea rules
HIstory of labored paradoxical breathing during sleep and sleepiness, hyperactivity, behavior problems, or learning problems
PSG criteria include one or more obstructive apneas per hour sleep and hypoventilation with PaCO2 greater than 50 mmHg for at least 25% of total sleep time with snoring flattening of the nasal pressure waveform or paradoxical thoracoabdominal motion
53
What type ventilation support is appropriate in neuromuscular disease at night
Bilevel spontaneously time mode is the most appropriate treatment and provides pressure support to treat the hypoventilation ST mode is appropriate for neuromuscular disease patients who may have trouble triggering the device
54
What therapies help high altitude central apnea or periodic breathing
acetazolamide
Theophylline
hypnotic agents
55
What percentage of sleep apnea patients have positional apnea
50%
56
What is Central sleep apnea
Failure of ventilatory drive (idiopathic) secondary causes include congestive heart failure neurologic disorders
57
Does snoring require increase in iPAP
If 3 minutes of snoring is observed iPAP may be increased
58
What factors are associated with greater oxygen desaturation in sleep apnea
Lower baseline awake supine in sleep SaO2
Longer duration of apnea or hypopneas shorter duration of ventilation between periods of apnea
Increased percentage of sleep time with apneas or hypopneas
Lower functional residual capacity and expiratory reserve volume
Presence of comorbid lung disorder such as COPD
59
What factors increased risk of developing central sleep apnea
High CO2 ventilatory drive
Male gender
age
High altitude
60
Which disorders and establish cause of secondary non-hypercapnic central sleep apnea
Congestive heart failure
Idiopathic
Reduced lung volume
Circulatory impairment
61
What factors contributed to increased arterial PC02 in obese individuals
```
Decreased chest wall compliance
Decreased ventilation
decreased expiratory reserve volume
decreased tidal volume
increased dead space
increased response to elevated PaCO2
```
62
What are Pediatric syndromes associated with OSA
Antlely-Bixl is associated with choanal atresia or stenosis
Apert syndrome Associated with small nasal passages a large jaw
Crouzon choanal atresia maxillary hypoplasia posterior displacement of the tongue and prolonged soft palate
Goldenhar syndrome is associated with mandibular hypoplasia
Down syndrome is associated with small nasal passages enlarged tongue maxillary hypoplasia in the short neck
63
What is appropriate treatment for central sleep apnea
Positive airway pressure
Acetasolamide
Zolpidem and triazolam
64
What Pediatric syndromes are associated with OSA
Antlely-Bixl is associated with choanal atresia or stenosis
Apert syndrome Associated with small nasal passages a large jaw
Crouzon choanal atresia or stenosis maxillary hypoplasia posterior displacement of the tongue and prolonged soft palate
Goldenhar syndrome is associated with mandibular hypoplasia
Down syndrome is associated with small nasal passages enlarged tongue maxillary hypoplasia in the short neck
65
What is Idiopathic central alveolar hypoventilation
Diagnosis is made in the presence of sleep related hypoventilation whether is no known medical or neurologic cause
Sleep related hypoventilation in the adult may be scored during polysomnography if arterial PCO2 is greater than 55 mg mercury for at least 10 minutes
Alternatively sleep related hypoventilation may be scored up arterial PCO2 is greater than 50 mg mercury for at least 10 minutes and if this value is at least 10 mg higher than evaluated determined while awake and supine
66
What is the effect of 10% weight gain on OSA
Increases odds of developing OSA by 6x, and increases AHI by 32%.
67
What are effects of weight loss on OSA
10% weight loss associated with 26% decrease in AHI in moderate to severe OSA.
68
What is the effect of a 10% weight gain on OSA
increases odds of developing OSA by 6x, and increases AHI by 32%.
