Sleep Medicine Flashcards
(38 cards)
Risk factors for OSA
- High BMI
- Male gender
- Older age
- Increased neck circumference
Males >43cm, Females >37cm - Snoring
- Witnessed apnoea
- Menopause
- Craniofacial abnormalities
Screening questionnaires for OSA
STOP-BANG - Snoring - Tiredness - Observed apnoea - Blood pressure - BMI - Age - Neck circumference - Gender Score /8 Intermediate to high risk of OSA if score ≥3/8
OSA50 - Obesity - Snoring - Apnoeas - >50 >5/10 score
Epworth Sleepiness Scale
STOP Bang and berlin questionnaires have the highest sensitivity + specificity
Diagnosis of OSA
Via polysomnography (PSG) AHI (apnoea/hypopnoea index)
AHI > 5/hr + symptoms OR
AHI > 15/hr +/- symptoms
Normal <5
Mild 5-15/hr
Moderate 15-30/hr
Severe 30+/hr
Complications of OSA
- Motor vehicle accidents - 4x increased risk with moderate/severe OSA
- Cardiovascular disease: HTN, CAD, CCF, AF, CVA
- Pulmonary HTN
- Metabolic dysregulation - increased risk of DM
- All cause mortality
Most common to least:
- AF
- Depression
- CCF
- Stroke
- HTN
- CAD
- Diabetes
Characteristics of obesity hypoventilation syndrome
Obesity Hypoventilation Syndrome (OHS) consists of a triad of:
• Awake hypercapnia (PaCO2 >45mmHg)
• BMI >30
• Sleep disordered breathing when other causes of hypoventilation excluded (eg: lung disease, neuromuscular disease)
How does obesity and OSA cause hypercapnia?
Obesity –> leptin resistance or increased mechanical load –> blunted ventilatory response –> chronic hypercapnia
OSA –> acute hypercapnia during sleep –> decreased compensatory hyperventilation or decreased HCO3 excretion rate –> increased serum HCO3 –> chronic hypercapnia
Conditions associated with OSA
- Increased mortality
- COPD
- Heart failure
- Diabetes
- CKD
- GORD
- NASH
- Systemic HTN is more common in patients with OSA than those without OSA
- Increased OSA severity corresponds to increased likelihood of systemic HT
- CPAP reduces BP but not as much as medication
- Consider OSA in patients with resistant HTN
Cardiovascular consequences of OSA
- Hypertension
- Pulmonary HTN
- Arrhythmias
- Diabetes
- CAD
- Stroke
- Dyslipidaemia
Women with OSA present differently to men
What are the main symptoms and risk factors of OSA in women
Higher prevalence symptoms
- Insomnia
- Depression, irritability, mood changes
- Anxiety
- Non-restorative sleep, lethargy, fatigue
RF
- PCOS
- Pregnancy
- Menopausal state
Efficacy of OSA treatment
(a) Symptoms - improve, residual sleepiness
(b) Hypertension - improve depending on patient and severity of htn
(c) Reduce incidence of cardiovascular disease and mortality
(d) Some studies suggest improvement in insulin resistance in non-diabetics + improve glycemic control in t2dm
Oral appliances vs CPAP for OSA
Reduction in AHI greater with CPAP
Surgery for OSA
Evidence primarily from case series
- Maxillo-mandibular advancement: high success rate reported in selected patients
- Bariatric surgery: improvements in AHI
- Hypoglossal nerve stimulation improves apnoea hypopnoea index, oxygen desaturation index, epworth sleepiness scale, QOL, reduced snoring
What is the difference between obstructive sleep apnoea and central apnoea
Two main types of sleep apnea include obstructive sleep apnea (most common) and central sleep apnea.
- OSA is where your upper airway gets partially or completely blocked while you sleep.
- Central sleep apnea (CSA), cessation of respiratory drive results in a lack of respiratory movements
What is central apnoea?
