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Sleep and Breathing
Davina LovegroveSenior Scientist & Training Coordinator
Respiratory and Sleep Specialists
Sleep – Why do we need it?
• Restorative function for brain • Learning and memory• Repair of cells and healing• Hormone secretions• Energy conservation
How much is enough?• Children and teenagers
– average of 10 hours per night
• Adults– Average of 8 hours per night
Hours of sleep /night 4 5 6 7 8 9 10 11 12
Consequences of reduced sleep
• Day time tiredness• Reduced reaction times• Mood disturbances• Fatigue & muscle weakness• Headaches• Double vision• Reduced motivation……..
Sleep Hygiene
What is sleep hygiene?• Sleep quantity• Bedroom / sleep routine
– Regular bedtimes– Routine before bed *– Dark environment– No bright lights– No pets in the room– No TV, computers & work in bed– Caffeine intake
Sleep Disorders• Sleep Apnoea• Insomnia• Narcolepsy• Periodic Limb Movements• Insufficient sleep syndrome• Post Traumatic Hypersomnia• Obesity Hypoventilation• Respiratory Failure• Night Terrors• REM Behaviour Disorder• Nocturnal Epilepsy
Obstructive Sleep Apnoea
What is OSA?• repeated obstruction of the upper airway during sleep
causing;– reduction in blood oxygen saturation – frequent sleep disturbance
Phillips & Naughton, 2004
How do we diagnose OSA?• Risk factors
– Obesity– Family history– Age – Smoking– Alcohol / sedative use
• Questionnaires– Epworth sleepiness scale
• Overnight sleep study (PSG)
How do we diagnose OSA?
ENLARGED UVULA
ELONGATED PALATAL FOLDS
NARROWUPPER AIRWAY
APERTURE
BACK OF TONGUE
Clinical Examination – risk factors
Consequences of OSA• Sleep disruption• Headaches• Hypertension• Heart disease (heart failure, CAD)• Type 2 diabetes / insulin resistance• Increased risk of stroke• Heart arrhythmias• Intellectual deterioration• Frequent urination at night• Personality changes
Treatment optionsLifestyle changes
– Weight loss– Drugs, alcohol, smoking– Sleep hygiene
Positional therapySurgery
– Tracheostomy– Uvulopalatopharyngoplasty– Gastric, bariatric Sx
Oral appliancesCPAP/APAP/Bilevel
Slide courtesy of Dr Darren O’Brien
• Gold Standard treatment• How it works
– Air passes through a mask into your nose and/or mouth then into your throat, where the slight pressure acts as a splint to keep your airway open and prevent apnoeas, hypopnoeas and snoring.
CPAP
CPAP
First Patient on CPAP, RPAH, 1980.
Sullivan et.al., Lancet 1981
Slide courtesy of Dr Darren O’Brien
Fixed Pressure CPAP Devices
10 cm H2O
Fixed pressure throughout the night
CPAP machines provide a single, fixed pressurethrough out the night.
The intent of CPAP is to splint open the upper airwayto prevent obstruction.
Auto Pressure CPAP Devices
4 cm H2O
Beginning of obstruction
Varying pressure throughout the night in response to events
Auto pressure devices automatically adjust the pressure in response tochanges in the patients airway.
Results in lower overall mean pressure. ?increased comfort for patient.
Bi-level Devices(NIV)
• Bi-level systems deliver two different pressures– a higher pressure on inspiration (IPAP)– a lower pressure on expiration (EPAP)
• Acts as a non-invasive VENTILATOR (NIV)
4 cm H2O
10 cm H2O
Inspiration
Expiration
Why do we need bi-level?
• Breathing basics….
In order to breath INour diaphragm and accessory chest muscles must contract to cause expansion of our rib cage and therefore air enters our lungs
When do we need bi-level?• When our diaphragm cannot
contract due to– Muscle weakness– Greatly increased load on the
muscles– Restricted movement
Breathing basics – gas exchange• With each breath our lungs transfer
– Oxygen (O2) from the air into our blood stream– Carbon dioxide (CO2) from our blood into the air
• When we don’t breath adequately– Blood oxygen levels drop (hypoxia)– Blood carbon dioxide levels increase (hypercapnia)
CO2
O2
CO2
O2
Breathing basics
• Not breathing adequately is called HYPOVENTILATION
• Hypoventilation hypoxia + hypercapnia
• Hypoxia + hypercapnia = respiratory failure= hospital admission
How does bi-level help?
• Assist and support patient’s own breathing efforts
• Rest fatigued respiratory muscles• Improve gas exchange by increasing tidal volume• Prevent nocturnal hypoventilation
• Increase nocturnal O2 levels
• Reduce nocturnal CO2 levels
• Improve daytime blood gases
• Stabilise upper airway
Case study
• Chest wall restriction secondary to Poliomyelitis
• Undergoing a split night sleep study– ½ night as a diagnostic study– ½ night as a bi-level study
Research
• Simonds et al 1995:• Outcomes of patients on home NIV were assessed
over 5 years in 180 patients with chronic respiratory failure
• NIV very well tolerated in post-polio patients:– 100% (n=30) of patients were still compliant at 5 year
follow-up (ie 100% survival at 5 years)– Blood oxygen (O2) and carbon-dioxide (CO2) levels were
improved and maintained at 5 years
Research
• Leger et al. 1994• NIV improved quality of life• NIV reduced number of days in hospital (from an
average of 34 days per year to 7 days per year)• NIV improved sleep quality in 70% of patients
• Buyse 2002• NIV is more beneficial in terms of survival, blood
gases, and lung function compared with long term oxygen alone in patients with kyphoscoliosis