69
When is positional therapy appropriate
May be beneficial in up to 75% with positional sleep apnea defined by AHI <5 in non-supine sleep
70
What is effect of OSA on Atrial fibrillation
Patients with AF and untreated OSA are less likely to
maintain sinus rhythm after cardioversion
CPAP may reduce the occurrence of paroxysmal AF and
increase the success rate of cardioversion
Recurrence of AF after cardioversion with CPAP
71
Ventricular arrhythmia
Frequency of PVCs during sleep by 58% with CPAP
72
What is the incidence of Stroke in OSA
Patients with OSA twice as likely to suffer
| stroke in 3.5 year follow up period
73
What are AASM PAP titration guidelines
Optimal titration: reduces RDI <5 for at least a 15- min,
includes supine REM sleep at the selected pressure
• Good titration: reduces RDI ≤10 or by 50% if baseline RDI <15,
includes supine REM sleep at the selected pressure
• Adequate titration: does not reduce the RDI ≤10 but reduces
the RDI by 75% from baseline (especially in severe OSA
patients); or meets optimal or good with the exception that
supine REM sleep did not occur at the selected pressure
74
What are contraindications for APAP
Congestive heart failure
Significant lung disease (COPD)
Expect nocturnal arterial oxyhemoglobin desaturation due to conditions other than OSA (e.g. OHS)
Patients who do not snore (either naturally or
as a result of palate surgery)
Central sleep apnea syndromes
75
When is BiPAP appropriate in OSA
```
– Optional with high pressures
– PAP intolerance
– Difficulty exhaling
– Co-existing hypoventilation
– Not shown to improve compliance
```
76
What are Indications for BIPAP ASV
* Complex sleep apnea, CPAP emergent central sleep apnea, central sleep apnea with EF >45%
* Shown to improve AHI versus CPAP and BiPAP in complex sleep apnea
* About ½ report improvement in sleep quality
77
What is the effect of Supplemental oxygen
Supplemental O2 alone may reduce nocturnal hypoxemia
| May prolong apneas (due to prolonged time to arousal after airway occlusion) and worsen nocturnal hypercapnia
78
What is Pediatric apnea scoring rules
A drop occurs in the PK signal by greater than 90% of the preevent baseline using apnea sensor Device flow titration or alternative apnea since or
The drop last at least the minimum duration
Event meets respiratory effort criteria for obstructive central or mixed apnea
79
What is pediatric obstructive apnea rule
Obstructive apnea meets apnea criteria for at least 2 breaths during baseline breathing and is associated with respiratory effort throughout the entire period of absent airflow
80
What is Pediatric mixed apnea rule
Score a respiratory event as mixed if it makes apnea criteria for at least the duration 2 breaths during breathing and is associated with absent respiratory effort during one portion of the event and inspiratory effort is present in another portion
81
What is Central apnea
The event last 20 seconds are longer
The event last the duration of 2 breaths during baseline breathing associated with a 3% anxious due to saturation
In infants younger than one age if the event last the duration of 2 breaths during baseline breathing and is associated with a heart rate 50 beats or less for 5 seconds or less or 60 beats a minute for 15 seconds
82
What is Obstructive Hypopneas rule
Peak signal excursion drops by greater than 30% of predicted event baseline using nasal pressure or PAP Device flow signal
Snoring during the event
Increased inspiratory flattening of the nasal pressure or PAP Device flow signal
83
What is the RERA rule
Sequence of breast last greater than 2 breaths when the breathing sequences characterized by increasing respiratory effort, flattening of the inspiratory portion of the nasal pressure, Device flow waveform, snoring or an elevation of the end tidal PCO2 leading to an arousal from sleep when the sequence of breaths does not meet criteria for apnea or hypoxia
84
Define Pediatric hypoventilation
Greater than 25% of the total sleep time as a manager either by arterial PCO2 or surrogate is spent with greater than 50 mmHg PCO2
85
What is pediatric periodic
| breathing
Greater than 3 episodes of central apnea lasting 3 seconds separated by 20 seconds of normal breathing
86
What is Adult hypoventilation
Score hypoventilation if there is an increase in arterial PCO2 to evaluate greater than 55 mmHg for 10 minutes
Score hypoventilation if there is a 10 mmHg increase in arterial PCO2 during sleep compared to value during wake and exceeding 50 mmHg for greater than 10 minutes
87
List APAP Contraindications
Patients with congestive heart failure
significant lung disease such as chronic obstructive pulmonary disease
patients expected to have nocturnal arterial oxyhemoglobin desaturation due to conditions other than OSA (e.g., obesity hypoventilation syndrome),
patients who do not snore (either naturally or as a result of palate surgery)
patients who have central sleep apnea syndromes are not currently candidates
for APAP titration or treatment.
88
What are Indications for APAP
Certain APAP devices may be initiated and used in the self-adjusting mode for unattended treatment of patients with moderate to severe OSA without significant comorbidities (CHF, COPD, central sleep apnea
syndromes, or hypoventilation syndromes).