Absent inspiratory effort for the duration of the apnoea
PSG finding: absence of airflow and thoraco-abdominal excursion >10s
- Central apnoea index > 5 events/hour and >50% of respiratory events are central
Types of central sleep apnoea
(A) Eucapnic or Hypocapnic CSA - High or irregular drive to breathe - No daytime hypoventilation - Examples Heart failure Post stroke Chronic renal failure, dialysis High altitude Idiopathic Treatment emergent CSA when starting PAP therapy
(B) Hypercapnic CSA - Low drive to breath - Nocturnal and daytime hypoventilation - Examples Neuromuscular disorders Pulmonary disorders Opioids Central congenital alveolar hypoventilation syndromes
Sleep disordered breathing in CCF
- Common in HFrEF, HFpEF
- OSA and CSA often co-exist
- RF: male, >60yo, AF, LVEF, daytime hypocapnia PaCO2 <38
- Associated with poor prognosis
Sleep disordered breathing treatment in CCF
OSA
- CPAP has been shown to improve symptoms and LVEF
Central Sleep Apnoea
- Medical management of CCF
- ?CPAP - improves AHI, oxygenation, ejection fraction by 4%, exercise capacity
- ?ASV (adaptive servoventilation) - increased mortality with EF < 45%
Diagnostic criteria for restless leg syndrome
All 3 need to be met
- An urge to move the legs, usually accompanied by or though to be caused by uncomfortable and unpleasant sensations in the legs
- Not due to another medical or behavioural condition
- Affection function
Essential:
URGE
- Urge to move limb: unpleasant and uncomfortable
- Rest (inactivity) worsens or precipitates symptoms
- Getting up and moving improves symptoms
- Evening (or bedtime) worsens or precipitates symptoms
Non-Essential
- Family hx (increase 3-5 times)
- Response to dopaminergic therapy
- Sleep disturbance
- PLMS or PLMW (periodic limb movement during sleep/wakefulness)
Causes and risk factors of restless leg syndrome
Primary Causes
- Early onset
- Younger, slowly progressive, family history, idiopathic
Secondary Causes:
- (brain) Iron deficiency - leading to reduced CNS dopamine as iron is dependent for dopamine synthesis
- ESRF
- Pregnancy
- Medication induced: antidepressants, antihistamines, lithium, D2 receptor blockers (antipsychotics)
Treatment for restless leg syndrome
Non Pharm
- Mental alerting activities
- Abstinence from caffeine, nicotine, alcohol
- Iron replacement if ferritin <50
- Evaluate medications that may worsen RLS
FIRST LINE
1. Dopamine Agonist: pramipexole (renally excreted), ropinirole (hepatic excreted), rotigotine patch (hepatic excreted)
SE: sleepiness, impulsive behaviours, augmentation (paradoxical worsening of RLS)
- Alpha delta ligands
- Pregablin, gabapentin
- SE: suicide ideation, weight gain, sleepiness
SECOND LINE
- Opioids: oxycodone (targin)
- Benzodiazepines
Correction of nutritional deficiences: Iron
Augmentation with the use of dopamine agonist in restless legs syndrome
(1) Augmentation (worsening of symptoms) are common
(a) Development of worsening RLS with increased doses of dopamine agonists
- Earlier onset of symptoms (2-4 hours +)
- Spread to arms or trunk
- Shorter duration of reponse to medications
(b) RF for augmentation
- Increasing total agonist dose
- Increasing duration of symptoms + treatment
- Lower iron stores
- Greater severity of symptoms pre-treatment
- Risk greater for levodopa than agonists and possibly more for intermediate compared to long acting agonists
(2) Impulse control disorders
- Pathological gambling
- Compulsive shopping
- Hypersexuality
Other therapies for restless leg syndrome
- Pregablin and gabapentin - a2delta Ligands
- iron replacement aim ferritin >100
- benzodiazepines especially clonazepam
- Opioids
Difference between dyssomnias and parasomnia
Dyssomnia: a group of primary sleeping disorders characterized by difficulty falling/staying asleep or hypersomnia (excessive daytime sleepiness)
EG: OSA, central sleep apnoea, narcolepsy, insomnia, hypersomnolence disorder
Parasomnia: a group of primary sleeping disorders characterized by abnormal behaviors or experiences that occur while falling asleep, during sleep, or while waking up
EG:
(a) NREM-related parasomnia: a group of parasomnias characterized by repeated episodes of brief but incomplete awakenings that typically occur during the first third of sleep: Sleepwalking disorder, Sleep terror disorder
(b) REM-related parasomnias: a group of parasomnias characterized by a dissociation between REM sleep and the awake state: Nightmare disorder, REM sleep behavior disorder, Recurrent isolated sleep paralysis,
(c) Restless legs syndrome
Nightmare disorder vs sleep terror disorder
I REMember my NIGHTMARE, and there were NO memorable TERRORists:” Nightmare disorder occurs during REM sleep and the experience is remembered, while sleep terror disorder occurs during non-REM sleep and is not remembered.
What is the biggest differences between night terrors and nightmares?
One of the biggest differences between nightmares and night terrors is the awareness on the part of the child. With nightmares, children can often recall the experience in vivid detail. With night terrors, they usually have no recollection of the event at all the next morning