Certain APAP devices may be used in an unattended way to determine a fixed CPAP treatment pressure for patients with moderate to severe OSA without significant comorbidities (CHF, COPD, central sleep apnea
syndromes, or hypoventilation syndromes).
89
What are starting pressures
The recommended minimum starting CPAP should be 4 cm H2O for pediatric and adult patients, and the recommended minimum starting IPAP and EPAP should be 8 cm H2O and 4 cm H2O, respectively, for pediatric and adult patients on BIPAP
90
What are the highest pressures for CPAP and BIPAP
The recommended maximum CPAP should be 15 cm H2O (or recommended maximum IPAP of 20 cm H2O if on BPAP) for patients <12 years, and 20 cm H2O (or recommended maximum IPAP of 30 cm H2O if on BPAP) for patients ≥12 years.
91
What is the IPAP EPAP differential
The recommended minimum IPAP-EPAP differential is 4 cm H2O and the recommended maximum IPAP-EPAP differential is 10 cm H2O
92
What are criteria for raising PAP pressures
CPAP (IPAP and/or EPAP for patients on BPAP depending on the type of event) should be increased by at least 1 cm H2O with an interval no shorter than 5 min, with the goal of eliminating obstructive respiratory events.
93
If there are obstructive apneas, how are pressures raised
CPAP (IPAP and EPAP for patients on BPAP) should be increased from any CPAP (or IPAP) level if at least 1 obstructive apnea is observed for patients <12 years, or if at least 2 obstructive apneas are observed forpatients ≥12 years.
94
If there are hypopneas, how are pressures raised
CPAP (IPAP for patients on BPAP) should be increased from any CPAP (or IPAP) level if at least 1 hypopnea is observed for patients <12 years, or if at least 3 hypopneas are observed for patients ≥12 years.
95
How do you raise the pressure raise for RERAs
CPAP (IPAP for patients on BPAP) should be increased from any CPAP (or IPAP) level if at least 3 RERAs are observed for patients <12 years, or if at least 5 RERAs are observed for patients ≥12 years.
96
What are pressure increase for snoring
CPAP (IPAP for patients on BPAP) may be increased from any CPAP (or IPAP) level if at least 1 min of loud or unambiguous snoring is observed for patients <12 years, or if at least 3 min of loud or unambiguous snoring are observed for patients ≥12 years.
97
When do you switch from CPAP to BIPAP
If there are continued obstructive respiratory events at 15 cm H2O of CPAP during the titration study, the patient may be switched to BPAP.
98
How are titrations graded
An optimal titration reduces RDI <5 for at least a 15-min duration and should include supine REM sleep at the selected pressure that is not continually interrupted by spontaneous arousals or awakenings.
A good titration reduces RDI ≤10 or by 50% if the baseline RDI <15 and should include supine REM sleep that is not continually interrupted by spontaneous arousals or awakenings at the selected pressure.
An adequate titration does not reduce the RDI ≤10 but reduces the RDI by 75% from baseline (especially in severe OSA patients), or one in which the titration grading criteria for optimal or good are met with the exception that supine REM sleep did not occur at the selected pressure.
99
what are treatments for What are signs and symptoms of CSAS in CHF
CPAP therapy targeted to normalize the apnea hypopnea index (AHI) is indicated for the initial treatment of CSAS related to CHF.
BPAP therapy in a spontaneous timed (ST) mode targeted to normalize the apnea hypopnea index (AHI) may be considered for the treatment of CSAS related to CHF only if there is no response to adequate trials of CPAP, ASV, and oxygen therapies.
Nocturnal oxygen therapy is indicated for the treatment of CSAS related to CHF.
100
CSAS in Renal Disease
The following possible treatment options for CSAS related to end stage renal disease may be considered: CPAP, supplemental oxygen, bicarbonate buffer use during dialysis, and nocturnal dialysis.
101
Define treatment of CSAS in Renal Disease
The following possible treatment options for CSAS related to end stage renal disease may be considered: CPAP, supplemental oxygen, bicarbonate buffer use during dialysis, and nocturnal dialysis.
102
What are the effects of elevation breathing
Approximately 25% of people examining periodic breathing at 8000 feet 100% of people demonstrate periodic breathing at 13,000 feet
Some people show periodic breathing at 5000 feet.
103
What are the symptoms of altitude sickness
The increase and ventilation attacks associated with hypoxemia causes hypocarbia-Alkalosis. The low PaCO2 causes a loss or reduction respiratory drive resulting in central apnea or hypoxia. The greater than ventilatory response to hypoxia, the greater than fallen PaCO2 PSG findings demonstrate recurrent central apneas with cycle time of less than 40 seconds. There is more prevalent in NREM sleep than in REM sleep
104
Which of the following is recommended to address sleepiness in myotonic dystrophy?
stimulants
naps
Treating obstructive and/or central sleep apnea
105
68-year-old patient with systolic heart failure, with LVEF of 35%, was diagnosed with severe central sleep apnea. He tried CPAP and BPAP S/T but struggled with its use and does not wish to continue. On the most recent ECHO, his estimated pulmonary artery systolic pressure is 30 mmHg. On the PSG, his mean oxygen saturation was 89% on room air.
When considering nocturnal supplemental oxygen therapy for this patient, which of the following is true?
Treatment guideline recommends supplemental oxygen
106
What are the Stop bang questions
Snoring
Tired
Observed
Pressure
BMI
Age
Neck
Gender
107
calculate the AA gradient
A- Alveolar pO2
a-Arterial pO2
A= 150-1.2(pCO2)
Normal A-a gradient:
– Age dependent and increases with age
– Normal 5 -10 mm Hg in young adults
– Increases by 1 mm Hg for each decade of life
108
Acid-base equations
Metabolic acidosis decreased pH decreased PaCO2 decreased bicarbonate
Metabolic alkalosis increased pH increased bicarbonate increased PaCO2
Respiratory acidosis decreased pH increased PaCO2 increased bicarbonate
Respiratory alkalosis increased pH decreased PaCO2 decreased bicarbonate
109
How do you tell acute from chronic acid-base
Acute vs Chronic
Acute: ph change of 0.08 for every PaCO2 change of 10 mm Hg
Chronic: ph change of 0.03 for every PaCO2
change of 10 mm Hg
110
Define hypoventilation
Hypoventilation is scored if either of the following occur:
– Increase of PCO2 or surrogate to value > 55 mm Hg for ≥ 10 minutes or
– Increase of PCO2 or surrogate during sleep (in comparison to awake
supine value) to a value > 50 mm HG for ≥ 10 minutes
• Other things to know:
– Persistent oxygen desaturation alone is not sufficient
– Duration of event not defined
111
How is breathing controlled
Cortex (conscious control of breathing)
Pons (adjusts breathing rate)
Medulla (controls breathing
rhythm)
112
Where do Problems with the Ventilatory Pump originate
Organ System or Anatomic Site Entities Associated with Ventilatory Pump Dysfunction
Brain, Brain Stem and Central Chemoreceptors
Brain stem stroke, Central Congenital Hypoventilation
Syndrome (CCHS), multiple sclerosis, Medications
(narcotics)
Spinal Cord Cervical spine injury Phrenic Nerves Phrenic nerve injury, Peripheral nerve diseases such as
ALS, Gullian Barre disease and Myasthenia gravis
Diaphragms Muscular dystrophy
Lungs and Chest wall Chronic obstructive lung disease, kyphosis and scoliosis compromise ability of lungs to expand
113
Obesity Hypoventilation Syndrome (OHS)
Diagnostic Criteria: ICSD 3
• Diagnostic Criteria: All must be met
– Presence of hypoventilation during wakefulness (PaCO2 > 45 mm Hg) as measured by arterial PCO2
, end-tidal PCO2 or
transcutaneous PCO2
– Presence of obesity
• BMI > 30 kg/m2
• BMI > 95 percentile for age and sex for children
– Hypoventilation is not primarily due to other etiologies
• Lung disease, chest wall disorders (other than mass loading from obesity), medication use, neurologic disorders, muscle weakness, congenital disease, or idiopathic central alveolar hypoventilation
syndrome
114
Role of oxygen treatment
No role as primary therapy
– May worsen hypercapnea
• Add oxygen to PAP therapy when hypoxemia persists in the following settings:
– Resolution of OSA (AHI < 10)
– Improvement/resolution of hypoventilation
– Intolerance to higher PAP pressures
• Remember:
– CMS requires resolution of OSA on PAP (AHI < 10) to
qualify for oxygen
– Reassess need for oxygen therapy based on clinical
improvement
115
Define Congenital Central Alveolar Hypoventilation Syndrome (CCHS)
• ICSD 3 diagnostic criteria:
– Presence of sleep related hypoventilation
– Mutation of the PHOX2B gene is present
• Autosomal dominant
• Poly-alanine repeat expansion mutations (PARMs)
116
What are characteristics of CCHS
Typically presents at birth or in early childhood with sleep related hypoventilation
• Severity of illness determined by PHOX2B mutation type:
– More poly-alanine repeats = More severe disease
• May present in adulthood with respiratory failure after anesthesia or a respiratory illness
– Typically due to a mild mutation of the PHOX2B gene
• Associated with Hirschspung’s disease, neural crest tumors and autonomic dysfunction
• Increased risk for neuroblastoma
• Treatment:
– Ventilatory support at night
– Case reports of diaphragmatic pacing
117
Late-Onset Central Hypoventilation with
| Hypothalamic Dysfunction
• Diagnostic Criteria:
– Presence of sleep related hypoventilation
– Symptoms absent during the first few years of life
– At least 2 of the following:
• Obesity
• Endocrine abnormalities of hypothalamic origin
• Severe emotional and behavioral disturbances
• Tumor of neural origin
– 40% with neural crest tumors
– Mutation of PHOX2B is not present
– Not better explained by other disorders
• Also known as ROHHAD:
– Rapid-onset obesity with hypothalamic dysfunction, hypoventilation,
and autonomic dysregulation
• Treatment: Ventilatory support
118
Idiopathic Central Alveolar Hypoventilation
• ICSD 3 diagnostic criteria:
– Sleep related hypoventilation is present
– Not better explained by other disorders
• Rare disease: Prevalence not known
• Often presents in adolescence or early adulthood
• Slowly progresses to respiratory failure
• Treatment: Ventilatory suppor
119
Obstructive Lung Disease and Alveolar Hypoventilation
* COPD
* Bronchiectasis
* Cystic fibrosis
120
Restrictive Lung Disease and Alveolar Hypoventilation
* Pulmonary fibrosis (end stage)
| * Chest wall disease (kyphoscoliosis)
121
Neuromuscular Weakness and Alveolar Hypoventilation
```
• Muscular dystrophies
• Myotonic dystrophy
• ALS
• Guillian Barre syndrome
• Myasthenia gravis
ALS:
• Riluzole is the only medication that affects survival. Best for patient with less severe disease
• NPPV may improve survival
```
122
What are possible consequences of carotid body resection and
Myxedema
Some Alveolar Hypoventilation
123
Chronic Obstructive Pulmonary Disease (COPD) Definition:
– Chronic obstructive lung disease
| – Post bronchodilator FEV1/FVC < 70%
124
Mechanisms Sleep Related Hypoxemia in COPD
• Hypoventilation
– Most important mechanism Decreased minute ventilation and tidal volume
• REM > NREM > Wake
• Decreased response to CO2 and hypoxemia
– REM > NREM > Wake
• Increase in upper airway resistance
• Reduction in FRC associated with sleep and supine position
• V/Q mismatch
Determinants of Hypoxemia
• ↓ SaO2 during wakefulness
125
Determinants of Hypoxemia Sleep Related Hypoxemia in COPD
```
– Major predictor of mean and lowest sats during sleep in COPD
• ↑ PaCO2 during wakefulness
• ↑ Duration of REM sleep
• ↑ Severity of obstruction
• ↑ Respiratory muscle dysfunction
• ↑ BMI
• Co-existence of OSA
```
126
What are the benefits COPD Treatment: Oxygen
• Improves survival in patients with resting hypoxemia (PaO2 < 60
mm Hg)
– More (duration) = Better outcomes
• Nocturnal Oxygen Therapy Trial (NOTT)
• Medical Research Council (MRC) Trial
• No data to support improved survival in patients with normal resting oxygen saturations
127
What is Overlap Syndrome
• Coexistence of COPD and OSA
• Prevalence of OSA similar to general population
• Associated with lower nocturnal mean oxygen saturations and lower oxygen desaturations compared to COPD patients without OSA
• Increased risk of death and severe COPD exacerbation leading to hospitalization if OSA untreated compared to group without concomitant OSA
• Risks of death or hospitalization reduced with CPAP treatment
– Outcomes no different than COPD group alone
– Improved CPAP adherence = Better survival
– Older age associated with reduced survival
128
Not APAP Candidates (AASM Standard)
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– Congestive heart failure
– COPD and chronic lung disease
– Obesity hypoventilation syndrome
– Other hypoventilation syndromes
– Lack of snoring
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Nocturnal NIPPV May Improve Survival in Stable Hypercapnic COPD
• Methods:
– 195 patients with stable GOLD stage IV,
– PCO2 > 52 mm Hg and ph > 7.35
– NIV targeted to reduce PCO2 by 20% or < 48 mm Hg
– Randomized to NIPPV or medical therapy
– Outcome: 12 month all-cause mortality
• Results: Mortality reduced in NIPPV group – Mortality 12% in NIPPV group vs 33% in control group
– HR = 0.24 (p = 0.0004)
• Conclusions:
– The addition of long-term NIPPV to standard treatment improves survival of patients with hypercapnic, stable COPD when NIPPV is targeted to reduce hypercapnia
– NIV plus oxygen may prolong the time to readmission or death within 12 months of a COPD exacerbation in patients with persistent hypercapnea
No role for patients without hypercapnea
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COPD: The Bottom Line
• Hypoventilation is the most important mechanism responsible for sleep related hypoxemia
• Oxygenation during wakefulness is the major predictor of mean and lowest oxygen saturation during sleep in COPD
• Consider PSG for concomitant OSA
• Nocturnal treatments and outcomes:
– Oxygen improves survival in COPD with resting hypoxemia
– CPAP improves survival and decreases exacerbations and hospitalizations in those with the overlap syndrome
• Better outcomes associated with greater CPAP adherence
– NIPPV targeted to reduce PaCO2 may improve survival in patients with stable COPD and hypercapnea (PaCO2 > 52 mm Hg)
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Sleep Related Hypoventilation due to Medication or Substance
• Opioids
– Long acting narcotics are the most common medication associated with hypoventilation
– Both in normal individuals and for patients with comorbid diseases
– May cause OSA, CSA, and or hypoventilation
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• Benzodiazepines for patients with comorbid diseases that may affect respiratory drive:
– COPD
– OHS
– Neuromuscular weakness
– CVA
– In combination with opioids
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Oxygen Therapy for the Boards: The Bottom Line
• OSA:
– Role of oxygen on outcomes is not clear and not recommended as primary therapy
– CPAP is better than oxygen for BP control in short term studies
– Add oxygen if hypoxemia persists after OSA is resolved with PAP therapy
• CSA syndromes:
– Useful for reducing CSA and symptoms in high altitude CSA
– Role of oxygen for other forms of CSA not clear
• COPD:
– Nocturnal and 24 hour oxygen therapy improves survival in patients with resting hypoxemia while awake
– Role in other groups not clear
• Hypoventilation syndromes:
– Be careful in patients with chronic hypercapnea who’s main respiratory drive is based on hypoxemia
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What are blood gases like in CCHS
Arterial blood gases may be normal during wakefulness will be abnormal and obtained from an arterial line during sleep. Decompensated respiratory acidosis may be present pulmonary hypertension may be present.
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What are the characteristics of ROHAD
Patients require ventilatory support during sleep. They breathe adequately during wakefulness. Hypoventilation persisted even at the patient's lose weight. Hormones may be increased or decreased and resulted in the following conditions: Diabetes insipidus, inappropriate IADH, precocious. Puberty, hypogonadism, hyperprolactinemia, hypothyroidism, and decreased growth hormone secretion. Mood and behavior disorders occur. Developmental delay may occur.
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What is Antlely-Bixl
Antlely-Bixl is associated with choanal atresia or stenosis
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What is Apert syndrome
Apert syndrome Associated with small nasal passages a large jaw
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What crouzon syndrome
Crouzon choanal atresia or stenosis maxillary hypoplasia posterior displacement of the tongue and prolonged soft palate
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What is goldenhar syndrome
Goldenhar syndrome is associated with mandibular hypoplasia
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What are features of Down’s syndrome
Down syndrome is associated with small nasal passages enlarged tongue maxillary hypoplasia in the short neck
